text: /*
   * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (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
   */
  
  /*
   * DSA low level APIs are deprecated for public use, but still ok for
   * internal use.
   */
  #include "internal/deprecated.h"
  
  #include <stdio.h>
  #include "internal/cryptlib.h"
  #include <openssl/asn1t.h>
  #include <openssl/x509.h>
  #include "crypto/asn1.h"
  #include "crypto/evp.h"
  #include "crypto/x509.h"
  #include <openssl/rsa.h>
  #include <openssl/dsa.h>
  #include <openssl/encoder.h>
  #include "internal/provider.h"
  
  struct X509_pubkey_st {
      X509_ALGOR *algor;
      ASN1_BIT_STRING *public_key;
      EVP_PKEY *pkey;
  
      /* extra data for the callback, used by d2i_PUBKEY_ex */
      OSSL_LIB_CTX *libctx;
      const char *propq;
  };
  
  static int x509_pubkey_decode(EVP_PKEY **pk, const X509_PUBKEY *key);
  
  /* Minor tweak to operation: free up EVP_PKEY */
  static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                       void *exarg)
  {
      X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  
      if (operation == ASN1_OP_FREE_POST) {
          EVP_PKEY_free(pubkey->pkey);
      } else if (operation == ASN1_OP_D2I_POST) {
          /* Attempt to decode public key and cache in pubkey structure. */
          EVP_PKEY_free(pubkey->pkey);
          pubkey->pkey = NULL;
          /*
           * Opportunistically decode the key but remove any non fatal errors
           * from the queue. Subsequent explicit attempts to decode/use the key
           * will return an appropriate error.
           */
          ERR_set_mark();
          if (x509_pubkey_decode(&pubkey->pkey, pubkey) == -1) {
              ERR_clear_last_mark();
              return 0;
          }
          ERR_pop_to_mark();
      }
      return 1;
  }
  
  ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {
          ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),
          ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING)
  } ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)
  
  IMPLEMENT_ASN1_FUNCTIONS(X509_PUBKEY)
  IMPLEMENT_ASN1_DUP_FUNCTION(X509_PUBKEY)
  
  /* TODO should better be called X509_PUBKEY_set1 */
  int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
  {
      X509_PUBKEY *pk = NULL;
  
      if (x == NULL)
          return 0;
  
      if (pkey == NULL)
          goto unsupported;
  
      if (pkey->ameth != NULL) {
          if ((pk = X509_PUBKEY_new()) == NULL) {
              X509err(X509_F_X509_PUBKEY_SET, ERR_R_MALLOC_FAILURE);
              goto error;
          }
          if (pkey->ameth->pub_encode != NULL) {
              if (!pkey->ameth->pub_encode(pk, pkey)) {
                  X509err(X509_F_X509_PUBKEY_SET,
                          X509_R_PUBLIC_KEY_ENCODE_ERROR);
                  goto error;
              }
          } else {
              X509err(X509_F_X509_PUBKEY_SET, X509_R_METHOD_NOT_SUPPORTED);
              goto error;
          }
      } else if (evp_pkey_is_provided(pkey)) {
          const OSSL_PROVIDER *pkprov = EVP_KEYMGMT_provider(pkey->keymgmt);
          OSSL_LIB_CTX *libctx = ossl_provider_libctx(pkprov);
          unsigned char *der = NULL;
          size_t derlen = 0;
          OSSL_ENCODER_CTX *ectx =
              OSSL_ENCODER_CTX_new_by_EVP_PKEY(pkey, "DER", EVP_PKEY_PUBLIC_KEY,
                                               libctx, NULL);
  
          if (OSSL_ENCODER_to_data(ectx, &der, &derlen)) {
              const unsigned char *pder = der;
  
              pk = d2i_X509_PUBKEY(NULL, &pder, (long)derlen);
          }
  
          OSSL_ENCODER_CTX_free(ectx);
          OPENSSL_free(der);
      }
  
      if (pk == NULL)
          goto unsupported;
  
      X509_PUBKEY_free(*x);
      if (!EVP_PKEY_up_ref(pkey)) {
          X509err(X509_F_X509_PUBKEY_SET, ERR_R_INTERNAL_ERROR);
          goto error;
      }
      *x = pk;
  
