opentnl-cvs

[Mark F. <mar...@us...>]

Update of /cvsroot/opentnl/tnl/libtomcrypt/pk/pkcs1
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv26694/libtomcrypt/pk/pkcs1

Added Files:
	pkcs_1_i2osp.c pkcs_1_mgf1.c pkcs_1_oaep_decode.c 
	pkcs_1_oaep_encode.c pkcs_1_os2ip.c pkcs_1_pss_decode.c 
	pkcs_1_pss_encode.c pkcs_1_v15_es_decode.c 
	pkcs_1_v15_es_encode.c pkcs_1_v15_sa_decode.c 
	pkcs_1_v15_sa_encode.c 
Log Message:
Updated to libtomcrypt 1.0.2
Not tested on linux or OS X

--- NEW FILE: pkcs_1_pss_encode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_pss_encode.c
  PKCS #1 PSS Signature Padding, Tom St Denis 
*/

#ifdef PKCS_1

/**
   PKCS #1 v2.00 Signature Encoding
   @param msghash          The hash to encode
   @param msghashlen       The length of the hash (octets)
   @param saltlen          The length of the salt desired (octets)
   @param prng             An active PRNG context
   @param prng_idx         The index of the PRNG desired
   @param hash_idx         The index of the hash desired
   @param modulus_bitlen   The bit length of the RSA modulus
   @param out              [out] The destination of the encoding
   @param outlen           [in/out] The max size and resulting size of the encoded data
   @return CRYPT_OK if successful
*/
int pkcs_1_pss_encode(const unsigned char *msghash, unsigned long msghashlen,
                            unsigned long saltlen,  prng_state   *prng,     
                            int           prng_idx, int           hash_idx,
                            unsigned long modulus_bitlen,
                            unsigned char *out,     unsigned long *outlen)
{
   unsigned char *DB, *mask, *salt, *hash;
   unsigned long x, y, hLen, modulus_len;
   int           err;
   hash_state    md;

   LTC_ARGCHK(msghash != NULL);
   LTC_ARGCHK(out     != NULL);
   LTC_ARGCHK(outlen  != NULL);

   /* ensure hash and PRNG are valid */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
      return err;
   }
   if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
      return err;
   }

   hLen        = hash_descriptor[hash_idx].hashsize;
   modulus_len = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);

   /* check sizes */
   if ((saltlen > modulus_len) || (modulus_len < hLen + saltlen + 2)) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* allocate ram for DB/mask/salt/hash of size modulus_len */
   DB   = XMALLOC(modulus_len);
   mask = XMALLOC(modulus_len);
   salt = XMALLOC(modulus_len);
   hash = XMALLOC(modulus_len);
   if (DB == NULL || mask == NULL || salt == NULL || hash == NULL) {
      if (DB != NULL) {
         XFREE(DB);
      }
      if (mask != NULL) {
         XFREE(mask);
      }
      if (salt != NULL) {
         XFREE(salt);
      }
      if (hash != NULL) {
         XFREE(hash);
      }
      return CRYPT_MEM;
   }


   /* generate random salt */
   if (saltlen > 0) {
      if (prng_descriptor[prng_idx].read(salt, saltlen, prng) != saltlen) {
         err = CRYPT_ERROR_READPRNG;
         goto LBL_ERR;
      }
   }

   /* M = (eight) 0x00 || msghash || salt, hash = H(M) */
   if ((err = hash_descriptor[hash_idx].init(&md)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   zeromem(DB, 8);
   if ((err = hash_descriptor[hash_idx].process(&md, DB, 8)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].process(&md, msghash, msghashlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].process(&md, salt, saltlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].done(&md, hash)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* generate DB = PS || 0x01 || salt, PS == modulus_len - saltlen - hLen - 2 zero bytes */
   for (x = 0; x < (modulus_len - saltlen - hLen - 2); x++) {
       DB[x] = 0x00;
   }
   DB[x++] = 0x01;
   for (y = 0; y < saltlen; y++) {
      DB[x++] = salt[y];
   }

