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Split ssl3_get_message

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The function ssl3_get_message gets a whole message from the underlying bio
and returns it to the state machine code. The new state machine code will
split this into two discrete steps: get the message header and get the
message body. This commit splits the existing function into these two
sub steps to facilitate the state machine implementation.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This commit is contained in:
Matt Caswell 2015-07-29 14:20:05 +01:00
parent 94b3664a52
commit 9ab930b27d
4 changed files with 175 additions and 119 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/openssl/ssl.h
View File

@ -2099,6 +2099,8 @@ void ERR_load_SSL_strings(void);
# define SSL_F_TLS1_PROCESS_HEARTBEAT 341
# define SSL_F_TLS1_SETUP_KEY_BLOCK 211
# define SSL_F_TLS1_SET_SERVER_SIGALGS 335
# define SSL_F_TLS_GET_MESSAGE_BODY 351
# define SSL_F_TLS_GET_MESSAGE_HEADER 350
# define SSL_F_USE_CERTIFICATE_CHAIN_FILE 220
/* Reason codes. */

288
ssl/s3_both.c
View File

@ -411,9 +411,8 @@ unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk)
long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
unsigned char *p;
unsigned long l;
long n;
int i, al, recvd_type;
int al, mtin;
if (s->s3->tmp.reuse_message) {
s->s3->tmp.reuse_message = 0;
@ -432,122 +431,168 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
p = (unsigned char *)s->init_buf->data;
if (s->state == st1) {
/* s->init_num < SSL3_HM_HEADER_LENGTH */
int skip_message;
do {
while (s->init_num < SSL3_HM_HEADER_LENGTH) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
&p[s->init_num], SSL3_HM_HEADER_LENGTH - s->init_num, 0);
if (i <= 0) {
s->rwstate = SSL_READING;
*ok = 0;
return i;
}
if (s->init_num == 0
&& recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC
&& (mt < 0 || mt == SSL3_MT_CHANGE_CIPHER_SPEC)) {
if (*p != SSL3_MT_CCS) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE,
SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
s->init_num = i - 1;
s->init_msg = p + 1;
s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
s->s3->tmp.message_size = i - 1;
s->state = stn;
*ok = 1;
if (s->msg_callback)
s->msg_callback(0, s->version,
SSL3_RT_CHANGE_CIPHER_SPEC, p, 1, s,
s->msg_callback_arg);
return i - 1;
} else if (recvd_type != SSL3_RT_HANDSHAKE) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
s->init_num += i;
if (tls_get_message_header(s, &mtin) == 0) {
/* Could be NBIO */
*ok = 0;
return -1;
}
s->state = stn;
if (s->init_num == 0
&& mtin == SSL3_MT_CHANGE_CIPHER_SPEC
&& (mt < 0 || mt == SSL3_MT_CHANGE_CIPHER_SPEC)) {
if (*p != SSL3_MT_CCS) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE,
SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
skip_message = 0;
if (!s->server)
if (p[0] == SSL3_MT_HELLO_REQUEST)
/*
* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them if
* their format is correct. Does not count for 'Finished'
* MAC.
*/
if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
s->init_num = 0;
skip_message = 1;
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, SSL3_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
}
} while (skip_message);
/* s->init_num == SSL3_HM_HEADER_LENGTH */
if ((mt >= 0) && (*p != mt)) {
s->init_msg = p + 1;
s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
s->s3->tmp.message_size = s->init_num;
*ok = 1;
if (s->msg_callback)
s->msg_callback(0, s->version,
SSL3_RT_CHANGE_CIPHER_SPEC, p, 1, s,
s->msg_callback_arg);
return s->init_num;
}
if (s->s3->tmp.message_size > (unsigned long)max) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if ((mt >= 0) && (mtin != mt)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
s->s3->tmp.message_type = *(p++);
if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
/*
* Only happens with SSLv3+ in an SSLv2 backward compatible
* ClientHello
*/
/*
* Total message size is the remaining record bytes to read
* plus the SSL3_HM_HEADER_LENGTH bytes that we already read
*/
l = RECORD_LAYER_get_rrec_length(&s->rlayer)
+ SSL3_HM_HEADER_LENGTH;
if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
goto err;
}
s->s3->tmp.message_size = l;
s->state = stn;
s->init_msg = s->init_buf->data;
s->init_num = SSL3_HM_HEADER_LENGTH;
} else {
n2l3(p, l);
if (l > (unsigned long)max) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
/* BUF_MEM_grow takes an 'int' parameter */
if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if (l && !BUF_MEM_grow_clean(s->init_buf,
(int)l + SSL3_HM_HEADER_LENGTH)) {
SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
goto err;
}
s->s3->tmp.message_size = l;
s->state = stn;
s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
s->init_num = 0;
}
}
/* next state (stn) */
if (tls_get_message_body(s, (unsigned long *)&n) == 0) {
*ok = 0;
return n;
}
*ok = 1;
return n;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
*ok = 0;
return 0;
}
int tls_get_message_header(SSL *s, int *mt)
{
/* s->init_num < SSL3_HM_HEADER_LENGTH */
int skip_message, i, recvd_type, al;
unsigned char *p;
unsigned long l;
p = (unsigned char *)s->init_buf->data;
do {
while (s->init_num < SSL3_HM_HEADER_LENGTH) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
&p[s->init_num], SSL3_HM_HEADER_LENGTH - s->init_num, 0);
if (i <= 0) {
s->rwstate = SSL_READING;
return 0;
}
if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
s->init_num = i - 1;
s->s3->tmp.message_size = i;
return 1;
} else if (recvd_type != SSL3_RT_HANDSHAKE) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
s->init_num += i;
}
skip_message = 0;
if (!s->server)
if (p[0] == SSL3_MT_HELLO_REQUEST)
/*
* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them if
* their format is correct. Does not count for 'Finished'
* MAC.
*/
if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
s->init_num = 0;
skip_message = 1;
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, SSL3_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
}
} while (skip_message);
/* s->init_num == SSL3_HM_HEADER_LENGTH */
*mt = *p;
s->s3->tmp.message_type = *(p++);
if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
/*
* Only happens with SSLv3+ in an SSLv2 backward compatible
* ClientHello
*/
/*
* Total message size is the remaining record bytes to read
* plus the SSL3_HM_HEADER_LENGTH bytes that we already read
*/
l = RECORD_LAYER_get_rrec_length(&s->rlayer)
+ SSL3_HM_HEADER_LENGTH;
if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
goto err;
}
s->s3->tmp.message_size = l;
s->init_msg = s->init_buf->data;
s->init_num = SSL3_HM_HEADER_LENGTH;
} else {
n2l3(p, l);
/* BUF_MEM_grow takes an 'int' parameter */
if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if (l && !BUF_MEM_grow_clean(s->init_buf,
(int)l + SSL3_HM_HEADER_LENGTH)) {
SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
goto err;
}
s->s3->tmp.message_size = l;
s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
s->init_num = 0;
}
return 1;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
return 0;
}
int tls_get_message_body(SSL *s, unsigned long *len)
{
long n;
unsigned char *p;
int i;
if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
/* We've already read everything in */
*len = (unsigned long)s->init_num;
return 1;
}
p = s->init_msg;
n = s->s3->tmp.message_size - s->init_num;
while (n > 0) {
@ -555,8 +600,8 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
&p[s->init_num], n, 0);
if (i <= 0) {
s->rwstate = SSL_READING;
*ok = 0;
return i;
*len = 0;
return 0;
}
s->init_num += i;
n -= i;
@ -586,13 +631,18 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
s->msg_callback_arg);
}
*ok = 1;
return s->init_num;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
*ok = 0;
return (-1);
/*
* init_num should never be negative...should probably be declared
* unsigned
*/
if (s->init_num < 0) {
SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
*len = 0;
return 0;
}
*len = (unsigned long)s->init_num;
return 1;
}
int ssl_cert_type(X509 *x, EVP_PKEY *pkey)

