text: /*
   * Copyright 1995-2016 The OpenSSL Project Authors. 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
   */
  
  #include <stdio.h>
  #include <time.h>
  #include <sys/types.h>
  
  #include "internal/cryptlib.h"
  
  #include <openssl/bn.h>
  #include <openssl/x509.h>
  #include <openssl/objects.h>
  #include <openssl/buffer.h>
  #include <openssl/evp.h>
  #include "internal/asn1_int.h"
  #include "internal/evp_int.h"
  
  #ifndef NO_ASN1_OLD
  
  int ASN1_verify(i2d_of_void *i2d, X509_ALGOR *a, ASN1_BIT_STRING *signature,
                  char *data, EVP_PKEY *pkey)
  {
      EVP_MD_CTX *ctx = EVP_MD_CTX_new();
      const EVP_MD *type;
      unsigned char *p, *buf_in = NULL;
      int ret = -1, i, inl;
  
      if (ctx == NULL) {
          ASN1err(ASN1_F_ASN1_VERIFY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      i = OBJ_obj2nid(a->algorithm);
      type = EVP_get_digestbyname(OBJ_nid2sn(i));
      if (type == NULL) {
          ASN1err(ASN1_F_ASN1_VERIFY, ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
          goto err;
      }
  
      if (signature->type == V_ASN1_BIT_STRING && signature->flags & 0x7) {
          ASN1err(ASN1_F_ASN1_VERIFY, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
          goto err;
      }
  
      inl = i2d(data, NULL);
      if (inl <= 0) {
          ASN1err(ASN1_F_ASN1_VERIFY, ERR_R_INTERNAL_ERROR);
          goto err;
      }
      buf_in = OPENSSL_malloc((unsigned int)inl);
      if (buf_in == NULL) {
          ASN1err(ASN1_F_ASN1_VERIFY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      p = buf_in;
  
      i2d(data, &p);
      ret = EVP_VerifyInit_ex(ctx, type, NULL)
          && EVP_VerifyUpdate(ctx, (unsigned char *)buf_in, inl);
  
      OPENSSL_clear_free(buf_in, (unsigned int)inl);
  
      if (!ret) {
          ASN1err(ASN1_F_ASN1_VERIFY, ERR_R_EVP_LIB);
          goto err;
      }
      ret = -1;
  
      if (EVP_VerifyFinal(ctx, (unsigned char *)signature->data,
                          (unsigned int)signature->length, pkey) <= 0) {
          ASN1err(ASN1_F_ASN1_VERIFY, ERR_R_EVP_LIB);
          ret = 0;
          goto err;
      }
      ret = 1;
   err:
      EVP_MD_CTX_free(ctx);
      return ret;
  }
  
  #endif
  
  int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a,
                       ASN1_BIT_STRING *signature, void *asn, EVP_PKEY *pkey)
  {
      EVP_MD_CTX *ctx = NULL;
      unsigned char *buf_in = NULL;
      int ret = -1, inl = 0;
      int mdnid, pknid;
      size_t inll = 0;
  
      if (!pkey) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
  
      if (signature->type == V_ASN1_BIT_STRING && signature->flags & 0x7) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
          return -1;
      }
  
      ctx = EVP_MD_CTX_new();
      if (ctx == NULL) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      /* Convert signature OID into digest and public key OIDs */
      if (!OBJ_find_sigid_algs(OBJ_obj2nid(a->algorithm), &mdnid, &pknid)) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
          goto err;
      }
      if (mdnid == NID_undef) {
          if (!pkey->ameth || !pkey->ameth->item_verify) {
              ASN1err(ASN1_F_ASN1_ITEM_VERIFY,
                      ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
              goto err;
          }
          ret = pkey->ameth->item_verify(ctx, it, asn, a, signature, pkey);
          /*
           * Return value of 2 means carry on, anything else means we exit
           * straight away: either a fatal error of the underlying verification
           * routine handles all verification.
           */
          if (ret != 2)
              goto err;
          ret = -1;
      } else {
          const EVP_MD *type = EVP_get_digestbynid(mdnid);
  
          if (type == NULL) {
              ASN1err(ASN1_F_ASN1_ITEM_VERIFY,
                      ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
              goto err;
          }
  
          /* Check public key OID matches public key type */
          if (EVP_PKEY_type(pknid) != pkey->ameth->pkey_id) {
              ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ASN1_R_WRONG_PUBLIC_KEY_TYPE);
              goto err;
          }
  
          if (!EVP_DigestVerifyInit(ctx, NULL, type, NULL, pkey)) {
              ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_EVP_LIB);
              ret = 0;
              goto err;
          }
  
      }
  
      inl = ASN1_item_i2d(asn, &buf_in, it);
      if (inl <= 0) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_INTERNAL_ERROR);
          goto err;
      }
      if (buf_in == NULL) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      inll = inl;
  
      ret = EVP_DigestVerify(ctx, signature->data, (size_t)signature->length,
                             buf_in, inl);
      if (ret <= 0) {
          ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_EVP_LIB);
          goto err;
      }
      ret = 1;
   err:
      OPENSSL_clear_free(buf_in, inll);
      EVP_MD_CTX_free(ctx);
      return ret;
  }
  