text: /*
   * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
   * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
   * Copyright 2005 Nokia. All rights reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #ifndef HEADER_SSL_LOCL_H
  # define HEADER_SSL_LOCL_H
  
  # include "e_os.h"              /* struct timeval for DTLS */
  # include <stdlib.h>
  # include <time.h>
  # include <string.h>
  # include <errno.h>
  
  # include <openssl/buffer.h>
  # include <openssl/comp.h>
  # include <openssl/bio.h>
  # include <openssl/rsa.h>
  # include <openssl/dsa.h>
  # include <openssl/err.h>
  # include <openssl/ssl.h>
  # include <openssl/async.h>
  # include <openssl/symhacks.h>
  # include <openssl/ct.h>
  # include <openssl/fs0rttkex.h>
  # include "record/record.h"
  # include "statem/statem.h"
  # include "packet_locl.h"
  # include "internal/dane.h"
  # include "internal/refcount.h"
  # include "internal/tsan_assist.h"
  
  # ifdef OPENSSL_BUILD_SHLIBSSL
  #  undef OPENSSL_EXTERN
  #  define OPENSSL_EXTERN OPENSSL_EXPORT
  # endif
  
  # define c2l(c,l)        (l = ((unsigned long)(*((c)++)))     , \
                           l|=(((unsigned long)(*((c)++)))<< 8), \
                           l|=(((unsigned long)(*((c)++)))<<16), \
                           l|=(((unsigned long)(*((c)++)))<<24))
  
  /* NOTE - c is not incremented as per c2l */
  # define c2ln(c,l1,l2,n) { \
                          c+=n; \
                          l1=l2=0; \
                          switch (n) { \
                          case 8: l2 =((unsigned long)(*(--(c))))<<24; \
                          case 7: l2|=((unsigned long)(*(--(c))))<<16; \
                          case 6: l2|=((unsigned long)(*(--(c))))<< 8; \
                          case 5: l2|=((unsigned long)(*(--(c))));     \
                          case 4: l1 =((unsigned long)(*(--(c))))<<24; \
                          case 3: l1|=((unsigned long)(*(--(c))))<<16; \
                          case 2: l1|=((unsigned long)(*(--(c))))<< 8; \
                          case 1: l1|=((unsigned long)(*(--(c))));     \
                                  } \
                          }
  
  # define l2c(l,c)        (*((c)++)=(unsigned char)(((l)    )&0xff), \
                           *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>16)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>24)&0xff))
  
  # define n2l(c,l)        (l =((unsigned long)(*((c)++)))<<24, \
                           l|=((unsigned long)(*((c)++)))<<16, \
                           l|=((unsigned long)(*((c)++)))<< 8, \
                           l|=((unsigned long)(*((c)++))))
  
  # define n2l8(c,l)       (l =((uint64_t)(*((c)++)))<<56, \
                           l|=((uint64_t)(*((c)++)))<<48, \
                           l|=((uint64_t)(*((c)++)))<<40, \
                           l|=((uint64_t)(*((c)++)))<<32, \
                           l|=((uint64_t)(*((c)++)))<<24, \
                           l|=((uint64_t)(*((c)++)))<<16, \
                           l|=((uint64_t)(*((c)++)))<< 8, \
                           l|=((uint64_t)(*((c)++))))
  
  
  # define l2n(l,c)        (*((c)++)=(unsigned char)(((l)>>24)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>16)&0xff), \
                           *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
                           *((c)++)=(unsigned char)(((l)    )&0xff))
  
  # define l2n6(l,c)       (*((c)++)=(unsigned char)(((l)>>40)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>32)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>24)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>16)&0xff), \
                           *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
                           *((c)++)=(unsigned char)(((l)    )&0xff))
  
  # define l2n8(l,c)       (*((c)++)=(unsigned char)(((l)>>56)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>48)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>40)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>32)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>24)&0xff), \
                           *((c)++)=(unsigned char)(((l)>>16)&0xff), \
                           *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
                           *((c)++)=(unsigned char)(((l)    )&0xff))
  
  /* NOTE - c is not incremented as per l2c */
  # define l2cn(l1,l2,c,n) { \
                          c+=n; \
                          switch (n) { \
                          case 8: *(--(c))=(unsigned char)(((l2)>>24)&0xff); \
                          case 7: *(--(c))=(unsigned char)(((l2)>>16)&0xff); \
                          case 6: *(--(c))=(unsigned char)(((l2)>> 8)&0xff); \
                          case 5: *(--(c))=(unsigned char)(((l2)    )&0xff); \
                          case 4: *(--(c))=(unsigned char)(((l1)>>24)&0xff); \
                          case 3: *(--(c))=(unsigned char)(((l1)>>16)&0xff); \
                          case 2: *(--(c))=(unsigned char)(((l1)>> 8)&0xff); \
                          case 1: *(--(c))=(unsigned char)(((l1)    )&0xff); \
                                  } \
                          }
  
  # define n2s(c,s)        ((s=(((unsigned int)((c)[0]))<< 8)| \
                               (((unsigned int)((c)[1]))    )),(c)+=2)
  # define s2n(s,c)        (((c)[0]=(unsigned char)(((s)>> 8)&0xff), \
                             (c)[1]=(unsigned char)(((s)    )&0xff)),(c)+=2)
  
  # define n2l3(c,l)       ((l =(((unsigned long)((c)[0]))<<16)| \
                                (((unsigned long)((c)[1]))<< 8)| \
                                (((unsigned long)((c)[2]))    )),(c)+=3)
  
  # define l2n3(l,c)       (((c)[0]=(unsigned char)(((l)>>16)&0xff), \
                             (c)[1]=(unsigned char)(((l)>> 8)&0xff), \
                             (c)[2]=(unsigned char)(((l)    )&0xff)),(c)+=3)
  
  /*
   * DTLS version numbers are strange because they're inverted. Except for
   * DTLS1_BAD_VER, which should be considered "lower" than the rest.
   */
  # define dtls_ver_ordinal(v1) (((v1) == DTLS1_BAD_VER) ? 0xff00 : (v1))
  # define DTLS_VERSION_GT(v1, v2) (dtls_ver_ordinal(v1) < dtls_ver_ordinal(v2))
  # define DTLS_VERSION_GE(v1, v2) (dtls_ver_ordinal(v1) <= dtls_ver_ordinal(v2))
  # define DTLS_VERSION_LT(v1, v2) (dtls_ver_ordinal(v1) > dtls_ver_ordinal(v2))
  # define DTLS_VERSION_LE(v1, v2) (dtls_ver_ordinal(v1) >= dtls_ver_ordinal(v2))
  
  
  /*
   * Define the Bitmasks for SSL_CIPHER.algorithms.
   * This bits are used packed as dense as possible. If new methods/ciphers
   * etc will be added, the bits a likely to change, so this information
   * is for internal library use only, even though SSL_CIPHER.algorithms
   * can be publicly accessed.
   * Use the according functions for cipher management instead.
   *
   * The bit mask handling in the selection and sorting scheme in
   * ssl_create_cipher_list() has only limited capabilities, reflecting
   * that the different entities within are mutually exclusive:
   * ONLY ONE BIT PER MASK CAN BE SET AT A TIME.
   */
  
  /* Bits for algorithm_mkey (key exchange algorithm) */
  /* RSA key exchange */
  # define SSL_kRSA                0x00000001U
  /* tmp DH key no DH cert */
  # define SSL_kDHE                0x00000002U
  /* synonym */
  # define SSL_kEDH                SSL_kDHE
  /* ephemeral ECDH */
  # define SSL_kECDHE              0x00000004U
  /* synonym */
  # define SSL_kEECDH              SSL_kECDHE
  /* PSK */
  # define SSL_kPSK                0x00000008U
  /* GOST key exchange */
  # define SSL_kGOST               0x00000010U
  /* SRP */
  # define SSL_kSRP                0x00000020U
  
  # define SSL_kRSAPSK             0x00000040U
  # define SSL_kECDHEPSK           0x00000080U
  # define SSL_kDHEPSK             0x00000100U
  
  /* all PSK */
  
  # define SSL_PSK     (SSL_kPSK | SSL_kRSAPSK | SSL_kECDHEPSK | SSL_kDHEPSK)
  
  /* Any appropriate key exchange algorithm (for TLS 1.3 ciphersuites) */
  # define SSL_kANY                0x00000000U
  
  /* Bits for algorithm_auth (server authentication) */
  /* RSA auth */
  # define SSL_aRSA                0x00000001U
  /* DSS auth */
  # define SSL_aDSS                0x00000002U
  /* no auth (i.e. use ADH or AECDH) */
  # define SSL_aNULL               0x00000004U
  /* ECDSA auth*/
  # define SSL_aECDSA              0x00000008U
  /* PSK auth */
  # define SSL_aPSK                0x00000010U
  /* GOST R 34.10-2001 signature auth */
  # define SSL_aGOST01             0x00000020U
  /* SRP auth */
  # define SSL_aSRP                0x00000040U
  /* GOST R 34.10-2012 signature auth */
  # define SSL_aGOST12             0x00000080U
  /* Any appropriate signature auth (for TLS 1.3 ciphersuites) */
  # define SSL_aANY                0x00000000U
  /* All bits requiring a certificate */
  #define SSL_aCERT \
      (SSL_aRSA | SSL_aDSS | SSL_aECDSA | SSL_aGOST01 | SSL_aGOST12)
  
  /* Bits for algorithm_enc (symmetric encryption) */
  # define SSL_DES                 0x00000001U
  # define SSL_3DES                0x00000002U
  # define SSL_RC4                 0x00000004U
  # define SSL_RC2                 0x00000008U
  # define SSL_IDEA                0x00000010U
  # define SSL_eNULL               0x00000020U
  # define SSL_AES128              0x00000040U
  # define SSL_AES256              0x00000080U
  # define SSL_CAMELLIA128         0x00000100U
  # define SSL_CAMELLIA256         0x00000200U
  # define SSL_eGOST2814789CNT     0x00000400U
  # define SSL_SEED                0x00000800U
  # define SSL_AES128GCM           0x00001000U
  # define SSL_AES256GCM           0x00002000U
  # define SSL_AES128CCM           0x00004000U
  # define SSL_AES256CCM           0x00008000U
  # define SSL_AES128CCM8          0x00010000U
  # define SSL_AES256CCM8          0x00020000U
  # define SSL_eGOST2814789CNT12   0x00040000U
  # define SSL_CHACHA20POLY1305    0x00080000U
  # define SSL_ARIA128GCM          0x00100000U
  # define SSL_ARIA256GCM          0x00200000U
  
  # define SSL_AESGCM              (SSL_AES128GCM | SSL_AES256GCM)
  # define SSL_AESCCM              (SSL_AES128CCM | SSL_AES256CCM | SSL_AES128CCM8 | SSL_AES256CCM8)
  # define SSL_AES                 (SSL_AES128|SSL_AES256|SSL_AESGCM|SSL_AESCCM)
  # define SSL_CAMELLIA            (SSL_CAMELLIA128|SSL_CAMELLIA256)
  # define SSL_CHACHA20            (SSL_CHACHA20POLY1305)
  # define SSL_ARIAGCM             (SSL_ARIA128GCM | SSL_ARIA256GCM)
  # define SSL_ARIA                (SSL_ARIAGCM)
  
  /* Bits for algorithm_mac (symmetric authentication) */
  
  # define SSL_MD5                 0x00000001U
  # define SSL_SHA1                0x00000002U
  # define SSL_GOST94      0x00000004U
  # define SSL_GOST89MAC   0x00000008U
  # define SSL_SHA256              0x00000010U
  # define SSL_SHA384              0x00000020U
  /* Not a real MAC, just an indication it is part of cipher */
  # define SSL_AEAD                0x00000040U
  # define SSL_GOST12_256          0x00000080U
  # define SSL_GOST89MAC12         0x00000100U
  # define SSL_GOST12_512          0x00000200U
  
  /*
   * When adding new digest in the ssl_ciph.c and increment SSL_MD_NUM_IDX make
   * sure to update this constant too
   */
  
  # define SSL_MD_MD5_IDX  0
  # define SSL_MD_SHA1_IDX 1
  # define SSL_MD_GOST94_IDX 2
  # define SSL_MD_GOST89MAC_IDX 3
  # define SSL_MD_SHA256_IDX 4
  # define SSL_MD_SHA384_IDX 5
  # define SSL_MD_GOST12_256_IDX  6
  # define SSL_MD_GOST89MAC12_IDX 7
  # define SSL_MD_GOST12_512_IDX  8
  # define SSL_MD_MD5_SHA1_IDX 9
  # define SSL_MD_SHA224_IDX 10
  # define SSL_MD_SHA512_IDX 11
  # define SSL_MAX_DIGEST 12
  
  /* Bits for algorithm2 (handshake digests and other extra flags) */
  
  /* Bits 0-7 are handshake MAC */
  # define SSL_HANDSHAKE_MAC_MASK  0xFF
  # define SSL_HANDSHAKE_MAC_MD5_SHA1 SSL_MD_MD5_SHA1_IDX
  # define SSL_HANDSHAKE_MAC_SHA256   SSL_MD_SHA256_IDX
  # define SSL_HANDSHAKE_MAC_SHA384   SSL_MD_SHA384_IDX
  # define SSL_HANDSHAKE_MAC_GOST94 SSL_MD_GOST94_IDX
  # define SSL_HANDSHAKE_MAC_GOST12_256 SSL_MD_GOST12_256_IDX
  # define SSL_HANDSHAKE_MAC_GOST12_512 SSL_MD_GOST12_512_IDX
  # define SSL_HANDSHAKE_MAC_DEFAULT  SSL_HANDSHAKE_MAC_MD5_SHA1
  
  /* Bits 8-15 bits are PRF */
  # define TLS1_PRF_DGST_SHIFT 8
  # define TLS1_PRF_SHA1_MD5 (SSL_MD_MD5_SHA1_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF_SHA256 (SSL_MD_SHA256_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF_SHA384 (SSL_MD_SHA384_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF_GOST94 (SSL_MD_GOST94_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF_GOST12_256 (SSL_MD_GOST12_256_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF_GOST12_512 (SSL_MD_GOST12_512_IDX << TLS1_PRF_DGST_SHIFT)
  # define TLS1_PRF            (SSL_MD_MD5_SHA1_IDX << TLS1_PRF_DGST_SHIFT)
  
