silcauth.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 2001 Pekka Riikonen
+ Copyright (C) 2001 - 2003 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
/* Authentication Payload structure */
struct SilcAuthPayloadStruct {
- unsigned short len;
- unsigned short auth_method;
- unsigned short random_len;
+ SilcUInt16 len;
+ SilcUInt16 auth_method;
+ SilcUInt16 random_len;
unsigned char *random_data;
- unsigned short auth_len;
+ SilcUInt16 auth_len;
unsigned char *auth_data;
};
/* Parses and returns Authentication Payload */
-SilcAuthPayload silc_auth_payload_parse(SilcBuffer buffer)
+SilcAuthPayload silc_auth_payload_parse(const unsigned char *data,
+ SilcUInt32 data_len)
{
- SilcAuthPayload new;
+ SilcBufferStruct buffer;
+ SilcAuthPayload newp;
int ret;
SILC_LOG_DEBUG(("Parsing Authentication Payload"));
- new = silc_calloc(1, sizeof(*new));
+ silc_buffer_set(&buffer, (unsigned char *)data, data_len);
+ newp = silc_calloc(1, sizeof(*newp));
+ if (!newp)
+ return NULL;
/* Parse the payload */
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI_SHORT(&new->len),
- SILC_STR_UI_SHORT(&new->auth_method),
- SILC_STR_UI16_NSTRING_ALLOC(&new->random_data,
- &new->random_len),
- SILC_STR_UI16_NSTRING_ALLOC(&new->auth_data,
- &new->auth_len),
+ ret = silc_buffer_unformat(&buffer,
+ SILC_STR_UI_SHORT(&newp->len),
+ SILC_STR_UI_SHORT(&newp->auth_method),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->random_data,
+ &newp->random_len),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->auth_data,
+ &newp->auth_len),
SILC_STR_END);
if (ret == -1) {
- silc_free(new);
+ silc_free(newp);
+ return NULL;
+ }
+
+ if (newp->len != buffer.len ||
+ newp->random_len + newp->auth_len > buffer.len - 8) {
+ silc_auth_payload_free(newp);
return NULL;
}
- if (new->len != buffer->len) {
- silc_auth_payload_free(new);
+ /* Authentication data must be provided */
+ if (newp->auth_len < 1) {
+ silc_auth_payload_free(newp);
return NULL;
}
/* If password authentication, random data must not be set */
- if (new->auth_method == SILC_AUTH_PASSWORD && new->random_len) {
- silc_auth_payload_free(new);
+ if (newp->auth_method == SILC_AUTH_PASSWORD && newp->random_len) {
+ silc_auth_payload_free(newp);
+ return NULL;
+ }
+
+ /* If public key authentication, random data must be at least 128 bytes */
+ if (newp->auth_method == SILC_AUTH_PUBLIC_KEY && newp->random_len < 128) {
+ silc_auth_payload_free(newp);
return NULL;
}
- return new;
+ return newp;
}
/* Encodes authentication payload into buffer and returns it */
SilcBuffer silc_auth_payload_encode(SilcAuthMethod method,
- unsigned char *random_data,
- unsigned short random_len,
- unsigned char *auth_data,
- unsigned short auth_len)
+ const unsigned char *random_data,
+ SilcUInt16 random_len,
+ const unsigned char *auth_data,
+ SilcUInt16 auth_len)
{
SilcBuffer buffer;
- unsigned int len;
+ SilcUInt32 len;
+ unsigned char *autf8 = NULL;
+ SilcUInt32 autf8_len;
SILC_LOG_DEBUG(("Encoding Authentication Payload"));
- len = 4 + 4 + random_len + auth_len;
- buffer = silc_buffer_alloc(len);
- silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
+ /* Passphrase MUST be UTF-8 encoded, encode if it is not */
+ if (method == SILC_AUTH_PASSWORD && !silc_utf8_valid(auth_data, auth_len)) {
+ autf8_len = silc_utf8_encoded_len(auth_data, auth_len, 0);
+ if (!autf8_len)
+ return NULL;
+ autf8 = silc_calloc(autf8_len, sizeof(*autf8));
+ auth_len = silc_utf8_encode(auth_data, auth_len, 0, autf8, autf8_len);
+ auth_data = (const unsigned char *)autf8;
+ }
+
+ len = 2 + 2 + 2 + random_len + 2 + auth_len;
+ buffer = silc_buffer_alloc_size(len);
+ if (!buffer) {
+ silc_free(autf8);
+ return NULL;
+ }
+
silc_buffer_format(buffer,
SILC_STR_UI_SHORT(len),
SILC_STR_UI_SHORT(method),
SILC_STR_UI_XNSTRING(auth_data, auth_len),
SILC_STR_END);
+ silc_free(autf8);
return buffer;
}
}
}
+/* Get authentication method */