   /* generate mask of length modulus_len - hLen - 1 from hash */
   if ((err = pkcs_1_mgf1(hash, hLen, hash_idx, mask, modulus_len - hLen - 1)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* xor against DB */
   for (y = 0; y < (modulus_len - hLen - 1); y++) {
      DB[y] ^= mask[y];
   }

   /* output is DB || hash || 0xBC */
   if (*outlen < modulus_len) {
      err = CRYPT_BUFFER_OVERFLOW;
      goto LBL_ERR;
   }

   /* DB */
   for (y = x = 0; x < modulus_len - hLen - 1; x++) {
       out[y++] = DB[x];
   }
   /* hash */
   for (x = 0; x < hLen; x++) {
       out[y++] = hash[x];
   }
   /* 0xBC */
   out[y] = 0xBC;

   /* now clear the 8*modulus_len - modulus_bitlen most significant bits */
   out[0] &= 0xFF >> ((modulus_len<<3) - (modulus_bitlen-1));

   /* store output size */
   *outlen = modulus_len;
   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(DB,   modulus_len);   
   zeromem(mask, modulus_len);   
   zeromem(salt, modulus_len);   
   zeromem(hash, modulus_len);   
#endif

   XFREE(hash);
   XFREE(salt);
   XFREE(mask);
   XFREE(DB);

   return err;
}

#endif /* PKCS_1 */

--- NEW FILE: pkcs_1_v15_es_decode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_v15_es_decode.c
  PKCS #1 v1.5 Encryption Padding, Tom St Denis 
*/

#ifdef PKCS_1

/**
  PKCS #1 v1.5 Encryption Decoding
  @param msg             The padded data
  @param msglen          The length of the padded data (octets)
  @param modulus_bitlen  The bit length of the RSA modulus
  @param out             [out] Where to store the decoded data
  @param outlen          The length of the decoded data
  @param res             [out] Result of the decoding, 1==valid, 0==invalid
  @return CRYPT_OK if successful
*/
int pkcs_1_v15_es_decode(const unsigned char *msg,  unsigned long msglen,
                               unsigned long modulus_bitlen,
                               unsigned char *out,  unsigned long outlen,
                               int           *res)
{
   unsigned long x, modulus_bytelen;

   LTC_ARGCHK(msg != NULL);
   LTC_ARGCHK(out != NULL);
   LTC_ARGCHK(res != NULL);
   
   /* default to failed */
   *res = 0;

   modulus_bytelen = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);

   /* must be at least modulus_bytelen bytes long */
   if (msglen != modulus_bytelen) {
      return CRYPT_INVALID_ARG;
   }

   /* should start with 0x00 0x02 */
   if (msg[0] != 0x00 || msg[1] != 0x02) {
      return CRYPT_OK;
   }
   
   /* skip over PS */
   x = 2 + (modulus_bytelen - outlen - 3);

   /* should be 0x00 */
   if (msg[x++] != 0x00) {
      return CRYPT_OK;
   }

   /* the message is left */
   if (x + outlen > modulus_bytelen) {
      return CRYPT_PK_INVALID_SIZE;
   }
   XMEMCPY(out, msg + x, outlen);
   *res = 1;
   return CRYPT_OK;
}

#endif 


--- NEW FILE: pkcs_1_os2ip.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_os2ip.c
  Octet to Integer OS2IP, Tom St Denis 
*/
#ifdef PKCS_1

/**
  Read a binary string into an mp_int
  @param n          [out] The mp_int destination
  @param in         The binary string to read
  @param inlen      The length of the binary string
  @return CRYPT_OK if successful
*/
int pkcs_1_os2ip(mp_int *n, unsigned char *in, unsigned long inlen)
{
   int err;
   /* read it */
   if ((err = mp_read_unsigned_bin(n, in, inlen)) != MP_OKAY) {
      return mpi_to_ltc_error(err);
   }
   return CRYPT_OK;
}

#endif /* PKCS_1 */


--- NEW FILE: pkcs_1_oaep_decode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_oaep_decode.c
  OAEP Padding for PKCS #1, Tom St Denis 
*/