  /*
   * Stream MAC for GOST ciphersuites from cryptopro draft (currently this also
   * goes into algorithm2)
   */
  # define TLS1_STREAM_MAC 0x10000
  
  # define SSL_STRONG_MASK         0x0000001FU
  # define SSL_DEFAULT_MASK        0X00000020U
  
  # define SSL_STRONG_NONE         0x00000001U
  # define SSL_LOW                 0x00000002U
  # define SSL_MEDIUM              0x00000004U
  # define SSL_HIGH                0x00000008U
  # define SSL_FIPS                0x00000010U
  # define SSL_NOT_DEFAULT         0x00000020U
  
  /* we have used 0000003f - 26 bits left to go */
  
  /* Flag used on OpenSSL ciphersuite ids to indicate they are for SSLv3+ */
  # define SSL3_CK_CIPHERSUITE_FLAG                0x03000000
  
  /* Check if an SSL structure is using DTLS */
  # define SSL_IS_DTLS(s)  (s->method->ssl3_enc->enc_flags & SSL_ENC_FLAG_DTLS)
  
  /* Check if we are using TLSv1.3 */
  # define SSL_IS_TLS13(s) (!SSL_IS_DTLS(s) \
                            && (s)->method->version >= TLS1_3_VERSION \
                            && (s)->method->version != TLS_ANY_VERSION)
  
  # define SSL_TREAT_AS_TLS13(s) \
      (SSL_IS_TLS13(s) || (s)->early_data_state == SSL_EARLY_DATA_CONNECTING \
       || (s)->early_data_state == SSL_EARLY_DATA_CONNECT_RETRY \
       || (s)->early_data_state == SSL_EARLY_DATA_WRITING \
       || (s)->early_data_state == SSL_EARLY_DATA_WRITE_RETRY \
       || (s)->hello_retry_request == SSL_HRR_PENDING)
  
  # define SSL_IS_FIRST_HANDSHAKE(S) ((s)->s3->tmp.finish_md_len == 0 \
                                      || (s)->s3->tmp.peer_finish_md_len == 0)
  
  /* See if we need explicit IV */
  # define SSL_USE_EXPLICIT_IV(s)  \
                  (s->method->ssl3_enc->enc_flags & SSL_ENC_FLAG_EXPLICIT_IV)
  /*
   * See if we use signature algorithms extension and signature algorithm
   * before signatures.
   */
  # define SSL_USE_SIGALGS(s)      \
                          (s->method->ssl3_enc->enc_flags & SSL_ENC_FLAG_SIGALGS)
  /*
   * Allow TLS 1.2 ciphersuites: applies to DTLS 1.2 as well as TLS 1.2: may
   * apply to others in future.
   */
  # define SSL_USE_TLS1_2_CIPHERS(s)       \
                  (s->method->ssl3_enc->enc_flags & SSL_ENC_FLAG_TLS1_2_CIPHERS)
  /*
   * Determine if a client can use TLS 1.2 ciphersuites: can't rely on method
   * flags because it may not be set to correct version yet.
   */
  # define SSL_CLIENT_USE_TLS1_2_CIPHERS(s)        \
      ((!SSL_IS_DTLS(s) && s->client_version >= TLS1_2_VERSION) || \
       (SSL_IS_DTLS(s) && DTLS_VERSION_GE(s->client_version, DTLS1_2_VERSION)))
  /*
   * Determine if a client should send signature algorithms extension:
   * as with TLS1.2 cipher we can't rely on method flags.
   */
  # define SSL_CLIENT_USE_SIGALGS(s)        \
      SSL_CLIENT_USE_TLS1_2_CIPHERS(s)
  
  # define IS_MAX_FRAGMENT_LENGTH_EXT_VALID(value) \
      (((value) >= TLSEXT_max_fragment_length_512) && \
       ((value) <= TLSEXT_max_fragment_length_4096))
  # define USE_MAX_FRAGMENT_LENGTH_EXT(session) \
      IS_MAX_FRAGMENT_LENGTH_EXT_VALID(session->ext.max_fragment_len_mode)
  # define GET_MAX_FRAGMENT_LENGTH(session) \
      (512U << (session->ext.max_fragment_len_mode - 1))
  
  # define SSL_READ_ETM(s) (s->s3->flags & TLS1_FLAGS_ENCRYPT_THEN_MAC_READ)
  # define SSL_WRITE_ETM(s) (s->s3->flags & TLS1_FLAGS_ENCRYPT_THEN_MAC_WRITE)
  
  /* Mostly for SSLv3 */
  # define SSL_PKEY_RSA            0
  # define SSL_PKEY_RSA_PSS_SIGN   1
  # define SSL_PKEY_DSA_SIGN       2
  # define SSL_PKEY_ECC            3
  # define SSL_PKEY_GOST01         4
  # define SSL_PKEY_GOST12_256     5
  # define SSL_PKEY_GOST12_512     6
  # define SSL_PKEY_ED25519        7
  # define SSL_PKEY_ED448          8
  # define SSL_PKEY_NUM            9
  
  /*-
   * SSL_kRSA <- RSA_ENC
   * SSL_kDH  <- DH_ENC & (RSA_ENC | RSA_SIGN | DSA_SIGN)
   * SSL_kDHE <- RSA_ENC | RSA_SIGN | DSA_SIGN
   * SSL_aRSA <- RSA_ENC | RSA_SIGN
   * SSL_aDSS <- DSA_SIGN
   */
  
  /*-
  #define CERT_INVALID            0
  #define CERT_PUBLIC_KEY         1
  #define CERT_PRIVATE_KEY        2
  */
  
  /* Post-Handshake Authentication state */
  typedef enum {
      SSL_PHA_NONE = 0,
      SSL_PHA_EXT_SENT,        /* client-side only: extension sent */
      SSL_PHA_EXT_RECEIVED,    /* server-side only: extension received */
      SSL_PHA_REQUEST_PENDING, /* server-side only: request pending */
      SSL_PHA_REQUESTED        /* request received by client, or sent by server */
  } SSL_PHA_STATE;
  
  /* CipherSuite length. SSLv3 and all TLS versions. */
  # define TLS_CIPHER_LEN 2
  /* used to hold info on the particular ciphers used */
  struct ssl_cipher_st {
      uint32_t valid;
      const char *name;           /* text name */
      const char *stdname;        /* RFC name */
      uint32_t id;                /* id, 4 bytes, first is version */
      /*
       * changed in 1.0.0: these four used to be portions of a single value
       * 'algorithms'
       */
      uint32_t algorithm_mkey;    /* key exchange algorithm */
      uint32_t algorithm_auth;    /* server authentication */
      uint32_t algorithm_enc;     /* symmetric encryption */
      uint32_t algorithm_mac;     /* symmetric authentication */
      int min_tls;                /* minimum SSL/TLS protocol version */
      int max_tls;                /* maximum SSL/TLS protocol version */
      int min_dtls;               /* minimum DTLS protocol version */
      int max_dtls;               /* maximum DTLS protocol version */
      uint32_t algo_strength;     /* strength and export flags */
      uint32_t algorithm2;        /* Extra flags */
      int32_t strength_bits;      /* Number of bits really used */
      uint32_t alg_bits;          /* Number of bits for algorithm */
  };
  
  /* Used to hold SSL/TLS functions */
  struct ssl_method_st {
      int version;
      unsigned flags;
      unsigned long mask;
      int (*ssl_new) (SSL *s);
      int (*ssl_clear) (SSL *s);
      void (*ssl_free) (SSL *s);
      int (*ssl_accept) (SSL *s);
      int (*ssl_connect) (SSL *s);
      int (*ssl_read) (SSL *s, void *buf, size_t len, size_t *readbytes);
      int (*ssl_peek) (SSL *s, void *buf, size_t len, size_t *readbytes);
      int (*ssl_write) (SSL *s, const void *buf, size_t len, size_t *written);
      int (*ssl_shutdown) (SSL *s);
      int (*ssl_renegotiate) (SSL *s);
      int (*ssl_renegotiate_check) (SSL *s, int);
      int (*ssl_read_bytes) (SSL *s, int type, int *recvd_type,
                             unsigned char *buf, size_t len, int peek,
                             size_t *readbytes);
      int (*ssl_write_bytes) (SSL *s, int type, const void *buf_, size_t len,
                              size_t *written);
      int (*ssl_dispatch_alert) (SSL *s);
      long (*ssl_ctrl) (SSL *s, int cmd, long larg, void *parg);
      long (*ssl_ctx_ctrl) (SSL_CTX *ctx, int cmd, long larg, void *parg);
      const SSL_CIPHER *(*get_cipher_by_char) (const unsigned char *ptr);
      int (*put_cipher_by_char) (const SSL_CIPHER *cipher, WPACKET *pkt,
                                 size_t *len);
      size_t (*ssl_pending) (const SSL *s);
      int (*num_ciphers) (void);
      const SSL_CIPHER *(*get_cipher) (unsigned ncipher);
      long (*get_timeout) (void);
      const struct ssl3_enc_method *ssl3_enc; /* Extra SSLv3/TLS stuff */
      int (*ssl_version) (void);
      long (*ssl_callback_ctrl) (SSL *s, int cb_id, void (*fp) (void));
      long (*ssl_ctx_callback_ctrl) (SSL_CTX *s, int cb_id, void (*fp) (void));
  };
  
  /*
   * Matches the length of PSK_MAX_PSK_LEN. We keep it the same value for
   * consistency, even in the event of OPENSSL_NO_PSK being defined.
   */
  # define TLS13_MAX_RESUMPTION_PSK_LENGTH      256
  
  /*-
   * Lets make this into an ASN.1 type structure as follows
   * SSL_SESSION_ID ::= SEQUENCE {
   *      version                 INTEGER,        -- structure version number
   *      SSLversion              INTEGER,        -- SSL version number
   *      Cipher                  OCTET STRING,   -- the 3 byte cipher ID
   *      Session_ID              OCTET STRING,   -- the Session ID
   *      Master_key              OCTET STRING,   -- the master key
   *      Key_Arg [ 0 ] IMPLICIT  OCTET STRING,   -- the optional Key argument
   *      Time [ 1 ] EXPLICIT     INTEGER,        -- optional Start Time
   *      Timeout [ 2 ] EXPLICIT  INTEGER,        -- optional Timeout ins seconds
   *      Peer [ 3 ] EXPLICIT     X509,           -- optional Peer Certificate
   *      Session_ID_context [ 4 ] EXPLICIT OCTET STRING,   -- the Session ID context
   *      Verify_result [ 5 ] EXPLICIT INTEGER,   -- X509_V_... code for `Peer'
   *      HostName [ 6 ] EXPLICIT OCTET STRING,   -- optional HostName from servername TLS extension
   *      PSK_identity_hint [ 7 ] EXPLICIT OCTET STRING, -- optional PSK identity hint
   *      PSK_identity [ 8 ] EXPLICIT OCTET STRING,  -- optional PSK identity
   *      Ticket_lifetime_hint [9] EXPLICIT INTEGER, -- server's lifetime hint for session ticket
   *      Ticket [10]             EXPLICIT OCTET STRING, -- session ticket (clients only)
   *      Compression_meth [11]   EXPLICIT OCTET STRING, -- optional compression method
   *      SRP_username [ 12 ] EXPLICIT OCTET STRING -- optional SRP username
   *      flags [ 13 ] EXPLICIT INTEGER -- optional flags
   *      }
   * Look in ssl/ssl_asn1.c for more details
   * I'm using EXPLICIT tags so I can read the damn things using asn1parse :-).
   */
  struct ssl_session_st {
      int ssl_version;            /* what ssl version session info is being kept
                                   * in here? */
      size_t master_key_length;
  
      /* TLSv1.3 early_secret used for external PSKs */
      unsigned char early_secret[EVP_MAX_MD_SIZE];
      /*
       * For <=TLS1.2 this is the master_key. For TLS1.3 this is the resumption
       * PSK
       */
      unsigned char master_key[TLS13_MAX_RESUMPTION_PSK_LENGTH];
      /* session_id - valid? */
      size_t session_id_length;
      unsigned char session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
      /*
       * this is used to determine whether the session is being reused in the
       * appropriate context. It is up to the application to set this, via
       * SSL_new
       */
      size_t sid_ctx_length;
      unsigned char sid_ctx[SSL_MAX_SID_CTX_LENGTH];
  # ifndef OPENSSL_NO_PSK
      char *psk_identity_hint;
      char *psk_identity;
  # endif
      /*
       * Used to indicate that session resumption is not allowed. Applications
       * can also set this bit for a new session via not_resumable_session_cb
       * to disable session caching and tickets.
       */
      int not_resumable;
      /* This is the cert and type for the other end. */
      X509 *peer;
      int peer_type;
      /* Certificate chain peer sent. */
      STACK_OF(X509) *peer_chain;
      /*
       * when app_verify_callback accepts a session where the peer's
       * certificate is not ok, we must remember the error for session reuse:
       */
      long verify_result;         /* only for servers */
      CRYPTO_REF_COUNT references;
      long timeout;
      long time;
      unsigned int compress_meth; /* Need to lookup the method */
      const SSL_CIPHER *cipher;
      unsigned long cipher_id;    /* when ASN.1 loaded, this needs to be used to
                                   * load the 'cipher' structure */
      CRYPTO_EX_DATA ex_data;     /* application specific data */
      /*
       * These are used to make removal of session-ids more efficient and to
       * implement a maximum cache size.
       */
      struct ssl_session_st *prev, *next;
  
      struct {
          char *hostname;
          /* RFC4507 info */
          unsigned char *tick; /* Session ticket */
          size_t ticklen;      /* Session ticket length */
          /* Session lifetime hint in seconds */
          unsigned long tick_lifetime_hint;
          uint32_t tick_age_add;
          /* Max number of bytes that can be sent as early data */
          uint32_t max_early_data;
          /* The ALPN protocol selected for this session */
          unsigned char *alpn_selected;
          size_t alpn_selected_len;
          /*
           * Maximum Fragment Length as per RFC 4366.
           * If this value does not contain RFC 4366 allowed values (1-4) then
           * either the Maximum Fragment Length Negotiation failed or was not
           * performed at all.
           */
          uint8_t max_fragment_len_mode;
      } ext;
  # ifndef OPENSSL_NO_SRP
      char *srp_username;
  # endif
      unsigned char *ticket_appdata;
      size_t ticket_appdata_len;
      uint32_t flags;
      CRYPTO_RWLOCK *lock;
  };
  
