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 "internal/cryptlib.h"
  #include <openssl/rand.h>
  #include <openssl/objects.h>
  #include <openssl/x509.h>
  #include <openssl/x509v3.h>
  #include <openssl/err.h>
  #include "pk7_local.h"
  
  static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
                           void *value);
  static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid);
  
  static int PKCS7_type_is_other(PKCS7 *p7)
  {
      int isOther = 1;
  
      int nid = OBJ_obj2nid(p7->type);
  
      switch (nid) {
      case NID_pkcs7_data:
      case NID_pkcs7_signed:
      case NID_pkcs7_enveloped:
      case NID_pkcs7_signedAndEnveloped:
      case NID_pkcs7_digest:
      case NID_pkcs7_encrypted:
          isOther = 0;
          break;
      default:
          isOther = 1;
      }
  
      return isOther;
  
  }
  
  static ASN1_OCTET_STRING *PKCS7_get_octet_string(PKCS7 *p7)
  {
      if (PKCS7_type_is_data(p7))
          return p7->d.data;
      if (PKCS7_type_is_other(p7) && p7->d.other
          && (p7->d.other->type == V_ASN1_OCTET_STRING))
          return p7->d.other->value.octet_string;
      return NULL;
  }
  
  static int pkcs7_bio_add_digest(BIO **pbio, X509_ALGOR *alg,
                                  const PKCS7_CTX *ctx)
  {
      BIO *btmp;
      const char *name;
      EVP_MD *fetched = NULL;
      const EVP_MD *md;
  
      if ((btmp = BIO_new(BIO_f_md())) == NULL) {
          PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, ERR_R_BIO_LIB);
          goto err;
      }
  
      name = OBJ_nid2sn(OBJ_obj2nid(alg->algorithm));
  
      (void)ERR_set_mark();
      fetched = EVP_MD_fetch(ctx->libctx, name, ctx->propq);
      if (fetched != NULL)
          md = fetched;
      else
          md = EVP_get_digestbyname(name);
  
      if (md == NULL) {
          (void)ERR_clear_last_mark();
          PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, PKCS7_R_UNKNOWN_DIGEST_TYPE);
          goto err;
      }
      (void)ERR_pop_to_mark();
  
      BIO_set_md(btmp, md);
      EVP_MD_free(fetched);
      if (*pbio == NULL)
          *pbio = btmp;
      else if (!BIO_push(*pbio, btmp)) {
          PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, ERR_R_BIO_LIB);
          goto err;
      }
      btmp = NULL;
  
      return 1;
  
   err:
      BIO_free(btmp);
      return 0;
  }
  
  static int pkcs7_encode_rinfo(PKCS7_RECIP_INFO *ri,
                                unsigned char *key, int keylen)
  {
      EVP_PKEY_CTX *pctx = NULL;
      EVP_PKEY *pkey = NULL;
      unsigned char *ek = NULL;
      int ret = 0;
      size_t eklen;
      const PKCS7_CTX *ctx = ri->ctx;
  
      pkey = X509_get0_pubkey(ri->cert);
      if (pkey == NULL)
          return 0;
  
      pctx = EVP_PKEY_CTX_new_from_pkey(ctx->libctx, pkey, ctx->propq);
      if (pctx == NULL)
          return 0;
  
      if (EVP_PKEY_encrypt_init(pctx) <= 0)
          goto err;
  
      if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_ENCRYPT,
                            EVP_PKEY_CTRL_PKCS7_ENCRYPT, 0, ri) <= 0) {
          PKCS7err(PKCS7_F_PKCS7_ENCODE_RINFO, PKCS7_R_CTRL_ERROR);
          goto err;
      }
  
      if (EVP_PKEY_encrypt(pctx, NULL, &eklen, key, keylen) <= 0)
          goto err;
  
      ek = OPENSSL_malloc(eklen);
  
      if (ek == NULL) {
          PKCS7err(PKCS7_F_PKCS7_ENCODE_RINFO, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (EVP_PKEY_encrypt(pctx, ek, &eklen, key, keylen) <= 0)
          goto err;
  
      ASN1_STRING_set0(ri->enc_key, ek, eklen);
      ek = NULL;
  
      ret = 1;
  
   err:
      EVP_PKEY_CTX_free(pctx);
      OPENSSL_free(ek);
      return ret;
  
  }
  
  static int pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen,
                                 PKCS7_RECIP_INFO *ri, EVP_PKEY *pkey,
                                 size_t fixlen)
  {
      EVP_PKEY_CTX *pctx = NULL;
      unsigned char *ek = NULL;
      size_t eklen;
      int ret = -1;
      const PKCS7_CTX *ctx = ri->ctx;
  
      pctx = EVP_PKEY_CTX_new_from_pkey(ctx->libctx, pkey, ctx->propq);
      if (pctx == NULL)
          return -1;
  
      if (EVP_PKEY_decrypt_init(pctx) <= 0)
          goto err;
  
      if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_DECRYPT,
                            EVP_PKEY_CTRL_PKCS7_DECRYPT, 0, ri) <= 0) {
          PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, PKCS7_R_CTRL_ERROR);
          goto err;
      }
  
      if (EVP_PKEY_decrypt(pctx, NULL, &eklen,
                           ri->enc_key->data, ri->enc_key->length) <= 0)
          goto err;
  
      ek = OPENSSL_malloc(eklen);
  
      if (ek == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (EVP_PKEY_decrypt(pctx, ek, &eklen,
                           ri->enc_key->data, ri->enc_key->length) <= 0
              || eklen == 0
              || (fixlen != 0 && eklen != fixlen)) {
          ret = 0;
          PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_EVP_LIB);
          goto err;
      }
  
      ret = 1;
  