#ifdef PKCS_1

/**
   PKCS #1 v2.00 OAEP decode
   @param msg              The encoded data to decode
   @param msglen           The length of the encoded data (octets)
   @param lparam           The session or system data (can be NULL)
   @param lparamlen        The length of the lparam
   @param modulus_bitlen   The bit length of the RSA modulus
   @param hash_idx         The index of the hash desired
   @param out              [out] Destination of decoding
   @param outlen           [in/out] The max size and resulting size of the decoding
   @param res              [out] Result of decoding, 1==valid, 0==invalid
   @return CRYPT_OK if successful (even if invalid)
*/
int pkcs_1_oaep_decode(const unsigned char *msg,    unsigned long msglen,
                       const unsigned char *lparam, unsigned long lparamlen,
                             unsigned long modulus_bitlen, int hash_idx,
                             unsigned char *out,    unsigned long *outlen,
                             int           *res)
{
   unsigned char *DB, *seed, *mask;
   unsigned long hLen, x, y, modulus_len;
   int           err;

   LTC_ARGCHK(msg    != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);
   LTC_ARGCHK(res    != NULL);

   /* default to invalid packet */
   *res = 0;
   
   /* test valid hash */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { 
      return err;
   }
   hLen        = hash_descriptor[hash_idx].hashsize;
   modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);

   /* test hash/message size */
   if ((2*hLen >= (modulus_len - 2)) || (msglen != modulus_len)) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* allocate ram for DB/mask/salt of size modulus_len */
   DB   = XMALLOC(modulus_len);
   mask = XMALLOC(modulus_len);
   seed = XMALLOC(modulus_len);
   if (DB == NULL || mask == NULL || seed == NULL) {
      if (DB != NULL) {
         XFREE(DB);
      }
      if (mask != NULL) {
         XFREE(mask);
      }
      if (seed != NULL) {
         XFREE(seed);
      }
      return CRYPT_MEM;
   }

   /* ok so it's now in the form
  
      0x00  || maskedseed || maskedDB 
  
       1    ||   hLen     ||  modulus_len - hLen - 1
   
    */

   /* must have leading 0x00 byte */
   if (msg[0] != 0x00) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* now read the masked seed */
   for (x = 1, y = 0; y < hLen; y++) {
      seed[y] = msg[x++];
   }

   /* now read the masked DB */
   for (y = 0; y < modulus_len - hLen - 1; y++) {
      DB[y] = msg[x++];
   }

   /* compute MGF1 of maskedDB (hLen) */ 
   if ((err = pkcs_1_mgf1(DB, modulus_len - hLen - 1, hash_idx, mask, hLen)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* XOR against seed */
   for (y = 0; y < hLen; y++) {
      seed[y] ^= mask[y];
   }

   /* compute MGF1 of seed (k - hlen - 1) */
   if ((err = pkcs_1_mgf1(seed, hLen, hash_idx, mask, modulus_len - hLen - 1)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* xor against DB */
   for (y = 0; y < (modulus_len - hLen - 1); y++) {
       DB[y] ^= mask[y]; 
   }

   /* now DB == lhash || PS || 0x01 || M, PS == k - mlen - 2hlen - 2 zeroes */

   /* compute lhash and store it in seed [reuse temps!] */
   x = modulus_len;
   if (lparam != NULL) {
      if ((err = hash_memory(hash_idx, lparam, lparamlen, seed, &x)) != CRYPT_OK) {
         goto LBL_ERR;
      }
   } else {
      /* can't pass hash_memory a NULL so use DB with zero length */
      if ((err = hash_memory(hash_idx, DB, 0, seed, &x)) != CRYPT_OK) {
         goto LBL_ERR;
      }
   }

   /* compare the lhash'es */
   if (memcmp(seed, DB, hLen) != 0) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* now zeroes before a 0x01 */
   for (x = hLen; x < (modulus_len - hLen - 1) && DB[x] == 0x00; x++) {
      /* step... */
   }

