/*
- silchmac.c
+ silchmac.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2001 Pekka Riikonen
+ Copyright (C) 1999 - 2001 Pekka Riikonen
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.
-
+ the Free Software Foundation; version 2 of the License.
+
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
#include "silcincludes.h"
+/* HMAC context */
+struct SilcHmacStruct {
+ SilcHmacObject *hmac;
+ SilcHash hash;
+ bool allocated_hash; /* TRUE if the hash was allocated */
+
+ unsigned char *key;
+ uint32 key_len;
+
+ unsigned char inner_pad[64];
+ unsigned char outer_pad[64];
+ void *hash_context;
+};
+
/* List of dynamically registered HMACs. */
SilcDList silc_hmac_list = NULL;
{ NULL, 0 }
};
+static void silc_hmac_init_internal(SilcHmac hmac, unsigned char *key,
+ uint32 key_len)
+{
+ SilcHash hash = hmac->hash;
+ unsigned char hvalue[20];
+ int i;
+
+ memset(hmac->inner_pad, 0, sizeof(hmac->inner_pad));
+ memset(hmac->outer_pad, 0, sizeof(hmac->outer_pad));
+
+ /* If the key length is more than block size of the hash function, the
+ key is hashed. */
+ if (key_len > hash->hash->block_len) {
+ silc_hash_make(hash, key, key_len, hvalue);
+ key = hvalue;
+ key_len = hash->hash->hash_len;
+ }
+
+ /* Copy the key into the pads */
+ memcpy(hmac->inner_pad, key, key_len);
+ memcpy(hmac->outer_pad, key, key_len);
+
+ /* XOR the key with pads */
+ for (i = 0; i < hash->hash->block_len; i++) {
+ hmac->inner_pad[i] ^= 0x36;
+ hmac->outer_pad[i] ^= 0x5c;
+ }
+}
+
/* Registers a new HMAC into the SILC. This function is used at the
initialization of the SILC. */
if (hmac) {
if (hmac->allocated_hash)
silc_hash_free(hmac->hash);
+
+ if (hmac->key) {
+ memset(hmac->key, 0, hmac->key_len);
+ silc_free(hmac->key);
+ }
+
+ silc_free(hmac->hash_context);
silc_free(hmac);
}
}
return hmac->hmac->len;
}
+/* Get hash context */
+
+SilcHash silc_hmac_get_hash(SilcHmac hmac)
+{
+ return hmac->hash;
+}
+
+/* Return name of hmac */
+
+const char *silc_hmac_get_name(SilcHmac hmac)
+{
+ return hmac->hmac->name;
+}
+
/* Returns TRUE if HMAC `name' is supported. */
bool silc_hmac_is_supported(const char *name)
memcpy(hmac->key, key, key_len);
}
-/* Creates the HMAC. The created keyed hash value is returned to
- return_hash argument. */
-
-void silc_hmac_make_internal(SilcHmac hmac, unsigned char *data,
- uint32 data_len, unsigned char *key,
- uint32 key_len, unsigned char *return_hash)
-{
- SilcHash hash = hmac->hash;
- unsigned char inner_pad[64];
- unsigned char outer_pad[64];
- unsigned char hvalue[20], mac[20];
- void *hash_context;
- int i;
-
- SILC_LOG_DEBUG(("Making HMAC for message"));
-
- hash_context = silc_calloc(1, hash->hash->context_len());
-
- memset(inner_pad, 0, sizeof(inner_pad));
- memset(outer_pad, 0, sizeof(outer_pad));
-
- /* If the key length is more than block size of the hash function, the
- key is hashed. */
- if (key_len > hash->hash->block_len) {
- silc_hash_make(hash, key, key_len, hvalue);
- key = hvalue;
- key_len = hash->hash->hash_len;
- }
-
- /* Copy the key into the pads */
- memcpy(inner_pad, key, key_len);
- memcpy(outer_pad, key, key_len);
-
- /* XOR the key with pads */
- for (i = 0; i < hash->hash->block_len; i++) {
- inner_pad[i] ^= 0x36;
- outer_pad[i] ^= 0x5c;
- }
-
- /* Do the HMAC transform (too bad I can't do make_hash directly, sigh) */
- hash->hash->init(hash_context);