+
+SilcAuthMethod silc_auth_get_method(SilcAuthPayload payload)
+{
+ return payload->auth_method;
+}
+
+/* Get the public data from the auth payload. */
+
+unsigned char *silc_auth_get_public_data(SilcAuthPayload payload,
+ SilcUInt32 *pubdata_len)
+{
+ if (pubdata_len)
+ *pubdata_len = (SilcUInt32)payload->random_len;
+
+ return payload->random_data;
+}
+
+/* Get the authentication data. If this is passphrase it is UTF-8 encoded. */
+
+unsigned char *silc_auth_get_data(SilcAuthPayload payload,
+ SilcUInt32 *auth_len)
+{
+ if (auth_len)
+ *auth_len = (SilcUInt32)payload->auth_len;
+
+ return payload->auth_data;
+}
+
/******************************************************************************
Authentication Routines
dictates. */
static unsigned char *
-silc_auth_public_key_encode_data(SilcPublicKey public_key,
- unsigned char *random,
- unsigned int random_len, void *id,
- SilcIdType type, unsigned int *ret_len)
+silc_auth_public_key_encode_data(SilcPublicKey public_key,
+ const unsigned char *randomdata,
+ SilcUInt32 random_len, const void *id,
+ SilcIdType type, SilcUInt32 *ret_len)
{
SilcBuffer buf;
unsigned char *pk, *id_data, *ret;
- unsigned int pk_len, id_len;
+ SilcUInt32 pk_len, id_len;
pk = silc_pkcs_public_key_encode(public_key, &pk_len);
if (!pk)
silc_free(pk);
return NULL;
}
- id_len = silc_id_get_len(type);
+ id_len = silc_id_get_len(id, type);
- buf = silc_buffer_alloc(random_len + pk_len);
- silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
+ buf = silc_buffer_alloc_size(random_len + id_len + pk_len);
+ if (!buf) {
+ silc_free(pk);
+ silc_free(id_data);
+ return NULL;
+ }
silc_buffer_format(buf,
- SILC_STR_UI_XNSTRING(random, random_len),
+ SILC_STR_UI_XNSTRING(randomdata, random_len),
SILC_STR_UI_XNSTRING(id_data, id_len),
SILC_STR_UI_XNSTRING(pk, pk_len),
SILC_STR_END);
-
- ret = silc_calloc(buf->len, sizeof(*ret));
- memcpy(ret, buf->data, buf->len);
- if (ret_len)
- *ret_len = buf->len;
+ ret = silc_buffer_steal(buf, ret_len);
silc_buffer_free(buf);
silc_free(id_data);
and the actual authentication data. Returns NULL on error. */
SilcBuffer silc_auth_public_key_auth_generate(SilcPublicKey public_key,
- SilcHash hash,
- void *id, SilcIdType type)
+ SilcPrivateKey private_key,
+ SilcRng rng, SilcHash hash,
+ const void *id, SilcIdType type)
+{
+ unsigned char *randomdata;
+ SilcBuffer buf;
+
+ /* Get 256 bytes of random data */
+ if (rng)
+ randomdata = silc_rng_get_rn_data(rng, 256);
+ else
+ randomdata = silc_rng_global_get_rn_data(256);
+ if (!randomdata)
+ return NULL;
+
+ buf = silc_auth_public_key_auth_generate_wpub(public_key, private_key,
+ randomdata, 256, hash,
+ id, type);
+
+ memset(randomdata, 0, 256);
+ silc_free(randomdata);
+
+ return buf;
+}
+
+/* Generates Authentication Payload with authentication data. This is used
+ to do public key based authentication. This generates the random data
+ and the actual authentication data. Returns NULL on error. */
+
+SilcBuffer
+silc_auth_public_key_auth_generate_wpub(SilcPublicKey public_key,
+ SilcPrivateKey private_key,
+ const unsigned char *pubdata,
+ SilcUInt32 pubdata_len,
+ SilcHash hash,
+ const void *id, SilcIdType type)
{
- unsigned char *random;
- unsigned char auth_data[32];
- unsigned int auth_len;
+ unsigned char auth_data[2048 + 1];
+ SilcUInt32 auth_len;
unsigned char *tmp;
- unsigned int tmp_len;
+ SilcUInt32 tmp_len;
SilcBuffer buf;
SilcPKCS pkcs;
SILC_LOG_DEBUG(("Generating Authentication Payload with data"));
- /* Get 256 bytes of random data */
- random = silc_rng_global_get_rn_data(256);
- if (!random)
- return NULL;
-
/* Encode the auth data */
- tmp = silc_auth_public_key_encode_data(public_key, random, 256, id, type,
- &tmp_len);
+ tmp = silc_auth_public_key_encode_data(public_key, pubdata, pubdata_len, id,
+ type, &tmp_len);
if (!tmp)
return NULL;
/* Allocate PKCS object */
- if (!silc_pkcs_alloc(public_key->name, &pkcs)) {