      OPENSSL_clear_free(*pek, *peklen);
      *pek = ek;
      *peklen = eklen;
  
   err:
      EVP_PKEY_CTX_free(pctx);
      if (!ret)
          OPENSSL_free(ek);
  
      return ret;
  }
  
  BIO *PKCS7_dataInit(PKCS7 *p7, BIO *bio)
  {
      int i;
      BIO *out = NULL, *btmp = NULL;
      X509_ALGOR *xa = NULL;
      EVP_CIPHER *fetched_cipher = NULL;
      const EVP_CIPHER *cipher;
      const EVP_CIPHER *evp_cipher = NULL;
      STACK_OF(X509_ALGOR) *md_sk = NULL;
      STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
      X509_ALGOR *xalg = NULL;
      PKCS7_RECIP_INFO *ri = NULL;
      ASN1_OCTET_STRING *os = NULL;
      const PKCS7_CTX *p7_ctx;
  
      if (p7 == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_INVALID_NULL_POINTER);
          return NULL;
      }
      p7_ctx = pkcs7_get0_ctx(p7);
  
      /*
       * The content field in the PKCS7 ContentInfo is optional, but that really
       * only applies to inner content (precisely, detached signatures).
       *
       * When reading content, missing outer content is therefore treated as an
       * error.
       *
       * When creating content, PKCS7_content_new() must be called before
       * calling this method, so a NULL p7->d is always an error.
       */
      if (p7->d.ptr == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_NO_CONTENT);
          return NULL;
      }
  
      i = OBJ_obj2nid(p7->type);
      p7->state = PKCS7_S_HEADER;
  
      switch (i) {
      case NID_pkcs7_signed:
          md_sk = p7->d.sign->md_algs;
          os = PKCS7_get_octet_string(p7->d.sign->contents);
          break;
      case NID_pkcs7_signedAndEnveloped:
          rsk = p7->d.signed_and_enveloped->recipientinfo;
          md_sk = p7->d.signed_and_enveloped->md_algs;
          xalg = p7->d.signed_and_enveloped->enc_data->algorithm;
          evp_cipher = p7->d.signed_and_enveloped->enc_data->cipher;
          if (evp_cipher == NULL) {
              PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_CIPHER_NOT_INITIALIZED);
              goto err;
          }
          break;
      case NID_pkcs7_enveloped:
          rsk = p7->d.enveloped->recipientinfo;
          xalg = p7->d.enveloped->enc_data->algorithm;
          evp_cipher = p7->d.enveloped->enc_data->cipher;
          if (evp_cipher == NULL) {
              PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_CIPHER_NOT_INITIALIZED);
              goto err;
          }
          break;
      case NID_pkcs7_digest:
          xa = p7->d.digest->md;
          os = PKCS7_get_octet_string(p7->d.digest->contents);
          break;
      case NID_pkcs7_data:
          break;
      default:
          PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
          goto err;
      }
  
      for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++)
          if (!pkcs7_bio_add_digest(&out, sk_X509_ALGOR_value(md_sk, i), p7_ctx))
              goto err;
  
      if (xa && !pkcs7_bio_add_digest(&out, xa, p7_ctx))
          goto err;
  
      if (evp_cipher != NULL) {
          unsigned char key[EVP_MAX_KEY_LENGTH];
          unsigned char iv[EVP_MAX_IV_LENGTH];
          int keylen, ivlen;
          EVP_CIPHER_CTX *ctx;
  
          if ((btmp = BIO_new(BIO_f_cipher())) == NULL) {
              PKCS7err(PKCS7_F_PKCS7_DATAINIT, ERR_R_BIO_LIB);
              goto err;
          }
          BIO_get_cipher_ctx(btmp, &ctx);
          keylen = EVP_CIPHER_key_length(evp_cipher);
          ivlen = EVP_CIPHER_iv_length(evp_cipher);
          xalg->algorithm = OBJ_nid2obj(EVP_CIPHER_type(evp_cipher));
          if (ivlen > 0)
              if (RAND_bytes_ex(p7_ctx->libctx, iv, ivlen) <= 0)
                  goto err;
  
          (void)ERR_set_mark();
          fetched_cipher = EVP_CIPHER_fetch(p7_ctx->libctx,
                                            EVP_CIPHER_name(evp_cipher),
                                            p7_ctx->propq);
          (void)ERR_pop_to_mark();
          if (fetched_cipher != NULL)
              cipher = fetched_cipher;
          else
              cipher = evp_cipher;
  
          if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, 1) <= 0)
              goto err;
  
          EVP_CIPHER_free(fetched_cipher);
          fetched_cipher = NULL;
  
          if (EVP_CIPHER_CTX_rand_key(ctx, key) <= 0)
              goto err;
          if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, 1) <= 0)
              goto err;
  
          if (ivlen > 0) {
              if (xalg->parameter == NULL) {
                  xalg->parameter = ASN1_TYPE_new();
                  if (xalg->parameter == NULL)
                      goto err;
              }
              if (EVP_CIPHER_param_to_asn1(ctx, xalg->parameter) < 0)
                  goto err;
          }
  
