diff options
Diffstat (limited to 'src/libstrongswan/plugins/openssl/openssl_hasher.c')
| -rw-r--r-- | src/libstrongswan/plugins/openssl/openssl_hasher.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/openssl/openssl_hasher.c b/src/libstrongswan/plugins/openssl/openssl_hasher.c new file mode 100644 index 000000000..1275cdfb0 --- /dev/null +++ b/src/libstrongswan/plugins/openssl/openssl_hasher.c @@ -0,0 +1,185 @@ +/* + * Copyright (C) 2008 Tobias Brunner + * 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: openssl_hasher.c 3898 2008-04-30 09:23:13Z tobias $ + */ + +#include "openssl_hasher.h" + +#include <openssl/evp.h> + +typedef struct private_openssl_hasher_t private_openssl_hasher_t; + +/** + * Private data of openssl_hasher_t + */ +struct private_openssl_hasher_t { + + /** + * Public part of this class. + */ + openssl_hasher_t public; + + /** + * the hasher to use + */ + const EVP_MD *hasher; + + /** + * the current digest context + */ + EVP_MD_CTX *ctx; +}; + +/** + * Mapping from the algorithms defined in IKEv2 to + * OpenSSL algorithm names + */ +typedef struct { + /** + * Identifier specified in IKEv2 + */ + int ikev2_id; + + /** + * Name of the algorithm, as used in OpenSSL + */ + char *name; +} openssl_algorithm_t; + +#define END_OF_LIST -1 + +/** + * Algorithms for integrity + */ +static openssl_algorithm_t integrity_algs[] = { + {HASH_MD2, "md2"}, + {HASH_MD5, "md5"}, + {HASH_SHA1, "sha1"}, + {HASH_SHA256, "sha256"}, + {HASH_SHA384, "sha384"}, + {HASH_SHA512, "sha512"}, + {END_OF_LIST, NULL}, +}; + +/** + * Look up an OpenSSL algorithm name + */ +static char* lookup_algorithm(openssl_algorithm_t *openssl_algo, + u_int16_t ikev2_algo) +{ + while (openssl_algo->ikev2_id != END_OF_LIST) + { + if (ikev2_algo == openssl_algo->ikev2_id) + { + return openssl_algo->name; + } + openssl_algo++; + } + return NULL; +} + +/** + * Implementation of hasher_t.get_hash_size. + */ +static size_t get_hash_size(private_openssl_hasher_t *this) +{ + return this->hasher->md_size; +} + +/** + * Implementation of hasher_t.reset. + */ +static void reset(private_openssl_hasher_t *this) +{ + EVP_DigestInit_ex(this->ctx, this->hasher, NULL); +} + +/** + * Implementation of hasher_t.get_hash. + */ +static void get_hash(private_openssl_hasher_t *this, chunk_t chunk, + u_int8_t *hash) +{ + EVP_DigestUpdate(this->ctx, chunk.ptr, chunk.len); + if (hash) + { + EVP_DigestFinal_ex(this->ctx, hash, NULL); + reset(this); + } +} + +/** + * Implementation of hasher_t.allocate_hash. + */ +static void allocate_hash(private_openssl_hasher_t *this, chunk_t chunk, + chunk_t *hash) +{ + if (hash) + { + *hash = chunk_alloc(get_hash_size(this)); + get_hash(this, chunk, hash->ptr); + } + else + { + get_hash(this, chunk, NULL); + } +} + +/** + * Implementation of hasher_t.destroy. + */ +static void destroy (private_openssl_hasher_t *this) +{ + EVP_MD_CTX_destroy(this->ctx); + free(this); +} + +/* + * Described in header + */ +openssl_hasher_t *openssl_hasher_create(hash_algorithm_t algo) +{ + private_openssl_hasher_t *this; + + char* name = lookup_algorithm(integrity_algs, algo); + if (!name) + { + /* algo unavailable */ + return NULL; + } + + this = malloc_thing(private_openssl_hasher_t); + + this->hasher = EVP_get_digestbyname(name); + if (!this->hasher) + { + /* OpenSSL does not support the requested algo */ + free(this); + return NULL; + } + + this->public.hasher_interface.get_hash = (void (*) (hasher_t*, chunk_t, u_int8_t*))get_hash; + this->public.hasher_interface.allocate_hash = (void (*) (hasher_t*, chunk_t, chunk_t*))allocate_hash; + this->public.hasher_interface.get_hash_size = (size_t (*) (hasher_t*))get_hash_size; + this->public.hasher_interface.reset = (void (*) (hasher_t*))reset; + this->public.hasher_interface.destroy = (void (*) (hasher_t*))destroy; + + this->ctx = EVP_MD_CTX_create(); + + /* initialization */ + reset(this); + + return &this->public; +} |