text: /*
   *  linux/include/linux/sunrpc/gss_krb5_types.h
   *
   *  Adapted from MIT Kerberos 5-1.2.1 lib/include/krb5.h,
   *  lib/gssapi/krb5/gssapiP_krb5.h, and others
   *
   *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
   *  All rights reserved.
   *
   *  Andy Adamson   <andros@umich.edu>
   *  Bruce Fields   <bfields@umich.edu>
   */
  
  /*
   * Copyright 1995 by the Massachusetts Institute of Technology.
   * All Rights Reserved.
   *
   * Export of this software from the United States of America may
   *   require a specific license from the United States Government.
   *   It is the responsibility of any person or organization contemplating
   *   export to obtain such a license before exporting.
   *
   * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
   * distribute this software and its documentation for any purpose and
   * without fee is hereby granted, provided that the above copyright
   * notice appear in all copies and that both that copyright notice and
   * this permission notice appear in supporting documentation, and that
   * the name of M.I.T. not be used in advertising or publicity pertaining
   * to distribution of the software without specific, written prior
   * permission.  Furthermore if you modify this software you must label
   * your software as modified software and not distribute it in such a
   * fashion that it might be confused with the original M.I.T. software.
   * M.I.T. makes no representations about the suitability of
   * this software for any purpose.  It is provided "as is" without express
   * or implied warranty.
   *
   */
  
  #include <linux/crypto.h>
  #include <linux/sunrpc/auth_gss.h>
  #include <linux/sunrpc/gss_err.h>
  #include <linux/sunrpc/gss_asn1.h>
  
  /* Length of constant used in key derivation */
  #define GSS_KRB5_K5CLENGTH (5)
  
  /* Maximum key length (in bytes) for the supported crypto algorithms*/
  #define GSS_KRB5_MAX_KEYLEN (32)
  
  /* Maximum checksum function output for the supported crypto algorithms */
  #define GSS_KRB5_MAX_CKSUM_LEN  (20)
  
  /* Maximum blocksize for the supported crypto algorithms */
  #define GSS_KRB5_MAX_BLOCKSIZE  (16)
  
  struct krb5_ctx;
  
  struct gss_krb5_enctype {
  	const u32		etype;		/* encryption (key) type */
  	const u32		ctype;		/* checksum type */
  	const char		*name;		/* "friendly" name */
  	const char		*encrypt_name;	/* crypto encrypt name */
  	const char		*cksum_name;	/* crypto checksum name */
  	const u16		signalg;	/* signing algorithm */
  	const u16		sealalg;	/* sealing algorithm */
  	const u32		blocksize;	/* encryption blocksize */
  	const u32		conflen;	/* confounder length
  						   (normally the same as
  						   the blocksize) */
  	const u32		cksumlength;	/* checksum length */
  	const u32		keyed_cksum;	/* is it a keyed cksum? */
  	const u32		keybytes;	/* raw key len, in bytes */
  	const u32		keylength;	/* final key len, in bytes */
  	u32 (*encrypt) (struct crypto_blkcipher *tfm,
  			void *iv, void *in, void *out,
  			int length);		/* encryption function */
  	u32 (*decrypt) (struct crypto_blkcipher *tfm,
  			void *iv, void *in, void *out,
  			int length);		/* decryption function */
  	u32 (*mk_key) (const struct gss_krb5_enctype *gk5e,
  		       struct xdr_netobj *in,
  		       struct xdr_netobj *out);	/* complete key generation */
  	u32 (*encrypt_v2) (struct krb5_ctx *kctx, u32 offset,
  			   struct xdr_buf *buf, int ec,
  			   struct page **pages); /* v2 encryption function */
  	u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset,
  			   struct xdr_buf *buf, u32 *headskip,
  			   u32 *tailskip);	/* v2 decryption function */
  };
  
  /* krb5_ctx flags definitions */
  #define KRB5_CTX_FLAG_INITIATOR         0x00000001
  #define KRB5_CTX_FLAG_CFX               0x00000002
  #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
  
  struct krb5_ctx {
  	int			initiate; /* 1 = initiating, 0 = accepting */
  	u32			enctype;
  	u32			flags;
  	const struct gss_krb5_enctype *gk5e; /* enctype-specific info */
  	struct crypto_blkcipher	*enc;
  	struct crypto_blkcipher	*seq;
  	struct crypto_blkcipher *acceptor_enc;
  	struct crypto_blkcipher *initiator_enc;
  	struct crypto_blkcipher *acceptor_enc_aux;
  	struct crypto_blkcipher *initiator_enc_aux;
  	u8			Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
  	u8			cksum[GSS_KRB5_MAX_KEYLEN];
  	s32			endtime;
  	u32			seq_send;
  	u64			seq_send64;
  	struct xdr_netobj	mech_used;
  	u8			initiator_sign[GSS_KRB5_MAX_KEYLEN];
  	u8			acceptor_sign[GSS_KRB5_MAX_KEYLEN];
  	u8			initiator_seal[GSS_KRB5_MAX_KEYLEN];
  	u8			acceptor_seal[GSS_KRB5_MAX_KEYLEN];
  	u8			initiator_integ[GSS_KRB5_MAX_KEYLEN];
  	u8			acceptor_integ[GSS_KRB5_MAX_KEYLEN];
  };
  
  extern spinlock_t krb5_seq_lock;
  