  /* Extended master secret support */
  # define SSL_SESS_FLAG_EXTMS             0x1
  
  # ifndef OPENSSL_NO_SRP
  
  typedef struct srp_ctx_st {
      /* param for all the callbacks */
      void *SRP_cb_arg;
      /* set client Hello login callback */
      int (*TLS_ext_srp_username_callback) (SSL *, int *, void *);
      /* set SRP N/g param callback for verification */
      int (*SRP_verify_param_callback) (SSL *, void *);
      /* set SRP client passwd callback */
      char *(*SRP_give_srp_client_pwd_callback) (SSL *, void *);
      char *login;
      BIGNUM *N, *g, *s, *B, *A;
      BIGNUM *a, *b, *v;
      char *info;
      int strength;
      unsigned long srp_Mask;
  } SRP_CTX;
  
  # endif
  
  typedef enum {
      SSL_EARLY_DATA_NONE = 0,
      SSL_EARLY_DATA_CONNECT_RETRY,
      SSL_EARLY_DATA_CONNECTING,
      SSL_EARLY_DATA_WRITE_RETRY,
      SSL_EARLY_DATA_WRITING,
      SSL_EARLY_DATA_WRITE_FLUSH,
      SSL_EARLY_DATA_UNAUTH_WRITING,
      SSL_EARLY_DATA_FINISHED_WRITING,
      SSL_EARLY_DATA_ACCEPT_RETRY,
      SSL_EARLY_DATA_ACCEPTING,
      SSL_EARLY_DATA_READ_RETRY,
      SSL_EARLY_DATA_READING,
      SSL_EARLY_DATA_FINISHED_READING
  } SSL_EARLY_DATA_STATE;
  
  /*
   * We check that the amount of unreadable early data doesn't exceed
   * max_early_data. max_early_data is given in plaintext bytes. However if it is
   * unreadable then we only know the number of ciphertext bytes. We also don't
   * know how much the overhead should be because it depends on the ciphersuite.
   * We make a small allowance. We assume 5 records of actual data plus the end
   * of early data alert record. Each record has a tag and a content type byte.
   * The longest tag length we know of is EVP_GCM_TLS_TAG_LEN. We don't count the
   * content of the alert record either which is 2 bytes.
   */
  # define EARLY_DATA_CIPHERTEXT_OVERHEAD ((6 * (EVP_GCM_TLS_TAG_LEN + 1)) + 2)
  
  typedef enum {
    FS_0RTT_KEX_STATE_NONE,
    FS_0RTT_KEX_STATE_OK, /* fs-0RTT KEX successful */
    FS_0RTT_KEX_STATE_KEY_SENT, /* client sent a key */
    FS_0RTT_KEX_STATE_KEY_RECEIVED, /* server received a key */
    FS_0RTT_KEX_STATE_INVALID_CTX_RECEIVED, /* server was unable to decrypt the ciphertext */
    FS_0RTT_KEX_STATE_NOT_SUPPORTED, /* received extensions, but not supported/enabled */
    FS_0RTT_KEX_STATE_ERROR /* some error occurred */
  } SSL_FS0RRT_KEX_STATE;
  
  /*
   * The allowance we have between the client's calculated ticket age and our own.
   * We allow for 10 seconds (units are in ms). If a ticket is presented and the
   * client's age calculation is different by more than this than our own then we
   * do not allow that ticket for early_data.
   */
  # define TICKET_AGE_ALLOWANCE   (10 * 1000)
  
  #define MAX_COMPRESSIONS_SIZE   255
  
  struct ssl_comp_st {
      int id;
      const char *name;
      COMP_METHOD *method;
  };
  
  typedef struct raw_extension_st {
      /* Raw packet data for the extension */
      PACKET data;
      /* Set to 1 if the extension is present or 0 otherwise */
      int present;
      /* Set to 1 if we have already parsed the extension or 0 otherwise */
      int parsed;
      /* The type of this extension, i.e. a TLSEXT_TYPE_* value */
      unsigned int type;
      /* Track what order extensions are received in (0-based). */
      size_t received_order;
  } RAW_EXTENSION;
  
  typedef struct {
      unsigned int isv2;
      unsigned int legacy_version;
      unsigned char random[SSL3_RANDOM_SIZE];
      size_t session_id_len;
      unsigned char session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
      size_t dtls_cookie_len;
      unsigned char dtls_cookie[DTLS1_COOKIE_LENGTH];
      PACKET ciphersuites;
      size_t compressions_len;
      unsigned char compressions[MAX_COMPRESSIONS_SIZE];
      PACKET extensions;
      size_t pre_proc_exts_len;
      RAW_EXTENSION *pre_proc_exts;
  } CLIENTHELLO_MSG;
  
  /*
   * Extension index values NOTE: Any updates to these defines should be mirrored
   * with equivalent updates to ext_defs in extensions.c
   */
  typedef enum tlsext_index_en {
      TLSEXT_IDX_renegotiate,
      TLSEXT_IDX_server_name,
      TLSEXT_IDX_max_fragment_length,
      TLSEXT_IDX_srp,
      TLSEXT_IDX_ec_point_formats,
      TLSEXT_IDX_supported_groups,
      TLSEXT_IDX_session_ticket,
      TLSEXT_IDX_status_request,
      TLSEXT_IDX_next_proto_neg,
      TLSEXT_IDX_application_layer_protocol_negotiation,
      TLSEXT_IDX_use_srtp,
      TLSEXT_IDX_encrypt_then_mac,
      TLSEXT_IDX_signed_certificate_timestamp,
      TLSEXT_IDX_extended_master_secret,
      TLSEXT_IDX_signature_algorithms_cert,
      TLSEXT_IDX_post_handshake_auth,
      TLSEXT_IDX_signature_algorithms,
      TLSEXT_IDX_supported_versions,
      TLSEXT_IDX_psk_kex_modes,
      TLSEXT_IDX_fs_0rtt_kex,
      TLSEXT_IDX_key_share,
      TLSEXT_IDX_cookie,
      TLSEXT_IDX_cryptopro_bug,
      TLSEXT_IDX_early_data,
      TLSEXT_IDX_certificate_authorities,
      TLSEXT_IDX_padding,
      TLSEXT_IDX_psk,
      /* Dummy index - must always be the last entry */
      TLSEXT_IDX_num_builtins
  } TLSEXT_INDEX;
  
  DEFINE_LHASH_OF(SSL_SESSION);
  /* Needed in ssl_cert.c */
  DEFINE_LHASH_OF(X509_NAME);
  
  # define TLSEXT_KEYNAME_LENGTH  16
  # define TLSEXT_TICK_KEY_LENGTH 32
  
  typedef struct ssl_ctx_ext_secure_st {
      unsigned char tick_hmac_key[TLSEXT_TICK_KEY_LENGTH];
      unsigned char tick_aes_key[TLSEXT_TICK_KEY_LENGTH];
  } SSL_CTX_EXT_SECURE;
  
  struct ssl_ctx_st {
      const SSL_METHOD *method;
      STACK_OF(SSL_CIPHER) *cipher_list;
      /* same as above but sorted for lookup */
      STACK_OF(SSL_CIPHER) *cipher_list_by_id;
      /* TLSv1.3 specific ciphersuites */
      STACK_OF(SSL_CIPHER) *tls13_ciphersuites;
      struct x509_store_st /* X509_STORE */ *cert_store;
      LHASH_OF(SSL_SESSION) *sessions;
      /*
       * Most session-ids that will be cached, default is
       * SSL_SESSION_CACHE_MAX_SIZE_DEFAULT. 0 is unlimited.
       */
      size_t session_cache_size;
      struct ssl_session_st *session_cache_head;
      struct ssl_session_st *session_cache_tail;
      /*
       * This can have one of 2 values, ored together, SSL_SESS_CACHE_CLIENT,
       * SSL_SESS_CACHE_SERVER, Default is SSL_SESSION_CACHE_SERVER, which
       * means only SSL_accept will cache SSL_SESSIONS.
       */
      uint32_t session_cache_mode;
      /*
       * If timeout is not 0, it is the default timeout value set when
       * SSL_new() is called.  This has been put in to make life easier to set
       * things up
       */
      long session_timeout;
      /*
       * If this callback is not null, it will be called each time a session id
       * is added to the cache.  If this function returns 1, it means that the
       * callback will do a SSL_SESSION_free() when it has finished using it.
       * Otherwise, on 0, it means the callback has finished with it. If
       * remove_session_cb is not null, it will be called when a session-id is
       * removed from the cache.  After the call, OpenSSL will
       * SSL_SESSION_free() it.
       */
      int (*new_session_cb) (struct ssl_st *ssl, SSL_SESSION *sess);
      void (*remove_session_cb) (struct ssl_ctx_st *ctx, SSL_SESSION *sess);
      SSL_SESSION *(*get_session_cb) (struct ssl_st *ssl,
                                      const unsigned char *data, int len,
                                      int *copy);
      struct {
          TSAN_QUALIFIER int sess_connect;       /* SSL new conn - started */
          TSAN_QUALIFIER int sess_connect_renegotiate; /* SSL reneg - requested */
          TSAN_QUALIFIER int sess_connect_good;  /* SSL new conne/reneg - finished */
          TSAN_QUALIFIER int sess_accept;        /* SSL new accept - started */
          TSAN_QUALIFIER int sess_accept_renegotiate; /* SSL reneg - requested */
          TSAN_QUALIFIER int sess_accept_good;   /* SSL accept/reneg - finished */
          TSAN_QUALIFIER int sess_miss;          /* session lookup misses */
          TSAN_QUALIFIER int sess_timeout;       /* reuse attempt on timeouted session */
          TSAN_QUALIFIER int sess_cache_full;    /* session removed due to full cache */
          TSAN_QUALIFIER int sess_hit;           /* session reuse actually done */
          TSAN_QUALIFIER int sess_cb_hit;        /* session-id that was not in
                                                  * the cache was passed back via
                                                  * the callback. This indicates
                                                  * that the application is
                                                  * supplying session-id's from
                                                  * other processes - spooky
                                                  * :-) */
      } stats;
  
      CRYPTO_REF_COUNT references;
  
      /* if defined, these override the X509_verify_cert() calls */
      int (*app_verify_callback) (X509_STORE_CTX *, void *);
      void *app_verify_arg;
      /*
       * before OpenSSL 0.9.7, 'app_verify_arg' was ignored
       * ('app_verify_callback' was called with just one argument)
       */
  
      /* Default password callback. */
      pem_password_cb *default_passwd_callback;
  
      /* Default password callback user data. */
      void *default_passwd_callback_userdata;
  
      /* get client cert callback */
      int (*client_cert_cb) (SSL *ssl, X509 **x509, EVP_PKEY **pkey);
  
      /* cookie generate callback */
      int (*app_gen_cookie_cb) (SSL *ssl, unsigned char *cookie,
                                unsigned int *cookie_len);
  
      /* verify cookie callback */
      int (*app_verify_cookie_cb) (SSL *ssl, const unsigned char *cookie,
                                   unsigned int cookie_len);
  
      /* TLS1.3 app-controlled cookie generate callback */
      int (*gen_stateless_cookie_cb) (SSL *ssl, unsigned char *cookie,
                                      size_t *cookie_len);
  
      /* TLS1.3 verify app-controlled cookie callback */
      int (*verify_stateless_cookie_cb) (SSL *ssl, const unsigned char *cookie,
                                         size_t cookie_len);
  
      CRYPTO_EX_DATA ex_data;
  
      const EVP_MD *md5;          /* For SSLv3/TLSv1 'ssl3-md5' */
      const EVP_MD *sha1;         /* For SSLv3/TLSv1 'ssl3->sha1' */
  
      STACK_OF(X509) *extra_certs;
      STACK_OF(SSL_COMP) *comp_methods; /* stack of SSL_COMP, SSLv3/TLSv1 */
  
      /* Default values used when no per-SSL value is defined follow */
  
      /* used if SSL's info_callback is NULL */
      void (*info_callback) (const SSL *ssl, int type, int val);
  
      /*
       * What we put in certificate_authorities extension for TLS 1.3
       * (ClientHello and CertificateRequest) or just client cert requests for
       * earlier versions. If client_ca_names is populated then it is only used
       * for client cert requests, and in preference to ca_names.
       */
      STACK_OF(X509_NAME) *ca_names;
      STACK_OF(X509_NAME) *client_ca_names;
  
      /*
       * Default values to use in SSL structures follow (these are copied by
       * SSL_new)
       */
  
      uint32_t options;
      uint32_t mode;
      int min_proto_version;
      int max_proto_version;
      size_t max_cert_list;
  
      struct cert_st /* CERT */ *cert;
      int read_ahead;
  
      /* callback that allows applications to peek at protocol messages */
      void (*msg_callback) (int write_p, int version, int content_type,
                            const void *buf, size_t len, SSL *ssl, void *arg);
      void *msg_callback_arg;
  
      uint32_t verify_mode;
      size_t sid_ctx_length;
      unsigned char sid_ctx[SSL_MAX_SID_CTX_LENGTH];
      /* called 'verify_callback' in the SSL */
      int (*default_verify_callback) (int ok, X509_STORE_CTX *ctx);
  
      /* Default generate session ID callback. */
      GEN_SESSION_CB generate_session_id;
  
      X509_VERIFY_PARAM *param;
  
      int quiet_shutdown;
  
  # ifndef OPENSSL_NO_CT
      CTLOG_STORE *ctlog_store;   /* CT Log Store */
      /*
       * Validates that the SCTs (Signed Certificate Timestamps) are sufficient.
       * If they are not, the connection should be aborted.
       */
      ssl_ct_validation_cb ct_validation_callback;
      void *ct_validation_callback_arg;
  # endif
  
      /*
       * If we're using more than one pipeline how should we divide the data
       * up between the pipes?
       */
      size_t split_send_fragment;
      /*
       * Maximum amount of data to send in one fragment. actual record size can
       * be more than this due to padding and MAC overheads.
       */
      size_t max_send_fragment;
  
      /* Up to how many pipelines should we use? If 0 then 1 is assumed */
      size_t max_pipelines;
  
      /* The default read buffer length to use (0 means not set) */
      size_t default_read_buf_len;
  
  # ifndef OPENSSL_NO_ENGINE
      /*
       * Engine to pass requests for client certs to
       */
      ENGINE *client_cert_engine;
  # endif
  
