silchmac.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2001 Pekka Riikonen
+ Copyright (C) 1999 - 2005 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
*/
/* $Id$ */
-#include "silcincludes.h"
+#include "silc.h"
+
+/* HMAC context */
+struct SilcHmacStruct {
+ SilcHmacObject *hmac;
+ SilcHash hash;
+ unsigned char inner_pad[64];
+ unsigned char outer_pad[64];
+ unsigned char *key;
+ unsigned int key_len : 31;
+ unsigned int allocated_hash : 1; /* TRUE if the hash was allocated */
+};
+#ifndef SILC_EPOC
/* List of dynamically registered HMACs. */
SilcDList silc_hmac_list = NULL;
+#endif /* SILC_EPOC */
+
+/* Default hmacs for silc_hmac_register_default(). */
+const SilcHmacObject silc_default_hmacs[] =
+{
+ { "hmac-sha256-96", 12 },
+ { "hmac-sha1-96", 12 },
+ { "hmac-md5-96", 12 },
+ { "hmac-sha256", 32 },
+ { "hmac-sha1", 20 },
+ { "hmac-md5", 16 },
+
+ { NULL, 0 }
+};
+
+static void silc_hmac_init_internal(SilcHmac hmac, unsigned char *key,
+ SilcUInt32 key_len)
+{
+ SilcHash hash = hmac->hash;
+ SilcUInt32 block_len;
+ unsigned char hvalue[SILC_HASH_MAXLEN];
+ int i;
+
+ memset(hmac->inner_pad, 0, sizeof(hmac->inner_pad));
+ memset(hmac->outer_pad, 0, sizeof(hmac->outer_pad));
+
+ block_len = silc_hash_block_len(hash);
+
+ /* If the key length is more than block size of the hash function, the
+ key is hashed. */
+ if (key_len > block_len) {
+ silc_hash_make(hash, key, key_len, hvalue);
+ key = hvalue;
+ key_len = silc_hash_len(hash);
+ }
+
+ /* 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 < 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. */
-int silc_hmac_register(SilcHmacObject *hmac)
+SilcBool silc_hmac_register(const SilcHmacObject *hmac)
{
+#ifndef SILC_EPOC
SilcHmacObject *new;
SILC_LOG_DEBUG(("Registering new HMAC `%s'", hmac->name));
+ /* Check for existing */
+ if (silc_hmac_list) {
+ SilcHmacObject *entry;
+ silc_dlist_start(silc_hmac_list);
+ while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
+ if (!strcmp(entry->name, hmac->name))
+ return FALSE;
+ }
+ }
+
new = silc_calloc(1, sizeof(*new));
new->name = strdup(hmac->name);
new->len = hmac->len;
silc_hmac_list = silc_dlist_init();
silc_dlist_add(silc_hmac_list, new);
+#endif /* SILC_EPOC */
return TRUE;
}
/* Unregister a HMAC from the SILC. */
-int silc_hmac_unregister(SilcHmacObject *hmac)
+SilcBool silc_hmac_unregister(SilcHmacObject *hmac)
{
+#ifndef SILC_EPOC
SilcHmacObject *entry;
SILC_LOG_DEBUG(("Unregistering HMAC"));
silc_dlist_start(silc_hmac_list);
while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
- if (entry == hmac) {
+ if (hmac == SILC_ALL_HMACS || entry == hmac) {
silc_dlist_del(silc_hmac_list, entry);
+ silc_free(entry->name);
+ silc_free(entry);
if (silc_dlist_count(silc_hmac_list) == 0) {
silc_dlist_uninit(silc_hmac_list);
}
}
+#endif /* SILC_EPOC */
return FALSE;
}
+/* Function that registers all the default hmacs (all builtin ones).