      /*
       * pk->pkey is NULL when using the legacy routine, but is non-NULL when
       * going through the encoder, and for all intents and purposes, it's
       * a perfect copy of |pkey|, just not the same instance.  In that case,
       * we could simply return early, right here.
       * However, in the interest of being cautious leaning on paranoia, some
       * application might very well depend on the passed |pkey| being used
       * and none other, so we spend a few more cycles throwing away the newly
       * created |pk->pkey| and replace it with |pkey|.
       * TODO(3.0) Investigate if it's safe to change to simply return here
       * if |pk->pkey != NULL|.
       */
      if (pk->pkey != NULL)
          EVP_PKEY_free(pk->pkey);
  
      pk->pkey = pkey;
      return 1;
  
   unsupported:
      X509err(X509_F_X509_PUBKEY_SET, X509_R_UNSUPPORTED_ALGORITHM);
  
   error:
      X509_PUBKEY_free(pk);
      return 0;
  }
  
  /*
   * Attempt to decode a public key.
   * Returns 1 on success, 0 for a decode failure and -1 for a fatal
   * error e.g. malloc failure.
   */
  
  
  static int x509_pubkey_decode(EVP_PKEY **ppkey, const X509_PUBKEY *key)
  {
      EVP_PKEY *pkey = EVP_PKEY_new();
  
      if (pkey == NULL) {
          X509err(X509_F_X509_PUBKEY_DECODE, ERR_R_MALLOC_FAILURE);
          return -1;
      }
  
      if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {
          X509err(X509_F_X509_PUBKEY_DECODE, X509_R_UNSUPPORTED_ALGORITHM);
          goto error;
      }
  
      if (pkey->ameth->pub_decode) {
          /*
           * Treat any failure of pub_decode as a decode error. In
           * future we could have different return codes for decode
           * errors and fatal errors such as malloc failure.
           */
          if (!pkey->ameth->pub_decode(pkey, key))
              goto error;
      } else {
          X509err(X509_F_X509_PUBKEY_DECODE, X509_R_METHOD_NOT_SUPPORTED);
          goto error;
      }
  
      *ppkey = pkey;
      return 1;
  
   error:
      EVP_PKEY_free(pkey);
      return 0;
  }
  
  EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key)
  {
      EVP_PKEY *ret = NULL;
  
      if (key == NULL || key->public_key == NULL)
          return NULL;
  
      if (key->pkey != NULL)
          return key->pkey;
  
      /*
       * When the key ASN.1 is initially parsed an attempt is made to
       * decode the public key and cache the EVP_PKEY structure. If this
       * operation fails the cached value will be NULL. Parsing continues
       * to allow parsing of unknown key types or unsupported forms.
       * We repeat the decode operation so the appropriate errors are left
       * in the queue.
       */
      x509_pubkey_decode(&ret, key);
      /* If decode doesn't fail something bad happened */
      if (ret != NULL) {
          X509err(X509_F_X509_PUBKEY_GET0, ERR_R_INTERNAL_ERROR);
          EVP_PKEY_free(ret);
      }
  
      return NULL;
  }
  
  EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key)
  {
      EVP_PKEY *ret = X509_PUBKEY_get0(key);
  
      if (ret != NULL && !EVP_PKEY_up_ref(ret)) {
          X509err(X509_F_X509_PUBKEY_GET, ERR_R_INTERNAL_ERROR);
          ret = NULL;
      }
      return ret;
  }
  
  /*
   * Now three pseudo ASN1 routines that take an EVP_PKEY structure and encode
   * or decode as X509_PUBKEY
   */
  
  EVP_PKEY *d2i_PUBKEY_ex(EVP_PKEY **a, const unsigned char **pp, long length,
                          OSSL_LIB_CTX *libctx, const char *propq)
  {
      X509_PUBKEY *xpk, *xpk2 = NULL, **pxpk = NULL;
      EVP_PKEY *pktmp = NULL;
      const unsigned char *q;
  
      q = *pp;
  