          /* Lets do the pub key stuff :-) */
          for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
              ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
              if (pkcs7_encode_rinfo(ri, key, keylen) <= 0)
                  goto err;
          }
          OPENSSL_cleanse(key, keylen);
  
          if (out == NULL)
              out = btmp;
          else
              BIO_push(out, btmp);
          btmp = NULL;
      }
  
      if (bio == NULL) {
          if (PKCS7_is_detached(p7)) {
              bio = BIO_new(BIO_s_null());
          } else if (os && os->length > 0) {
              bio = BIO_new_mem_buf(os->data, os->length);
          } else {
              bio = BIO_new(BIO_s_mem());
              if (bio == NULL)
                  goto err;
              BIO_set_mem_eof_return(bio, 0);
          }
          if (bio == NULL)
              goto err;
      }
      if (out)
          BIO_push(out, bio);
      else
          out = bio;
      return out;
  
   err:
      EVP_CIPHER_free(fetched_cipher);
      BIO_free_all(out);
      BIO_free_all(btmp);
      return NULL;
  }
  
  static int pkcs7_cmp_ri(PKCS7_RECIP_INFO *ri, X509 *pcert)
  {
      int ret;
      ret = X509_NAME_cmp(ri->issuer_and_serial->issuer,
                          X509_get_issuer_name(pcert));
      if (ret)
          return ret;
      return ASN1_INTEGER_cmp(X509_get0_serialNumber(pcert),
                              ri->issuer_and_serial->serial);
  }
  
  /* int */
  BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
  {
      int i, len;
      BIO *out = NULL, *btmp = NULL, *etmp = NULL, *bio = NULL;
      X509_ALGOR *xa;
      ASN1_OCTET_STRING *data_body = NULL;
      EVP_MD *evp_md = NULL;
      const EVP_MD *md;
      EVP_CIPHER *evp_cipher = NULL;
      const EVP_CIPHER *cipher = NULL;
      EVP_CIPHER_CTX *evp_ctx = NULL;
      X509_ALGOR *enc_alg = NULL;
      STACK_OF(X509_ALGOR) *md_sk = NULL;
      STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
      PKCS7_RECIP_INFO *ri = NULL;
      unsigned char *ek = NULL, *tkey = NULL;
      int eklen = 0, tkeylen = 0;
      const char *name;
      const PKCS7_CTX *p7_ctx;
  
      if (p7 == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_INVALID_NULL_POINTER);
          return NULL;
      }
  
      p7_ctx = pkcs7_get0_ctx(p7);
  
      if (p7->d.ptr == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_NO_CONTENT);
          return NULL;
      }
  
      i = OBJ_obj2nid(p7->type);
      p7->state = PKCS7_S_HEADER;
  
      switch (i) {
      case NID_pkcs7_signed:
          /*
           * p7->d.sign->contents is a PKCS7 structure consisting of a contentType
           * field and optional content.
           * data_body is NULL if that structure has no (=detached) content
           * or if the contentType is wrong (i.e., not "data").
           */
          data_body = PKCS7_get_octet_string(p7->d.sign->contents);
          if (!PKCS7_is_detached(p7) && data_body == NULL) {
              PKCS7err(PKCS7_F_PKCS7_DATADECODE,
                       PKCS7_R_INVALID_SIGNED_DATA_TYPE);
              goto err;
          }
          md_sk = p7->d.sign->md_algs;
          break;
      case NID_pkcs7_signedAndEnveloped:
          rsk = p7->d.signed_and_enveloped->recipientinfo;
          md_sk = p7->d.signed_and_enveloped->md_algs;
          /* data_body is NULL if the optional EncryptedContent is missing. */
          data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
          enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
  
          name = OBJ_nid2sn(OBJ_obj2nid(enc_alg->algorithm));
  
          (void)ERR_set_mark();
          evp_cipher = EVP_CIPHER_fetch(p7_ctx->libctx, name, p7_ctx->propq);
          if (evp_cipher != NULL)
              cipher = evp_cipher;
          else
              cipher = EVP_get_cipherbyname(name);
  
          if (cipher == NULL) {
              (void)ERR_clear_last_mark();
              PKCS7err(PKCS7_F_PKCS7_DATADECODE,
                       PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
              goto err;
          }
          (void)ERR_pop_to_mark();
          break;
      case NID_pkcs7_enveloped:
          rsk = p7->d.enveloped->recipientinfo;
          enc_alg = p7->d.enveloped->enc_data->algorithm;
          /* data_body is NULL if the optional EncryptedContent is missing. */
          data_body = p7->d.enveloped->enc_data->enc_data;
          name = OBJ_nid2sn(OBJ_obj2nid(enc_alg->algorithm));
  
          (void)ERR_set_mark();
          evp_cipher = EVP_CIPHER_fetch(p7_ctx->libctx, name, p7_ctx->propq);
          if (evp_cipher != NULL)
              cipher = evp_cipher;
          else
              cipher = EVP_get_cipherbyname(name);
  
          if (cipher == NULL) {
              (void)ERR_clear_last_mark();
              PKCS7err(PKCS7_F_PKCS7_DATADECODE,
                       PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
              goto err;
          }
          (void)ERR_pop_to_mark();
          break;
      default:
          PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
          goto err;
      }
  
