diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | Makefile.in | 2 | ||||
| -rw-r--r-- | pkcs1-decrypt.c | 72 | ||||
| -rw-r--r-- | pkcs1.h | 6 | ||||
| -rw-r--r-- | rsa-decrypt.c | 44 |
5 files changed, 92 insertions, 39 deletions
@@ -1,3 +1,10 @@ +2012-04-09 Niels Möller <nisse@lysator.liu.se> + + * Makefile.in (hogweed_SOURCES): Added pkcs1-decrypt.c. + * rsa-decrypt.c (rsa_decrypt): Use pkcs1_decrypt. + * pkcs1-decrypt.c (pkcs1_decrypt): New file and function, + extracted from rsa_decrypt. + 2012-04-01 Niels Möller <nisse@lysator.liu.se> * salsa20.c (LE_SWAP32): Typo fix for big-endian case. diff --git a/Makefile.in b/Makefile.in index 4d3c89a6..cc36a672 100644 --- a/Makefile.in +++ b/Makefile.in @@ -99,7 +99,7 @@ hogweed_SOURCES = sexp.c sexp-format.c \ bignum.c bignum-next-prime.c \ bignum-random.c bignum-random-prime.c \ sexp2bignum.c \ - pkcs1.c pkcs1-rsa-md5.c pkcs1-rsa-sha1.c \ + pkcs1.c pkcs1-decrypt.c pkcs1-rsa-md5.c pkcs1-rsa-sha1.c \ pkcs1-rsa-sha256.c pkcs1-rsa-sha512.c \ rsa.c rsa-sign.c rsa-verify.c \ rsa-md5-sign.c rsa-md5-verify.c \ diff --git a/pkcs1-decrypt.c b/pkcs1-decrypt.c new file mode 100644 index 00000000..bd21f88b --- /dev/null +++ b/pkcs1-decrypt.c @@ -0,0 +1,72 @@ +/* pkcs1-decrypt.c + * + */ + +/* nettle, low-level cryptographics library + * + * Copyright (C) 2001, 2012 Niels Möller + * + * The nettle library is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 of the License, or (at your + * option) any later version. + * + * The nettle library 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 Lesser General Public + * License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the nettle library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +#if HAVE_CONFIG_H +# include "config.h" +#endif + +#include <string.h> + +#include "pkcs1.h" + +#include "bignum.h" +#include "nettle-internal.h" + +int +pkcs1_decrypt (unsigned key_size, + const mpz_t m, + unsigned *length, uint8_t *message) +{ + TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_BITS / 8); + uint8_t *terminator; + unsigned padding; + unsigned message_length; + + TMP_ALLOC(em, key_size); + nettle_mpz_get_str_256(key_size, em, m); + + /* Check format */ + if (em[0] || em[1] != 2) + return 0; + + terminator = memchr(em + 2, 0, key_size - 2); + + if (!terminator) + return 0; + + padding = terminator - (em + 2); + if (padding < 8) + return 0; + + message_length = key_size - 3 - padding; + + if (*length < message_length) + return 0; + + memcpy(message, terminator + 1, message_length); + *length = message_length; + + return 1; +} + @@ -43,6 +43,7 @@ extern "C" { #define pkcs1_rsa_sha256_encode_digest nettle_pkcs1_rsa_sha256_encode_digest #define pkcs1_rsa_sha512_encode nettle_pkcs1_rsa_sha512_encode #define pkcs1_rsa_sha512_encode_digest nettle_pkcs1_rsa_sha512_encode_digest +#define pkcs1_decrypt nettle_pkcs1_decrypt struct md5_ctx; struct sha1_ctx; @@ -57,6 +58,11 @@ pkcs1_signature_prefix(unsigned size, unsigned digest_size); int +pkcs1_decrypt (unsigned key_size, + const mpz_t m, + unsigned *length, uint8_t *message); + +int pkcs1_rsa_md5_encode(mpz_t m, unsigned length, struct md5_ctx *hash); int diff --git a/rsa-decrypt.c b/rsa-decrypt.c index fe6de23e..cde0d3ce 100644 --- a/rsa-decrypt.c +++ b/rsa-decrypt.c @@ -1,11 +1,11 @@ -/* rsa_decrypt.c +/* rsa-decrypt.c * * The RSA publickey algorithm. PKCS#1 encryption. */ /* nettle, low-level cryptographics library * - * Copyright (C) 2001 Niels Möller + * Copyright (C) 2001, 2012 Niels Möller * * The nettle library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by @@ -27,54 +27,22 @@ # include "config.h" #endif -#include <assert.h> -#include <stdlib.h> -#include <string.h> - #include "rsa.h" -#include "bignum.h" -#include "nettle-internal.h" +#include "pkcs1.h" int rsa_decrypt(const struct rsa_private_key *key, unsigned *length, uint8_t *message, const mpz_t gibberish) { - TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_BITS / 8); - uint8_t *terminator; - unsigned padding; - unsigned message_length; - mpz_t m; + int res; mpz_init(m); rsa_compute_root(key, m, gibberish); - TMP_ALLOC(em, key->size); - nettle_mpz_get_str_256(key->size, em, m); + res = pkcs1_decrypt (key->size, m, length, message); mpz_clear(m); - - /* Check format */ - if (em[0] || em[1] != 2) - return 0; - - terminator = memchr(em + 2, 0, key->size - 2); - - if (!terminator) - return 0; - - padding = terminator - (em + 2); - if (padding < 8) - return 0; - - message_length = key->size - 3 - padding; - - if (*length < message_length) - return 0; - - memcpy(message, terminator + 1, message_length); - *length = message_length; - - return 1; + return res; } |