text: /* crypto/rsa/rsa_saos.c */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  #include "cryptlib.h"
  #include <openssl/bn.h>
  #include <openssl/rsa.h>
  #include <openssl/objects.h>
  #include <openssl/x509.h>
  
  int RSA_sign_ASN1_OCTET_STRING(int type,
                                 const unsigned char *m, unsigned int m_len,
                                 unsigned char *sigret, unsigned int *siglen,
                                 RSA *rsa)
  {
      ASN1_OCTET_STRING sig;
      int i, j, ret = 1;
      unsigned char *p, *s;
  
      sig.type = V_ASN1_OCTET_STRING;
      sig.length = m_len;
      sig.data = (unsigned char *)m;
  
      i = i2d_ASN1_OCTET_STRING(&sig, NULL);
      j = RSA_size(rsa);
      if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
          RSAerr(RSA_F_RSA_SIGN_ASN1_OCTET_STRING,
                 RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
          return (0);
      }
      s = (unsigned char *)OPENSSL_malloc((unsigned int)j + 1);
      if (s == NULL) {
          RSAerr(RSA_F_RSA_SIGN_ASN1_OCTET_STRING, ERR_R_MALLOC_FAILURE);
          return (0);
      }
      p = s;
      i2d_ASN1_OCTET_STRING(&sig, &p);
      i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
      if (i <= 0)
          ret = 0;
      else
          *siglen = i;
  
      OPENSSL_cleanse(s, (unsigned int)j + 1);
      OPENSSL_free(s);
      return (ret);
  }
  
  int RSA_verify_ASN1_OCTET_STRING(int dtype,
                                   const unsigned char *m,
                                   unsigned int m_len, unsigned char *sigbuf,
                                   unsigned int siglen, RSA *rsa)
  {
      int i, ret = 0;
      unsigned char *s;
      const unsigned char *p;
      ASN1_OCTET_STRING *sig = NULL;
  
      if (siglen != (unsigned int)RSA_size(rsa)) {
          RSAerr(RSA_F_RSA_VERIFY_ASN1_OCTET_STRING,
                 RSA_R_WRONG_SIGNATURE_LENGTH);
          return (0);
      }
  
      s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen);
      if (s == NULL) {
          RSAerr(RSA_F_RSA_VERIFY_ASN1_OCTET_STRING, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING);
  
      if (i <= 0)
          goto err;
  
      p = s;
      sig = d2i_ASN1_OCTET_STRING(NULL, &p, (long)i);
      if (sig == NULL)
          goto err;
  
      if (((unsigned int)sig->length != m_len) ||
          (memcmp(m, sig->data, m_len) != 0)) {
          RSAerr(RSA_F_RSA_VERIFY_ASN1_OCTET_STRING, RSA_R_BAD_SIGNATURE);
      } else
          ret = 1;
   err:
      ASN1_OCTET_STRING_free(sig);
      if (s != NULL) {
          OPENSSL_cleanse(s, (unsigned int)siglen);
          OPENSSL_free(s);
      }
      return (ret);
  }
  