diff options
Diffstat (limited to 'src/libstrongswan/plugins/hmac/hmac_signer.c')
| -rw-r--r-- | src/libstrongswan/plugins/hmac/hmac_signer.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/hmac/hmac_signer.c b/src/libstrongswan/plugins/hmac/hmac_signer.c new file mode 100644 index 000000000..cdfc819f1 --- /dev/null +++ b/src/libstrongswan/plugins/hmac/hmac_signer.c @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2005-2008 Martin Willi + * Copyright (C) 2005 Jan Hutter + * Hochschule fuer Technik Rapperswil + * + * This program 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 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program 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. + * + * $Id: hmac_signer.c 3488 2008-02-21 15:10:02Z martin $ + */ + +#include <string.h> + +#include "hmac_signer.h" +#include "hmac.h" + +typedef struct private_hmac_signer_t private_hmac_signer_t; + +/** + * Private data structure with signing context. + */ +struct private_hmac_signer_t { + /** + * Public interface of hmac_signer_t. + */ + hmac_signer_t public; + + /** + * Assigned hmac function. + */ + hmac_t *hmac; + + /** + * Block size (truncation of HMAC Hash) + */ + size_t block_size; +}; + +/** + * Implementation of signer_t.get_signature. + */ +static void get_signature(private_hmac_signer_t *this, + chunk_t data, u_int8_t *buffer) +{ + if (buffer == NULL) + { /* append mode */ + this->hmac->get_mac(this->hmac, data, NULL); + } + else + { + u_int8_t mac[this->hmac->get_block_size(this->hmac)]; + + this->hmac->get_mac(this->hmac, data, mac); + memcpy(buffer, mac, this->block_size); + } +} + +/** + * Implementation of signer_t.allocate_signature. + */ +static void allocate_signature (private_hmac_signer_t *this, + chunk_t data, chunk_t *chunk) +{ + if (chunk == NULL) + { /* append mode */ + this->hmac->get_mac(this->hmac, data, NULL); + } + else + { + u_int8_t mac[this->hmac->get_block_size(this->hmac)]; + + this->hmac->get_mac(this->hmac, data, mac); + + chunk->ptr = malloc(this->block_size); + chunk->len = this->block_size; + + memcpy(chunk->ptr, mac, this->block_size); + } +} + +/** + * Implementation of signer_t.verify_signature. + */ +static bool verify_signature(private_hmac_signer_t *this, + chunk_t data, chunk_t signature) +{ + u_int8_t mac[this->hmac->get_block_size(this->hmac)]; + + this->hmac->get_mac(this->hmac, data, mac); + + if (signature.len != this->block_size) + { + return FALSE; + } + return memeq(signature.ptr, mac, this->block_size); +} + +/** + * Implementation of signer_t.get_key_size. + */ +static size_t get_key_size(private_hmac_signer_t *this) +{ + return this->hmac->get_block_size(this->hmac); +} + +/** + * Implementation of signer_t.get_block_size. + */ +static size_t get_block_size(private_hmac_signer_t *this) +{ + return this->block_size; +} + +/** + * Implementation of signer_t.set_key. + */ +static void set_key(private_hmac_signer_t *this, chunk_t key) +{ + this->hmac->set_key(this->hmac, key); +} + +/** + * Implementation of signer_t.destroy. + */ +static status_t destroy(private_hmac_signer_t *this) +{ + this->hmac->destroy(this->hmac); + free(this); + return SUCCESS; +} + +/* + * Described in header + */ +hmac_signer_t *hmac_signer_create(integrity_algorithm_t algo) +{ + private_hmac_signer_t *this; + size_t trunc; + hash_algorithm_t hash; + + switch (algo) + { + case AUTH_HMAC_SHA1_96: + hash = HASH_SHA1; + trunc = 12; + break; + case AUTH_HMAC_SHA1_128: + hash = HASH_SHA1; + trunc = 16; + break; + case AUTH_HMAC_MD5_96: + hash = HASH_MD5; + trunc = 12; + break; + case AUTH_HMAC_SHA2_256_128: + hash = HASH_SHA256; + trunc = 16; + break; + case AUTH_HMAC_SHA2_384_192: + hash = HASH_SHA384; + trunc = 24; + break; + case AUTH_HMAC_SHA2_512_256: + hash = HASH_SHA512; + trunc = 32; + break; + default: + return NULL; + } + + this = malloc_thing(private_hmac_signer_t); + this->hmac = hmac_create(hash); + if (this->hmac == NULL) + { + free(this); + return NULL; + } + /* prevent invalid truncation */ + this->block_size = min(trunc, this->hmac->get_block_size(this->hmac)); + + /* interface functions */ + this->public.signer_interface.get_signature = (void (*) (signer_t*, chunk_t, u_int8_t*))get_signature; + this->public.signer_interface.allocate_signature = (void (*) (signer_t*, chunk_t, chunk_t*))allocate_signature; + this->public.signer_interface.verify_signature = (bool (*) (signer_t*, chunk_t, chunk_t))verify_signature; + this->public.signer_interface.get_key_size = (size_t (*) (signer_t*))get_key_size; + this->public.signer_interface.get_block_size = (size_t (*) (signer_t*))get_block_size; + this->public.signer_interface.set_key = (void (*) (signer_t*,chunk_t))set_key; + this->public.signer_interface.destroy = (void (*) (signer_t*))destroy; + + return &(this->public); +} + |