      /*
       * If libctx or propq are non-NULL, we take advantage of the reuse
       * feature.  It's not generally recommended, but is safe enough for
       * newly created structures.
       */
      if (libctx != NULL || propq != NULL) {
          xpk2 = OPENSSL_zalloc(sizeof(*xpk2));
          if (xpk2 == NULL) {
              ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
              return NULL;
          }
          xpk2->libctx = libctx;
          xpk2->propq = propq;
          pxpk = &xpk2;
      }
      xpk = d2i_X509_PUBKEY(pxpk, &q, length);
      if (xpk == NULL)
          goto end;
      pktmp = X509_PUBKEY_get(xpk);
      X509_PUBKEY_free(xpk);
      xpk2 = NULL;                 /* We know that xpk == xpk2 */
      if (pktmp == NULL)
          goto end;
      *pp = q;
      if (a != NULL) {
          EVP_PKEY_free(*a);
          *a = pktmp;
      }
   end:
      X509_PUBKEY_free(xpk2);
      return pktmp;
  }
  
  EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
  {
      return d2i_PUBKEY_ex(a, pp, length, NULL, NULL);
  }
  
  int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp)
  {
      int ret = -1;
  
      if (a == NULL)
          return 0;
      if (a->ameth != NULL) {
          X509_PUBKEY *xpk = NULL;
  
          if ((xpk = X509_PUBKEY_new()) == NULL)
              return -1;
  
          /* pub_encode() only encode parameters, not the key itself */
          if (a->ameth->pub_encode != NULL && a->ameth->pub_encode(xpk, a)) {
              xpk->pkey = (EVP_PKEY *)a;
              ret = i2d_X509_PUBKEY(xpk, pp);
              xpk->pkey = NULL;
          }
          X509_PUBKEY_free(xpk);
      } else if (a->keymgmt != NULL) {
          const OSSL_PROVIDER *pkprov = EVP_KEYMGMT_provider(a->keymgmt);
          OSSL_LIB_CTX *libctx = ossl_provider_libctx(pkprov);
          OSSL_ENCODER_CTX *ctx =
              OSSL_ENCODER_CTX_new_by_EVP_PKEY(a, "DER", EVP_PKEY_PUBLIC_KEY,
                                               libctx, NULL);
          BIO *out = BIO_new(BIO_s_mem());
          BUF_MEM *buf = NULL;
  
          if (OSSL_ENCODER_CTX_get_num_encoders(ctx) != 0
              && out != NULL
              && OSSL_ENCODER_to_bio(ctx, out)
              && BIO_get_mem_ptr(out, &buf) > 0) {
              ret = buf->length;
  
              if (pp != NULL) {
                  if (*pp == NULL) {
                      *pp = (unsigned char *)buf->data;
                      buf->length = 0;
                      buf->data = NULL;
                  } else {
                      memcpy(*pp, buf->data, ret);
                      *pp += ret;
                  }
              }
          }
          BIO_free(out);
          OSSL_ENCODER_CTX_free(ctx);
      }
  
      return ret;
  }
  
  /*
   * The following are equivalents but which return RSA and DSA keys
   */
  #ifndef OPENSSL_NO_RSA
  RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)
  {
      EVP_PKEY *pkey;
      RSA *key;
      const unsigned char *q;
  
      q = *pp;
      pkey = d2i_PUBKEY(NULL, &q, length);
      if (pkey == NULL)
          return NULL;
      key = EVP_PKEY_get1_RSA(pkey);
      EVP_PKEY_free(pkey);
      if (key == NULL)
          return NULL;
      *pp = q;
      if (a != NULL) {
          RSA_free(*a);
          *a = key;
      }
      return key;
  }
  
  int i2d_RSA_PUBKEY(const RSA *a, unsigned char **pp)
  {
      EVP_PKEY *pktmp;
      int ret;
      if (!a)
          return 0;
      pktmp = EVP_PKEY_new();
      if (pktmp == NULL) {
          ASN1err(ASN1_F_I2D_RSA_PUBKEY, ERR_R_MALLOC_FAILURE);
          return -1;
      }
      (void)EVP_PKEY_assign_RSA(pktmp, (RSA *)a);
      ret = i2d_PUBKEY(pktmp, pp);
      pktmp->pkey.ptr = NULL;
      EVP_PKEY_free(pktmp);
      return ret;
  }
  #endif
  