      /* Detached content must be supplied via in_bio instead. */
      if (data_body == NULL && in_bio == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_NO_CONTENT);
          goto err;
      }
  
      /* We will be checking the signature */
      if (md_sk != NULL) {
          for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
              xa = sk_X509_ALGOR_value(md_sk, i);
              if ((btmp = BIO_new(BIO_f_md())) == NULL) {
                  PKCS7err(PKCS7_F_PKCS7_DATADECODE, ERR_R_BIO_LIB);
                  goto err;
              }
  
              name = OBJ_nid2sn(OBJ_obj2nid(xa->algorithm));
  
              (void)ERR_set_mark();
              evp_md = EVP_MD_fetch(p7_ctx->libctx, name, p7_ctx->propq);
              if (evp_md != NULL)
                  md = evp_md;
              else
                  md = EVP_get_digestbyname(name);
  
              if (md == NULL) {
                  (void)ERR_clear_last_mark();
                  PKCS7err(PKCS7_F_PKCS7_DATADECODE,
                           PKCS7_R_UNKNOWN_DIGEST_TYPE);
                  goto err;
              }
              (void)ERR_pop_to_mark();
  
              BIO_set_md(btmp, md);
              EVP_MD_free(evp_md);
              if (out == NULL)
                  out = btmp;
              else
                  BIO_push(out, btmp);
              btmp = NULL;
          }
      }
  
      if (cipher != NULL) {
          if ((etmp = BIO_new(BIO_f_cipher())) == NULL) {
              PKCS7err(PKCS7_F_PKCS7_DATADECODE, ERR_R_BIO_LIB);
              goto err;
          }
  
          /*
           * It was encrypted, we need to decrypt the secret key with the
           * private key
           */
  
          /*
           * Find the recipientInfo which matches the passed certificate (if
           * any)
           */
  
          if (pcert) {
              for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
                  ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
                  if (!pkcs7_cmp_ri(ri, pcert))
                      break;
                  ri = NULL;
              }
              if (ri == NULL) {
                  PKCS7err(PKCS7_F_PKCS7_DATADECODE,
                           PKCS7_R_NO_RECIPIENT_MATCHES_CERTIFICATE);
                  goto err;
              }
          }
  
          /* If we haven't got a certificate try each ri in turn */
          if (pcert == NULL) {
              /*
               * Always attempt to decrypt all rinfo even after success as a
               * defence against MMA timing attacks.
               */
              for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
                  ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
                  ri->ctx = p7_ctx;
                  if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey,
                          EVP_CIPHER_key_length(cipher)) < 0)
                      goto err;
                  ERR_clear_error();
              }
          } else {
              ri->ctx = p7_ctx;
              /* Only exit on fatal errors, not decrypt failure */
              if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey, 0) < 0)
                  goto err;
              ERR_clear_error();
          }
  
          evp_ctx = NULL;
          BIO_get_cipher_ctx(etmp, &evp_ctx);
          if (EVP_CipherInit_ex(evp_ctx, cipher, NULL, NULL, NULL, 0) <= 0)
              goto err;
          if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
              goto err;
          /* Generate random key as MMA defence */
          len = EVP_CIPHER_CTX_key_length(evp_ctx);
          if (len <= 0)
              goto err;
          tkeylen = (size_t)len;
          tkey = OPENSSL_malloc(tkeylen);
          if (tkey == NULL)
              goto err;
          if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
              goto err;
          if (ek == NULL) {
              ek = tkey;
              eklen = tkeylen;
              tkey = NULL;
          }
  
          if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
              /*
               * Some S/MIME clients don't use the same key and effective key
               * length. The key length is determined by the size of the
               * decrypted RSA key.
               */
              if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen)) {
                  /* Use random key as MMA defence */
                  OPENSSL_clear_free(ek, eklen);
                  ek = tkey;
                  eklen = tkeylen;
                  tkey = NULL;
              }
          }
          /* Clear errors so we don't leak information useful in MMA */
          ERR_clear_error();
          if (EVP_CipherInit_ex(evp_ctx, NULL, NULL, ek, NULL, 0) <= 0)
              goto err;
  
          OPENSSL_clear_free(ek, eklen);
          ek = NULL;
          OPENSSL_clear_free(tkey, tkeylen);
          tkey = NULL;
  
          if (out == NULL)
              out = etmp;
          else
              BIO_push(out, etmp);
          etmp = NULL;
      }
      if (in_bio != NULL) {
          bio = in_bio;
      } else {
          if (data_body->length > 0)
              bio = BIO_new_mem_buf(data_body->data, data_body->length);
          else {
              bio = BIO_new(BIO_s_mem());
              if (bio == NULL)
                  goto err;
              BIO_set_mem_eof_return(bio, 0);
          }
          if (bio == NULL)
              goto err;
      }
      BIO_push(out, bio);
      bio = NULL;
      EVP_CIPHER_free(evp_cipher);
      return out;
  
   err:
      EVP_CIPHER_free(evp_cipher);
      OPENSSL_clear_free(ek, eklen);
      OPENSSL_clear_free(tkey, tkeylen);
      BIO_free_all(out);
      BIO_free_all(btmp);
      BIO_free_all(etmp);
      BIO_free_all(bio);
      return NULL;
  }
  
