flm01/openwrt/package/luci/libs/nixio/axTLS/ssl/tls1_svr.c

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/*
* Copyright (c) 2007, Cameron Rich
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of the axTLS project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "ssl.h"
static const uint8_t g_hello_done[] = { HS_SERVER_HELLO_DONE, 0, 0, 0 };
static int process_client_hello(SSL *ssl);
static int send_server_hello_sequence(SSL *ssl);
static int send_server_hello(SSL *ssl);
static int send_server_hello_done(SSL *ssl);
static int process_client_key_xchg(SSL *ssl);
#ifdef CONFIG_SSL_CERT_VERIFICATION
static int send_certificate_request(SSL *ssl);
static int process_cert_verify(SSL *ssl);
#endif
/*
* Establish a new SSL connection to an SSL client.
*/
EXP_FUNC SSL * STDCALL ssl_server_new(SSL_CTX *ssl_ctx, int client_fd)
{
SSL *ssl;
ssl = ssl_new(ssl_ctx, client_fd);
ssl->next_state = HS_CLIENT_HELLO;
#ifdef CONFIG_SSL_FULL_MODE
if (ssl_ctx->chain_length == 0)
printf("Warning - no server certificate defined\n"); TTY_FLUSH();
#endif
return ssl;
}
/*
* Process the handshake record.
*/
int do_svr_handshake(SSL *ssl, int handshake_type, uint8_t *buf, int hs_len)
{
int ret = SSL_OK;
ssl->hs_status = SSL_NOT_OK; /* not connected */
/* To get here the state must be valid */
switch (handshake_type)
{
case HS_CLIENT_HELLO:
if ((ret = process_client_hello(ssl)) == SSL_OK)
ret = send_server_hello_sequence(ssl);
break;
#ifdef CONFIG_SSL_CERT_VERIFICATION
case HS_CERTIFICATE:/* the client sends its cert */
ret = process_certificate(ssl, &ssl->x509_ctx);
if (ret == SSL_OK) /* verify the cert */
{
int cert_res;
cert_res = x509_verify(
ssl->ssl_ctx->ca_cert_ctx, ssl->x509_ctx);
ret = (cert_res == 0) ? SSL_OK : SSL_X509_ERROR(cert_res);
}
break;
case HS_CERT_VERIFY:
ret = process_cert_verify(ssl);
add_packet(ssl, buf, hs_len); /* needs to be done after */
break;
#endif
case HS_CLIENT_KEY_XCHG:
ret = process_client_key_xchg(ssl);
break;
case HS_FINISHED:
ret = process_finished(ssl, hs_len);
disposable_free(ssl); /* free up some memory */
break;
}
return ret;
}
/*
* Process a client hello message.
*/
static int process_client_hello(SSL *ssl)
{
uint8_t *buf = ssl->bm_data;
uint8_t *record_buf = ssl->hmac_header;
int pkt_size = ssl->bm_index;
int i, j, cs_len, id_len, offset = 6 + SSL_RANDOM_SIZE;
int version = (record_buf[1] << 4) + record_buf[2];
int ret = SSL_OK;
/* should be v3.1 (TLSv1) or better - we'll send in v3.1 mode anyway */
if (version < 0x31)
{
ret = SSL_ERROR_INVALID_VERSION;
ssl_display_error(ret);
goto error;
}
memcpy(ssl->dc->client_random, &buf[6], SSL_RANDOM_SIZE);
/* process the session id */
id_len = buf[offset++];
if (id_len > SSL_SESSION_ID_SIZE)
{
return SSL_ERROR_INVALID_SESSION;
}
#ifndef CONFIG_SSL_SKELETON_MODE
ssl->session = ssl_session_update(ssl->ssl_ctx->num_sessions,
ssl->ssl_ctx->ssl_sessions, ssl, id_len ? &buf[offset] : NULL);
#endif
offset += id_len;
cs_len = (buf[offset]<<8) + buf[offset+1];
offset += 3; /* add 1 due to all cipher suites being 8 bit */
PARANOIA_CHECK(pkt_size, offset);
/* work out what cipher suite we are going to use */
for (j = 0; j < NUM_PROTOCOLS; j++)
{
for (i = 0; i < cs_len; i += 2)
{
if (ssl_prot_prefs[j] == buf[offset+i]) /* got a match? */
{
ssl->cipher = ssl_prot_prefs[j];
goto do_state;
}
}
}
/* ouch! protocol is not supported */
ret = SSL_ERROR_NO_CIPHER;
do_state:
error:
return ret;
}
#ifdef CONFIG_SSL_ENABLE_V23_HANDSHAKE
/*
* Some browsers use a hybrid SSLv2 "client hello"
*/
int process_sslv23_client_hello(SSL *ssl)
{
uint8_t *buf = ssl->bm_data;
int bytes_needed = ((buf[0] & 0x7f) << 8) + buf[1];
int version = (buf[3] << 4) + buf[4];
int ret = SSL_OK;
/* we have already read 3 extra bytes so far */
int read_len = SOCKET_READ(ssl->client_fd, buf, bytes_needed-3);