+ if (!silc_pkcs_alloc(private_key->name, &pkcs)) {
memset(tmp, 0, tmp_len);
silc_free(tmp);
return NULL;
}
+ silc_pkcs_public_key_set(pkcs, public_key);
+ silc_pkcs_private_key_set(pkcs, private_key);
/* Compute the hash and the signature. */
- if (!silc_pkcs_sign_with_hash(pkcs, hash, tmp, tmp_len, auth_data,
+ if (silc_pkcs_get_key_len(pkcs) / 8 > sizeof(auth_data) - 1 ||
+ !silc_pkcs_sign_with_hash(pkcs, hash, tmp, tmp_len, auth_data,
&auth_len)) {
- memset(random, 0, 256);
memset(tmp, 0, tmp_len);
silc_free(tmp);
- silc_free(random);
silc_pkcs_free(pkcs);
return NULL;
}
/* Encode Authentication Payload */
- buf = silc_auth_payload_encode(SILC_AUTH_PUBLIC_KEY, random, 256,
+ buf = silc_auth_payload_encode(SILC_AUTH_PUBLIC_KEY, pubdata, pubdata_len,
auth_data, auth_len);
memset(tmp, 0, tmp_len);
memset(auth_data, 0, sizeof(auth_data));
- memset(random, 0, 256);
silc_free(tmp);
- silc_free(random);
silc_pkcs_free(pkcs);
return buf;
}
/* Verifies the authentication data. Returns TRUE if authentication was
- successfull. */
+ successful. */
-int silc_auth_public_key_auth_verify(SilcAuthPayload payload,
- SilcPublicKey public_key, SilcHash hash,
- void *id, SilcIdType type)
+bool silc_auth_public_key_auth_verify(SilcAuthPayload payload,
+ SilcPublicKey public_key, SilcHash hash,
+ const void *id, SilcIdType type)
{
unsigned char *tmp;
- unsigned int tmp_len;
+ SilcUInt32 tmp_len;
SilcPKCS pkcs;
SILC_LOG_DEBUG(("Verifying authentication data"));
/* Encode auth data */
- tmp = silc_auth_public_key_encode_data(public_key, payload->random_data,
- payload->random_len,
+ tmp = silc_auth_public_key_encode_data(public_key, payload->random_data,
+ payload->random_len,
id, type, &tmp_len);
if (!tmp) {
SILC_LOG_DEBUG(("Authentication failed"));
silc_free(tmp);
return FALSE;
}
+ silc_pkcs_public_key_set(pkcs, public_key);
/* Verify the authentication data */
if (!silc_pkcs_verify_with_hash(pkcs, hash, payload->auth_data,
silc_free(tmp);
silc_pkcs_free(pkcs);
- SILC_LOG_DEBUG(("Authentication successfull"));
+ SILC_LOG_DEBUG(("Authentication successful"));
return TRUE;
}
/* Same as above but the payload is not parsed yet. This will parse it. */
-int silc_auth_public_key_auth_verify_data(SilcBuffer payload,
- SilcPublicKey public_key,
- SilcHash hash,
- void *id, SilcIdType type)
+bool silc_auth_public_key_auth_verify_data(const unsigned char *payload,
+ SilcUInt32 payload_len,
+ SilcPublicKey public_key,
+ SilcHash hash,
+ const void *id, SilcIdType type)
{
SilcAuthPayload auth_payload;
int ret;
- auth_payload = silc_auth_payload_parse(payload);
+ auth_payload = silc_auth_payload_parse(payload, payload_len);
if (!auth_payload) {
SILC_LOG_DEBUG(("Authentication failed"));
return FALSE;
}
- ret = silc_auth_public_key_auth_verify(auth_payload, public_key, hash,
+ ret = silc_auth_public_key_auth_verify(auth_payload, public_key, hash,
id, type);
silc_auth_payload_free(auth_payload);
return ret;
}
-/* Verifies the authentication data directly from the Authentication
+/* Verifies the authentication data directly from the Authentication
Payload. Supports all authentication methods. If the authentication
method is passphrase based then the `auth_data' and `auth_data_len'
are the passphrase and its length. If the method is public key
authentication then the `auth_data' is the SilcPublicKey and the
`auth_data_len' is ignored. */
-int silc_auth_verify(SilcAuthPayload payload, SilcAuthMethod auth_method,
- void *auth_data, unsigned int auth_data_len,
- SilcHash hash, void *id, SilcIdType type)
+bool silc_auth_verify(SilcAuthPayload payload, SilcAuthMethod auth_method,
+ const void *auth_data, SilcUInt32 auth_data_len,
+ SilcHash hash, const void *id, SilcIdType type)
{
SILC_LOG_DEBUG(("Verifying authentication"));
- if (auth_method != payload->auth_method)
+ if (!payload || auth_method != payload->auth_method)
return FALSE;
switch (payload->auth_method) {