  static BIO *PKCS7_find_digest(EVP_MD_CTX **pmd, BIO *bio, int nid)
  {
      for (;;) {
          bio = BIO_find_type(bio, BIO_TYPE_MD);
          if (bio == NULL) {
              PKCS7err(PKCS7_F_PKCS7_FIND_DIGEST,
                       PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
              return NULL;
          }
          BIO_get_md_ctx(bio, pmd);
          if (*pmd == NULL) {
              PKCS7err(PKCS7_F_PKCS7_FIND_DIGEST, ERR_R_INTERNAL_ERROR);
              return NULL;
          }
          if (EVP_MD_CTX_type(*pmd) == nid)
              return bio;
          bio = BIO_next(bio);
      }
      return NULL;
  }
  
  static int do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
  {
      unsigned char md_data[EVP_MAX_MD_SIZE];
      unsigned int md_len;
  
      /* Add signing time if not already present */
      if (!PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime)) {
          if (!PKCS7_add0_attrib_signing_time(si, NULL)) {
              PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_MALLOC_FAILURE);
              return 0;
          }
      }
  
      /* Add digest */
      if (!EVP_DigestFinal_ex(mctx, md_data, &md_len)) {
          PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_EVP_LIB);
          return 0;
      }
      if (!PKCS7_add1_attrib_digest(si, md_data, md_len)) {
          PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      /* Now sign the attributes */
      if (!PKCS7_SIGNER_INFO_sign(si))
          return 0;
  
      return 1;
  }
  
  int PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
  {
      int ret = 0;
      int i, j;
      BIO *btmp;
      PKCS7_SIGNER_INFO *si;
      EVP_MD_CTX *mdc, *ctx_tmp;
      STACK_OF(X509_ATTRIBUTE) *sk;
      STACK_OF(PKCS7_SIGNER_INFO) *si_sk = NULL;
      ASN1_OCTET_STRING *os = NULL;
      const PKCS7_CTX *p7_ctx;
  
      if (p7 == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_INVALID_NULL_POINTER);
          return 0;
      }
  
      p7_ctx = pkcs7_get0_ctx(p7);
  
      if (p7->d.ptr == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_NO_CONTENT);
          return 0;
      }
  
      ctx_tmp = EVP_MD_CTX_new();
      if (ctx_tmp == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      i = OBJ_obj2nid(p7->type);
      p7->state = PKCS7_S_HEADER;
  
      switch (i) {
      case NID_pkcs7_data:
          os = p7->d.data;
          break;
      case NID_pkcs7_signedAndEnveloped:
          /* XXXXXXXXXXXXXXXX */
          si_sk = p7->d.signed_and_enveloped->signer_info;
          os = p7->d.signed_and_enveloped->enc_data->enc_data;
          if (os == NULL) {
              os = ASN1_OCTET_STRING_new();
              if (os == NULL) {
                  PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
              p7->d.signed_and_enveloped->enc_data->enc_data = os;
          }
          break;
      case NID_pkcs7_enveloped:
          /* XXXXXXXXXXXXXXXX */
          os = p7->d.enveloped->enc_data->enc_data;
          if (os == NULL) {
              os = ASN1_OCTET_STRING_new();
              if (os == NULL) {
                  PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
              p7->d.enveloped->enc_data->enc_data = os;
          }
          break;
      case NID_pkcs7_signed:
          si_sk = p7->d.sign->signer_info;
          os = PKCS7_get_octet_string(p7->d.sign->contents);
          /* If detached data then the content is excluded */
          if (PKCS7_type_is_data(p7->d.sign->contents) && p7->detached) {
              ASN1_OCTET_STRING_free(os);
              os = NULL;
              p7->d.sign->contents->d.data = NULL;
          }
          break;
  
      case NID_pkcs7_digest:
          os = PKCS7_get_octet_string(p7->d.digest->contents);
          /* If detached data then the content is excluded */
          if (PKCS7_type_is_data(p7->d.digest->contents) && p7->detached) {
              ASN1_OCTET_STRING_free(os);
              os = NULL;
              p7->d.digest->contents->d.data = NULL;
          }
          break;
  
      default:
          PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
          goto err;
      }
  
      if (si_sk != NULL) {
          for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(si_sk); i++) {
              si = sk_PKCS7_SIGNER_INFO_value(si_sk, i);
              if (si->pkey == NULL)
                  continue;
  
              j = OBJ_obj2nid(si->digest_alg->algorithm);
  
              btmp = bio;
  
              btmp = PKCS7_find_digest(&mdc, btmp, j);
  
              if (btmp == NULL)
                  goto err;
  
              /*
               * We now have the EVP_MD_CTX, lets do the signing.
               */
              if (!EVP_MD_CTX_copy_ex(ctx_tmp, mdc))
                  goto err;
  
              sk = si->auth_attr;
  
