int ssl3_read_change_cipher_spec(SSL *ssl) {
SSL3_RECORD *rr = &ssl->s3->rrec;
if (rr->length == 0) {
int ret = ssl3_get_record(ssl);
if (ret <= 0) {
return ret;
}
}
if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
return -1;
}
if (rr->length != 1 || rr->data[0] != SSL3_MT_CCS) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return -1;
}
ssl_do_msg_callback(ssl, 0 /* read */, ssl->version,
SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, rr->length);
rr->length = 0;
ssl_read_buffer_discard(ssl);
return 1;
}
/* ssl3_do_write sends |ssl->init_buf| in records of type 'type'
* (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC). It returns 1 on success
* and <= 0 on error. */
int ssl3_do_write(SSL *ssl, int type) {
int ret = ssl3_write_bytes(ssl, type, ssl->init_buf->data, ssl->init_num);
if (ret <= 0) {
return ret;
}
/* ssl3_write_bytes writes the data in its entirety. */
assert(ret == ssl->init_num);
ssl_do_msg_callback(ssl, 1 /* write */, ssl->version, type,
ssl->init_buf->data, (size_t)ssl->init_num);
ssl->init_num = 0;
return 1;
}
int ssl3_dispatch_alert(SSL *ssl) {
ssl->s3->alert_dispatch = 0;
int ret = do_ssl3_write(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2);
if (ret <= 0) {
ssl->s3->alert_dispatch = 1;
return ret;
}
/* If the alert is fatal, flush the BIO now. */
if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {
BIO_flush(ssl->wbio);
}
ssl_do_msg_callback(ssl, 1 /* write */, ssl->version, SSL3_RT_ALERT,
ssl->s3->send_alert, 2);
int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1];
ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, alert);
return 1;
}
/* Obtain handshake message of message type |msg_type| (any if |msg_type| ==
* -1). */
long ssl3_get_message(SSL *ssl, int msg_type,
enum ssl_hash_message_t hash_message, int *ok) {
*ok = 0;
if (ssl->s3->tmp.reuse_message) {
/* A ssl_dont_hash_message call cannot be combined with reuse_message; the
* ssl_dont_hash_message would have to have been applied to the previous
* call. */
assert(hash_message == ssl_hash_message);
assert(ssl->s3->tmp.message_complete);
ssl->s3->tmp.reuse_message = 0;
if (msg_type >= 0 && ssl->s3->tmp.message_type != msg_type) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
return -1;
}
*ok = 1;
assert(ssl->init_buf->length >= 4);
ssl->init_msg = (uint8_t *)ssl->init_buf->data + 4;
ssl->init_num = (int)ssl->init_buf->length - 4;
return ssl->init_num;
}
again:
if (ssl->s3->tmp.message_complete) {
ssl->s3->tmp.message_complete = 0;
ssl->init_buf->length = 0;
}
/* Read the message header, if we haven't yet. */
int ret = extend_handshake_buffer(ssl, 4);
if (ret <= 0) {
return ret;
}
/* Parse out the length. Cap it so the peer cannot force us to buffer up to
* 2^24 bytes. */
const uint8_t *p = (uint8_t *)ssl->init_buf->data;
size_t msg_len = (((uint32_t)p[1]) << 16) | (((uint32_t)p[2]) << 8) | p[3];
if (msg_len > ssl_max_handshake_message_len(ssl)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE);
return -1;
}
/* Read the message body, if we haven't yet. */
ret = extend_handshake_buffer(ssl, 4 + msg_len);
if (ret <= 0) {
return ret;
}
/* We have now received a complete message. */
ssl->s3->tmp.message_complete = 1;
ssl_do_msg_callback(ssl, 0 /* read */, ssl->version, SSL3_RT_HANDSHAKE,
ssl->init_buf->data, ssl->init_buf->length);
static const uint8_t kHelloRequest[4] = {SSL3_MT_HELLO_REQUEST, 0, 0, 0};
if (!ssl->server && ssl->init_buf->length == sizeof(kHelloRequest) &&
memcmp(kHelloRequest, ssl->init_buf->data, sizeof(kHelloRequest)) == 0) {
/* 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. */
goto again;
}
uint8_t actual_type = ((const uint8_t *)ssl->init_buf->data)[0];
if (msg_type >= 0 && actual_type != msg_type) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
return -1;
}
ssl->s3->tmp.message_type = actual_type;
ssl->init_msg = (uint8_t*)ssl->init_buf->data + 4;
ssl->init_num = ssl->init_buf->length - 4;
/* Feed this message into MAC computation. */
if (hash_message == ssl_hash_message && !ssl3_hash_current_message(ssl)) {
return -1;
}
*ok = 1;
return ssl->init_num;
}
/* Return up to 'len' payload bytes received in 'type' records.