      /* ClientHello callback.  Mostly for extensions, but not entirely. */
      SSL_client_hello_cb_fn client_hello_cb;
      void *client_hello_cb_arg;
  
      /* TLS extensions. */
      struct {
          /* TLS extensions servername callback */
          int (*servername_cb) (SSL *, int *, void *);
          void *servername_arg;
          /* RFC 4507 session ticket keys */
          unsigned char tick_key_name[TLSEXT_KEYNAME_LENGTH];
          SSL_CTX_EXT_SECURE *secure;
          /* Callback to support customisation of ticket key setting */
          int (*ticket_key_cb) (SSL *ssl,
                                unsigned char *name, unsigned char *iv,
                                EVP_CIPHER_CTX *ectx, HMAC_CTX *hctx, int enc);
  
          /* certificate status request info */
          /* Callback for status request */
          int (*status_cb) (SSL *ssl, void *arg);
          void *status_arg;
          /* ext status type used for CSR extension (OCSP Stapling) */
          int status_type;
          /* RFC 4366 Maximum Fragment Length Negotiation */
          uint8_t max_fragment_len_mode;
  
  # ifndef OPENSSL_NO_EC
          /* EC extension values inherited by SSL structure */
          size_t ecpointformats_len;
          unsigned char *ecpointformats;
          size_t supportedgroups_len;
          uint16_t *supportedgroups;
  # endif                         /* OPENSSL_NO_EC */
  
          /*
           * ALPN information (we are in the process of transitioning from NPN to
           * ALPN.)
           */
  
          /*-
           * For a server, this contains a callback function that allows the
           * server to select the protocol for the connection.
           *   out: on successful return, this must point to the raw protocol
           *        name (without the length prefix).
           *   outlen: on successful return, this contains the length of |*out|.
           *   in: points to the client's list of supported protocols in
           *       wire-format.
           *   inlen: the length of |in|.
           */
          int (*alpn_select_cb) (SSL *s,
                                 const unsigned char **out,
                                 unsigned char *outlen,
                                 const unsigned char *in,
                                 unsigned int inlen, void *arg);
          void *alpn_select_cb_arg;
  
          /*
           * For a client, this contains the list of supported protocols in wire
           * format.
           */
          unsigned char *alpn;
          size_t alpn_len;
  
  # ifndef OPENSSL_NO_NEXTPROTONEG
          /* Next protocol negotiation information */
  
          /*
           * For a server, this contains a callback function by which the set of
           * advertised protocols can be provided.
           */
          SSL_CTX_npn_advertised_cb_func npn_advertised_cb;
          void *npn_advertised_cb_arg;
          /*
           * For a client, this contains a callback function that selects the next
           * protocol from the list provided by the server.
           */
          SSL_CTX_npn_select_cb_func npn_select_cb;
          void *npn_select_cb_arg;
  # endif
  
          unsigned char cookie_hmac_key[SHA256_DIGEST_LENGTH];
  
          /*
           * Settings for the fs-0RTT-KEX extension
           */
          struct {
            int enabled;
  
            /* server-side secret and public key */
            FS0RTT_skey_t* skey;
            FS0RTT_pkey_t* pkey;
            /* list of public keys */
            FS0RTT_pkey_t** pkeys;
            size_t pkeys_len;
          } fs_0rtt_kex;
      } ext;
  
  # ifndef OPENSSL_NO_PSK
      SSL_psk_client_cb_func psk_client_callback;
      SSL_psk_server_cb_func psk_server_callback;
  # endif
      SSL_psk_find_session_cb_func psk_find_session_cb;
      SSL_psk_use_session_cb_func psk_use_session_cb;
  
  # ifndef OPENSSL_NO_SRP
      SRP_CTX srp_ctx;            /* ctx for SRP authentication */
  # endif
  
      /* Shared DANE context */
      struct dane_ctx_st dane;
  
  # ifndef OPENSSL_NO_SRTP
      /* SRTP profiles we are willing to do from RFC 5764 */
      STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
  # endif
      /*
       * Callback for disabling session caching and ticket support on a session
       * basis, depending on the chosen cipher.
       */
      int (*not_resumable_session_cb) (SSL *ssl, int is_forward_secure);
  
      CRYPTO_RWLOCK *lock;
  
      /*
       * Callback for logging key material for use with debugging tools like
       * Wireshark. The callback should log `line` followed by a newline.
       */
      SSL_CTX_keylog_cb_func keylog_callback;
  
      /*
       * The maximum number of bytes advertised in session tickets that can be
       * sent as early data.
       */
      uint32_t max_early_data;
  
      /*
       * The maximum number of bytes of early data that a server will tolerate
       * (which should be at least as much as max_early_data).
       */
      uint32_t recv_max_early_data;
  
      /* TLS1.3 padding callback */
      size_t (*record_padding_cb)(SSL *s, int type, size_t len, void *arg);
      void *record_padding_arg;
      size_t block_padding;
  
      /* Session ticket appdata */
      SSL_CTX_generate_session_ticket_fn generate_ticket_cb;
      SSL_CTX_decrypt_session_ticket_fn decrypt_ticket_cb;
      void *ticket_cb_data;
  
      /* The number of TLS1.3 tickets to automatically send */
      size_t num_tickets;
  
      /* Callback to determine if early_data is acceptable or not */
      SSL_allow_early_data_cb_fn allow_early_data_cb;
      void *allow_early_data_cb_data;
  
      /* Do we advertise Post-handshake auth support? */
      int pha_enabled;
  };
  
  struct ssl_st {
      /*
       * protocol version (one of SSL2_VERSION, SSL3_VERSION, TLS1_VERSION,
       * DTLS1_VERSION)
       */
      int version;
      /* SSLv3 */
      const SSL_METHOD *method;
      /*
       * There are 2 BIO's even though they are normally both the same.  This
       * is so data can be read and written to different handlers
       */
      /* used by SSL_read */
      BIO *rbio;
      /* used by SSL_write */
      BIO *wbio;
      /* used during session-id reuse to concatenate messages */
      BIO *bbio;
      /*
       * This holds a variable that indicates what we were doing when a 0 or -1
       * is returned.  This is needed for non-blocking IO so we know what
       * request needs re-doing when in SSL_accept or SSL_connect
       */
      int rwstate;
      int (*handshake_func) (SSL *);
      /*
       * Imagine that here's a boolean member "init" that is switched as soon
       * as SSL_set_{accept/connect}_state is called for the first time, so
       * that "state" and "handshake_func" are properly initialized.  But as
       * handshake_func is == 0 until then, we use this test instead of an
       * "init" member.
       */
      /* are we the server side? */
      int server;
      /*
       * Generate a new session or reuse an old one.
       * NB: For servers, the 'new' session may actually be a previously
       * cached session or even the previous session unless
       * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is set
       */
      int new_session;
      /* don't send shutdown packets */
      int quiet_shutdown;
      /* we have shut things down, 0x01 sent, 0x02 for received */
      int shutdown;
      /* where we are */
      OSSL_STATEM statem;
      SSL_EARLY_DATA_STATE early_data_state;
      BUF_MEM *init_buf;          /* buffer used during init */
      void *init_msg;             /* pointer to handshake message body, set by
                                   * ssl3_get_message() */
      size_t init_num;               /* amount read/written */
      size_t init_off;               /* amount read/written */
      struct ssl3_state_st *s3;   /* SSLv3 variables */
      struct dtls1_state_st *d1;  /* DTLSv1 variables */
      /* callback that allows applications to peek at protocol messages */
      void (*msg_callback) (int write_p, int version, int content_type,
                            const void *buf, size_t len, SSL *ssl, void *arg);
      void *msg_callback_arg;
      int hit;                    /* reusing a previous session */
      X509_VERIFY_PARAM *param;
      /* Per connection DANE state */
      SSL_DANE dane;
      /* crypto */
      STACK_OF(SSL_CIPHER) *peer_ciphers;
      STACK_OF(SSL_CIPHER) *cipher_list;
      STACK_OF(SSL_CIPHER) *cipher_list_by_id;
      /* TLSv1.3 specific ciphersuites */
      STACK_OF(SSL_CIPHER) *tls13_ciphersuites;
      /*
       * These are the ones being used, the ones in SSL_SESSION are the ones to
       * be 'copied' into these ones
       */
      uint32_t mac_flags;
      /*
       * The TLS1.3 secrets.
       */
      unsigned char early_secret[EVP_MAX_MD_SIZE];
      unsigned char handshake_secret[EVP_MAX_MD_SIZE];
      unsigned char master_secret[EVP_MAX_MD_SIZE];
      unsigned char resumption_master_secret[EVP_MAX_MD_SIZE];
      unsigned char client_finished_secret[EVP_MAX_MD_SIZE];
      unsigned char server_finished_secret[EVP_MAX_MD_SIZE];
      unsigned char server_finished_hash[EVP_MAX_MD_SIZE];
      unsigned char handshake_traffic_hash[EVP_MAX_MD_SIZE];
      unsigned char client_app_traffic_secret[EVP_MAX_MD_SIZE];
      unsigned char server_app_traffic_secret[EVP_MAX_MD_SIZE];
      unsigned char exporter_master_secret[EVP_MAX_MD_SIZE];
      unsigned char early_exporter_master_secret[EVP_MAX_MD_SIZE];
      EVP_CIPHER_CTX *enc_read_ctx; /* cryptographic state */
      unsigned char read_iv[EVP_MAX_IV_LENGTH]; /* TLSv1.3 static read IV */
      EVP_MD_CTX *read_hash;      /* used for mac generation */
      COMP_CTX *compress;         /* compression */
      COMP_CTX *expand;           /* uncompress */
      EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
      unsigned char write_iv[EVP_MAX_IV_LENGTH]; /* TLSv1.3 static write IV */
      EVP_MD_CTX *write_hash;     /* used for mac generation */
      /* session info */
      /* client cert? */
      /* This is used to hold the server certificate used */
      struct cert_st /* CERT */ *cert;
  
      /*
       * The hash of all messages prior to the CertificateVerify, and the length
       * of that hash.
       */
      unsigned char cert_verify_hash[EVP_MAX_MD_SIZE];
      size_t cert_verify_hash_len;
  
      /* Flag to indicate whether we should send a HelloRetryRequest or not */
      enum {SSL_HRR_NONE = 0, SSL_HRR_PENDING, SSL_HRR_COMPLETE}
          hello_retry_request;
  
      /*
       * the session_id_context is used to ensure sessions are only reused in
       * the appropriate context
       */
      size_t sid_ctx_length;
      unsigned char sid_ctx[SSL_MAX_SID_CTX_LENGTH];
      /* This can also be in the session once a session is established */
      SSL_SESSION *session;
      /* TLSv1.3 PSK session */
      SSL_SESSION *psksession;
      unsigned char *psksession_id;
      size_t psksession_id_len;
      /* Default generate session ID callback. */
      GEN_SESSION_CB generate_session_id;
      /*
       * The temporary TLSv1.3 session id. This isn't really a session id at all
       * but is a random value sent in the legacy session id field.
       */
      unsigned char tmp_session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
      size_t tmp_session_id_len;
      /* Used in SSL3 */
      /*
       * 0 don't care about verify failure.
       * 1 fail if verify fails
       */
      uint32_t verify_mode;
      /* fail if callback returns 0 */
      int (*verify_callback) (int ok, X509_STORE_CTX *ctx);
      /* optional informational callback */
      void (*info_callback) (const SSL *ssl, int type, int val);
      /* error bytes to be written */
      int error;
      /* actual code */
      int error_code;
  # ifndef OPENSSL_NO_PSK
      SSL_psk_client_cb_func psk_client_callback;
      SSL_psk_server_cb_func psk_server_callback;
  # endif
      SSL_psk_find_session_cb_func psk_find_session_cb;
      SSL_psk_use_session_cb_func psk_use_session_cb;
  
      SSL_CTX *ctx;
      /* Verified chain of peer */
      STACK_OF(X509) *verified_chain;
      long verify_result;
      /* extra application data */
      CRYPTO_EX_DATA ex_data;
      /*
       * What we put in certificate_authorities extension for TLS 1.3
       * (ClientHello and CertificateRequest) or just client cert requests for
       * earlier versions. If client_ca_names is populated then it is only used
       * for client cert requests, and in preference to ca_names.
       */
      STACK_OF(X509_NAME) *ca_names;
      STACK_OF(X509_NAME) *client_ca_names;
      CRYPTO_REF_COUNT references;
      /* protocol behaviour */
      uint32_t options;
      /* API behaviour */
      uint32_t mode;
      int min_proto_version;
      int max_proto_version;
      size_t max_cert_list;
      int first_packet;
      /*
       * What was passed in ClientHello.legacy_version. Used for RSA pre-master
       * secret and SSLv3/TLS (<=1.2) rollback check
       */
      int client_version;
      /*
       * If we're using more than one pipeline how should we divide the data
       * up between the pipes?
       */
      size_t split_send_fragment;
      /*
       * Maximum amount of data to send in one fragment. actual record size can
       * be more than this due to padding and MAC overheads.
       */
      size_t max_send_fragment;
      /* Up to how many pipelines should we use? If 0 then 1 is assumed */
      size_t max_pipelines;
  
      struct {
          /* Built-in extension flags */
          uint8_t extflags[TLSEXT_IDX_num_builtins];
          /* TLS extension debug callback */
          void (*debug_cb)(SSL *s, int client_server, int type,
                           const unsigned char *data, int len, void *arg);
          void *debug_arg;
          char *hostname;
          /* certificate status request info */
          /* Status type or -1 if no status type */
          int status_type;
          /* Raw extension data, if seen */
          unsigned char *scts;
          /* Length of raw extension data, if seen */
          uint16_t scts_len;
          /* Expect OCSP CertificateStatus message */
          int status_expected;
  
          struct {
              /* OCSP status request only */
              STACK_OF(OCSP_RESPID) *ids;
              X509_EXTENSIONS *exts;
              /* OCSP response received or to be sent */
              unsigned char *resp;
              size_t resp_len;
          } ocsp;
  
          /* RFC4507 session ticket expected to be received or sent */
          int ticket_expected;
  # ifndef OPENSSL_NO_EC
          size_t ecpointformats_len;
          /* our list */
          unsigned char *ecpointformats;
  
          size_t peer_ecpointformats_len;
          /* peer's list */
          unsigned char *peer_ecpointformats;
  # endif                         /* OPENSSL_NO_EC */
          size_t supportedgroups_len;
          /* our list */
          uint16_t *supportedgroups;
  
          size_t peer_supportedgroups_len;
           /* peer's list */
          uint16_t *peer_supportedgroups;
  