              /*
               * If there are attributes, we add the digest attribute and only
               * sign the attributes
               */
              if (sk_X509_ATTRIBUTE_num(sk) > 0) {
                  if (!do_pkcs7_signed_attrib(si, ctx_tmp))
                      goto err;
              } else {
                  unsigned char *abuf = NULL;
                  unsigned int abuflen;
                  abuflen = EVP_PKEY_size(si->pkey);
                  abuf = OPENSSL_malloc(abuflen);
                  if (abuf == NULL)
                      goto err;
  
                  if (!EVP_SignFinal_ex(ctx_tmp, abuf, &abuflen, si->pkey,
                                        p7_ctx->libctx, p7_ctx->propq)) {
                      OPENSSL_free(abuf);
                      PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_EVP_LIB);
                      goto err;
                  }
                  ASN1_STRING_set0(si->enc_digest, abuf, abuflen);
              }
          }
      } else if (i == NID_pkcs7_digest) {
          unsigned char md_data[EVP_MAX_MD_SIZE];
          unsigned int md_len;
          if (!PKCS7_find_digest(&mdc, bio,
                                 OBJ_obj2nid(p7->d.digest->md->algorithm)))
              goto err;
          if (!EVP_DigestFinal_ex(mdc, md_data, &md_len))
              goto err;
          if (!ASN1_OCTET_STRING_set(p7->d.digest->digest, md_data, md_len))
              goto err;
      }
  
      if (!PKCS7_is_detached(p7)) {
          /*
           * NOTE(emilia): I think we only reach os == NULL here because detached
           * digested data support is broken.
           */
          if (os == NULL)
              goto err;
          if (!(os->flags & ASN1_STRING_FLAG_NDEF)) {
              char *cont;
              long contlen;
              btmp = BIO_find_type(bio, BIO_TYPE_MEM);
              if (btmp == NULL) {
                  PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_UNABLE_TO_FIND_MEM_BIO);
                  goto err;
              }
              contlen = BIO_get_mem_data(btmp, &cont);
              /*
               * Mark the BIO read only then we can use its copy of the data
               * instead of making an extra copy.
               */
              BIO_set_flags(btmp, BIO_FLAGS_MEM_RDONLY);
              BIO_set_mem_eof_return(btmp, 0);
              ASN1_STRING_set0(os, (unsigned char *)cont, contlen);
          }
      }
      ret = 1;
   err:
      EVP_MD_CTX_free(ctx_tmp);
      return ret;
  }
  
  int PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO *si)
  {
      EVP_MD_CTX *mctx;
      EVP_PKEY_CTX *pctx = NULL;
      unsigned char *abuf = NULL;
      int alen;
      size_t siglen;
      const EVP_MD *md = NULL;
      const PKCS7_CTX *ctx = si->ctx;
  
      md = EVP_get_digestbyobj(si->digest_alg->algorithm);
      if (md == NULL)
          return 0;
  
      mctx = EVP_MD_CTX_new();
      if (mctx == NULL) {
          PKCS7err(0, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (EVP_DigestSignInit_ex(mctx, &pctx, EVP_MD_name(md), ctx->libctx,
                                ctx->propq, si->pkey) <= 0)
          goto err;
  
      /*
       * TODO(3.0): This causes problems when providers are in use, so disabled
       * for now. Can we get rid of this completely? AFAICT this ctrl has never
       * been used since it was first put in. All internal implementations just
       * return 1 and ignore this ctrl and have always done so by the looks of
       * things. To fix this we could convert this ctrl into a param, which would
       * require us to send all the signer info data as a set of params...but that
       * is non-trivial and since this isn't used by anything it may be better
       * just to remove it. The original commit that added it had this
       * justification in CHANGES:
       *
       * "During PKCS7 signing pass the PKCS7 SignerInfo structure to the
       *  EVP_PKEY_METHOD before and after signing via the
       *  EVP_PKEY_CTRL_PKCS7_SIGN ctrl. It can then customise the structure
       *  before and/or after signing if necessary."
       */
  #if 0
      if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
                            EVP_PKEY_CTRL_PKCS7_SIGN, 0, si) <= 0) {
          PKCS7err(0, PKCS7_R_CTRL_ERROR);
          goto err;
      }
  #endif
  
      alen = ASN1_item_i2d((ASN1_VALUE *)si->auth_attr, &abuf,
                           ASN1_ITEM_rptr(PKCS7_ATTR_SIGN));
      if (!abuf)
          goto err;
      if (EVP_DigestSignUpdate(mctx, abuf, alen) <= 0)
          goto err;
      OPENSSL_free(abuf);
      abuf = NULL;
      if (EVP_DigestSignFinal(mctx, NULL, &siglen) <= 0)
          goto err;
      abuf = OPENSSL_malloc(siglen);
      if (abuf == NULL)
          goto err;
      if (EVP_DigestSignFinal(mctx, abuf, &siglen) <= 0)
          goto err;
  
      /*
       * TODO(3.0): This causes problems when providers are in use, so disabled
       * for now. Can we get rid of this completely? AFAICT this ctrl has never
       * been used since it was first put in. All internal implementations just
       * return 1 and ignore this ctrl and have always done so by the looks of
       * things. To fix this we could convert this ctrl into a param, which would
       * require us to send all the signer info data as a set of params...but that
       * is non-trivial and since this isn't used by anything it may be better
       * just to remove it. The original commit that added it had this
       * justification in CHANGES:
       *
       * "During PKCS7 signing pass the PKCS7 SignerInfo structure to the
       *  EVP_PKEY_METHOD before and after signing via the
       *  EVP_PKEY_CTRL_PKCS7_SIGN ctrl. It can then customise the structure
       *  before and/or after signing if necessary."
       */
  #if 0
      if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
                            EVP_PKEY_CTRL_PKCS7_SIGN, 1, si) <= 0) {
          PKCS7err(0, PKCS7_R_CTRL_ERROR);
          goto err;
      }
  #endif
  
