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
   */
  
  #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 "crypto/asn1.h"
  #include "crypto/evp.h"
  
  #ifndef OPENSSL_NO_DEPRECATED_3_0
  
  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) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      i = OBJ_obj2nid(a->algorithm);
      type = EVP_get_digestbyname(OBJ_nid2sn(i));
      if (type == NULL) {
          ERR_raise(ERR_LIB_ASN1, ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
          goto err;
      }
  
      if (signature->type == V_ASN1_BIT_STRING && signature->flags & 0x7) {
          ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
          goto err;
      }
  
      inl = i2d(data, NULL);
      if (inl <= 0) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_INTERNAL_ERROR);
          goto err;
      }
      buf_in = OPENSSL_malloc((unsigned int)inl);
      if (buf_in == NULL) {
          ERR_raise(ERR_LIB_ASN1, 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) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_EVP_LIB);
          goto err;
      }
      ret = -1;
  
      if (EVP_VerifyFinal(ctx, (unsigned char *)signature->data,
                          (unsigned int)signature->length, pkey) <= 0) {
          ERR_raise(ERR_LIB_ASN1, 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, const X509_ALGOR *alg,
                       const ASN1_BIT_STRING *signature, const void *data,
                       EVP_PKEY *pkey)
  {
      return ASN1_item_verify_ex(it, alg, signature, data, NULL, pkey, NULL, NULL);
  }
  
  int ASN1_item_verify_ex(const ASN1_ITEM *it, const X509_ALGOR *alg,
                          const ASN1_BIT_STRING *signature, const void *data,
                          const ASN1_OCTET_STRING *id, EVP_PKEY *pkey,
                          OSSL_LIB_CTX *libctx, const char *propq)
  {
      EVP_MD_CTX *ctx;
      int rv = -1;
  
      if ((ctx = evp_md_ctx_new_ex(pkey, id, libctx, propq)) != NULL) {
          rv = ASN1_item_verify_ctx(it, alg, signature, data, ctx);
          EVP_PKEY_CTX_free(EVP_MD_CTX_pkey_ctx(ctx));
          EVP_MD_CTX_free(ctx);
      }
      return rv;
  }
  
  int ASN1_item_verify_ctx(const ASN1_ITEM *it, const X509_ALGOR *alg,
                           const ASN1_BIT_STRING *signature, const void *data,
                           EVP_MD_CTX *ctx)
  {
      EVP_PKEY *pkey;
      unsigned char *buf_in = NULL;
      int ret = -1, inl = 0;
      int mdnid, pknid;
      size_t inll = 0;
  
      pkey = EVP_PKEY_CTX_get0_pkey(EVP_MD_CTX_pkey_ctx(ctx));
  
      if (pkey == NULL) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_PASSED_NULL_PARAMETER);
          return -1;
      }
  
      if (signature->type == V_ASN1_BIT_STRING && signature->flags & 0x7) {
          ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
          return -1;
      }
  
      /* Convert signature OID into digest and public key OIDs */
      if (!OBJ_find_sigid_algs(OBJ_obj2nid(alg->algorithm), &mdnid, &pknid)) {
          ERR_raise(ERR_LIB_ASN1, ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
          goto err;
      }
  
      if (mdnid == NID_undef) {
          if (pkey->ameth == NULL || pkey->ameth->item_verify == NULL) {
              ERR_raise(ERR_LIB_ASN1, ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
              goto err;
          }
          ret = pkey->ameth->item_verify(ctx, it, data, alg, signature, pkey);
          /*
           * Return values meaning:
           * <=0: error.
           *   1: method does everything.
           *   2: carry on as normal, method has called EVP_DigestVerifyInit()
           */
          if (ret <= 0)
              ERR_raise(ERR_LIB_ASN1, ERR_R_EVP_LIB);
          if (ret <= 1)
              goto err;
      } else {
          const EVP_MD *type = EVP_get_digestbynid(mdnid);
  
          if (type == NULL) {
              ERR_raise(ERR_LIB_ASN1, ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
              goto err;
          }
  
          /* Check public key OID matches public key type */
          if (!EVP_PKEY_is_a(pkey, OBJ_nid2sn(pknid))) {
              ERR_raise(ERR_LIB_ASN1, ASN1_R_WRONG_PUBLIC_KEY_TYPE);
              goto err;
          }
  
          if (!EVP_DigestVerifyInit(ctx, NULL, type, NULL, pkey)) {
              ERR_raise(ERR_LIB_ASN1, ERR_R_EVP_LIB);
              ret = 0;
              goto err;
          }
      }
  
      inl = ASN1_item_i2d(data, &buf_in, it);
      if (inl <= 0) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_INTERNAL_ERROR);
          goto err;
      }
      if (buf_in == NULL) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      inll = inl;
  
      ret = EVP_DigestVerify(ctx, signature->data, (size_t)signature->length,
                             buf_in, inl);
      if (ret <= 0) {
          ERR_raise(ERR_LIB_ASN1, ERR_R_EVP_LIB);
          goto err;
      }
      ret = 1;
   err:
      OPENSSL_clear_free(buf_in, inll);
      return ret;
  }
  