   /* error out if wasn't 0x01 */
   if (x == (modulus_len - hLen - 1) || DB[x] != 0x01) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* rest is the message (and skip 0x01) */
   if ((modulus_len - hLen - 1) - ++x > *outlen) {
      err = CRYPT_BUFFER_OVERFLOW;
      goto LBL_ERR;
   }

   /* copy message */
   *outlen = (modulus_len - hLen - 1) - x;
   for (y = 0; x != (modulus_len - hLen - 1); ) {
       out[y++] = DB[x++];
   }

   /* valid packet */
   *res = 1;

   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(DB,   modulus_len);
   zeromem(seed, modulus_len);
   zeromem(mask, modulus_len);
#endif

   XFREE(seed);
   XFREE(mask);
   XFREE(DB);

   return err;
}

#endif /* PKCS_1 */

--- NEW FILE: pkcs_1_mgf1.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_mgf1.c
  The Mask Generation Function (MGF1) for PKCS #1, Tom St Denis 
*/

#ifdef PKCS_1

/**
   Perform PKCS #1 MGF1 (internal)
   @param seed        The seed for MGF1
   @param seedlen     The length of the seed
   @param hash_idx    The index of the hash desired
   @param mask        [out] The destination
   @param masklen     The length of the mask desired
   @return CRYPT_OK if successful
*/
int pkcs_1_mgf1(const unsigned char *seed, unsigned long seedlen,
                      int            hash_idx,
                      unsigned char *mask, unsigned long masklen)
{
   unsigned long hLen, x;
   ulong32       counter;
   int           err;
   hash_state    *md;
   unsigned char *buf;
 
   LTC_ARGCHK(seed != NULL);
   LTC_ARGCHK(mask != NULL);

   /* ensure valid hash */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { 
      return err;
   }

   /* get hash output size */
   hLen = hash_descriptor[hash_idx].hashsize;

   /* allocate memory */
   md  = XMALLOC(sizeof(hash_state));
   buf = XMALLOC(hLen);
   if (md == NULL || buf == NULL) {
      if (md != NULL) {
         XFREE(md);
      }
      if (buf != NULL) {
         XFREE(buf);
      }
      return CRYPT_MEM;
   }

   /* start counter */
   counter = 0;

   while (masklen > 0) {
       /* handle counter */
       STORE32H(counter, buf);
       ++counter;

       /* get hash of seed || counter */
       if ((err = hash_descriptor[hash_idx].init(md)) != CRYPT_OK) {
          goto LBL_ERR;
       }
       if ((err = hash_descriptor[hash_idx].process(md, seed, seedlen)) != CRYPT_OK) {
          goto LBL_ERR;
       }
       if ((err = hash_descriptor[hash_idx].process(md, buf, 4)) != CRYPT_OK) {
          goto LBL_ERR;
       }
       if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) {
          goto LBL_ERR;
       }

       /* store it */
       for (x = 0; x < hLen && masklen > 0; x++, masklen--) {
          *mask++ = buf[x];
       }
   }

   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(buf, hLen);
   zeromem(md,  sizeof(hash_state));
#endif

   XFREE(buf);
   XFREE(md);

   return err;
}

#endif /* PKCS_1 */

--- NEW FILE: pkcs_1_i2osp.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_i2osp.c
  Integer to Octet I2OSP, Tom St Denis 
*/

#ifdef PKCS_1

/* always stores the same # of bytes, pads with leading zero bytes
   as required
 */

/**
   PKCS #1 Integer to binary
   @param n             The integer to store
   @param modulus_len   The length of the RSA modulus
   @param out           [out] The destination for the integer
   @return CRYPT_OK if successful
*/
int pkcs_1_i2osp(mp_int *n, unsigned long modulus_len, unsigned char *out)
{
   int err;
   unsigned long size;

   size = mp_unsigned_bin_size(n);

   if (size > modulus_len) {
      return CRYPT_BUFFER_OVERFLOW;
   }

   /* store it */
   zeromem(out, modulus_len);
   if ((err = mp_to_unsigned_bin(n, out+(modulus_len-size))) != MP_OKAY) {
      return mpi_to_ltc_error(err);
   }
   return CRYPT_OK;
}