+ The application may use this to register the default hmacs if
+ specific hmacs in any specific order is not wanted. */
+
+SilcBool silc_hmac_register_default(void)
+{
+#ifndef SILC_EPOC
+ int i;
+
+ for (i = 0; silc_default_hmacs[i].name; i++)
+ silc_hmac_register(&(silc_default_hmacs[i]));
+
+#endif /* SILC_EPOC */
+ return TRUE;
+}
+
+SilcBool silc_hmac_unregister_all(void)
+{
+#ifndef SILC_EPOC
+ SilcHmacObject *entry;
+
+ if (!silc_hmac_list)
+ return FALSE;
+
+ silc_dlist_start(silc_hmac_list);
+ while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
+ silc_hmac_unregister(entry);
+ if (!silc_hmac_list)
+ break;
+ }
+#endif /* SILC_EPOC */
+ return TRUE;
+}
+
/* Allocates a new SilcHmac object of name of `name'. The `hash' may
be provided as argument. If provided it is used as the hash function
of the HMAC. If it is NULL then the hash function is allocated and
the name of the hash algorithm is derived from the `name'. */
-int silc_hmac_alloc(char *name, SilcHash hash, SilcHmac *new_hmac)
+SilcBool silc_hmac_alloc(const char *name, SilcHash hash, SilcHmac *new_hmac)
{
- SilcHmacObject *entry;
-
SILC_LOG_DEBUG(("Allocating new HMAC"));
/* Allocate the new object */
if (!silc_hash_alloc(hname, &hash)) {
silc_free(tmp);
+ silc_free(*new_hmac);
+ *new_hmac = NULL;
return FALSE;
}
(*new_hmac)->hash = hash;
+#ifndef SILC_EPOC
if (silc_hmac_list) {
+ SilcHmacObject *entry;
silc_dlist_start(silc_hmac_list);
while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
if (!strcmp(entry->name, name)) {
- (*new_hmac)->hmac = entry;
+ (*new_hmac)->hmac = entry;
+ return TRUE;
+ }
+ }
+ }
+#else
+ {
+ /* On EPOC which don't have globals we check our constant hash list. */
+ int i;
+ for (i = 0; silc_default_hmacs[i].name; i++) {
+ if (!strcmp(silc_default_hmacs[i].name, name)) {
+ (*new_hmac)->hmac = (SilcHmacObject *)&(silc_default_hmacs[i]);
return TRUE;
}
}
}
+#endif /* SILC_EPOC */
+ silc_free(*new_hmac);
+ *new_hmac = NULL;
return FALSE;
}
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);
}
}
/* Returns the length of the MAC that the HMAC will produce. */
-unsigned int silc_hmac_len(SilcHmac hmac)
+SilcUInt32 silc_hmac_len(SilcHmac 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. */
-int silc_hmac_is_supported(const char *name)
+SilcBool silc_hmac_is_supported(const char *name)
{
+#ifndef SILC_EPOC
SilcHmacObject *entry;
if (!name)
return FALSE;
-
+
if (silc_hmac_list) {
silc_dlist_start(silc_hmac_list);
while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
return TRUE;
}
}
-
+#else
+ {
+ int i;
+ for (i = 0; silc_default_hmacs[i].name; i++)
+ if (!strcmp(silc_default_hmacs[i].name, name))
+ return TRUE;
+ }
+#endif /* SILC_EPOC */
return FALSE;
}
{
SilcHmacObject *entry;
char *list = NULL;
- int len;
+ int len = 0;
- len = 0;
+#ifndef SILC_EPOC
if (silc_hmac_list) {
silc_dlist_start(silc_hmac_list);
while ((entry = silc_dlist_get(silc_hmac_list)) != SILC_LIST_END) {
len += strlen(entry->name);
list = silc_realloc(list, len + 1);
-
- memcpy(list + (len - strlen(entry->name)),
+
+ memcpy(list + (len - strlen(entry->name)),
+ entry->name, strlen(entry->name));
+ memcpy(list + len, ",", 1);
+ len++;
+ }
+ }
+#else
+ {
+ int i;
+ for (i = 0; silc_default_hmacs[i].name; i++) {
+ entry = (SilcHmacObject *)&(silc_default_hmacs[i]);
+ len += strlen(entry->name);