case SILC_AUTH_PASSWORD:
/* Passphrase based authentication. The `pkcs', `hash', `id' and `type'
arguments are not needed. */
- if (!memcmp(payload->auth_data, auth_data, payload->auth_len)) {
- SILC_LOG_DEBUG(("Authentication successfull"));
+
+ /* Sanity checks */
+ if ((payload->auth_len == 0) || !auth_data ||
+ payload->auth_len != auth_data_len)
+ break;
+
+ if (!memcmp(payload->auth_data, auth_data, auth_data_len)) {
+ SILC_LOG_DEBUG(("Passphrase Authentication successful"));
return TRUE;
}
break;
/* Same as above but parses the authentication payload before verify. */
-int silc_auth_verify_data(unsigned char *payload, unsigned int payload_len,
- SilcAuthMethod auth_method, void *auth_data,
- unsigned int auth_data_len, SilcHash hash,
- void *id, SilcIdType type)
+bool silc_auth_verify_data(const unsigned char *payload,
+ SilcUInt32 payload_len,
+ SilcAuthMethod auth_method, const void *auth_data,
+ SilcUInt32 auth_data_len, SilcHash hash,
+ const void *id, SilcIdType type)
{
SilcAuthPayload auth_payload;
- SilcBuffer buffer;
- int ret;
+ bool ret;
- buffer = silc_buffer_alloc(payload_len);
- silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
- silc_buffer_put(buffer, payload, payload_len);
- auth_payload = silc_auth_payload_parse(buffer);
- if (!auth_payload) {
- silc_buffer_free(buffer);
+ auth_payload = silc_auth_payload_parse(payload, payload_len);
+ if (!auth_payload || (auth_payload->auth_len == 0))
return FALSE;
- }
- ret = silc_auth_verify(auth_payload, auth_method, auth_data, auth_data_len,
+ ret = silc_auth_verify(auth_payload, auth_method, auth_data, auth_data_len,
hash, id, type);
silc_auth_payload_free(auth_payload);
- silc_buffer_free(buffer);
return ret;
}
/* The Key Agreement protocol structure */
struct SilcKeyAgreementPayloadStruct {
- unsigned short hostname_len;
+ SilcUInt16 hostname_len;
unsigned char *hostname;
- unsigned int port;
+ SilcUInt32 port;
};
/* Parses and returns an allocated Key Agreement payload. */
-SilcKeyAgreementPayload silc_key_agreement_payload_parse(SilcBuffer buffer)
+SilcKeyAgreementPayload
+silc_key_agreement_payload_parse(const unsigned char *payload,
+ SilcUInt32 payload_len)
{
- SilcKeyAgreementPayload new;
+ SilcBufferStruct buffer;
+ SilcKeyAgreementPayload newp;
int ret;
SILC_LOG_DEBUG(("Parsing Key Agreement Payload"));
- new = silc_calloc(1, sizeof(*new));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
+ newp = silc_calloc(1, sizeof(*newp));
+ if (!newp)
+ return NULL;
/* Parse the payload */
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI16_NSTRING_ALLOC(&new->hostname,
- &new->hostname_len),
- SILC_STR_UI_INT(&new->port),
+ ret = silc_buffer_unformat(&buffer,
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->hostname,
+ &newp->hostname_len),
+ SILC_STR_UI_INT(&newp->port),
SILC_STR_END);
- if (ret == -1) {
- silc_free(new);
+ if (ret == -1 || newp->hostname_len > buffer.len - 6) {
+ silc_free(newp);
return NULL;
}
- return new;
+ return newp;
}
/* Encodes the Key Agreement protocol and returns the encoded buffer */
-SilcBuffer silc_key_agreement_payload_encode(char *hostname,
- unsigned int port)
+SilcBuffer silc_key_agreement_payload_encode(const char *hostname,
+ SilcUInt32 port)
{
SilcBuffer buffer;
- unsigned int len = hostname ? strlen(hostname) : 0;
+ SilcUInt32 len = hostname ? strlen(hostname) : 0;
SILC_LOG_DEBUG(("Encoding Key Agreement Payload"));
- buffer = silc_buffer_alloc(2 + len + 4);
- silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
+ buffer = silc_buffer_alloc_size(2 + len + 4);
+ if (!buffer)
+ return NULL;
silc_buffer_format(buffer,
SILC_STR_UI_SHORT(len),
SILC_STR_UI_XNSTRING(hostname, len),
/* Returns the port in the payload */
-unsigned int silc_key_agreement_get_port(SilcKeyAgreementPayload payload)
+SilcUInt32 silc_key_agreement_get_port(SilcKeyAgreementPayload payload)
{
return payload->port;
}