int cs_len = buf[1];
int id_len = buf[3];
int ch_len = buf[5];
int i, j, offset = 8; /* start at first cipher */
int random_offset = 0;
DISPLAY_BYTES(ssl, "received %d bytes", buf, read_len, read_len);
/* should be v3.1 (TLSv1) or better - we'll send in v3.1 mode anyway */
if (version < 0x31)
{
return SSL_ERROR_INVALID_VERSION;
}
add_packet(ssl, buf, read_len);
/* connection has gone, so die */
if (bytes_needed < 0)
{
return SSL_ERROR_CONN_LOST;
}
/* now work out what cipher suite we are going to use */
for (j = 0; j < NUM_PROTOCOLS; j++)
{
for (i = 0; i < cs_len; i += 3)
{
if (ssl_prot_prefs[j] == buf[offset+i])
{
ssl->cipher = ssl_prot_prefs[j];
goto server_hello;
}
}
}
/* ouch! protocol is not supported */
ret = SSL_ERROR_NO_CIPHER;
goto error;
server_hello:
/* get the session id */
offset += cs_len - 2; /* we've gone 2 bytes past the end */
#ifndef CONFIG_SSL_SKELETON_MODE
ssl->session = ssl_session_update(ssl->ssl_ctx->num_sessions,
ssl->ssl_ctx->ssl_sessions, ssl, id_len ? &buf[offset] : NULL);
#endif
/* get the client random data */
offset += id_len;
/* random can be anywhere between 16 and 32 bytes long - so it is padded
* with 0's to the left */
if (ch_len == 0x10)
{
random_offset += 0x10;
}
memcpy(&ssl->dc->client_random[random_offset], &buf[offset], ch_len);
ret = send_server_hello_sequence(ssl);
error:
return ret;
}
#endif
/*
* Send the entire server hello sequence
*/
static int send_server_hello_sequence(SSL *ssl)
{
int ret;
if ((ret = send_server_hello(ssl)) == SSL_OK)
{
#ifndef CONFIG_SSL_SKELETON_MODE
/* resume handshake? */
if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME))
{
if ((ret = send_change_cipher_spec(ssl)) == SSL_OK)
{
ret = send_finished(ssl);
ssl->next_state = HS_FINISHED;
}
}
else
#endif
if ((ret = send_certificate(ssl)) == SSL_OK)
{
#ifdef CONFIG_SSL_CERT_VERIFICATION
/* ask the client for its certificate */
if (IS_SET_SSL_FLAG(SSL_CLIENT_AUTHENTICATION))
{
if ((ret = send_certificate_request(ssl)) == SSL_OK)
{
ret = send_server_hello_done(ssl);
ssl->next_state = HS_CERTIFICATE;
}
}
else
#endif
{
ret = send_server_hello_done(ssl);
ssl->next_state = HS_CLIENT_KEY_XCHG;
}
}
}
return ret;
}
/*
* Send a server hello message.
*/
static int send_server_hello(SSL *ssl)
{
uint8_t *buf = ssl->bm_data;
int offset = 0;
buf[0] = HS_SERVER_HELLO;
buf[1] = 0;
buf[2] = 0;
/* byte 3 is calculated later */
buf[4] = 0x03;
buf[5] = 0x01;
/* server random value */
get_random(SSL_RANDOM_SIZE, &buf[6]);
memcpy(ssl->dc->server_random, &buf[6], SSL_RANDOM_SIZE);
offset = 6 + SSL_RANDOM_SIZE;
#ifndef CONFIG_SSL_SKELETON_MODE
if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME))
{
/* retrieve id from session cache */
buf[offset++] = SSL_SESSION_ID_SIZE;
memcpy(&buf[offset], ssl->session->session_id, SSL_SESSION_ID_SIZE);
memcpy(ssl->session_id, ssl->session->session_id, SSL_SESSION_ID_SIZE);
ssl->sess_id_size = SSL_SESSION_ID_SIZE;
offset += SSL_SESSION_ID_SIZE;
}
else /* generate our own session id */
#endif
{
#ifndef CONFIG_SSL_SKELETON_MODE
buf[offset++] = SSL_SESSION_ID_SIZE;
get_random(SSL_SESSION_ID_SIZE, &buf[offset]);
memcpy(ssl->session_id, &buf[offset], SSL_SESSION_ID_SIZE);
ssl->sess_id_size = SSL_SESSION_ID_SIZE;
/* store id in session cache */
if (ssl->ssl_ctx->num_sessions)
{
memcpy(ssl->session->session_id,
ssl->session_id, SSL_SESSION_ID_SIZE);
}
offset += SSL_SESSION_ID_SIZE;
#else
buf[offset++] = 0; /* don't bother with session id in skelton mode */
#endif
}
buf[offset++] = 0; /* cipher we are using */
buf[offset++] = ssl->cipher;
buf[offset++] = 0; /* no compression */
buf[3] = offset - 4; /* handshake size */
return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, offset);
}
/*
* Send the server hello done message.