#endif /* PKCS_1 */


--- NEW FILE: pkcs_1_v15_sa_decode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_v15_sa_decode.c
  PKCS #1 v1.5 Signature Padding, Tom St Denis 
*/

#ifdef PKCS_1

/**
  Perform PKCS #1 v1.5 Signature Decoding
  @param msghash         The hash that was signed
  @param msghashlen      The length of the hash
  @param sig             The signature [padded data]
  @param siglen          The length of the signature
  @param hash_idx        The index of the hash used
  @param modulus_bitlen  The bit length of the RSA modulus 
  @param res             [out]  Result of comparison, 1==valid, 0==invalid
  @return CRYPT_OK if successful
*/
int pkcs_1_v15_sa_decode(const unsigned char *msghash, unsigned long msghashlen,
                         const unsigned char *sig,     unsigned long siglen,
                               int           hash_idx, unsigned long modulus_bitlen, 
                               int          *res)
{
   unsigned long x, y, modulus_bytelen, derlen;
   int err;
   
   LTC_ARGCHK(msghash != NULL);
   LTC_ARGCHK(sig     != NULL);
   LTC_ARGCHK(res     != NULL);

   /* default to invalid */
   *res = 0;

   /* valid hash ? */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
      return err;
   }

   /* get derlen */
   derlen = hash_descriptor[hash_idx].DERlen;

   /* get modulus len */
   modulus_bytelen = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);

   /* valid sizes? */
   if ((msghashlen + 3 + derlen > modulus_bytelen) || (siglen != modulus_bytelen)) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* packet is 0x00 0x01 PS 0x00 T, where PS == 0xFF repeated modulus_bytelen - 3 - derlen - msghashlen times, T == DER || hash */
   x = 0;
   if (sig[x++] != 0x00 || sig[x++] != 0x01) {
      return CRYPT_OK;
   }

   /* now follows (modulus_bytelen - 3 - derlen - msghashlen) 0xFF bytes */
   for (y = 0; y < (modulus_bytelen - 3 - derlen - msghashlen); y++) {
     if (sig[x++] != 0xFF) {
        return CRYPT_OK;
     }
   }

   if (sig[x++] != 0x00) {
      return CRYPT_OK;
   }

   for (y = 0; y < derlen; y++) {
      if (sig[x++] != hash_descriptor[hash_idx].DER[y]) {
         return CRYPT_OK;
      }
   }

   if (memcmp(msghash, sig+x, msghashlen) == 0) {
      *res = 1;
   }
   return CRYPT_OK;
}

#endif 

--- NEW FILE: pkcs_1_pss_decode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_pss_decode.c
  PKCS #1 PSS Signature Padding, Tom St Denis 
*/

#ifdef PKCS_1

/**
   PKCS #1 v2.00 PSS decode
   @param  msghash         The hash to verify
   @param  msghashlen      The length of the hash (octets)
   @param  sig             The signature data (encoded data)
   @param  siglen          The length of the signature data (octets)
   @param  saltlen         The length of the salt used (octets)
   @param  hash_idx        The index of the hash desired
   @param  modulus_bitlen  The bit length of the RSA modulus
   @param  res             [out] The result of the comparison, 1==valid, 0==invalid
   @return CRYPT_OK if successful (even if the comparison failed)
*/
int pkcs_1_pss_decode(const unsigned char *msghash, unsigned long msghashlen,
                      const unsigned char *sig,     unsigned long siglen,
                            unsigned long saltlen,  int           hash_idx,
                            unsigned long modulus_bitlen, int    *res)
{
   unsigned char *DB, *mask, *salt, *hash;
   unsigned long x, y, hLen, modulus_len;
   int           err;
   hash_state    md;

   LTC_ARGCHK(msghash != NULL);
   LTC_ARGCHK(res     != NULL);

   /* default to invalid */
   *res = 0;

   /* ensure hash is valid */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
      return err;
   }

   hLen        = hash_descriptor[hash_idx].hashsize;
   modulus_len = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);

