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Diffstat (limited to 'src/util/rsa.c')
| -rw-r--r-- | src/util/rsa.c | 916 |
1 files changed, 0 insertions, 916 deletions
diff --git a/src/util/rsa.c b/src/util/rsa.c deleted file mode 100644 index 866aeb044..000000000 --- a/src/util/rsa.c +++ /dev/null @@ -1,916 +0,0 @@ -/* NOTE: this is obsolete logic, we should migrate to the - GNUNET_CRYPTO_rsa-API as soon as possible */ - -/* - This file is part of TALER - (C) 2014 Christian Grothoff (and other contributing authors) - - TALER is free software; you can redistribute it and/or modify it under the - terms of the GNU General Public License as published by the Free Software - Foundation; either version 3, or (at your option) any later version. - - TALER is distributed in the hope that it will be useful, but WITHOUT ANY - WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR - A PARTICULAR PURPOSE. See the GNU General Public License for more details. - - You should have received a copy of the GNU General Public License along with - TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/> -*/ - -/** - * @file util/rsa.c - * @brief RSA key management utilities. Most of the code here is taken from - * gnunet-0.9.5a - * @author Sree Harsha Totakura <sreeharsha@totakura.in> - * - * Authors of the gnunet code: - * Christian Grothoff - * Krista Bennett - * Gerd Knorr <kraxel@bytesex.org> - * Ioana Patrascu - * Tzvetan Horozov - */ - -#include "platform.h" -#include "gcrypt.h" -#include "gnunet/gnunet_util_lib.h" -#include "taler_rsa.h" - - - -#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) - -#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall) - -#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename) - -/** - * Log an error message at log-level 'level' that indicates - * a failure of the command 'cmd' with the message given - * by gcry_strerror(rc). - */ -#define LOG_GCRY(level, cmd, rc) do { LOG(level, _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, gcry_strerror(rc)); } while(0) - -/** - * Shorthand to cleanup non null mpi data types - */ -#define mpi_release_non_null(mpi) \ - if (NULL != mpi) gcry_mpi_release (mpi); - -/** - * The private information of an RSA key pair. - * NOTE: this must match the definition in crypto_ksk.c and gnunet-rsa.c! - */ -struct TALER_RSA_PrivateKey -{ - /** - * Libgcrypt S-expression for the ECC key. - */ - gcry_sexp_t sexp; -}; - - -/** - * Extract values from an S-expression. - * - * @param array where to store the result(s) - * @param sexp S-expression to parse - * @param topname top-level name in the S-expression that is of interest - * @param elems names of the elements to extract - * @return 0 on success - */ -static int -key_from_sexp (gcry_mpi_t * array, gcry_sexp_t sexp, const char *topname, - const char *elems) -{ - gcry_sexp_t list; - gcry_sexp_t l2; - const char *s; - unsigned int i; - unsigned int idx; - - if (! (list = gcry_sexp_find_token (sexp, topname, 0))) - return 1; - l2 = gcry_sexp_cadr (list); - gcry_sexp_release (list); - list = l2; - if (! list) - return 2; - idx = 0; - for (s = elems; *s; s++, idx++) - { - if (! (l2 = gcry_sexp_find_token (list, s, 1))) - { - for (i = 0; i < idx; i++) - { - gcry_free (array[i]); - array[i] = NULL; - } - gcry_sexp_release (list); - return 3; /* required