  /* The length of the Kerberos GSS token header */
  #define GSS_KRB5_TOK_HDR_LEN	(16)
  
  #define KG_TOK_MIC_MSG    0x0101
  #define KG_TOK_WRAP_MSG   0x0201
  
  #define KG2_TOK_INITIAL     0x0101
  #define KG2_TOK_RESPONSE    0x0202
  #define KG2_TOK_MIC         0x0404
  #define KG2_TOK_WRAP        0x0504
  
  #define KG2_TOKEN_FLAG_SENTBYACCEPTOR   0x01
  #define KG2_TOKEN_FLAG_SEALED           0x02
  #define KG2_TOKEN_FLAG_ACCEPTORSUBKEY   0x04
  
  #define KG2_RESP_FLAG_ERROR             0x0001
  #define KG2_RESP_FLAG_DELEG_OK          0x0002
  
  enum sgn_alg {
  	SGN_ALG_DES_MAC_MD5 = 0x0000,
  	SGN_ALG_MD2_5 = 0x0001,
  	SGN_ALG_DES_MAC = 0x0002,
  	SGN_ALG_3 = 0x0003,		/* not published */
  	SGN_ALG_HMAC_MD5 = 0x0011,	/* microsoft w2k; no support */
  	SGN_ALG_HMAC_SHA1_DES3_KD = 0x0004
  };
  enum seal_alg {
  	SEAL_ALG_NONE = 0xffff,
  	SEAL_ALG_DES = 0x0000,
  	SEAL_ALG_1 = 0x0001,		/* not published */
  	SEAL_ALG_MICROSOFT_RC4 = 0x0010,/* microsoft w2k; no support */
  	SEAL_ALG_DES3KD = 0x0002
  };
  
  #define CKSUMTYPE_CRC32			0x0001
  #define CKSUMTYPE_RSA_MD4		0x0002
  #define CKSUMTYPE_RSA_MD4_DES		0x0003
  #define CKSUMTYPE_DESCBC		0x0004
  #define CKSUMTYPE_RSA_MD5		0x0007
  #define CKSUMTYPE_RSA_MD5_DES		0x0008
  #define CKSUMTYPE_NIST_SHA		0x0009
  #define CKSUMTYPE_HMAC_SHA1_DES3	0x000c
  #define CKSUMTYPE_HMAC_SHA1_96_AES128   0x000f
  #define CKSUMTYPE_HMAC_SHA1_96_AES256   0x0010
  #define CKSUMTYPE_HMAC_MD5_ARCFOUR      -138 /* Microsoft md5 hmac cksumtype */
  
  /* from gssapi_err_krb5.h */
  #define KG_CCACHE_NOMATCH                        (39756032L)
  #define KG_KEYTAB_NOMATCH                        (39756033L)
  #define KG_TGT_MISSING                           (39756034L)
  #define KG_NO_SUBKEY                             (39756035L)
  #define KG_CONTEXT_ESTABLISHED                   (39756036L)
  #define KG_BAD_SIGN_TYPE                         (39756037L)
  #define KG_BAD_LENGTH                            (39756038L)
  #define KG_CTX_INCOMPLETE                        (39756039L)
  #define KG_CONTEXT                               (39756040L)
  #define KG_CRED                                  (39756041L)
  #define KG_ENC_DESC                              (39756042L)
  #define KG_BAD_SEQ                               (39756043L)
  #define KG_EMPTY_CCACHE                          (39756044L)
  #define KG_NO_CTYPES                             (39756045L)
  
  /* per Kerberos v5 protocol spec crypto types from the wire. 
   * these get mapped to linux kernel crypto routines.  
   */
  #define ENCTYPE_NULL            0x0000
  #define ENCTYPE_DES_CBC_CRC     0x0001	/* DES cbc mode with CRC-32 */
  #define ENCTYPE_DES_CBC_MD4     0x0002	/* DES cbc mode with RSA-MD4 */
  #define ENCTYPE_DES_CBC_MD5     0x0003	/* DES cbc mode with RSA-MD5 */
  #define ENCTYPE_DES_CBC_RAW     0x0004	/* DES cbc mode raw */
  #define ENCTYPE_DES3_CBC_SHA    0x0005	/* DES-3 cbc mode with NIST-SHA */
  #define ENCTYPE_DES3_CBC_RAW    0x0006	/* DES-3 cbc mode raw */
  #define ENCTYPE_DES_HMAC_SHA1   0x0008
  #define ENCTYPE_DES3_CBC_SHA1   0x0010
  #define ENCTYPE_AES128_CTS_HMAC_SHA1_96 0x0011
  #define ENCTYPE_AES256_CTS_HMAC_SHA1_96 0x0012
  #define ENCTYPE_ARCFOUR_HMAC            0x0017
  #define ENCTYPE_ARCFOUR_HMAC_EXP        0x0018
  #define ENCTYPE_UNKNOWN         0x01ff
  