          /* TLS Session Ticket extension override */
          TLS_SESSION_TICKET_EXT *session_ticket;
          /* TLS Session Ticket extension callback */
          tls_session_ticket_ext_cb_fn session_ticket_cb;
          void *session_ticket_cb_arg;
          /* TLS pre-shared secret session resumption */
          tls_session_secret_cb_fn session_secret_cb;
          void *session_secret_cb_arg;
          /*
           * For a client, this contains the list of supported protocols in wire
           * format.
           */
          unsigned char *alpn;
          size_t alpn_len;
          /*
           * Next protocol negotiation. For the client, this is the protocol that
           * we sent in NextProtocol and is set when handling ServerHello
           * extensions. For a server, this is the client's selected_protocol from
           * NextProtocol and is set when handling the NextProtocol message, before
           * the Finished message.
           */
          unsigned char *npn;
          size_t npn_len;
  
          /* The available PSK key exchange modes */
          int psk_kex_mode;
  
          /* Set to one if we have negotiated ETM */
          int use_etm;
  
          /* Are we expecting to receive early data? */
          int early_data;
          /* Is the session suitable for early data? */
          int early_data_ok;
  
          /* May be sent by a server in HRR. Must be echoed back in ClientHello */
          unsigned char *tls13_cookie;
          size_t tls13_cookie_len;
          /* Have we received a cookie from the client? */
          int cookieok;
  
          /*
           * Maximum Fragment Length as per RFC 4366.
           * If this member contains one of the allowed values (1-4)
           * then we should include Maximum Fragment Length Negotiation
           * extension in Client Hello.
           * Please note that value of this member does not have direct
           * effect. The actual (binding) value is stored in SSL_SESSION,
           * as this extension is optional on server side.
           */
          uint8_t max_fragment_len_mode;
  
          /*
           * On the client side the number of ticket identities we sent in the
           * ClientHello. On the server side the identity of the ticket we
           * selected.
           */
          int tick_identity;
  
          /*
           * Per-session state of fs-0RTT KEX
           */
          struct {
            int state;
            /* the session */
            SSL_SESSION* session;
            uint8_t* key;
            size_t key_size;
          } fs_0rtt_kex;
      } ext;
  
      /*
       * Parsed form of the ClientHello, kept around across client_hello_cb
       * calls.
       */
      CLIENTHELLO_MSG *clienthello;
  
      /*-
       * no further mod of servername
       * 0 : call the servername extension callback.
       * 1 : prepare 2, allow last ack just after in server callback.
       * 2 : don't call servername callback, no ack in server hello
       */
      int servername_done;
  # ifndef OPENSSL_NO_CT
      /*
       * Validates that the SCTs (Signed Certificate Timestamps) are sufficient.
       * If they are not, the connection should be aborted.
       */
      ssl_ct_validation_cb ct_validation_callback;
      /* User-supplied argument that is passed to the ct_validation_callback */
      void *ct_validation_callback_arg;
      /*
       * Consolidated stack of SCTs from all sources.
       * Lazily populated by CT_get_peer_scts(SSL*)
       */
      STACK_OF(SCT) *scts;
      /* Have we attempted to find/parse SCTs yet? */
      int scts_parsed;
  # endif
      SSL_CTX *session_ctx;       /* initial ctx, used to store sessions */
  # ifndef OPENSSL_NO_SRTP
      /* What we'll do */
      STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
      /* What's been chosen */
      SRTP_PROTECTION_PROFILE *srtp_profile;
  # endif
      /*-
       * 1 if we are renegotiating.
       * 2 if we are a server and are inside a handshake
       * (i.e. not just sending a HelloRequest)
       */
      int renegotiate;
      /* If sending a KeyUpdate is pending */
      int key_update;
      /* Post-handshake authentication state */
      SSL_PHA_STATE post_handshake_auth;
      int pha_enabled;
      uint8_t* pha_context;
      size_t pha_context_len;
      int certreqs_sent;
      EVP_MD_CTX *pha_dgst; /* this is just the digest through ClientFinished */
  
  # ifndef OPENSSL_NO_SRP
      /* ctx for SRP authentication */
      SRP_CTX srp_ctx;
  # endif
      /*
       * Callback for disabling session caching and ticket support on a session
       * basis, depending on the chosen cipher.
       */
      int (*not_resumable_session_cb) (SSL *ssl, int is_forward_secure);
      RECORD_LAYER rlayer;
      /* Default password callback. */
      pem_password_cb *default_passwd_callback;
      /* Default password callback user data. */
      void *default_passwd_callback_userdata;
      /* Async Job info */
      ASYNC_JOB *job;
      ASYNC_WAIT_CTX *waitctx;
      size_t asyncrw;
  
      /*
       * The maximum number of bytes advertised in session tickets that can be
       * sent as early data.
       */
      uint32_t max_early_data;
      /*
       * The maximum number of bytes of early data that a server will tolerate
       * (which should be at least as much as max_early_data).
       */
      uint32_t recv_max_early_data;
  
      /*
       * The number of bytes of early data received so far. If we accepted early
       * data then this is a count of the plaintext bytes. If we rejected it then
       * this is a count of the ciphertext bytes.
       */
      uint32_t early_data_count;
  
      /* TLS1.3 padding callback */
      size_t (*record_padding_cb)(SSL *s, int type, size_t len, void *arg);
      void *record_padding_arg;
      size_t block_padding;
  
      CRYPTO_RWLOCK *lock;
  
      /* The number of TLS1.3 tickets to automatically send */
      size_t num_tickets;
      /* The number of TLS1.3 tickets actually sent so far */
      size_t sent_tickets;
      /* The next nonce value to use when we send a ticket on this connection */
      uint64_t next_ticket_nonce;
  
      /* Callback to determine if early_data is acceptable or not */
      SSL_allow_early_data_cb_fn allow_early_data_cb;
      void *allow_early_data_cb_data;
  
      /*
       * Signature algorithms shared by client and server: cached because these
       * are used most often.
       */
      const struct sigalg_lookup_st **shared_sigalgs;
      size_t shared_sigalgslen;
  };
  
  /*
   * Structure containing table entry of values associated with the signature
   * algorithms (signature scheme) extension
  */
  typedef struct sigalg_lookup_st {
      /* TLS 1.3 signature scheme name */
      const char *name;
      /* Raw value used in extension */
      uint16_t sigalg;
      /* NID of hash algorithm or NID_undef if no hash */
      int hash;
      /* Index of hash algorithm or -1 if no hash algorithm */
      int hash_idx;
      /* NID of signature algorithm */
      int sig;
      /* Index of signature algorithm */
      int sig_idx;
      /* Combined hash and signature NID, if any */
      int sigandhash;
      /* Required public key curve (ECDSA only) */
      int curve;
  } SIGALG_LOOKUP;
  
  typedef struct tls_group_info_st {
      int nid;                    /* Curve NID */
      int secbits;                /* Bits of security (from SP800-57) */
      uint16_t flags;             /* Flags: currently just group type */
  } TLS_GROUP_INFO;
  
  /* flags values */
  # define TLS_CURVE_TYPE          0x3 /* Mask for group type */
  # define TLS_CURVE_PRIME         0x0
  # define TLS_CURVE_CHAR2         0x1
  # define TLS_CURVE_CUSTOM        0x2
  
  typedef struct cert_pkey_st CERT_PKEY;
  
  /*
   * Structure containing table entry of certificate info corresponding to
   * CERT_PKEY entries
   */
  typedef struct {
      int nid; /* NID of public key algorithm */
      uint32_t amask; /* authmask corresponding to key type */
  } SSL_CERT_LOOKUP;
  
  typedef struct ssl3_state_st {
      long flags;
      size_t read_mac_secret_size;
      unsigned char read_mac_secret[EVP_MAX_MD_SIZE];
      size_t write_mac_secret_size;
      unsigned char write_mac_secret[EVP_MAX_MD_SIZE];
      unsigned char server_random[SSL3_RANDOM_SIZE];
      unsigned char client_random[SSL3_RANDOM_SIZE];
      /* flags for countermeasure against known-IV weakness */
      int need_empty_fragments;
      int empty_fragment_done;
      /* used during startup, digest all incoming/outgoing packets */
      BIO *handshake_buffer;
      /*
       * When handshake digest is determined, buffer is hashed and
       * freed and MD_CTX for the required digest is stored here.
       */
      EVP_MD_CTX *handshake_dgst;
      /*
       * Set whenever an expected ChangeCipherSpec message is processed.
       * Unset when the peer's Finished message is received.
       * Unexpected ChangeCipherSpec messages trigger a fatal alert.
       */
      int change_cipher_spec;
      int warn_alert;
      int fatal_alert;
      /*
       * we allow one fatal and one warning alert to be outstanding, send close
       * alert via the warning alert
       */
      int alert_dispatch;
      unsigned char send_alert[2];
      /*
       * This flag is set when we should renegotiate ASAP, basically when there
       * is no more data in the read or write buffers
       */
      int renegotiate;
      int total_renegotiations;
      int num_renegotiations;
      int in_read_app_data;
      struct {
          /* actually only need to be 16+20 for SSLv3 and 12 for TLS */
          unsigned char finish_md[EVP_MAX_MD_SIZE * 2];
          size_t finish_md_len;
          unsigned char peer_finish_md[EVP_MAX_MD_SIZE * 2];
          size_t peer_finish_md_len;
          size_t message_size;
          int message_type;
          /* used to hold the new cipher we are going to use */
          const SSL_CIPHER *new_cipher;
  # if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
          EVP_PKEY *pkey;         /* holds short lived DH/ECDH key */
  # endif
          /* used for certificate requests */
          int cert_req;
          /* Certificate types in certificate request message. */
          uint8_t *ctype;
          size_t ctype_len;
          /* Certificate authorities list peer sent */
          STACK_OF(X509_NAME) *peer_ca_names;
          size_t key_block_length;
          unsigned char *key_block;
          const EVP_CIPHER *new_sym_enc;
          const EVP_MD *new_hash;
          int new_mac_pkey_type;
          size_t new_mac_secret_size;
  # ifndef OPENSSL_NO_COMP
          const SSL_COMP *new_compression;
  # else
          char *new_compression;
  # endif
          int cert_request;
          /* Raw values of the cipher list from a client */
          unsigned char *ciphers_raw;
          size_t ciphers_rawlen;
          /* Temporary storage for premaster secret */
          unsigned char *pms;
          size_t pmslen;
  # ifndef OPENSSL_NO_PSK
          /* Temporary storage for PSK key */
          unsigned char *psk;
          size_t psklen;
  # endif
          /* Signature algorithm we actually use */
          const SIGALG_LOOKUP *sigalg;
          /* Pointer to certificate we use */
          CERT_PKEY *cert;
          /*
           * signature algorithms peer reports: e.g. supported signature
           * algorithms extension for server or as part of a certificate
           * request for client.
           * Keep track of the algorithms for TLS and X.509 usage separately.
           */
          uint16_t *peer_sigalgs;
          uint16_t *peer_cert_sigalgs;
          /* Size of above arrays */
          size_t peer_sigalgslen;
          size_t peer_cert_sigalgslen;
          /* Sigalg peer actually uses */
          const SIGALG_LOOKUP *peer_sigalg;
          /*
           * Set if corresponding CERT_PKEY can be used with current
           * SSL session: e.g. appropriate curve, signature algorithms etc.
           * If zero it can't be used at all.
           */
          uint32_t valid_flags[SSL_PKEY_NUM];
          /*
           * For servers the following masks are for the key and auth algorithms
           * that are supported by the certs below. For clients they are masks of
           * *disabled* algorithms based on the current session.
           */
          uint32_t mask_k;
          uint32_t mask_a;
          /*
           * The following are used by the client to see if a cipher is allowed or
           * not.  It contains the minimum and maximum version the client's using
           * based on what it knows so far.
           */
          int min_ver;
          int max_ver;
      } tmp;
  
      /* Connection binding to prevent renegotiation attacks */
      unsigned char previous_client_finished[EVP_MAX_MD_SIZE];
      size_t previous_client_finished_len;
      unsigned char previous_server_finished[EVP_MAX_MD_SIZE];
      size_t previous_server_finished_len;
      int send_connection_binding; /* TODOEKR */
  
  # ifndef OPENSSL_NO_NEXTPROTONEG
      /*
       * Set if we saw the Next Protocol Negotiation extension from our peer.
       */
      int npn_seen;
  # endif
  
      /*
       * ALPN information (we are in the process of transitioning from NPN to
       * ALPN.)
       */
  
      /*
       * In a server these point to the selected ALPN protocol after the
       * ClientHello has been processed. In a client these contain the protocol
       * that the server selected once the ServerHello has been processed.
       */
      unsigned char *alpn_selected;
      size_t alpn_selected_len;
      /* used by the server to know what options were proposed */
      unsigned char *alpn_proposed;
      size_t alpn_proposed_len;
      /* used by the client to know if it actually sent alpn */
      int alpn_sent;
  
  # ifndef OPENSSL_NO_EC
      /*
       * This is set to true if we believe that this is a version of Safari
       * running on OS X 10.6 or newer. We wish to know this because Safari on
       * 10.8 .. 10.8.3 has broken ECDHE-ECDSA support.
       */
      char is_probably_safari;
  # endif                         /* !OPENSSL_NO_EC */
  
      /* For clients: peer temporary key */
  # if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
      /* The group_id for the DH/ECDH key */
      uint16_t group_id;
      EVP_PKEY *peer_tmp;
  # endif
  
  } SSL3_STATE;
  
  /* DTLS structures */
  
  # ifndef OPENSSL_NO_SCTP
  #  define DTLS1_SCTP_AUTH_LABEL   "EXPORTER_DTLS_OVER_SCTP"
  # endif
  
  /* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
  # define DTLS1_MAX_MTU_OVERHEAD                   48
  