- hash->hash->update(hash_context, inner_pad, hash->hash->block_len);
- hash->hash->update(hash_context, data, data_len);
- hash->hash->final(hash_context, mac);
- hash->hash->init(hash_context);
- hash->hash->update(hash_context, outer_pad, hash->hash->block_len);
- hash->hash->update(hash_context, mac, hash->hash->hash_len);
- hash->hash->final(hash_context, mac);
- memcpy(return_hash, mac, hmac->hmac->len);
- memset(mac, 0, sizeof(mac));
- silc_free(hash_context);
-}
-
/* Create the HMAC. This is thee make_hmac function pointer. This
uses the internal key set with silc_hmac_set_key. */
uint32 data_len, unsigned char *return_hash,
uint32 *return_len)
{
- silc_hmac_make_internal(hmac, data, data_len, hmac->key,
- hmac->key_len, return_hash);
- if (return_len)
- *return_len = hmac->hmac->len;
+ SILC_LOG_DEBUG(("Making HMAC for message"));
+
+ silc_hmac_init(hmac);
+ silc_hmac_update(hmac, data, data_len);
+ silc_hmac_final(hmac, return_hash, return_len);
}
/* Creates HMAC just as above except that this doesn't use the internal
unsigned char *return_hash,
uint32 *return_len)
{
- silc_hmac_make_internal(hmac, data, data_len, key, key_len, return_hash);
- if (return_len)
- *return_len = hmac->hmac->len;
+ SILC_LOG_DEBUG(("Making HMAC for message"));
+
+ silc_hmac_init_with_key(hmac, key, key_len);
+ silc_hmac_update(hmac, data, data_len);
+ silc_hmac_final(hmac, return_hash, return_len);
}
/* Creates the HMAC just as above except that the hash value is truncated
{
unsigned char hvalue[20];
- silc_hmac_make_internal(hmac, data, data_len,
- hmac->key, hmac->key_len, hvalue);
+ SILC_LOG_DEBUG(("Making HMAC for message"));
+
+ silc_hmac_init(hmac);
+ silc_hmac_update(hmac, data, data_len);
+ silc_hmac_final(hmac, return_hash, NULL);
memcpy(return_hash, hvalue, truncated_len);
memset(hvalue, 0, sizeof(hvalue));
}
+
+/* Init HMAC for silc_hmac_update and silc_hmac_final. */
+
+void silc_hmac_init(SilcHmac hmac)
+{
+ silc_hmac_init_with_key(hmac, hmac->key, hmac->key_len);
+}
+
+/* Same as above but with specific key */
+
+void silc_hmac_init_with_key(SilcHmac hmac, const unsigned char *key,
+ uint32 key_len)
+{
+ SilcHash hash = hmac->hash;
+
+ silc_hmac_init_internal(hmac, hmac->key, hmac->key_len);
+
+ if (!hmac->hash_context)
+ hmac->hash_context = silc_calloc(1, hash->hash->context_len());
+
+ hash->hash->init(hmac->hash_context);
+ hash->hash->update(hmac->hash_context, hmac->inner_pad,
+ hash->hash->block_len);
+}
+
+/* Add data to be used in the MAC computation. */
+
+void silc_hmac_update(SilcHmac hmac, const unsigned char *data,
+ uint32 data_len)
+{
+ SilcHash hash = hmac->hash;
+ hash->hash->update(hmac->hash_context, (unsigned char *)data, data_len);
+}
+
+/* Compute the final MAC. */
+
+void silc_hmac_final(SilcHmac hmac, unsigned char *return_hash,
+ uint32 *return_len)
+{
+ SilcHash hash = hmac->hash;
+ unsigned char mac[20];
+
+ hash->hash->final(hmac->hash_context, mac);
+ hash->hash->init(hmac->hash_context);
+ hash->hash->update(hmac->hash_context, hmac->outer_pad,
+ hash->hash->block_len);
+ hash->hash->update(hmac->hash_context, mac, hash->hash->hash_len);
+ hash->hash->final(hmac->hash_context, mac);
+ memcpy(return_hash, mac, hmac->hmac->len);
+ memset(mac, 0, sizeof(mac));
+
+ if (return_len)
+ *return_len = hmac->hmac->len;
+}
projects / silc.git / blobdiff