*/
static int send_server_hello_done(SSL *ssl)
{
return send_packet(ssl, PT_HANDSHAKE_PROTOCOL,
g_hello_done, sizeof(g_hello_done));
}
/*
* Pull apart a client key exchange message. Decrypt the pre-master key (using
* our RSA private key) and then work out the master key. Initialise the
* ciphers.
*/
static int process_client_key_xchg(SSL *ssl)
{
uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index];
int pkt_size = ssl->bm_index;
int premaster_size, secret_length = (buf[2] << 8) + buf[3];
uint8_t premaster_secret[MAX_KEY_BYTE_SIZE];
RSA_CTX *rsa_ctx = ssl->ssl_ctx->rsa_ctx;
int offset = 4;
int ret = SSL_OK;
if (rsa_ctx == NULL)
{
ret = SSL_ERROR_NO_CERT_DEFINED;
goto error;
}
/* is there an extra size field? */
if ((secret_length - 2) == rsa_ctx->num_octets)
offset += 2;
PARANOIA_CHECK(pkt_size, rsa_ctx->num_octets+offset);
/* rsa_ctx->bi_ctx is not thread-safe */
SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
premaster_size = RSA_decrypt(rsa_ctx, &buf[offset], premaster_secret, 1);
SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
if (premaster_size != SSL_SECRET_SIZE ||
premaster_secret[0] != 0x03 || /* check version is 3.1 (TLS) */
premaster_secret[1] != 0x01)
{
/* guard against a Bleichenbacher attack */
memset(premaster_secret, 0, SSL_SECRET_SIZE);
/* and continue - will die eventually when checking the mac */
}
#if 0
print_blob("pre-master", premaster_secret, SSL_SECRET_SIZE);
#endif
generate_master_secret(ssl, premaster_secret);
#ifdef CONFIG_SSL_CERT_VERIFICATION
ssl->next_state = IS_SET_SSL_FLAG(SSL_CLIENT_AUTHENTICATION) ?
HS_CERT_VERIFY : HS_FINISHED;
#else
ssl->next_state = HS_FINISHED;
#endif
error:
ssl->dc->bm_proc_index += rsa_ctx->num_octets+offset;
return ret;
}
#ifdef CONFIG_SSL_CERT_VERIFICATION
static const uint8_t g_cert_request[] = { HS_CERT_REQ, 0, 0, 4, 1, 0, 0, 0 };
/*
* Send the certificate request message.
*/
static int send_certificate_request(SSL *ssl)
{
return send_packet(ssl, PT_HANDSHAKE_PROTOCOL,
g_cert_request, sizeof(g_cert_request));
}
/*
* Ensure the client has the private key by first decrypting the packet and
* then checking the packet digests.
*/
static int process_cert_verify(SSL *ssl)
{
uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index];
int pkt_size = ssl->bm_index;
uint8_t dgst_buf[MAX_KEY_BYTE_SIZE];
uint8_t dgst[MD5_SIZE+SHA1_SIZE];
X509_CTX *x509_ctx = ssl->x509_ctx;
int ret = SSL_OK;
int n;
PARANOIA_CHECK(pkt_size, x509_ctx->rsa_ctx->num_octets+6);
DISPLAY_RSA(ssl, x509_ctx->rsa_ctx);
/* rsa_ctx->bi_ctx is not thread-safe */
SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
n = RSA_decrypt(x509_ctx->rsa_ctx, &buf[6], dgst_buf, 0);
SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
if (n != SHA1_SIZE + MD5_SIZE)
{
ret = SSL_ERROR_INVALID_KEY;
goto end_cert_vfy;
}
finished_digest(ssl, NULL, dgst); /* calculate the digest */
if (memcmp(dgst_buf, dgst, MD5_SIZE + SHA1_SIZE))
{
ret = SSL_ERROR_INVALID_KEY;
}
end_cert_vfy:
ssl->next_state = HS_FINISHED;
error:
return ret;
}
#endif