parameter not found */ - } - array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG); - gcry_sexp_release (l2); - if (! array[idx]) - { - for (i = 0; i < idx; i++) - { - gcry_free (array[i]); - array[i] = NULL; - } - gcry_sexp_release (list); - return 4; /* required parameter is invalid */ - } - } - gcry_sexp_release (list); - return 0; -} - -/** - * If target != size, move target bytes to the - * end of the size-sized buffer and zero out the - * first target-size bytes. - * - * @param buf original buffer - * @param size number of bytes in the buffer - * @param target target size of the buffer - */ -static void -adjust (unsigned char *buf, size_t size, size_t target) -{ - if (size < target) - { - memmove (&buf[target - size], buf, size); - memset (buf, 0, target - size); - } -} - - -/** - * Create a new private key. Caller must free return value. - * - * @return fresh private key - */ -struct TALER_RSA_PrivateKey * -TALER_RSA_key_create () -{ - struct TALER_RSA_PrivateKey *ret; - gcry_sexp_t s_key; - gcry_sexp_t s_keyparam; - - GNUNET_assert (0 == - gcry_sexp_build (&s_keyparam, NULL, - "(genkey(rsa(nbits %d)(rsa-use-e 3:257)))", - 2048)); - GNUNET_assert (0 == gcry_pk_genkey (&s_key, s_keyparam)); - gcry_sexp_release (s_keyparam); -#if EXTRA_CHECKS - GNUNET_assert (0 == gcry_pk_testkey (s_key)); -#endif - ret = GNUNET_malloc (sizeof (struct TALER_RSA_PrivateKey)); - ret->sexp = s_key; - return ret; -} - - -/** - * Free memory occupied by the private key. - * - * @param key pointer to the memory to free - */ -void -TALER_RSA_key_free (struct TALER_RSA_PrivateKey *key) -{ - gcry_sexp_release (key->sexp); - GNUNET_free (key); -} - - -/** - * Encode the private key in a format suitable for - * storing it into a file. - * @return encoding of the private key - */ -struct TALER_RSA_PrivateKeyBinaryEncoded * -TALER_RSA_encode_key (const struct TALER_RSA_PrivateKey *hostkey) -{ - struct TALER_RSA_PrivateKeyBinaryEncoded *retval; - gcry_mpi_t pkv[6]; - void *pbu[6]; - size_t sizes[6]; - int rc; - int i; - int size; - -#if EXTRA_CHECKS - if (gcry_pk_testkey (hostkey->sexp)) - { - GNUNET_break (0); - return NULL; - } -#endif - - memset (pkv, 0, sizeof (gcry_mpi_t) * 6); - rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "nedpqu"); - if (rc) - rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "nedpqu"); - if (rc) - rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "nedpq"); - if (rc) - rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "nedpq"); - if (rc) - rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "ned"); - if (rc) - rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "ned"); - GNUNET_assert (0 == rc); - size = sizeof (struct TALER_RSA_PrivateKeyBinaryEncoded); - for (i = 0; i < 6; i++) - { - if (NULL != pkv[i]) - { - GNUNET_assert (0 == - gcry_mpi_aprint (GCRYMPI_FMT_USG, - (unsigned char **) &pbu[i], &sizes[i], - pkv[i])); - size += sizes[i]; - } - else - { - pbu[i] = NULL; - sizes[i] = 0; - } - } - GNUNET_assert (size < 65536); - retval = GNUNET_malloc (size); - retval->len = htons (size); - i = 0; - retval->sizen = htons (sizes[0]); - memcpy (&((char *) (&retval[1]))[i], pbu[0], sizes[0]); - i += sizes[0]; - retval->sizee = htons (sizes[1]); - memcpy (&((char *) (&retval[1]))[i], pbu[1], sizes[1]); - i += sizes[1]; - retval->sized = htons (sizes[2]); - memcpy (&((char *) (&retval[1]))[i], pbu[2], sizes[2]); - i += sizes[2]; - /* swap p and q! */ - retval->sizep = htons (sizes[4]); - memcpy (&((char *) (&retval[1]))[i], pbu[4], sizes[4]); - i += sizes[4]; - retval->sizeq = htons (sizes[3]); - memcpy (&((char *) (&retval[1]))[i], pbu[3], sizes[3]); - i += sizes[3]; - retval->sizedmp1 = htons (0); - retval->sizedmq1 = htons (0); - memcpy (&((char *) (&retval[1]))[i], pbu[5], sizes[5]); - for (i = 0; i < 6; i++) - { - if (pkv[i] != NULL) - gcry_mpi_release (pkv[i]); - if (pbu[i] != NULL) - free (pbu[i]); - } - return retval; -} - - -/** - * Extract the public key of the given private key. - * - * @param priv the private key - * @param pub where to write the public key - */ -void -TALER_RSA_key_get_public (const struct TALER_RSA_PrivateKey *priv, - struct TALER_RSA_PublicKeyBinaryEncoded *pub) -{ - gcry_mpi_t skey[2]; - size_t size; - int rc; - - rc = key_from_sexp (skey, priv->sexp, "public-key", "ne"); - if (0 != rc) - rc = key_from_sexp (skey, priv->sexp, "private-key", "ne"); - if (0 != rc) - rc = key_from_sexp (skey, priv->sexp, "rsa", "ne"); - GNUNET_assert (0 == rc); - pub->len = - htons (sizeof (struct TALER_RSA_PublicKeyBinaryEncoded) - - sizeof (pub->padding)); - pub->sizen = htons (TALER_RSA_DATA_ENCODING_LENGTH); - pub->padding = 0; - size = TALER_RSA_DATA_ENCODING_LENGTH; - GNUNET_assert (0 == - gcry_mpi_print (GCRYMPI_FMT_USG, &pub->key[0], size, &size, - skey[0])); - adjust (&pub->key[0], size, TALER_RSA_DATA_ENCODING_LENGTH); - size = TALER_RSA_KEY_LENGTH - TALER_RSA_DATA_ENCODING_LENGTH; - GNUNET_assert (0 == - gcry_mpi_print (GCRYMPI_FMT_USG, - &pub->key - [TALER_RSA_DATA_ENCODING_LENGTH], size, - &size, skey[1])); - adjust (&pub->key[TALER_RSA_DATA_ENCODING_LENGTH], size, - TALER_RSA_KEY_LENGTH - - TALER_RSA_DATA_ENCODING_LENGTH); - gcry_mpi_release (skey[0]); - gcry_mpi_release (skey[1]); -} - - -/** - * Decode the private key from the data-format back - * to the "normal", internal format. - * - * @param buf the buffer where the private key data is stored - * @param len the length of the data in 'buffer' - * @return NULL on error - */ -struct TALER_RSA_PrivateKey * -TALER_RSA_decode_key (const char *buf, uint16_t len) -{ - struct TALER_RSA_PrivateKey *ret; - const struct TALER_RSA_PrivateKeyBinaryEncoded *encoding = - (const struct TALER_RSA_PrivateKeyBinaryEncoded *) buf; - gcry_sexp_t res; - gcry_mpi_t n; - gcry_mpi_t e; - gcry_mpi_t d; - gcry_mpi_t p; - gcry_mpi_t q; - gcry_mpi_t u; - int rc; - size_t size; - size_t pos; - uint16_t enc_len; - size_t erroff; - - enc_len = ntohs (encoding->len); - if (len != enc_len) - return NULL; - - pos = 0; - size = ntohs (encoding->sizen); - rc = gcry_mpi_scan (&n, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - pos += ntohs (encoding->sizen); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - return NULL; - } - size = ntohs (encoding->sizee); - rc = gcry_mpi_scan (&e, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - pos += ntohs (encoding->sizee); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - return NULL; - } - size = ntohs (encoding->sized); - rc = gcry_mpi_scan (&d, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - pos += ntohs (encoding->sized); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - gcry_mpi_release (e); - return