   /* check sizes */
   if ((saltlen > modulus_len) || 
       (modulus_len < hLen + saltlen + 2) || (siglen != modulus_len)) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* allocate ram for DB/mask/salt/hash of size modulus_len */
   DB   = XMALLOC(modulus_len);
   mask = XMALLOC(modulus_len);
   salt = XMALLOC(modulus_len);
   hash = XMALLOC(modulus_len);
   if (DB == NULL || mask == NULL || salt == NULL || hash == NULL) {
      if (DB != NULL) {
         XFREE(DB);
      }
      if (mask != NULL) {
         XFREE(mask);
      }
      if (salt != NULL) {
         XFREE(salt);
      }
      if (hash != NULL) {
         XFREE(hash);
      }
      return CRYPT_MEM;
   }

   /* ensure the 0xBC byte */
   if (sig[siglen-1] != 0xBC) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* copy out the DB */
   for (x = 0; x < modulus_len - hLen - 1; x++) {
      DB[x] = sig[x];
   }

   /* copy out the hash */
   for (y = 0; y < hLen; y++) {
      hash[y] = sig[x++];
   }

   /* check the MSB */
   if ((sig[0] & ~(0xFF >> ((modulus_len<<3) - (modulus_bitlen-1)))) != 0) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* generate mask of length modulus_len - hLen - 1 from hash */
   if ((err = pkcs_1_mgf1(hash, hLen, hash_idx, mask, modulus_len - hLen - 1)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* xor against DB */
   for (y = 0; y < (modulus_len - hLen - 1); y++) {
      DB[y] ^= mask[y];
   }
   
   /* now clear the first byte [make sure smaller than modulus] */
   DB[0] &= 0xFF >> ((modulus_len<<3) - (modulus_bitlen-1));

   /* DB = PS || 0x01 || salt, PS == modulus_len - saltlen - hLen - 2 zero bytes */

   /* check for zeroes and 0x01 */
   for (x = 0; x < modulus_len - saltlen - hLen - 2; x++) {
       if (DB[x] != 0x00) {
          err = CRYPT_OK;
          goto LBL_ERR;
       }
   }

   /* check for the 0x01 */
   if (DB[x++] != 0x01) {
      err = CRYPT_OK;
      goto LBL_ERR;
   }

   /* M = (eight) 0x00 || msghash || salt, mask = H(M) */
   if ((err = hash_descriptor[hash_idx].init(&md)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   zeromem(mask, 8);
   if ((err = hash_descriptor[hash_idx].process(&md, mask, 8)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].process(&md, msghash, msghashlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].process(&md, DB+x, saltlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   if ((err = hash_descriptor[hash_idx].done(&md, mask)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* mask == hash means valid signature */
   if (memcmp(mask, hash, hLen) == 0) {
      *res = 1;
   }

   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(DB,   modulus_len);   
   zeromem(mask, modulus_len);   
   zeromem(salt, modulus_len);   
   zeromem(hash, modulus_len);   
#endif

   XFREE(hash);
   XFREE(salt);
   XFREE(mask);
   XFREE(DB);

   return err;
}

#endif /* PKCS_1 */

--- NEW FILE: pkcs_1_oaep_encode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/**
  @file pkcs_1_oaep_encode.c
  OAEP Padding for PKCS #1, Tom St Denis 
*/

#ifdef PKCS_1

/**
  PKCS #1 v2.00 OAEP encode
  @param msg             The data to encode
  @param msglen          The length of the data to encode (octets)
  @param lparam          A session or system parameter (can be NULL)
  @param lparamlen       The length of the lparam data
  @param modulus_bitlen  The bit length of the RSA modulus
  @param prng            An active PRNG state
  @param prng_idx        The index of the PRNG desired
  @param hash_idx        The index of the hash desired
  @param out             [out] The destination for the encoded data
  @param outlen          [in/out] The max size and resulting size of the encoded data
  @return CRYPT_OK if successful
*/
int pkcs_1_oaep_encode(const unsigned char *msg,    unsigned long msglen,
                       const unsigned char *lparam, unsigned long lparamlen,
                             unsigned long modulus_bitlen, prng_state *prng,
                             int           prng_idx,         int  hash_idx,
                             unsigned char *out,    unsigned long *outlen)
{
   unsigned char *DB, *seed, *mask;
   unsigned long hLen, x, y, modulus_len;
   int           err;