+ list = silc_realloc(list, len + 1);
+
+ memcpy(list + (len - strlen(entry->name)),
entry->name, strlen(entry->name));
memcpy(list + len, ",", 1);
len++;
}
}
+#endif /* SILC_EPOC */
list[len - 1] = 0;
/* Sets the HMAC key used in the HMAC creation */
void silc_hmac_set_key(SilcHmac hmac, const unsigned char *key,
- unsigned int key_len)
+ SilcUInt32 key_len)
{
if (hmac->key) {
memset(hmac->key, 0, hmac->key_len);
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,
- unsigned int data_len, unsigned char *key,
- unsigned int key_len, unsigned char *return_hash)
-{
- SilcHash hash = hmac->hash;
- unsigned char inner_pad[hash->hash->block_len + 1];
- unsigned char outer_pad[hash->hash->block_len + 1];
- unsigned char hvalue[hash->hash->hash_len];
- unsigned char mac[128];
- 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));
-}
-
/* Create the HMAC. This is thee make_hmac function pointer. This
uses the internal key set with silc_hmac_set_key. */
void silc_hmac_make(SilcHmac hmac, unsigned char *data,
- unsigned int data_len, unsigned char *return_hash,
- unsigned int *return_len)
+ SilcUInt32 data_len, unsigned char *return_hash,
+ SilcUInt32 *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
key. The key is sent as argument to the function. */
void silc_hmac_make_with_key(SilcHmac hmac, unsigned char *data,
- unsigned int data_len,
- unsigned char *key, unsigned int key_len,
+ SilcUInt32 data_len,
+ unsigned char *key, SilcUInt32 key_len,
unsigned char *return_hash,
- unsigned int *return_len)
+ SilcUInt32 *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
to the truncated_len sent as argument. NOTE: One should not truncate to
- less than half of the length of original hash value. However, this
+ less than half of the length of original hash value. However, this
routine allows these dangerous truncations. */
void silc_hmac_make_truncated(SilcHmac hmac, unsigned char *data,
- unsigned int data_len,
- unsigned int truncated_len,
+ SilcUInt32 data_len,
+ SilcUInt32 truncated_len,
unsigned char *return_hash)
{
- unsigned char hvalue[hmac->hash->hash->hash_len];
+ unsigned char hvalue[SILC_HASH_MAXLEN];
+
+ SILC_LOG_DEBUG(("Making HMAC for message"));
- silc_hmac_make_internal(hmac, data, data_len,
- hmac->key, hmac->key_len, hvalue);
+ 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,
+ SilcUInt32 key_len)
+{
+ SilcHash hash = hmac->hash;
+ silc_hmac_init_internal(hmac, (unsigned char *)key, key_len);
+ silc_hash_init(hash);
+ silc_hash_update(hash, hmac->inner_pad, silc_hash_block_len(hash));
+}
+
+/* Add data to be used in the MAC computation. */
+
+void silc_hmac_update(SilcHmac hmac, const unsigned char *data,
+ SilcUInt32 data_len)
+{
+ SilcHash hash = hmac->hash;
+ silc_hash_update(hash, data, data_len);
+}
+
+/* Compute the final MAC. */
+
+void silc_hmac_final(SilcHmac hmac, unsigned char *return_hash,
+ SilcUInt32 *return_len)
+{
+ SilcHash hash = hmac->hash;
+ unsigned char mac[SILC_HASH_MAXLEN];
+
+ silc_hash_final(hash, mac);
+ silc_hash_init(hash);
+ silc_hash_update(hash, hmac->outer_pad, silc_hash_block_len(hash));
+ silc_hash_update(hash, mac, silc_hash_len(hash));
+ silc_hash_final(hash, mac);
+ memcpy(return_hash, mac, hmac->hmac->len);
+ memset(mac, 0, sizeof(mac));
+
+ if (return_len)
+ *return_len = hmac->hmac->len;
+}
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