NULL; - } - /* swap p and q! */ - size = ntohs (encoding->sizep); - if (size > 0) - { - rc = gcry_mpi_scan (&q, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - pos += ntohs (encoding->sizep); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - gcry_mpi_release (e); - gcry_mpi_release (d); - return NULL; - } - } - else - q = NULL; - size = ntohs (encoding->sizeq); - if (size > 0) - { - rc = gcry_mpi_scan (&p, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - pos += ntohs (encoding->sizeq); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - gcry_mpi_release (e); - gcry_mpi_release (d); - if (NULL != q) - gcry_mpi_release (q); - return NULL; - } - } - else - p = NULL; - pos += ntohs (encoding->sizedmp1); - pos += ntohs (encoding->sizedmq1); - size = - ntohs (encoding->len) - sizeof (struct TALER_RSA_PrivateKeyBinaryEncoded) - pos; - if (size > 0) - { - rc = gcry_mpi_scan (&u, GCRYMPI_FMT_USG, - &((const unsigned char *) (&encoding[1]))[pos], size, - &size); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - gcry_mpi_release (e); - gcry_mpi_release (d); - if (NULL != p) - gcry_mpi_release (p); - if (NULL != q) - gcry_mpi_release (q); - return NULL; - } - } - else - u = NULL; - - if ((NULL != p) && (NULL != q) && (NULL != u)) - { - rc = gcry_sexp_build (&res, &erroff, - "(private-key(rsa(n %m)(e %m)(d %m)(p %m)(q %m)(u %m)))", - n, e, d, p, q, u); - } - else - { - if ((NULL != p) && (NULL != q)) - { - rc = gcry_sexp_build (&res, &erroff, - "(private-key(rsa(n %m)(e %m)(d %m)(p %m)(q %m)))", - n, e, d, p, q); - } - else - { - rc = gcry_sexp_build (&res, &erroff, - "(private-key(rsa(n %m)(e %m)(d %m)))", n, e, d); - } - } - gcry_mpi_release (n); - gcry_mpi_release (e); - gcry_mpi_release (d); - if (NULL != p) - gcry_mpi_release (p); - if (NULL != q) - gcry_mpi_release (q); - if (NULL != u) - gcry_mpi_release (u); - - if (0 != rc) - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); - if (0 != (rc = gcry_pk_testkey (res))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_pk_testkey", rc); - return NULL; - } - ret = GNUNET_malloc (sizeof (struct TALER_RSA_PrivateKey)); - ret->sexp = res; - return ret; -} - - -/** - * Convert a public key to a string. - * - * @param pub key to convert - * @return string representing 'pub' - */ -char * -TALER_RSA_public_key_to_string (const struct TALER_RSA_PublicKeyBinaryEncoded *pub) -{ - char *pubkeybuf; - size_t keylen = (sizeof (struct TALER_RSA_PublicKeyBinaryEncoded)) * 8; - char *end; - - if (keylen % 5 > 0) - keylen += 5 - keylen % 5; - keylen /= 5; - pubkeybuf = GNUNET_malloc (keylen + 1); - end = GNUNET_STRINGS_data_to_string ((unsigned char *) pub, - sizeof (struct TALER_RSA_PublicKeyBinaryEncoded), - pubkeybuf, - keylen); - if (NULL == end) - { - GNUNET_free (pubkeybuf); - return NULL; - } - *end = '\0'; - return pubkeybuf; -} - - -/** - * Convert a string representing a public key to a public key. - * - * @param enc encoded public key - * @param enclen number of bytes in enc (without 0-terminator) - * @param pub where to store the public key - * @return GNUNET_OK on success - */ -int -TALER_RSA_public_key_from_string (const char *enc, - size_t enclen, - struct TALER_RSA_PublicKeyBinaryEncoded *pub) -{ - size_t keylen = (sizeof (struct TALER_RSA_PublicKeyBinaryEncoded)) * 8; - - if (keylen % 5 > 0) - keylen += 5 - keylen % 5; - keylen /= 5; - if (enclen != keylen) - return GNUNET_SYSERR; - - if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen, - (unsigned char*) pub, - sizeof (struct TALER_RSA_PublicKeyBinaryEncoded))) - return GNUNET_SYSERR; - if ( (ntohs (pub->len) != sizeof (struct TALER_RSA_PublicKeyBinaryEncoded)) || - (ntohs (pub->padding) != 0) || - (ntohs (pub->sizen) != TALER_RSA_DATA_ENCODING_LENGTH) ) - return GNUNET_SYSERR; - return GNUNET_OK; -} - - -/** - * Convert the data specified in the given purpose argument to an - * S-expression suitable for signature operations. - * - * @param ptr pointer to the data to convert - * @param size the size of the data - * @return converted s-expression - */ -static gcry_sexp_t -data_to_sexp (const void *ptr, size_t size) -{ - gcry_mpi_t value; - gcry_sexp_t data; - - value = NULL; - data = NULL; - GNUNET_assert (0 == gcry_mpi_scan (&value, GCRYMPI_FMT_USG, ptr, size, NULL)); - GNUNET_assert (0 == gcry_sexp_build (&data, NULL, "(data (flags raw) (value %M))", value)); - gcry_mpi_release (value); - return data; -} - - -/** - * Sign the given message. The size of the message should be less than - * TALER_RSA_DATA_ENCODING_LENGTH (256) bytes. - * - * @param key private key to use for the signing - * @param msg the message - * @param size the size of the message - * @param sig where to write the signature - * @return GNUNET_SYSERR on error, GNUNET_OK on success - */ -int -TALER_RSA_sign (const struct TALER_RSA_PrivateKey *key, - const void *msg, - size_t size, - struct TALER_RSA_Signature *sig) -{ - gcry_sexp_t result; - gcry_sexp_t data; - size_t ssize; - gcry_mpi_t rval; - - GNUNET_assert (size <= TALER_RSA_DATA_ENCODING_LENGTH); - if (size > TALER_RSA_DATA_ENCODING_LENGTH) - return GNUNET_SYSERR; - data = data_to_sexp (msg, size); - GNUNET_assert (0 == gcry_pk_sign (&result, data, key->sexp)); - gcry_sexp_release (data); - GNUNET_assert (0 == key_from_sexp (&rval, result, "rsa", "s")); - gcry_sexp_release (result); - ssize = sizeof (struct TALER_RSA_Signature); - GNUNET_assert (0 == - gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) sig, ssize, - &ssize, rval)); - gcry_mpi_release (rval); - adjust (sig->sig, ssize, sizeof (struct TALER_RSA_Signature)); - return GNUNET_OK; -} - - -/** - * Convert the given public key from the network format to the - * S-expression that can be used by libgcrypt. - * - * @param publicKey public key to decode - * @return NULL on error - */ -static gcry_sexp_t -decode_public_key (const struct TALER_RSA_PublicKeyBinaryEncoded *publicKey) -{ - gcry_sexp_t result; - gcry_mpi_t n; - gcry_mpi_t e; - size_t size; - size_t erroff; - int rc; - - if ((ntohs (publicKey->sizen) != TALER_RSA_DATA_ENCODING_LENGTH) || - (ntohs (publicKey->len) != - sizeof (struct TALER_RSA_PublicKeyBinaryEncoded) - - sizeof (publicKey->padding))) - { - GNUNET_break (0); - return NULL; - } - size = TALER_RSA_DATA_ENCODING_LENGTH; - if (0 != (rc = gcry_mpi_scan (&n, GCRYMPI_FMT_USG, &publicKey->key[0], size, &size))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - return NULL; - } - size = TALER_RSA_KEY_LENGTH - TALER_RSA_DATA_ENCODING_LENGTH; - if (0 != (rc = gcry_mpi_scan (&e, GCRYMPI_FMT_USG, - &publicKey->key[TALER_RSA_DATA_ENCODING_LENGTH], - size, &size))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - gcry_mpi_release (n); - return NULL; - } - rc = gcry_sexp_build (&result, &erroff, "(public-key(rsa(n %m)(e %m)))", n, - e); - gcry_mpi_release (n); - gcry_mpi_release (e); - if (0 != rc) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); /* erroff gives more info */ - return NULL; - } - return result; -} - - -/** - * Verify signature on the given message. The size of the message should be - * less than TALER_RSA_DATA_ENCODING_LENGTH (256) bytes. - * - * @param msg the message - * @param size the size of the message - * @param sig signature that is being validated - * @param publicKey public key of the signer - * @returns GNUNET_OK if ok, GNUNET_SYSERR if invalid - */ -int -TALER_RSA_verify (const void *msg, size_t size, - const struct TALER_RSA_Signature *sig, - const struct TALER_RSA_PublicKeyBinaryEncoded *publicKey) -{ - gcry_sexp_t data; - gcry_sexp_t sigdata; - size_t sig_size; - gcry_mpi_t val; - gcry_sexp_t psexp; - size_t erroff; - gcry_error_t rc; - - GNUNET_assert (size <= TALER_RSA_DATA_ENCODING_LENGTH); - if (size > TALER_RSA_DATA_ENCODING_LENGTH) - return GNUNET_SYSERR; - GNUNET_assert (0 == - gcry_mpi_scan (&val, GCRYMPI_FMT_USG, - (const unsigned char *) sig, - sizeof (struct TALER_RSA_Signature), - &sig_size)); - GNUNET_assert (sizeof (struct TALER_RSA_Signature) == sig_size); - GNUNET_assert (0 == - gcry_sexp_build (&sigdata, &erroff, "(sig-val(rsa(s %m)))", - val)); - gcry_mpi_release (val); - data = data_to_sexp (msg, size); - if (! (psexp = decode_public_key (publicKey))) - { - gcry_sexp_release (data); - gcry_sexp_release (sigdata); - return GNUNET_SYSERR; - } - rc = gcry_pk_verify (sigdata, data, psexp); - gcry_sexp_release (psexp); - gcry_sexp_release (data); - gcry_sexp_release (sigdata); - if (rc) - { - LOG (GNUNET_ERROR_TYPE_WARNING, - _("RSA signature verification failed at %s:%d: %s\n"), __FILE__, - __LINE__, gcry_strerror (rc)); - return GNUNET_SYSERR; - } - return GNUNET_OK; -} - -/** - * The blinding key is equal in length to the RSA modulus - */ -#define TALER_RSA_BLINDING_KEY_LEN TALER_RSA_DATA_ENCODING_LENGTH - -struct TALER_RSA_BlindingKey -{ - /** - * The blinding factor - */ - gcry_mpi_t r; -}; - -struct TALER_RSA_BlindingKey * -TALER_RSA_blinding_key_create () -{ - struct TALER_RSA_BlindingKey *blind; - - blind = GNUNET_new (struct TALER_RSA_BlindingKey); - blind->r = gcry_mpi_new (TALER_RSA_BLINDING_KEY_LEN * 8); - gcry_mpi_randomize (blind->r, TALER_RSA_BLINDING_KEY_LEN * 8, GCRY_STRONG_RANDOM); - return blind; -} - - -void -TALER_RSA_blinding_key_destroy (struct TALER_RSA_BlindingKey *bkey) -{ - gcry_mpi_release (bkey->r); - GNUNET_free (bkey); -} - - -struct TALER_RSA_BlindedSignaturePurpose * -TALER_RSA_message_blind (const void *msg, size_t size, - struct TALER_RSA_BlindingKey *bkey, - struct TALER_RSA_PublicKeyBinaryEncoded *pkey) -{ - struct TALER_RSA_BlindedSignaturePurpose *bsp; - gcry_sexp_t psexp; - gcry_mpi_t data; - gcry_mpi_t skey[2]; - gcry_mpi_t r_e; - gcry_mpi_t data_r_e; - size_t rsize; - gcry_error_t rc; - int ret; - - bsp = NULL; - psexp = NULL; - data = NULL; - skey[0] = skey[1] = NULL; - r_e = NULL; - data_r_e = NULL; - rsize = 0; - rc = 0; - ret = 0; - if (! (psexp = decode_public_key (pkey))) - return NULL; - ret = key_from_sexp (skey, psexp, "public-key", "ne"); - if (0 != ret) - ret = key_from_sexp (skey, psexp, "rsa", "ne"); - gcry_sexp_release (psexp); - psexp = NULL; - GNUNET_assert (0 == ret); - if (0 != (rc=gcry_mpi_scan (&data, GCRYMPI_FMT_USG, - (const unsigned char *) msg, size, &rsize))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_WARNING, "gcry_mpi_scan", rc); - goto cleanup; - } - r_e = gcry_mpi_new (0); - gcry_mpi_powm (r_e, bkey->r, - skey[1], /* e */ - skey[0]); /* n */ - - data_r_e = gcry_mpi_new (0); - gcry_mpi_mulm (data_r_e, data, r_e, skey[0]); - - bsp = GNUNET_new (struct TALER_RSA_BlindedSignaturePurpose); - rc = gcry_mpi_print (GCRYMPI_FMT_USG, - (unsigned char *) bsp, - sizeof (struct TALER_RSA_BlindedSignaturePurpose), - &rsize, - data_r_e); - GNUNET_assert (0 == rc); - adjust ((unsigned char *) bsp, rsize, - sizeof (struct TALER_RSA_BlindedSignaturePurpose)); - - cleanup: - if (NULL != psexp) gcry_sexp_release (psexp); - mpi_release_non_null (skey[0]); - mpi_release_non_null (skey[1]); - mpi_release_non_null (data); - mpi_release_non_null (r_e); - mpi_release_non_null (data_r_e); - return bsp; -} - - -int -TALER_RSA_unblind (struct TALER_RSA_Signature *sig, - struct TALER_RSA_BlindingKey *bkey, - struct TALER_RSA_PublicKeyBinaryEncoded *pkey) -{ - gcry_sexp_t psexp; - gcry_mpi_t skey; - gcry_mpi_t sigval; - gcry_mpi_t r_inv; - gcry_mpi_t ubsig; - size_t rsize; - gcry_error_t rc; - int ret; - - psexp = NULL; - skey = NULL; - sigval = NULL; - r_inv = NULL; - ubsig = NULL; - rsize = 0; - rc = 0; - ret = GNUNET_SYSERR; - if (! (psexp = decode_public_key (pkey))) - return GNUNET_SYSERR; - ret = key_from_sexp (&skey, psexp, "public-key", "n"); - if (0 != ret) - ret = key_from_sexp (&skey, psexp, "rsa", "n"); - gcry_sexp_release (psexp); - psexp = NULL; - if (0 != (rc = gcry_mpi_scan (&sigval, GCRYMPI_FMT_USG, - (const unsigned char *) sig, - sizeof (struct TALER_RSA_Signature), - &rsize))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); - goto cleanup; - } - r_inv = gcry_mpi_new (0); - GNUNET_assert (1 == gcry_mpi_invm (r_inv, bkey->r, skey)); /* n: skey */ - ubsig = gcry_mpi_new (0); - gcry_mpi_mulm (ubsig, sigval, r_inv, skey); - rc = gcry_mpi_print (GCRYMPI_FMT_USG, - (unsigned char *) sig, - sizeof (struct TALER_RSA_Signature), - &rsize, - ubsig); - GNUNET_assert (0 == rc); - adjust ((unsigned char *) sig, rsize, sizeof (struct TALER_RSA_Signature)); - ret = GNUNET_OK; - - cleanup: - if (NULL != psexp) gcry_sexp_release (psexp); - mpi_release_non_null (skey); - mpi_release_non_null (sigval); - mpi_release_non_null (r_inv); - mpi_release_non_null (ubsig); - return ret; -} - - -/** - * Encode a blinding key - * - * @param bkey the blinding key to encode - * @param bkey_enc where to store the encoded binary key - * @return #GNUNET_OK upon successful encoding; #GNUNET_SYSERR upon failure - */ -int -TALER_RSA_blinding_key_encode (struct TALER_RSA_BlindingKey *bkey, - struct TALER_RSA_BlindingKeyBinaryEncoded *bkey_enc) -{ - GNUNET_abort (); /* FIXME: not implemented */ -} - - -/** - * Decode a blinding key from its encoded form - * - * @param bkey_enc the encoded blinding key - * @return the decoded blinding key; NULL upon error - */ -struct TALER_RSA_BlindingKey * -TALER_RSA_blinding_key_decode (struct TALER_RSA_BlindingKeyBinaryEncoded *bkey_enc) -{ - GNUNET_abort (); /* FIXME: not implemented */ -} - -/* end of util/rsa.c */ |