   LTC_ARGCHK(msg    != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);

   /* test valid hash */
   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { 
      return err;
   }

   /* valid prng */
   if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
      return err;
   }

   hLen        = hash_descriptor[hash_idx].hashsize;
   modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);

   /* test message size */
   if ((2*hLen >= (modulus_len - 2)) || (msglen > (modulus_len - 2*hLen - 2))) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* allocate ram for DB/mask/salt of size modulus_len */
   DB   = XMALLOC(modulus_len);
   mask = XMALLOC(modulus_len);
   seed = XMALLOC(modulus_len);
   if (DB == NULL || mask == NULL || seed == NULL) {
      if (DB != NULL) {
         XFREE(DB);
      }
      if (mask != NULL) {
         XFREE(mask);
      }
      if (seed != NULL) {
         XFREE(seed);
      }
      return CRYPT_MEM;
   }

   /* get lhash */
   /* DB == lhash || PS || 0x01 || M, PS == k - mlen - 2hlen - 2 zeroes */
   x = modulus_len;
   if (lparam != NULL) {
      if ((err = hash_memory(hash_idx, lparam, lparamlen, DB, &x)) != CRYPT_OK) {
         goto LBL_ERR;
      }
   } else {
      /* can't pass hash_memory a NULL so use DB with zero length */
      if ((err = hash_memory(hash_idx, DB, 0, DB, &x)) != CRYPT_OK) {
         goto LBL_ERR;
      }
   }

   /* append PS then 0x01 (to lhash)  */
   x = hLen;
   y = modulus_len - msglen - 2*hLen - 2;
   while (y--) {
      DB[x++] = 0x00;
   }
   DB[x++] = 0x01;

   /* message */
   y = msglen;
   while (y--) {
     DB[x++] = *msg++;
   }

   /* now choose a random seed */
   if (prng_descriptor[prng_idx].read(seed, hLen, prng) != hLen) {
      err = CRYPT_ERROR_READPRNG;
      goto LBL_ERR;
   }

   /* compute MGF1 of seed (k - hlen - 1) */
   if ((err = pkcs_1_mgf1(seed, hLen, hash_idx, mask, modulus_len - hLen - 1)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* xor against DB */
   for (y = 0; y < (modulus_len - hLen - 1); y++) {
       DB[y] ^= mask[y]; 
   }

   /* compute MGF1 of maskedDB (hLen) */ 
   if ((err = pkcs_1_mgf1(DB, modulus_len - hLen - 1, hash_idx, mask, hLen)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   /* XOR against seed */
   for (y = 0; y < hLen; y++) {
      seed[y] ^= mask[y];
   }

   /* create string of length modulus_len */
   if (*outlen < modulus_len) {
      err = CRYPT_BUFFER_OVERFLOW;
      goto LBL_ERR;
   }

   /* start output which is 0x00 || maskedSeed || maskedDB */
   x = 0;
   out[x++] = 0x00;
   for (y = 0; y < hLen; y++) {
      out[x++] = seed[y];
   }
   for (y = 0; y < modulus_len - hLen - 1; y++) {
      out[x++] = DB[y];
   }
   *outlen = x;
    
   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(DB,   modulus_len);
   zeromem(seed, modulus_len);
   zeromem(mask, modulus_len);
#endif

   XFREE(seed);
   XFREE(mask);
   XFREE(DB);

   return err;
}

#endif /* PKCS_1 */


--- NEW FILE: pkcs_1_v15_es_encode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_v15_es_encode.c
  v1.5 Encryption Padding for PKCS #1, Tom St Denis 
*/