* 'type' is one of the following:
*
* - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
* - SSL3_RT_APPLICATION_DATA (when ssl3_read_app_data calls us)
*
* If we don't have stored data to work from, read a SSL/TLS record first
* (possibly multiple records if we still don't have anything to return).
*
* This function must handle any surprises the peer may have for us, such as
* Alert records (e.g. close_notify) or renegotiation requests. */
int ssl3_read_bytes(SSL *ssl, int type, uint8_t *buf, int len, int peek) {
int al, i, ret;
unsigned int n;
SSL3_RECORD *rr;
if ((type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) ||
(peek && type != SSL3_RT_APPLICATION_DATA)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
start:
/* ssl->s3->rrec.type - is the type of record
* ssl->s3->rrec.data - data
* ssl->s3->rrec.off - offset into 'data' for next read
* ssl->s3->rrec.length - number of bytes. */
rr = &ssl->s3->rrec;
/* get new packet if necessary */
if (rr->length == 0) {
ret = ssl3_get_record(ssl);
if (ret <= 0) {
return ret;
}
}
/* we now have a packet which can be read and processed */
if (type == rr->type) {
/* Discard empty records. */
if (rr->length == 0) {
goto start;
}
if (len <= 0) {
return len;
}
if ((unsigned int)len > rr->length) {
n = rr->length;
} else {
n = (unsigned int)len;
}
memcpy(buf, rr->data, n);
if (!peek) {
rr->length -= n;
rr->data += n;
if (rr->length == 0) {
/* The record has been consumed, so we may now clear the buffer. */
ssl_read_buffer_discard(ssl);
}
}
return n;
}
/* Process unexpected records. */
if (type == SSL3_RT_APPLICATION_DATA && rr->type == SSL3_RT_HANDSHAKE) {
/* If peer renegotiations are disabled, all out-of-order handshake records
* are fatal. Renegotiations as a server are never supported. */
if (ssl->server || !ssl3_can_renegotiate(ssl)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* This must be a HelloRequest, possibly fragmented over multiple records.
* Consume data from the handshake protocol until it is complete. */
static const uint8_t kHelloRequest[] = {SSL3_MT_HELLO_REQUEST, 0, 0, 0};
while (ssl->s3->hello_request_len < sizeof(kHelloRequest)) {
if (rr->length == 0) {
/* Get a new record. */
goto start;
}
if (rr->data[0] != kHelloRequest[ssl->s3->hello_request_len]) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HELLO_REQUEST);
goto f_err;
}
rr->data++;
rr->length--;
ssl->s3->hello_request_len++;
}
ssl->s3->hello_request_len = 0;
ssl_do_msg_callback(ssl, 0 /* read */, ssl->version, SSL3_RT_HANDSHAKE,
kHelloRequest, sizeof(kHelloRequest));
if (ssl->renegotiate_mode == ssl_renegotiate_ignore) {
goto start;
}
/* Renegotiation is only supported at quiescent points in the application
* protocol, namely in HTTPS, just before reading the HTTP response. Require
* the record-layer be idle and avoid complexities of sending a handshake
* record while an application_data record is being written. */
if (ssl_write_buffer_is_pending(ssl)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* Begin a new handshake. */
ssl->s3->total_renegotiations++;
ssl->state = SSL_ST_CONNECT;
i = ssl->handshake_func(ssl);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
/* The handshake completed synchronously. Continue reading records. */
goto start;
}
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
return -1;
}