  /*
   * Flag used in message reuse to indicate the buffer contains the record
   * header as well as the handshake message header.
   */
  # define DTLS1_SKIP_RECORD_HEADER                 2
  
  struct dtls1_retransmit_state {
      EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
      EVP_MD_CTX *write_hash;     /* used for mac generation */
      COMP_CTX *compress;         /* compression */
      SSL_SESSION *session;
      unsigned short epoch;
  };
  
  struct hm_header_st {
      unsigned char type;
      size_t msg_len;
      unsigned short seq;
      size_t frag_off;
      size_t frag_len;
      unsigned int is_ccs;
      struct dtls1_retransmit_state saved_retransmit_state;
  };
  
  struct dtls1_timeout_st {
      /* Number of read timeouts so far */
      unsigned int read_timeouts;
      /* Number of write timeouts so far */
      unsigned int write_timeouts;
      /* Number of alerts received so far */
      unsigned int num_alerts;
  };
  
  typedef struct hm_fragment_st {
      struct hm_header_st msg_header;
      unsigned char *fragment;
      unsigned char *reassembly;
  } hm_fragment;
  
  typedef struct pqueue_st pqueue;
  typedef struct pitem_st pitem;
  
  struct pitem_st {
      unsigned char priority[8];  /* 64-bit value in big-endian encoding */
      void *data;
      pitem *next;
  };
  
  typedef struct pitem_st *piterator;
  
  pitem *pitem_new(unsigned char *prio64be, void *data);
  void pitem_free(pitem *item);
  pqueue *pqueue_new(void);
  void pqueue_free(pqueue *pq);
  pitem *pqueue_insert(pqueue *pq, pitem *item);
  pitem *pqueue_peek(pqueue *pq);
  pitem *pqueue_pop(pqueue *pq);
  pitem *pqueue_find(pqueue *pq, unsigned char *prio64be);
  pitem *pqueue_iterator(pqueue *pq);
  pitem *pqueue_next(piterator *iter);
  size_t pqueue_size(pqueue *pq);
  
  typedef struct dtls1_state_st {
      unsigned char cookie[DTLS1_COOKIE_LENGTH];
      size_t cookie_len;
      unsigned int cookie_verified;
      /* handshake message numbers */
      unsigned short handshake_write_seq;
      unsigned short next_handshake_write_seq;
      unsigned short handshake_read_seq;
      /* Buffered handshake messages */
      pqueue *buffered_messages;
      /* Buffered (sent) handshake records */
      pqueue *sent_messages;
      size_t link_mtu;      /* max on-the-wire DTLS packet size */
      size_t mtu;           /* max DTLS packet size */
      struct hm_header_st w_msg_hdr;
      struct hm_header_st r_msg_hdr;
      struct dtls1_timeout_st timeout;
      /*
       * Indicates when the last handshake msg sent will timeout
       */
      struct timeval next_timeout;
      /* Timeout duration */
      unsigned int timeout_duration_us;
  
      unsigned int retransmitting;
  # ifndef OPENSSL_NO_SCTP
      int shutdown_received;
  # endif
  
      DTLS_timer_cb timer_cb;
  
  } DTLS1_STATE;
  
  # ifndef OPENSSL_NO_EC
  /*
   * From ECC-TLS draft, used in encoding the curve type in ECParameters
   */
  #  define EXPLICIT_PRIME_CURVE_TYPE  1
  #  define EXPLICIT_CHAR2_CURVE_TYPE  2
  #  define NAMED_CURVE_TYPE           3
  # endif                         /* OPENSSL_NO_EC */
  
  struct cert_pkey_st {
      X509 *x509;
      EVP_PKEY *privatekey;
      /* Chain for this certificate */
      STACK_OF(X509) *chain;
      /*-
       * serverinfo data for this certificate.  The data is in TLS Extension
       * wire format, specifically it's a series of records like:
       *   uint16_t extension_type; // (RFC 5246, 7.4.1.4, Extension)
       *   uint16_t length;
       *   uint8_t data[length];
       */
      unsigned char *serverinfo;
      size_t serverinfo_length;
  };
  /* Retrieve Suite B flags */
  # define tls1_suiteb(s)  (s->cert->cert_flags & SSL_CERT_FLAG_SUITEB_128_LOS)
  /* Uses to check strict mode: suite B modes are always strict */
  # define SSL_CERT_FLAGS_CHECK_TLS_STRICT \
          (SSL_CERT_FLAG_SUITEB_128_LOS|SSL_CERT_FLAG_TLS_STRICT)
  
  typedef enum {
      ENDPOINT_CLIENT = 0,
      ENDPOINT_SERVER,
      ENDPOINT_BOTH
  } ENDPOINT;
  
  
  typedef struct {
      unsigned short ext_type;
      ENDPOINT role;
      /* The context which this extension applies to */
      unsigned int context;
      /*
       * Per-connection flags relating to this extension type: not used if
       * part of an SSL_CTX structure.
       */
      uint32_t ext_flags;
      SSL_custom_ext_add_cb_ex add_cb;
      SSL_custom_ext_free_cb_ex free_cb;
      void *add_arg;
      SSL_custom_ext_parse_cb_ex parse_cb;
      void *parse_arg;
  } custom_ext_method;
  
  /* ext_flags values */
  
  /*
   * Indicates an extension has been received. Used to check for unsolicited or
   * duplicate extensions.
   */
  # define SSL_EXT_FLAG_RECEIVED   0x1
  /*
   * Indicates an extension has been sent: used to enable sending of
   * corresponding ServerHello extension.
   */
  # define SSL_EXT_FLAG_SENT       0x2
  
  typedef struct {
      custom_ext_method *meths;
      size_t meths_count;
  } custom_ext_methods;
  
  typedef struct cert_st {
      /* Current active set */
      /*
       * ALWAYS points to an element of the pkeys array
       * Probably it would make more sense to store
       * an index, not a pointer.
       */
      CERT_PKEY *key;
  # ifndef OPENSSL_NO_DH
      EVP_PKEY *dh_tmp;
      DH *(*dh_tmp_cb) (SSL *ssl, int is_export, int keysize);
      int dh_tmp_auto;
  # endif
      /* Flags related to certificates */
      uint32_t cert_flags;
      CERT_PKEY pkeys[SSL_PKEY_NUM];
      /* Custom certificate types sent in certificate request message. */
      uint8_t *ctype;
      size_t ctype_len;
      /*
       * supported signature algorithms. When set on a client this is sent in
       * the client hello as the supported signature algorithms extension. For
       * servers it represents the signature algorithms we are willing to use.
       */
      uint16_t *conf_sigalgs;
      /* Size of above array */
      size_t conf_sigalgslen;
      /*
       * Client authentication signature algorithms, if not set then uses
       * conf_sigalgs. On servers these will be the signature algorithms sent
       * to the client in a certificate request for TLS 1.2. On a client this
       * represents the signature algorithms we are willing to use for client
       * authentication.
       */
      uint16_t *client_sigalgs;
      /* Size of above array */
      size_t client_sigalgslen;
      /*
       * Certificate setup callback: if set is called whenever a certificate
       * may be required (client or server). the callback can then examine any
       * appropriate parameters and setup any certificates required. This
       * allows advanced applications to select certificates on the fly: for
       * example based on supported signature algorithms or curves.
       */
      int (*cert_cb) (SSL *ssl, void *arg);
      void *cert_cb_arg;
      /*
       * Optional X509_STORE for chain building or certificate validation If
       * NULL the parent SSL_CTX store is used instead.
       */
      X509_STORE *chain_store;
      X509_STORE *verify_store;
      /* Custom extensions */
      custom_ext_methods custext;
      /* Security callback */
      int (*sec_cb) (const SSL *s, const SSL_CTX *ctx, int op, int bits, int nid,
                     void *other, void *ex);
      /* Security level */
      int sec_level;
      void *sec_ex;
  # ifndef OPENSSL_NO_PSK
      /* If not NULL psk identity hint to use for servers */
      char *psk_identity_hint;
  # endif
      CRYPTO_REF_COUNT references;             /* >1 only if SSL_copy_session_id is used */
      CRYPTO_RWLOCK *lock;
  } CERT;
  
  # define FP_ICC  (int (*)(const void *,const void *))
  
  /*
   * This is for the SSLv3/TLSv1.0 differences in crypto/hash stuff It is a bit
   * of a mess of functions, but hell, think of it as an opaque structure :-)
   */
  typedef struct ssl3_enc_method {
      int (*enc) (SSL *, SSL3_RECORD *, size_t, int);
      int (*mac) (SSL *, SSL3_RECORD *, unsigned char *, int);
      int (*setup_key_block) (SSL *);
      int (*generate_master_secret) (SSL *, unsigned char *, unsigned char *,
                                     size_t, size_t *);
      int (*change_cipher_state) (SSL *, int);
      size_t (*final_finish_mac) (SSL *, const char *, size_t, unsigned char *);
      const char *client_finished_label;
      size_t client_finished_label_len;
      const char *server_finished_label;
      size_t server_finished_label_len;
      int (*alert_value) (int);
      int (*export_keying_material) (SSL *, unsigned char *, size_t,
                                     const char *, size_t,
                                     const unsigned char *, size_t,
                                     int use_context);
      /* Various flags indicating protocol version requirements */
      uint32_t enc_flags;
      /* Set the handshake header */
      int (*set_handshake_header) (SSL *s, WPACKET *pkt, int type);
      /* Close construction of the handshake message */
      int (*close_construct_packet) (SSL *s, WPACKET *pkt, int htype);
      /* Write out handshake message */
      int (*do_write) (SSL *s);
  } SSL3_ENC_METHOD;
  
  # define ssl_set_handshake_header(s, pkt, htype) \
          s->method->ssl3_enc->set_handshake_header((s), (pkt), (htype))
  # define ssl_close_construct_packet(s, pkt, htype) \
          s->method->ssl3_enc->close_construct_packet((s), (pkt), (htype))
  # define ssl_do_write(s)  s->method->ssl3_enc->do_write(s)
  
  /* Values for enc_flags */
  
  /* Uses explicit IV for CBC mode */
  # define SSL_ENC_FLAG_EXPLICIT_IV        0x1
  /* Uses signature algorithms extension */
  # define SSL_ENC_FLAG_SIGALGS            0x2
  /* Uses SHA256 default PRF */
  # define SSL_ENC_FLAG_SHA256_PRF         0x4
  /* Is DTLS */
  # define SSL_ENC_FLAG_DTLS               0x8
  /*
   * Allow TLS 1.2 ciphersuites: applies to DTLS 1.2 as well as TLS 1.2: may
   * apply to others in future.
   */
  # define SSL_ENC_FLAG_TLS1_2_CIPHERS     0x10
  
  # ifndef OPENSSL_NO_COMP
  /* Used for holding the relevant compression methods loaded into SSL_CTX */
  typedef struct ssl3_comp_st {
      int comp_id;                /* The identifier byte for this compression
                                   * type */
      char *name;                 /* Text name used for the compression type */
      COMP_METHOD *method;        /* The method :-) */
  } SSL3_COMP;
  # endif
  
  typedef enum downgrade_en {
      DOWNGRADE_NONE,
      DOWNGRADE_TO_1_2,
      DOWNGRADE_TO_1_1
  } DOWNGRADE;
  
  /*
   * Dummy status type for the status_type extension. Indicates no status type
   * set
   */
  #define TLSEXT_STATUSTYPE_nothing  -1
  
  /* Sigalgs values */
  #define TLSEXT_SIGALG_ecdsa_secp256r1_sha256                    0x0403
  #define TLSEXT_SIGALG_ecdsa_secp384r1_sha384                    0x0503
  #define TLSEXT_SIGALG_ecdsa_secp521r1_sha512                    0x0603
  #define TLSEXT_SIGALG_ecdsa_sha224                              0x0303
  #define TLSEXT_SIGALG_ecdsa_sha1                                0x0203
  #define TLSEXT_SIGALG_rsa_pss_rsae_sha256                       0x0804
  #define TLSEXT_SIGALG_rsa_pss_rsae_sha384                       0x0805
  #define TLSEXT_SIGALG_rsa_pss_rsae_sha512                       0x0806
  #define TLSEXT_SIGALG_rsa_pss_pss_sha256                        0x0809
  #define TLSEXT_SIGALG_rsa_pss_pss_sha384                        0x080a
  #define TLSEXT_SIGALG_rsa_pss_pss_sha512                        0x080b
  #define TLSEXT_SIGALG_rsa_pkcs1_sha256                          0x0401
  #define TLSEXT_SIGALG_rsa_pkcs1_sha384                          0x0501
  #define TLSEXT_SIGALG_rsa_pkcs1_sha512                          0x0601
  #define TLSEXT_SIGALG_rsa_pkcs1_sha224                          0x0301
  #define TLSEXT_SIGALG_rsa_pkcs1_sha1                            0x0201
  #define TLSEXT_SIGALG_dsa_sha256                                0x0402
  #define TLSEXT_SIGALG_dsa_sha384                                0x0502
  #define TLSEXT_SIGALG_dsa_sha512                                0x0602
  #define TLSEXT_SIGALG_dsa_sha224                                0x0302
  #define TLSEXT_SIGALG_dsa_sha1                                  0x0202
  #define TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256       0xeeee
  #define TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512       0xefef
  #define TLSEXT_SIGALG_gostr34102001_gostr3411                   0xeded
  
  #define TLSEXT_SIGALG_ed25519                                   0x0807
  #define TLSEXT_SIGALG_ed448                                     0x0808
  
  /* Known PSK key exchange modes */
  #define TLSEXT_KEX_MODE_KE                                      0x00
  #define TLSEXT_KEX_MODE_KE_DHE                                  0x01
  
  /*
   * Internal representations of key exchange modes
   */
  #define TLSEXT_KEX_MODE_FLAG_NONE                               0
  #define TLSEXT_KEX_MODE_FLAG_KE                                 1
  #define TLSEXT_KEX_MODE_FLAG_KE_DHE                             2
  
  #define SSL_USE_PSS(s) (s->s3->tmp.peer_sigalg != NULL && \
                          s->s3->tmp.peer_sigalg->sig == EVP_PKEY_RSA_PSS)
  
  /* A dummy signature value not valid for TLSv1.2 signature algs */
  #define TLSEXT_signature_rsa_pss                                0x0101
  
  /* TLSv1.3 downgrade protection sentinel values */
  extern const unsigned char tls11downgrade[8];
  extern const unsigned char tls12downgrade[8];
  
  extern SSL3_ENC_METHOD ssl3_undef_enc_method;
  