#ifdef PKCS_1

/**
  PKCS #1 v1.5 Encryption Padding
  @param msg            The data to encode
  @param msglen         The length of the data (octets)
  @param modulus_bitlen The bit length of the RSA modulus
  @param prng           An active PRNG
  @param prng_idx       The index of the PRNG desired
  @param out            [out] The destination of the padding
  @param outlen         [in/out] The max size and resulting size of the padding
  @return CRYPT_OK if successful
*/
int pkcs_1_v15_es_encode(const unsigned char *msg,    unsigned long msglen,
                               unsigned long  modulus_bitlen, 
                               prng_state    *prng,   int           prng_idx,
                               unsigned char *out,    unsigned long *outlen)
{ 
   unsigned long modulus_bytelen, x, y;

   LTC_ARGCHK(msg    != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);

   /* get modulus len */
   modulus_bytelen = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);
   if (modulus_bytelen < 12) {
      return CRYPT_INVALID_ARG;
   }

   /* verify length */
   if (msglen > (modulus_bytelen - 11) || *outlen < modulus_bytelen) {
      return CRYPT_PK_INVALID_SIZE;
   }

   /* 0x00 0x02 PS 0x00 M */
   x = 0;
   out[x++] = 0x00;
   out[x++] = 0x02;
   y = modulus_bytelen - msglen - 3;
   if (prng_descriptor[prng_idx].read(out+x, y, prng) != y) {
      return CRYPT_ERROR_READPRNG;
   }
   x += y;
   out[x++] = 0x00;
   XMEMCPY(out+x, msg, msglen);
   *outlen = modulus_bytelen;

   return CRYPT_OK;
}

#endif /* PKCS_1 */

--- NEW FILE: pkcs_1_v15_sa_encode.c ---
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tom...@gm..., http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
  @file pkcs_1_v15_sa_encode.c
  PKCS #1 v1.5 Signature Padding, Tom St Denis 
*/

#ifdef PKCS_1

/**
  Perform PKCS #1 v1.5 Signature Padding
  @param msghash         The hash you wish to incorporate in the padding
  @param msghashlen      The length of the hash
  @param hash_idx        The index of the hash used
  @param modulus_bitlen  The length of the RSA modulus that will sign this (bits)
  @param out             [out] Where to store the padded data
  @param outlen          [in/out] Max size and resulting size of the padded data
  @return CRYPT_OK if successful
*/
int pkcs_1_v15_sa_encode(const unsigned char *msghash,  unsigned long msghashlen,
                               int            hash_idx, unsigned long modulus_bitlen,
                               unsigned char *out,      unsigned long *outlen)
{
  unsigned long derlen, modulus_bytelen, x, y;
  int err;

  LTC_ARGCHK(msghash != NULL)
  LTC_ARGCHK(out     != NULL);
  LTC_ARGCHK(outlen  != NULL);

  if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
     return err;
  }

  /* hack, to detect any hash without a DER OID */
  if (hash_descriptor[hash_idx].DERlen == 0) {
     return CRYPT_INVALID_ARG; 
  }

  /* get modulus len */
  modulus_bytelen = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);

  /* get der len ok?  Forgive my lame German accent.... */
  derlen = hash_descriptor[hash_idx].DERlen;

  /* valid sizes? */
  if (msghashlen + 3 + derlen > modulus_bytelen) {
     return CRYPT_PK_INVALID_SIZE;
  }

  if (*outlen < modulus_bytelen) {
     return CRYPT_BUFFER_OVERFLOW;
  }

  /* packet is 0x00 0x01 PS 0x00 T, where PS == 0xFF repeated modulus_bytelen - 3 - derlen - msghashlen times, T == DER || hash */
  x = 0;
  out[x++] = 0x00;
  out[x++] = 0x01;
  for (y = 0; y < (modulus_bytelen - 3 - derlen - msghashlen); y++) {
     out[x++] = 0xFF;
  }
  out[x++] = 0x00;
  for (y = 0; y < derlen; y++) {
     out[x++] = hash_descriptor[hash_idx].DER[y];
  }
  for (y = 0; y < msghashlen; y++) {
     out[x++] = msghash[y];
  }

  *outlen = modulus_bytelen;
  return CRYPT_OK;
}

#endif /* PKCS_1 */