generic-library/openssl
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

PACKET: simplify ServerHello parsing

Browse Source 
Reviewed-by: Tim Hudson <tjh@openssl.org>
This commit is contained in:
Emilia Kasper 2015-09-18 14:09:37 +02:00
parent cf7f85927c
commit fc5ce51d17
1 changed files with 35 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
ssl/s3_clnt.c
View File

@ -928,10 +928,11 @@ int ssl3_get_server_hello(SSL *s)
{
STACK_OF(SSL_CIPHER) *sk;
const SSL_CIPHER *c;
PACKET pkt;
unsigned char *session_id, *cipherchars;
PACKET pkt, session_id;
size_t session_id_len;
unsigned char *cipherchars;
int i, al = SSL_AD_INTERNAL_ERROR, ok;
unsigned int j;
unsigned int compression;
long n;
#ifndef OPENSSL_NO_COMP
SSL_COMP *comp;
@ -1075,15 +1076,26 @@ int ssl3_get_server_hello(SSL *s)
s->hit = 0;
/* get the session-id length */
if (!PACKET_get_1(&pkt, &j)
|| (j > sizeof s->session->session_id)
|| (j > SSL3_SESSION_ID_SIZE)) {
/* Get the session-id. */
if (!PACKET_get_length_prefixed_1(&pkt, &session_id)) {
al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
goto f_err;
}
session_id_len = PACKET_remaining(&session_id);
if (session_id_len > sizeof s->session->session_id
|| session_id_len > SSL3_SESSION_ID_SIZE) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_SSL3_SESSION_ID_TOO_LONG);
goto f_err;
}
if (!PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
/*
* Check if we can resume the session based on external pre-shared secret.
* EAP-FAST (RFC 4851) supports two types of session resumption.
@ -1099,13 +1111,6 @@ int ssl3_get_server_hello(SSL *s)
if (s->version >= TLS1_VERSION && s->tls_session_secret_cb &&
s->session->tlsext_tick) {
SSL_CIPHER *pref_cipher = NULL;
PACKET bookmark = pkt;
if (!PACKET_forward(&pkt, j)
|| !PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
s->session->master_key_length = sizeof(s->session->master_key);
if (s->tls_session_secret_cb(s, s->session->master_key,
&s->session->master_key_length,
@ -1118,18 +1123,11 @@ int ssl3_get_server_hello(SSL *s)
al = SSL_AD_INTERNAL_ERROR;
goto f_err;
}
pkt = bookmark;
}
/* Get the session id */
if (!PACKET_get_bytes(&pkt, &session_id, j)) {
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
if (j != 0 && j == s->session->session_id_length
&& memcmp(session_id, s->session->session_id, j) == 0) {
if (session_id_len != 0 && session_id_len == s->session->session_id_length
&& memcmp(PACKET_data(&session_id), s->session->session_id,
session_id_len) == 0) {
if (s->sid_ctx_length != s->session->sid_ctx_length
|| memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
/* actually a client application bug */
@ -1152,15 +1150,13 @@ int ssl3_get_server_hello(SSL *s)
goto f_err;
}
}
s->session->session_id_length = j;
memcpy(s->session->session_id, session_id, j); /* j could be 0 */
s->session->session_id_length = session_id_len;
/* session_id_len could be 0 */
memcpy(s->session->session_id, PACKET_data(&session_id),
session_id_len);
}
if (!PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
c = ssl_get_cipher_by_char(s, cipherchars);
if (c == NULL) {
/* unknown cipher */
@ -1214,13 +1210,13 @@ int ssl3_get_server_hello(SSL *s)
goto f_err;
/* lets get the compression algorithm */
/* COMPRESSION */
if (!PACKET_get_1(&pkt, &j)) {
if (!PACKET_get_1(&pkt, &compression)) {
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
#ifdef OPENSSL_NO_COMP
if (j != 0) {
if (compression != 0) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
@ -1235,22 +1231,23 @@ int ssl3_get_server_hello(SSL *s)
goto f_err;
}
#else
if (s->hit && j != s->session->compress_meth) {
if (s->hit && compression != s->session->compress_meth) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
goto f_err;
}
if (j == 0)
if (compression == 0)
comp = NULL;
else if (!ssl_allow_compression(s)) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_COMPRESSION_DISABLED);
goto f_err;
} else
comp = ssl3_comp_find(s->ctx->comp_methods, j);
} else {
comp = ssl3_comp_find(s->ctx->comp_methods, compression);
}
if ((j != 0) && (comp == NULL)) {
if (compression != 0 && comp == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);