  /*
   * Constants used for key derivation
   */
  /* for 3DES */
  #define KG_USAGE_SEAL (22)
  #define KG_USAGE_SIGN (23)
  #define KG_USAGE_SEQ  (24)
  
  /* from rfc3961 */
  #define KEY_USAGE_SEED_CHECKSUM         (0x99)
  #define KEY_USAGE_SEED_ENCRYPTION       (0xAA)
  #define KEY_USAGE_SEED_INTEGRITY        (0x55)
  
  /* from rfc4121 */
  #define KG_USAGE_ACCEPTOR_SEAL  (22)
  #define KG_USAGE_ACCEPTOR_SIGN  (23)
  #define KG_USAGE_INITIATOR_SEAL (24)
  #define KG_USAGE_INITIATOR_SIGN (25)
  
  /*
   * This compile-time check verifies that we will not exceed the
   * slack space allotted by the client and server auth_gss code
   * before they call gss_wrap().
   */
  #define GSS_KRB5_MAX_SLACK_NEEDED \
  	(GSS_KRB5_TOK_HDR_LEN     /* gss token header */         \
  	+ GSS_KRB5_MAX_CKSUM_LEN  /* gss token checksum */       \
  	+ GSS_KRB5_MAX_BLOCKSIZE  /* confounder */               \
  	+ GSS_KRB5_MAX_BLOCKSIZE  /* possible padding */         \
  	+ GSS_KRB5_TOK_HDR_LEN    /* encrypted hdr in v2 token */\
  	+ GSS_KRB5_MAX_CKSUM_LEN  /* encryption hmac */          \
  	+ 4 + 4                   /* RPC verifier */             \
  	+ GSS_KRB5_TOK_HDR_LEN                                   \
  	+ GSS_KRB5_MAX_CKSUM_LEN)
  
  u32
  make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
  		struct xdr_buf *body, int body_offset, u8 *cksumkey,
  		unsigned int usage, struct xdr_netobj *cksumout);
  
  u32
  make_checksum_v2(struct krb5_ctx *, char *header, int hdrlen,
  		 struct xdr_buf *body, int body_offset, u8 *key,
  		 unsigned int usage, struct xdr_netobj *cksum);
  
  u32 gss_get_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
  		struct xdr_netobj *);
  
  u32 gss_verify_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
  		struct xdr_netobj *);
  
  u32
  gss_wrap_kerberos(struct gss_ctx *ctx_id, int offset,
  		struct xdr_buf *outbuf, struct page **pages);
  
  u32
  gss_unwrap_kerberos(struct gss_ctx *ctx_id, int offset,
  		struct xdr_buf *buf);
  
  
  u32
  krb5_encrypt(struct crypto_blkcipher *key,
  	     void *iv, void *in, void *out, int length);
  
  u32
  krb5_decrypt(struct crypto_blkcipher *key,
  	     void *iv, void *in, void *out, int length); 
  
  int
  gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *outbuf,
  		    int offset, struct page **pages);
  
  int
  gss_decrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *inbuf,
  		    int offset);
  
  s32
  krb5_make_seq_num(struct krb5_ctx *kctx,
  		struct crypto_blkcipher *key,
  		int direction,
  		u32 seqnum, unsigned char *cksum, unsigned char *buf);
  
  s32
  krb5_get_seq_num(struct krb5_ctx *kctx,
  	       unsigned char *cksum,
  	       unsigned char *buf, int *direction, u32 *seqnum);
  
  int
  xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen);
  
  u32
  krb5_derive_key(const struct gss_krb5_enctype *gk5e,
  		const struct xdr_netobj *inkey,
  		struct xdr_netobj *outkey,
  		const struct xdr_netobj *in_constant,
  		gfp_t gfp_mask);
  
  u32
  gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
  		       struct xdr_netobj *randombits,
  		       struct xdr_netobj *key);
  
  u32
  gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
  		      struct xdr_netobj *randombits,
  		      struct xdr_netobj *key);
  
  u32
  gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
  		     struct xdr_buf *buf, int ec,
  		     struct page **pages);
  
  u32
  gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset,
  		     struct xdr_buf *buf, u32 *plainoffset,
  		     u32 *plainlen);
  
  int
  krb5_rc4_setup_seq_key(struct krb5_ctx *kctx,
  		       struct crypto_blkcipher *cipher,
  		       unsigned char *cksum);
  
  int
  krb5_rc4_setup_enc_key(struct krb5_ctx *kctx,
  		       struct crypto_blkcipher *cipher,
  		       s32 seqnum);
  void
  gss_krb5_make_confounder(char *p, u32 conflen);
  