  __owur const SSL_METHOD *ssl_bad_method(int ver);
  __owur const SSL_METHOD *sslv3_method(void);
  __owur const SSL_METHOD *sslv3_server_method(void);
  __owur const SSL_METHOD *sslv3_client_method(void);
  __owur const SSL_METHOD *tlsv1_method(void);
  __owur const SSL_METHOD *tlsv1_server_method(void);
  __owur const SSL_METHOD *tlsv1_client_method(void);
  __owur const SSL_METHOD *tlsv1_1_method(void);
  __owur const SSL_METHOD *tlsv1_1_server_method(void);
  __owur const SSL_METHOD *tlsv1_1_client_method(void);
  __owur const SSL_METHOD *tlsv1_2_method(void);
  __owur const SSL_METHOD *tlsv1_2_server_method(void);
  __owur const SSL_METHOD *tlsv1_2_client_method(void);
  __owur const SSL_METHOD *tlsv1_3_method(void);
  __owur const SSL_METHOD *tlsv1_3_server_method(void);
  __owur const SSL_METHOD *tlsv1_3_client_method(void);
  __owur const SSL_METHOD *dtlsv1_method(void);
  __owur const SSL_METHOD *dtlsv1_server_method(void);
  __owur const SSL_METHOD *dtlsv1_client_method(void);
  __owur const SSL_METHOD *dtls_bad_ver_client_method(void);
  __owur const SSL_METHOD *dtlsv1_2_method(void);
  __owur const SSL_METHOD *dtlsv1_2_server_method(void);
  __owur const SSL_METHOD *dtlsv1_2_client_method(void);
  
  extern const SSL3_ENC_METHOD TLSv1_enc_data;
  extern const SSL3_ENC_METHOD TLSv1_1_enc_data;
  extern const SSL3_ENC_METHOD TLSv1_2_enc_data;
  extern const SSL3_ENC_METHOD TLSv1_3_enc_data;
  extern const SSL3_ENC_METHOD SSLv3_enc_data;
  extern const SSL3_ENC_METHOD DTLSv1_enc_data;
  extern const SSL3_ENC_METHOD DTLSv1_2_enc_data;
  
  /*
   * Flags for SSL methods
   */
  # define SSL_METHOD_NO_FIPS      (1U<<0)
  # define SSL_METHOD_NO_SUITEB    (1U<<1)
  
  # define IMPLEMENT_tls_meth_func(version, flags, mask, func_name, s_accept, \
                                   s_connect, enc_data) \
  const SSL_METHOD *func_name(void)  \
          { \
          static const SSL_METHOD func_name##_data= { \
                  version, \
                  flags, \
                  mask, \
                  tls1_new, \
                  tls1_clear, \
                  tls1_free, \
                  s_accept, \
                  s_connect, \
                  ssl3_read, \
                  ssl3_peek, \
                  ssl3_write, \
                  ssl3_shutdown, \
                  ssl3_renegotiate, \
                  ssl3_renegotiate_check, \
                  ssl3_read_bytes, \
                  ssl3_write_bytes, \
                  ssl3_dispatch_alert, \
                  ssl3_ctrl, \
                  ssl3_ctx_ctrl, \
                  ssl3_get_cipher_by_char, \
                  ssl3_put_cipher_by_char, \
                  ssl3_pending, \
                  ssl3_num_ciphers, \
                  ssl3_get_cipher, \
                  tls1_default_timeout, \
                  &enc_data, \
                  ssl_undefined_void_function, \
                  ssl3_callback_ctrl, \
                  ssl3_ctx_callback_ctrl, \
          }; \
          return &func_name##_data; \
          }
  
  # define IMPLEMENT_ssl3_meth_func(func_name, s_accept, s_connect) \
  const SSL_METHOD *func_name(void)  \
          { \
          static const SSL_METHOD func_name##_data= { \
                  SSL3_VERSION, \
                  SSL_METHOD_NO_FIPS | SSL_METHOD_NO_SUITEB, \
                  SSL_OP_NO_SSLv3, \
                  ssl3_new, \
                  ssl3_clear, \
                  ssl3_free, \
                  s_accept, \
                  s_connect, \
                  ssl3_read, \
                  ssl3_peek, \
                  ssl3_write, \
                  ssl3_shutdown, \
                  ssl3_renegotiate, \
                  ssl3_renegotiate_check, \
                  ssl3_read_bytes, \
                  ssl3_write_bytes, \
                  ssl3_dispatch_alert, \
                  ssl3_ctrl, \
                  ssl3_ctx_ctrl, \
                  ssl3_get_cipher_by_char, \
                  ssl3_put_cipher_by_char, \
                  ssl3_pending, \
                  ssl3_num_ciphers, \
                  ssl3_get_cipher, \
                  ssl3_default_timeout, \
                  &SSLv3_enc_data, \
                  ssl_undefined_void_function, \
                  ssl3_callback_ctrl, \
                  ssl3_ctx_callback_ctrl, \
          }; \
          return &func_name##_data; \
          }
  
  # define IMPLEMENT_dtls1_meth_func(version, flags, mask, func_name, s_accept, \
                                          s_connect, enc_data) \
  const SSL_METHOD *func_name(void)  \
          { \
          static const SSL_METHOD func_name##_data= { \
                  version, \
                  flags, \
                  mask, \
                  dtls1_new, \
                  dtls1_clear, \
                  dtls1_free, \
                  s_accept, \
                  s_connect, \
                  ssl3_read, \
                  ssl3_peek, \
                  ssl3_write, \
                  dtls1_shutdown, \
                  ssl3_renegotiate, \
                  ssl3_renegotiate_check, \
                  dtls1_read_bytes, \
                  dtls1_write_app_data_bytes, \
                  dtls1_dispatch_alert, \
                  dtls1_ctrl, \
                  ssl3_ctx_ctrl, \
                  ssl3_get_cipher_by_char, \
                  ssl3_put_cipher_by_char, \
                  ssl3_pending, \
                  ssl3_num_ciphers, \
                  ssl3_get_cipher, \
                  dtls1_default_timeout, \
                  &enc_data, \
                  ssl_undefined_void_function, \
                  ssl3_callback_ctrl, \
                  ssl3_ctx_callback_ctrl, \
          }; \
          return &func_name##_data; \
          }
  
  struct openssl_ssl_test_functions {
      int (*p_ssl_init_wbio_buffer) (SSL *s);
      int (*p_ssl3_setup_buffers) (SSL *s);
  };
  
  const char *ssl_protocol_to_string(int version);
  
  /* Returns true if certificate and private key for 'idx' are present */
  static ossl_inline int ssl_has_cert(const SSL *s, int idx)
  {
      if (idx < 0 || idx >= SSL_PKEY_NUM)
          return 0;
      return s->cert->pkeys[idx].x509 != NULL
          && s->cert->pkeys[idx].privatekey != NULL;
  }
  
  static ossl_inline void tls1_get_peer_groups(SSL *s, const uint16_t **pgroups,
                                               size_t *pgroupslen)
  {
      *pgroups = s->ext.peer_supportedgroups;
      *pgroupslen = s->ext.peer_supportedgroups_len;
  }
  
  # ifndef OPENSSL_UNIT_TEST
  
  __owur int ssl_read_internal(SSL *s, void *buf, size_t num, size_t *readbytes);
  __owur int ssl_write_internal(SSL *s, const void *buf, size_t num, size_t *written);
  void ssl_clear_cipher_ctx(SSL *s);
  int ssl_clear_bad_session(SSL *s);
  __owur CERT *ssl_cert_new(void);
  __owur CERT *ssl_cert_dup(CERT *cert);
  void ssl_cert_clear_certs(CERT *c);
  void ssl_cert_free(CERT *c);
  __owur int ssl_generate_session_id(SSL *s, SSL_SESSION *ss);
  __owur int ssl_get_new_session(SSL *s, int session);
  __owur SSL_SESSION *lookup_sess_in_cache(SSL *s, const unsigned char *sess_id,
                                           size_t sess_id_len);
  __owur int ssl_get_prev_session(SSL *s, CLIENTHELLO_MSG *hello);
  __owur SSL_SESSION *ssl_session_dup(SSL_SESSION *src, int ticket);
  __owur int ssl_cipher_id_cmp(const SSL_CIPHER *a, const SSL_CIPHER *b);
  DECLARE_OBJ_BSEARCH_GLOBAL_CMP_FN(SSL_CIPHER, SSL_CIPHER, ssl_cipher_id);
  __owur int ssl_cipher_ptr_id_cmp(const SSL_CIPHER *const *ap,
                                   const SSL_CIPHER *const *bp);
  __owur STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method,
                                                      STACK_OF(SSL_CIPHER) *tls13_ciphersuites,
                                                      STACK_OF(SSL_CIPHER) **cipher_list,
                                                      STACK_OF(SSL_CIPHER) **cipher_list_by_id,
                                                      const char *rule_str,
                                                      CERT *c);
  __owur int ssl_cache_cipherlist(SSL *s, PACKET *cipher_suites, int sslv2format);
  __owur int bytes_to_cipher_list(SSL *s, PACKET *cipher_suites,
                                  STACK_OF(SSL_CIPHER) **skp,
                                  STACK_OF(SSL_CIPHER) **scsvs, int sslv2format,
                                  int fatal);
  void ssl_update_cache(SSL *s, int mode);
  __owur int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
                                const EVP_MD **md, int *mac_pkey_type,
                                size_t *mac_secret_size, SSL_COMP **comp,
                                int use_etm);
  __owur int ssl_cipher_get_overhead(const SSL_CIPHER *c, size_t *mac_overhead,
                                     size_t *int_overhead, size_t *blocksize,
                                     size_t *ext_overhead);
  __owur int ssl_cert_is_disabled(size_t idx);
  __owur const SSL_CIPHER *ssl_get_cipher_by_char(SSL *ssl,
                                                  const unsigned char *ptr,
                                                  int all);
  __owur int ssl_cert_set0_chain(SSL *s, SSL_CTX *ctx, STACK_OF(X509) *chain);
  __owur int ssl_cert_set1_chain(SSL *s, SSL_CTX *ctx, STACK_OF(X509) *chain);
  __owur int ssl_cert_add0_chain_cert(SSL *s, SSL_CTX *ctx, X509 *x);
  __owur int ssl_cert_add1_chain_cert(SSL *s, SSL_CTX *ctx, X509 *x);
  __owur int ssl_cert_select_current(CERT *c, X509 *x);
  __owur int ssl_cert_set_current(CERT *c, long arg);
  void ssl_cert_set_cert_cb(CERT *c, int (*cb) (SSL *ssl, void *arg), void *arg);
  
  __owur int ssl_verify_cert_chain(SSL *s, STACK_OF(X509) *sk);
  __owur int ssl_build_cert_chain(SSL *s, SSL_CTX *ctx, int flags);
  __owur int ssl_cert_set_cert_store(CERT *c, X509_STORE *store, int chain,
                                     int ref);
  
  __owur int ssl_security(const SSL *s, int op, int bits, int nid, void *other);
  __owur int ssl_ctx_security(const SSL_CTX *ctx, int op, int bits, int nid,
                              void *other);
  
  __owur int ssl_cert_lookup_by_nid(int nid, size_t *pidx);
  __owur const SSL_CERT_LOOKUP *ssl_cert_lookup_by_pkey(const EVP_PKEY *pk,
                                                        size_t *pidx);
  __owur const SSL_CERT_LOOKUP *ssl_cert_lookup_by_idx(size_t idx);
  
  int ssl_undefined_function(SSL *s);
  __owur int ssl_undefined_void_function(void);
  __owur int ssl_undefined_const_function(const SSL *s);
  __owur int ssl_get_server_cert_serverinfo(SSL *s,
                                            const unsigned char **serverinfo,
                                            size_t *serverinfo_length);
  void ssl_set_masks(SSL *s);
  __owur STACK_OF(SSL_CIPHER) *ssl_get_ciphers_by_id(SSL *s);
  __owur int ssl_x509err2alert(int type);
  void ssl_sort_cipher_list(void);
  int ssl_load_ciphers(void);
  __owur int ssl_fill_hello_random(SSL *s, int server, unsigned char *field,
                                   size_t len, DOWNGRADE dgrd);
  __owur int ssl_generate_master_secret(SSL *s, unsigned char *pms, size_t pmslen,
                                        int free_pms);
  __owur EVP_PKEY *ssl_generate_pkey(EVP_PKEY *pm);
  __owur int ssl_derive(SSL *s, EVP_PKEY *privkey, EVP_PKEY *pubkey,
                        int genmaster);
  __owur EVP_PKEY *ssl_dh_to_pkey(DH *dh);
  __owur unsigned int ssl_get_max_send_fragment(const SSL *ssl);
  __owur unsigned int ssl_get_split_send_fragment(const SSL *ssl);
  
  __owur const SSL_CIPHER *ssl3_get_cipher_by_id(uint32_t id);
  __owur const SSL_CIPHER *ssl3_get_cipher_by_std_name(const char *stdname);
  __owur const SSL_CIPHER *ssl3_get_cipher_by_char(const unsigned char *p);
  __owur int ssl3_put_cipher_by_char(const SSL_CIPHER *c, WPACKET *pkt,
                                     size_t *len);
  int ssl3_init_finished_mac(SSL *s);
  __owur int ssl3_setup_key_block(SSL *s);
  __owur int ssl3_change_cipher_state(SSL *s, int which);
  void ssl3_cleanup_key_block(SSL *s);
  __owur int ssl3_do_write(SSL *s, int type);
  int ssl3_send_alert(SSL *s, int level, int desc);
  __owur int ssl3_generate_master_secret(SSL *s, unsigned char *out,
                                         unsigned char *p, size_t len,
                                         size_t *secret_size);
  __owur int ssl3_get_req_cert_type(SSL *s, WPACKET *pkt);
  __owur int ssl3_num_ciphers(void);
  __owur const SSL_CIPHER *ssl3_get_cipher(unsigned int u);
  int ssl3_renegotiate(SSL *ssl);
  int ssl3_renegotiate_check(SSL *ssl, int initok);
  __owur int ssl3_dispatch_alert(SSL *s);
  __owur size_t ssl3_final_finish_mac(SSL *s, const char *sender, size_t slen,
                                      unsigned char *p);
  __owur int ssl3_finish_mac(SSL *s, const unsigned char *buf, size_t len);
  void ssl3_free_digest_list(SSL *s);
  __owur unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt,
                                              CERT_PKEY *cpk);
  __owur const SSL_CIPHER *ssl3_choose_cipher(SSL *ssl,
                                              STACK_OF(SSL_CIPHER) *clnt,
                                              STACK_OF(SSL_CIPHER) *srvr);
  __owur int ssl3_digest_cached_records(SSL *s, int keep);
  __owur int ssl3_new(SSL *s);
  void ssl3_free(SSL *s);
  __owur int ssl3_read(SSL *s, void *buf, size_t len, size_t *readbytes);
  __owur int ssl3_peek(SSL *s, void *buf, size_t len, size_t *readbytes);
  __owur int ssl3_write(SSL *s, const void *buf, size_t len, size_t *written);
  __owur int ssl3_shutdown(SSL *s);
  int ssl3_clear(SSL *s);
  __owur long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg);
  __owur long ssl3_ctx_ctrl(SSL_CTX *s, int cmd, long larg, void *parg);
  __owur long ssl3_callback_ctrl(SSL *s, int cmd, void (*fp) (void));
  __owur long ssl3_ctx_callback_ctrl(SSL_CTX *s, int cmd, void (*fp) (void));
  