      EVP_MD_CTX_free(mctx);
  
      ASN1_STRING_set0(si->enc_digest, abuf, siglen);
  
      return 1;
  
   err:
      OPENSSL_free(abuf);
      EVP_MD_CTX_free(mctx);
      return 0;
  }
  
  int PKCS7_dataVerify(X509_STORE *cert_store, X509_STORE_CTX *ctx, BIO *bio,
                       PKCS7 *p7, PKCS7_SIGNER_INFO *si)
  {
      PKCS7_ISSUER_AND_SERIAL *ias;
      int ret = 0, i;
      STACK_OF(X509) *cert;
      X509 *x509;
  
      if (p7 == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_INVALID_NULL_POINTER);
          return 0;
      }
  
      if (p7->d.ptr == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_NO_CONTENT);
          return 0;
      }
  
      if (PKCS7_type_is_signed(p7)) {
          cert = p7->d.sign->cert;
      } else if (PKCS7_type_is_signedAndEnveloped(p7)) {
          cert = p7->d.signed_and_enveloped->cert;
      } else {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_WRONG_PKCS7_TYPE);
          goto err;
      }
      /* XXXXXXXXXXXXXXXXXXXXXXX */
      ias = si->issuer_and_serial;
  
      x509 = X509_find_by_issuer_and_serial(cert, ias->issuer, ias->serial);
  
      /* were we able to find the cert in passed to us */
      if (x509 == NULL) {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY,
                   PKCS7_R_UNABLE_TO_FIND_CERTIFICATE);
          goto err;
      }
  
      /* Lets verify */
      if (!X509_STORE_CTX_init(ctx, cert_store, x509, cert)) {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, ERR_R_X509_LIB);
          goto err;
      }
      X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_SMIME_SIGN);
      i = X509_verify_cert(ctx);
      if (i <= 0) {
          PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, ERR_R_X509_LIB);
          X509_STORE_CTX_cleanup(ctx);
          goto err;
      }
      X509_STORE_CTX_cleanup(ctx);
  
      return PKCS7_signatureVerify(bio, p7, si, x509);
   err:
      return ret;
  }
  
  int PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si,
                            X509 *x509)
  {
      ASN1_OCTET_STRING *os;
      EVP_MD_CTX *mdc_tmp, *mdc;
      const EVP_MD *md;
      EVP_MD *fetched_md = NULL;
      int ret = 0, i;
      int md_type;
      STACK_OF(X509_ATTRIBUTE) *sk;
      BIO *btmp;
      EVP_PKEY *pkey;
      const PKCS7_CTX *ctx = pkcs7_get0_ctx(p7);
  
      mdc_tmp = EVP_MD_CTX_new();
      if (mdc_tmp == NULL) {
          PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (!PKCS7_type_is_signed(p7) && !PKCS7_type_is_signedAndEnveloped(p7)) {
          PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_WRONG_PKCS7_TYPE);
          goto err;
      }
  
      md_type = OBJ_obj2nid(si->digest_alg->algorithm);
  
      btmp = bio;
      for (;;) {
          if ((btmp == NULL) ||
              ((btmp = BIO_find_type(btmp, BIO_TYPE_MD)) == NULL)) {
              PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY,
                       PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
              goto err;
          }
          BIO_get_md_ctx(btmp, &mdc);
          if (mdc == NULL) {
              PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, ERR_R_INTERNAL_ERROR);
              goto err;
          }
          if (EVP_MD_CTX_type(mdc) == md_type)
              break;
          /*
           * Workaround for some broken clients that put the signature OID
           * instead of the digest OID in digest_alg->algorithm
           */
          if (EVP_MD_pkey_type(EVP_MD_CTX_md(mdc)) == md_type)
              break;
          btmp = BIO_next(btmp);
      }
  
      /*
       * mdc is the digest ctx that we want, unless there are attributes, in
       * which case the digest is the signed attributes
       */
      if (!EVP_MD_CTX_copy_ex(mdc_tmp, mdc))
          goto err;
  
      sk = si->auth_attr;
      if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0)) {
          unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
          unsigned int md_len;
          int alen;
          ASN1_OCTET_STRING *message_digest;
  
          if (!EVP_DigestFinal_ex(mdc_tmp, md_dat, &md_len))
              goto err;
          message_digest = PKCS7_digest_from_attributes(sk);
          if (!message_digest) {
              PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY,
                       PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
              goto err;
          }
          if ((message_digest->length != (int)md_len) ||
              (memcmp(message_digest->data, md_dat, md_len))) {
              PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_DIGEST_FAILURE);
              ret = -1;
              goto err;
          }
  
          (void)ERR_set_mark();
          fetched_md = EVP_MD_fetch(ctx->libctx, OBJ_nid2sn(md_type), ctx->propq);
  
          if (fetched_md != NULL)
              md = fetched_md;
          else
              md = EVP_get_digestbynid(md_type);
  
          if (md == NULL || !EVP_VerifyInit_ex(mdc_tmp, md, NULL)) {
              (void)ERR_clear_last_mark();
              goto err;
          }
          (void)ERR_pop_to_mark();
  
          alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
                               ASN1_ITEM_rptr(PKCS7_ATTR_VERIFY));
          if (alen <= 0) {
              PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, ERR_R_ASN1_LIB);
              ret = -1;
              goto err;
          }
          if (!EVP_VerifyUpdate(mdc_tmp, abuf, alen))
              goto err;
  