2
ssl/ssl_err.c
View File

@ -331,6 +331,8 @@ static ERR_STRING_DATA SSL_str_functs[] = {
{ERR_FUNC(SSL_F_TLS1_PROCESS_HEARTBEAT), "tls1_process_heartbeat"},
{ERR_FUNC(SSL_F_TLS1_SETUP_KEY_BLOCK), "tls1_setup_key_block"},
{ERR_FUNC(SSL_F_TLS1_SET_SERVER_SIGALGS), "tls1_set_server_sigalgs"},
{ERR_FUNC(SSL_F_TLS_GET_MESSAGE_BODY), "tls_get_message_body"},
{ERR_FUNC(SSL_F_TLS_GET_MESSAGE_HEADER), "tls_get_message_header"},
{ERR_FUNC(SSL_F_USE_CERTIFICATE_CHAIN_FILE), "use_certificate_chain_file"},
{0, NULL}
};

2
ssl/ssl_locl.h
View File

@ -1930,6 +1930,8 @@ __owur int ssl3_generate_master_secret(SSL *s, unsigned char *out,
unsigned char *p, int len);
__owur int ssl3_get_req_cert_type(SSL *s, unsigned char *p);
__owur long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok);
__owur int tls_get_message_header(SSL *s, int *mt);
__owur int tls_get_message_body(SSL *s, unsigned long *len);
__owur int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen);
__owur int ssl3_num_ciphers(void);
__owur const SSL_CIPHER *ssl3_get_cipher(unsigned int u);