  __owur int ssl3_do_change_cipher_spec(SSL *ssl);
  __owur long ssl3_default_timeout(void);
  
  __owur int ssl3_set_handshake_header(SSL *s, WPACKET *pkt, int htype);
  __owur int tls_close_construct_packet(SSL *s, WPACKET *pkt, int htype);
  __owur int tls_setup_handshake(SSL *s);
  __owur int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype);
  __owur int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype);
  __owur int ssl3_handshake_write(SSL *s);
  
  __owur int ssl_allow_compression(SSL *s);
  
  __owur int ssl_version_supported(const SSL *s, int version,
                                   const SSL_METHOD **meth);
  
  __owur int ssl_set_client_hello_version(SSL *s);
  __owur int ssl_check_version_downgrade(SSL *s);
  __owur int ssl_set_version_bound(int method_version, int version, int *bound);
  __owur int ssl_choose_server_version(SSL *s, CLIENTHELLO_MSG *hello,
                                       DOWNGRADE *dgrd);
  __owur int ssl_choose_client_version(SSL *s, int version,
                                       RAW_EXTENSION *extensions);
  __owur int ssl_get_min_max_version(const SSL *s, int *min_version,
                                     int *max_version, int *real_max);
  
  __owur long tls1_default_timeout(void);
  __owur int dtls1_do_write(SSL *s, int type);
  void dtls1_set_message_header(SSL *s,
                                unsigned char mt,
                                size_t len,
                                size_t frag_off, size_t frag_len);
  
  int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, size_t len,
                                 size_t *written);
  
  __owur int dtls1_read_failed(SSL *s, int code);
  __owur int dtls1_buffer_message(SSL *s, int ccs);
  __owur int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found);
  __owur int dtls1_get_queue_priority(unsigned short seq, int is_ccs);
  int dtls1_retransmit_buffered_messages(SSL *s);
  void dtls1_clear_received_buffer(SSL *s);
  void dtls1_clear_sent_buffer(SSL *s);
  void dtls1_get_message_header(unsigned char *data,
                                struct hm_header_st *msg_hdr);
  __owur long dtls1_default_timeout(void);
  __owur struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft);
  __owur int dtls1_check_timeout_num(SSL *s);
  __owur int dtls1_handle_timeout(SSL *s);
  void dtls1_start_timer(SSL *s);
  void dtls1_stop_timer(SSL *s);
  __owur int dtls1_is_timer_expired(SSL *s);
  void dtls1_double_timeout(SSL *s);
  __owur int dtls_raw_hello_verify_request(WPACKET *pkt, unsigned char *cookie,
                                           size_t cookie_len);
  __owur size_t dtls1_min_mtu(SSL *s);
  void dtls1_hm_fragment_free(hm_fragment *frag);
  __owur int dtls1_query_mtu(SSL *s);
  
  __owur int tls1_new(SSL *s);
  void tls1_free(SSL *s);
  int tls1_clear(SSL *s);
  
  __owur int dtls1_new(SSL *s);
  void dtls1_free(SSL *s);
  int dtls1_clear(SSL *s);
  long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg);
  __owur int dtls1_shutdown(SSL *s);
  
  __owur int dtls1_dispatch_alert(SSL *s);
  
  __owur int ssl_init_wbio_buffer(SSL *s);
  int ssl_free_wbio_buffer(SSL *s);
  
  __owur int tls1_change_cipher_state(SSL *s, int which);
  __owur int tls1_setup_key_block(SSL *s);
  __owur size_t tls1_final_finish_mac(SSL *s, const char *str, size_t slen,
                                      unsigned char *p);
  __owur int tls1_generate_master_secret(SSL *s, unsigned char *out,
                                         unsigned char *p, size_t len,
                                         size_t *secret_size);
  __owur int tls13_setup_key_block(SSL *s);
  __owur size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
                                       unsigned char *p);
  __owur int tls13_change_cipher_state(SSL *s, int which);
  __owur int tls13_update_key(SSL *s, int send);
  __owur int tls13_hkdf_expand(SSL *s, const EVP_MD *md,
                               const unsigned char *secret,
                               const unsigned char *label, size_t labellen,
                               const unsigned char *data, size_t datalen,
                               unsigned char *out, size_t outlen, int fatal);
  __owur int tls13_derive_key(SSL *s, const EVP_MD *md,
                              const unsigned char *secret, unsigned char *key,
                              size_t keylen);
  __owur int tls13_derive_iv(SSL *s, const EVP_MD *md,
                             const unsigned char *secret, unsigned char *iv,
                             size_t ivlen);
  __owur int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
                                      const unsigned char *secret,
                                      unsigned char *fin, size_t finlen);
  int tls13_generate_secret(SSL *s, const EVP_MD *md,
                            const unsigned char *prevsecret,
                            const unsigned char *insecret,
                            size_t insecretlen,
                            unsigned char *outsecret);
  __owur int tls13_generate_handshake_secret(SSL *s,
                                             const unsigned char *insecret,
                                             size_t insecretlen);
  __owur int tls13_generate_master_secret(SSL *s, unsigned char *out,
                                          unsigned char *prev, size_t prevlen,
                                          size_t *secret_size);
  __owur int tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen,
                                         const char *label, size_t llen,
                                         const unsigned char *p, size_t plen,
                                         int use_context);
  __owur int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
                                          const char *label, size_t llen,
                                          const unsigned char *context,
                                          size_t contextlen, int use_context);
  __owur int tls13_export_keying_material_early(SSL *s, unsigned char *out,
                                                size_t olen, const char *label,
                                                size_t llen,
                                                const unsigned char *context,
                                                size_t contextlen);
  __owur int tls1_alert_code(int code);
  __owur int tls13_alert_code(int code);
  __owur int ssl3_alert_code(int code);
  
  #  ifndef OPENSSL_NO_EC
  __owur int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s);
  #  endif
  
  SSL_COMP *ssl3_comp_find(STACK_OF(SSL_COMP) *sk, int n);
  
  #  ifndef OPENSSL_NO_EC
  
  __owur const TLS_GROUP_INFO *tls1_group_id_lookup(uint16_t curve_id);
  __owur int tls1_check_group_id(SSL *s, uint16_t group_id, int check_own_curves);
  __owur uint16_t tls1_shared_group(SSL *s, int nmatch);
  __owur int tls1_set_groups(uint16_t **pext, size_t *pextlen,
                             int *curves, size_t ncurves);
  __owur int tls1_set_groups_list(uint16_t **pext, size_t *pextlen,
                                  const char *str);
  void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
                           size_t *num_formats);
  __owur int tls1_check_ec_tmp_key(SSL *s, unsigned long id);
  __owur EVP_PKEY *ssl_generate_pkey_group(SSL *s, uint16_t id);
  __owur EVP_PKEY *ssl_generate_param_group(uint16_t id);
  #  endif                        /* OPENSSL_NO_EC */
  
  __owur int tls_curve_allowed(SSL *s, uint16_t curve, int op);
  void tls1_get_supported_groups(SSL *s, const uint16_t **pgroups,
                                 size_t *pgroupslen);
  
  __owur int tls1_set_server_sigalgs(SSL *s);
  
  __owur SSL_TICKET_STATUS tls_get_ticket_from_client(SSL *s, CLIENTHELLO_MSG *hello,
                                                      SSL_SESSION **ret);
  __owur SSL_TICKET_STATUS tls_decrypt_ticket(SSL *s, const unsigned char *etick,
                                              size_t eticklen,
                                              const unsigned char *sess_id,
                                              size_t sesslen, SSL_SESSION **psess);
  
  __owur int tls_use_ticket(SSL *s);
  
  void ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op);
  
  __owur int tls1_set_sigalgs_list(CERT *c, const char *str, int client);
  __owur int tls1_set_raw_sigalgs(CERT *c, const uint16_t *psigs, size_t salglen,
                                  int client);
  __owur int tls1_set_sigalgs(CERT *c, const int *salg, size_t salglen,
                              int client);
  int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
                       int idx);
  void tls1_set_cert_validity(SSL *s);
  
  #  ifndef OPENSSL_NO_CT
  __owur int ssl_validate_ct(SSL *s);
  #  endif
  
  #  ifndef OPENSSL_NO_DH
  __owur DH *ssl_get_auto_dh(SSL *s);
  #  endif
  
  __owur int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee);
  __owur int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *ex,
                                     int vfy);
  
  int tls_choose_sigalg(SSL *s, int fatalerrs);
  
  __owur EVP_MD_CTX *ssl_replace_hash(EVP_MD_CTX **hash, const EVP_MD *md);
  void ssl_clear_hash_ctx(EVP_MD_CTX **hash);
  __owur long ssl_get_algorithm2(SSL *s);
  __owur int tls12_copy_sigalgs(SSL *s, WPACKET *pkt,
                                const uint16_t *psig, size_t psiglen);
  __owur int tls1_save_u16(PACKET *pkt, uint16_t **pdest, size_t *pdestlen);
  __owur int tls1_save_sigalgs(SSL *s, PACKET *pkt, int cert);
  __owur int tls1_process_sigalgs(SSL *s);
  __owur int tls1_set_peer_legacy_sigalg(SSL *s, const EVP_PKEY *pkey);
  __owur int tls1_lookup_md(const SIGALG_LOOKUP *lu, const EVP_MD **pmd);
  __owur size_t tls12_get_psigalgs(SSL *s, int sent, const uint16_t **psigs);
  #  ifndef OPENSSL_NO_EC
  __owur int tls_check_sigalg_curve(const SSL *s, int curve);
  #  endif
  __owur int tls12_check_peer_sigalg(SSL *s, uint16_t, EVP_PKEY *pkey);
  __owur int ssl_set_client_disabled(SSL *s);
  __owur int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op, int echde);
  
  __owur int ssl_handshake_hash(SSL *s, unsigned char *out, size_t outlen,
                                   size_t *hashlen);
  __owur const EVP_MD *ssl_md(int idx);
  __owur const EVP_MD *ssl_handshake_md(SSL *s);
  __owur const EVP_MD *ssl_prf_md(SSL *s);
  
  /*
   * ssl_log_rsa_client_key_exchange logs |premaster| to the SSL_CTX associated
   * with |ssl|, if logging is enabled. It returns one on success and zero on
   * failure. The entry is identified by the first 8 bytes of
   * |encrypted_premaster|.
   */
  __owur int ssl_log_rsa_client_key_exchange(SSL *ssl,
                                             const uint8_t *encrypted_premaster,
                                             size_t encrypted_premaster_len,
                                             const uint8_t *premaster,
                                             size_t premaster_len);
  
  /*
   * ssl_log_secret logs |secret| to the SSL_CTX associated with |ssl|, if
   * logging is available. It returns one on success and zero on failure. It tags
   * the entry with |label|.
   */
  __owur int ssl_log_secret(SSL *ssl, const char *label,
                            const uint8_t *secret, size_t secret_len);
  
  #define MASTER_SECRET_LABEL "CLIENT_RANDOM"
  #define CLIENT_EARLY_LABEL "CLIENT_EARLY_TRAFFIC_SECRET"
  #define CLIENT_HANDSHAKE_LABEL "CLIENT_HANDSHAKE_TRAFFIC_SECRET"
  #define SERVER_HANDSHAKE_LABEL "SERVER_HANDSHAKE_TRAFFIC_SECRET"
  #define CLIENT_APPLICATION_LABEL "CLIENT_TRAFFIC_SECRET_0"
  #define SERVER_APPLICATION_LABEL "SERVER_TRAFFIC_SECRET_0"
  #define EARLY_EXPORTER_SECRET_LABEL "EARLY_EXPORTER_SECRET"
  #define EXPORTER_SECRET_LABEL "EXPORTER_SECRET"
  
  /* s3_cbc.c */
  __owur char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx);
  __owur int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
                                    unsigned char *md_out,
                                    size_t *md_out_size,
                                    const unsigned char header[13],
                                    const unsigned char *data,
                                    size_t data_plus_mac_size,
                                    size_t data_plus_mac_plus_padding_size,
                                    const unsigned char *mac_secret,
                                    size_t mac_secret_length, char is_sslv3);
  
  __owur int srp_generate_server_master_secret(SSL *s);
  __owur int srp_generate_client_master_secret(SSL *s);
  __owur int srp_verify_server_param(SSL *s);
  
  /* statem/statem_srvr.c */
  
  __owur int send_certificate_request(SSL *s);
  
  /* statem/extensions_cust.c */
  
  custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
                                     ENDPOINT role, unsigned int ext_type,
                                     size_t *idx);
  
  void custom_ext_init(custom_ext_methods *meths);
  
  __owur int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type,
                              const unsigned char *ext_data, size_t ext_size,
                              X509 *x, size_t chainidx);
  __owur int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x,
                            size_t chainidx, int maxversion);
  
  __owur int custom_exts_copy(custom_ext_methods *dst,
                              const custom_ext_methods *src);
  __owur int custom_exts_copy_flags(custom_ext_methods *dst,
                                    const custom_ext_methods *src);
  void custom_exts_free(custom_ext_methods *exts);
  
  void ssl_comp_free_compression_methods_int(void);
  
  /* ssl_mcnf.c */
  void ssl_ctx_system_config(SSL_CTX *ctx);
  
  # else /* OPENSSL_UNIT_TEST */
  
  #  define ssl_init_wbio_buffer SSL_test_functions()->p_ssl_init_wbio_buffer
  #  define ssl3_setup_buffers SSL_test_functions()->p_ssl3_setup_buffers
  
  # endif
  #endif
  