diff options
Diffstat (limited to 'src/libstrongswan/crypto/rsa/rsa_public_key.c')
| -rw-r--r-- | src/libstrongswan/crypto/rsa/rsa_public_key.c | 117 |
1 files changed, 93 insertions, 24 deletions
diff --git a/src/libstrongswan/crypto/rsa/rsa_public_key.c b/src/libstrongswan/crypto/rsa/rsa_public_key.c index 6f2158d2b..10af0527e 100644 --- a/src/libstrongswan/crypto/rsa/rsa_public_key.c +++ b/src/libstrongswan/crypto/rsa/rsa_public_key.c @@ -6,8 +6,10 @@ */ /* - * Copyright (C) 2005-2006 Martin Willi * Copyright (C) 2005 Jan Hutter + * Copyright (C) 2005-2006 Martin Willi + * Copyright (C) 2007-2008 Andreas Steffen + * * Hochschule fuer Technik Rapperswil * * This program is free software; you can redistribute it and/or modify it @@ -20,7 +22,7 @@ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * - * RCSID $Id: rsa_public_key.c 3303 2007-10-12 22:49:39Z andreas $ + * RCSID $Id: rsa_public_key.c 3428 2008-01-27 20:58:52Z andreas $ */ #include <gmp.h> @@ -32,6 +34,7 @@ #include "rsa_public_key.h" #include <debug.h> +#include <utils/randomizer.h> #include <crypto/hashers/hasher.h> #include <asn1/asn1.h> #include <asn1/pem.h> @@ -110,8 +113,6 @@ struct private_rsa_public_key_t { chunk_t (*rsavp1) (const private_rsa_public_key_t *this, chunk_t data); }; -private_rsa_public_key_t *rsa_public_key_create_empty(void); - /** * Implementation of private_rsa_public_key_t.rsaep and private_rsa_public_key_t.rsavp1 */ @@ -137,6 +138,55 @@ static chunk_t rsaep(const private_rsa_public_key_t *this, chunk_t data) } /** + * Implementation of rsa_public_key_t.eme_pkcs1_encrypt. + */ +static status_t pkcs1_encrypt(private_rsa_public_key_t *this, + chunk_t in, chunk_t *out) +{ + chunk_t em; + u_char *pos; + int padding = this->k - in.len - 3; + + if (padding < 8) + { + DBG1("rsa padding of %d bytes is too small", padding); + return FAILED; + } + em.len = this->k; + em.ptr = pos = malloc(em.len); + + /* add padding according to PKCS#1 7.2.1 1.+2. */ + *pos++ = 0x00; + *pos++ = 0x02; + + /* pad with pseudo random bytes unequal to zero */ + { + randomizer_t *randomizer = randomizer_create(); + + /* pad with pseudo random bytes unequal to zero */ + while (padding--) + { + randomizer->get_pseudo_random_bytes(randomizer, 1, pos); + while (!*pos) + { + randomizer->get_pseudo_random_bytes(randomizer, 1, pos); + } + pos++; + } + randomizer->destroy(randomizer); + } + + /* append the padding terminator */ + *pos++ = 0x00; + + /* now add the data */ + memcpy(pos, in.ptr, in.len); + *out = this->rsaep(this, em); + free(em.ptr); + return SUCCESS; +} + +/** * Implementation of rsa_public_key.verify_emsa_pkcs1_signature. */ static status_t verify_emsa_pkcs1_signature(const private_rsa_public_key_t *this, @@ -297,19 +347,30 @@ static size_t get_keysize(const private_rsa_public_key_t *this) */ chunk_t rsa_public_key_info_to_asn1(const mpz_t n, const mpz_t e) { - chunk_t rawKey = asn1_wrap(ASN1_SEQUENCE, "mm", + chunk_t publicKey = asn1_wrap(ASN1_SEQUENCE, "mm", asn1_integer_from_mpz(n), asn1_integer_from_mpz(e)); - chunk_t publicKey; - u_char *pos = build_asn1_object(&publicKey, ASN1_BIT_STRING, 1 + rawKey.len); + return asn1_wrap(ASN1_SEQUENCE, "cm", + asn1_algorithmIdentifier(OID_RSA_ENCRYPTION), + asn1_bitstring("m", publicKey)); +} - *pos++ = 0x00; - memcpy(pos, rawKey.ptr, rawKey.len); - free(rawKey.ptr); +/** + * Form the RSA keyid as a SHA-1 hash of a publicKeyInfo object + * Also used in rsa_private_key.c. + */ +chunk_t rsa_public_key_id_create(mpz_t n, mpz_t e) +{ + chunk_t keyid; + chunk_t publicKeyInfo = rsa_public_key_info_to_asn1(n, e); + hasher_t *hasher = hasher_create(HASH_SHA1); + + hasher->allocate_hash(hasher, publicKeyInfo, &keyid); + hasher->destroy(hasher); + free(publicKeyInfo.ptr); - return asn1_wrap(ASN1_SEQUENCE, "cm", ASN1_rsaEncryption_id, - publicKey); + return keyid; } /** @@ -328,6 +389,9 @@ static chunk_t get_keyid(const private_rsa_public_key_t *this) return this->keyid; } +/* forward declaration used by rsa_public_key_t.clone */ +private_rsa_public_key_t *rsa_public_key_create_empty(void); + /** * Implementation of rsa_public_key_t.clone. */ @@ -362,6 +426,7 @@ private_rsa_public_key_t *rsa_public_key_create_empty(void) private_rsa_public_key_t *this = malloc_thing(private_rsa_public_key_t); /* public functions */ + this->public.pkcs1_encrypt = (status_t (*) (rsa_public_key_t*,chunk_t,chunk_t*))pkcs1_encrypt; this->public.verify_emsa_pkcs1_signature = (status_t (*) (const rsa_public_key_t*,hash_algorithm_t,chunk_t,chunk_t))verify_emsa_pkcs1_signature; this->public.get_modulus = (mpz_t *(*) (const rsa_public_key_t*))get_modulus; this->public.get_keysize = (size_t (*) (const rsa_public_key_t*))get_keysize; @@ -380,6 +445,20 @@ private_rsa_public_key_t *rsa_public_key_create_empty(void) /* * See header */ +rsa_public_key_t *rsa_public_key_create(mpz_t n, mpz_t e) +{ + private_rsa_public_key_t *this = rsa_public_key_create_empty(); + + mpz_init_set(this->n, n); + mpz_init_set(this->e, e); + + this->k = (mpz_sizeinbase(n, 2) + 7) / BITS_PER_BYTE; + this->keyid = rsa_public_key_id_create(n, e); + return &this->public; +} +/* + * See header + */ rsa_public_key_t *rsa_public_key_create_from_chunk(chunk_t blob) { asn1_ctx_t ctx; @@ -412,19 +491,9 @@ rsa_public_key_t *rsa_public_key_create_from_chunk(chunk_t blob) } objectID++; } - - this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8; - - /* form the keyid as a SHA-1 hash of a publicKeyInfo object */ - { - chunk_t publicKeyInfo = rsa_public_key_info_to_asn1(this->n, this->e); - hasher_t *hasher = hasher_create(HASH_SHA1); - - hasher->allocate_hash(hasher, publicKeyInfo, &this->keyid); - hasher->destroy(hasher); - free(publicKeyInfo.ptr); - } + this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE; + this->keyid = rsa_public_key_id_create(this->n, this->e); return &this->public; } |