          OPENSSL_free(abuf);
      }
  
      os = si->enc_digest;
      pkey = X509_get0_pubkey(x509);
      if (pkey == NULL) {
          ret = -1;
          goto err;
      }
  
      i = EVP_VerifyFinal_ex(mdc_tmp, os->data, os->length, pkey, ctx->libctx,
                             ctx->propq);
      if (i <= 0) {
          PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_SIGNATURE_FAILURE);
          ret = -1;
          goto err;
      }
      ret = 1;
   err:
      EVP_MD_CTX_free(mdc_tmp);
      EVP_MD_free(fetched_md);
      return ret;
  }
  
  PKCS7_ISSUER_AND_SERIAL *PKCS7_get_issuer_and_serial(PKCS7 *p7, int idx)
  {
      STACK_OF(PKCS7_RECIP_INFO) *rsk;
      PKCS7_RECIP_INFO *ri;
      int i;
  
      i = OBJ_obj2nid(p7->type);
      if (i != NID_pkcs7_signedAndEnveloped)
          return NULL;
      if (p7->d.signed_and_enveloped == NULL)
          return NULL;
      rsk = p7->d.signed_and_enveloped->recipientinfo;
      if (rsk == NULL)
          return NULL;
      if (sk_PKCS7_RECIP_INFO_num(rsk) <= idx)
          return NULL;
      ri = sk_PKCS7_RECIP_INFO_value(rsk, idx);
      return ri->issuer_and_serial;
  }
  
  ASN1_TYPE *PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO *si, int nid)
  {
      return get_attribute(si->auth_attr, nid);
  }
  
  ASN1_TYPE *PKCS7_get_attribute(PKCS7_SIGNER_INFO *si, int nid)
  {
      return get_attribute(si->unauth_attr, nid);
  }
  
  static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid)
  {
      int idx;
      X509_ATTRIBUTE *xa;
      idx = X509at_get_attr_by_NID(sk, nid, -1);
      xa = X509at_get_attr(sk, idx);
      return X509_ATTRIBUTE_get0_type(xa, 0);
  }
  
  ASN1_OCTET_STRING *PKCS7_digest_from_attributes(STACK_OF(X509_ATTRIBUTE) *sk)
  {
      ASN1_TYPE *astype;
      if ((astype = get_attribute(sk, NID_pkcs9_messageDigest)) == NULL)
          return NULL;
      return astype->value.octet_string;
  }
  
  int PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO *p7si,
                                  STACK_OF(X509_ATTRIBUTE) *sk)
  {
      int i;
  
      sk_X509_ATTRIBUTE_pop_free(p7si->auth_attr, X509_ATTRIBUTE_free);
      p7si->auth_attr = sk_X509_ATTRIBUTE_dup(sk);
      if (p7si->auth_attr == NULL)
          return 0;
      for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
          if ((sk_X509_ATTRIBUTE_set(p7si->auth_attr, i,
                                     X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value
                                                        (sk, i))))
              == NULL)
              return 0;
      }
      return 1;
  }
  
  int PKCS7_set_attributes(PKCS7_SIGNER_INFO *p7si,
                           STACK_OF(X509_ATTRIBUTE) *sk)
  {
      int i;
  
      sk_X509_ATTRIBUTE_pop_free(p7si->unauth_attr, X509_ATTRIBUTE_free);
      p7si->unauth_attr = sk_X509_ATTRIBUTE_dup(sk);
      if (p7si->unauth_attr == NULL)
          return 0;
      for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
          if ((sk_X509_ATTRIBUTE_set(p7si->unauth_attr, i,
                                     X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value
                                                        (sk, i))))
              == NULL)
              return 0;
      }
      return 1;
  }
  
  int PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
                                 void *value)
  {
      return add_attribute(&(p7si->auth_attr), nid, atrtype, value);
  }
  
  int PKCS7_add_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
                          void *value)
  {
      return add_attribute(&(p7si->unauth_attr), nid, atrtype, value);
  }
  
  static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
                           void *value)
  {
      X509_ATTRIBUTE *attr = NULL;
  
      if (*sk == NULL) {
          if ((*sk = sk_X509_ATTRIBUTE_new_null()) == NULL)
              return 0;
   new_attrib:
          if ((attr = X509_ATTRIBUTE_create(nid, atrtype, value)) == NULL)
              return 0;
          if (!sk_X509_ATTRIBUTE_push(*sk, attr)) {
              X509_ATTRIBUTE_free(attr);
              return 0;
          }
      } else {
          int i;
  
          for (i = 0; i < sk_X509_ATTRIBUTE_num(*sk); i++) {
              attr = sk_X509_ATTRIBUTE_value(*sk, i);
              if (OBJ_obj2nid(X509_ATTRIBUTE_get0_object(attr)) == nid) {
                  X509_ATTRIBUTE_free(attr);
                  attr = X509_ATTRIBUTE_create(nid, atrtype, value);
                  if (attr == NULL)
                      return 0;
                  if (!sk_X509_ATTRIBUTE_set(*sk, i, attr)) {
                      X509_ATTRIBUTE_free(attr);
                      return 0;
                  }
                  goto end;
              }
          }
          goto new_attrib;
      }
   end:
      return 1;
  }
  