  #ifndef OPENSSL_NO_DSA
  DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)
  {
      EVP_PKEY *pkey;
      DSA *key;
      const unsigned char *q;
  
      q = *pp;
      pkey = d2i_PUBKEY(NULL, &q, length);
      if (pkey == NULL)
          return NULL;
      key = EVP_PKEY_get1_DSA(pkey);
      EVP_PKEY_free(pkey);
      if (key == NULL)
          return NULL;
      *pp = q;
      if (a != NULL) {
          DSA_free(*a);
          *a = key;
      }
      return key;
  }
  
  int i2d_DSA_PUBKEY(const DSA *a, unsigned char **pp)
  {
      EVP_PKEY *pktmp;
      int ret;
      if (!a)
          return 0;
      pktmp = EVP_PKEY_new();
      if (pktmp == NULL) {
          ASN1err(ASN1_F_I2D_DSA_PUBKEY, ERR_R_MALLOC_FAILURE);
          return -1;
      }
      (void)EVP_PKEY_assign_DSA(pktmp, (DSA *)a);
      ret = i2d_PUBKEY(pktmp, pp);
      pktmp->pkey.ptr = NULL;
      EVP_PKEY_free(pktmp);
      return ret;
  }
  #endif
  
  #ifndef OPENSSL_NO_EC
  EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)
  {
      EVP_PKEY *pkey;
      EC_KEY *key;
      const unsigned char *q;
  
      q = *pp;
      pkey = d2i_PUBKEY(NULL, &q, length);
      if (pkey == NULL)
          return NULL;
      key = EVP_PKEY_get1_EC_KEY(pkey);
      EVP_PKEY_free(pkey);
      if (key == NULL)
          return NULL;
      *pp = q;
      if (a != NULL) {
          EC_KEY_free(*a);
          *a = key;
      }
      return key;
  }
  
  int i2d_EC_PUBKEY(const EC_KEY *a, unsigned char **pp)
  {
      EVP_PKEY *pktmp;
      int ret;
  
      if (a == NULL)
          return 0;
      if ((pktmp = EVP_PKEY_new()) == NULL) {
          ASN1err(ASN1_F_I2D_EC_PUBKEY, ERR_R_MALLOC_FAILURE);
          return -1;
      }
      (void)EVP_PKEY_assign_EC_KEY(pktmp, (EC_KEY *)a);
      ret = i2d_PUBKEY(pktmp, pp);
      pktmp->pkey.ptr = NULL;
      EVP_PKEY_free(pktmp);
      return ret;
  }
  #endif
  
  int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
                             int ptype, void *pval,
                             unsigned char *penc, int penclen)
  {
      if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))
          return 0;
      if (penc) {
          OPENSSL_free(pub->public_key->data);
          pub->public_key->data = penc;
          pub->public_key->length = penclen;
          /* Set number of unused bits to zero */
          pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
          pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
      }
      return 1;
  }
  
  int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
                             const unsigned char **pk, int *ppklen,
                             X509_ALGOR **pa, const X509_PUBKEY *pub)
  {
      if (ppkalg)
          *ppkalg = pub->algor->algorithm;
      if (pk) {
          *pk = pub->public_key->data;
          *ppklen = pub->public_key->length;
      }
      if (pa)
          *pa = pub->algor;
      return 1;
  }
  
  ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)
  {
      if (x == NULL)
          return NULL;
      return x->cert_info.key->public_key;
  }
  
  /* Returns 1 for equal, 0, for non-equal, < 0 on error */
  int X509_PUBKEY_eq(const X509_PUBKEY *a, const X509_PUBKEY *b)
  {
      X509_ALGOR *algA, *algB;
      EVP_PKEY *pA, *pB;
  
      if (a == b)
          return 1;
      if (a == NULL || b == NULL)
          return 0;
      if (!X509_PUBKEY_get0_param(NULL, NULL, NULL, &algA, a) || algA == NULL
          || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algB, b) || algB == NULL)
          return -2;
      if (X509_ALGOR_cmp(algA, algB) != 0)
          return 0;
      if ((pA = X509_PUBKEY_get0(a)) == NULL
          || (pB = X509_PUBKEY_get0(b)) == NULL)
          return -2;
      return EVP_PKEY_eq(pA, pB);
  }
  
  int X509_PUBKEY_get0_libctx(OSSL_LIB_CTX **plibctx, const char **ppropq,
                              const X509_PUBKEY *key)
  {
      if (plibctx)
          *plibctx = key->libctx;
      if (ppropq)
          *ppropq = key->propq;
      return 1;
  }
  