int ssl_read_buffer_extend_to(SSL *ssl, size_t len) {
/* |ssl_read_buffer_extend_to| implicitly discards any consumed data. */
ssl_read_buffer_discard(ssl);
if (!setup_read_buffer(ssl)) {
return -1;
}
if (ssl->rbio == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BIO_NOT_SET);
return -1;
}
ERR_clear_system_error();
int ret;
if (SSL_IS_DTLS(ssl)) {
/* |len| is ignored for a datagram transport. */
ret = dtls_read_buffer_next_packet(ssl);
} else {
ret = tls_read_buffer_extend_to(ssl, len);
}
if (ret <= 0) {
/* If the buffer was empty originally and remained empty after attempting to
* extend it, release the buffer until the next attempt. */
ssl_read_buffer_discard(ssl);
}
return ret;
}
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;
}
static int consume_record(SSL *ssl, uint8_t *out, int len, int peek) {
SSL3_RECORD *rr = &ssl->s3->rrec;
if (len <= 0) {
return len;
}
if (len > (int)rr->length) {
len = (int)rr->length;
}
memcpy(out, rr->data, len);
if (!peek) {
rr->length -= len;
rr->data += len;
if (rr->length == 0) {
/* The record has been consumed, so we may now clear the buffer. */
ssl_read_buffer_discard(ssl);
}
}
return len;
}
/* 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 calls us)
* - 0 (during a shutdown, no data has to be returned)
*
* 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), ChangeCipherSpec records (not really
* a surprise, but handled as if it were), or renegotiation requests.
* Also if record payloads contain fragments too small to process, we store
* them until there is enough for the respective protocol (the record protocol
* may use arbitrary fragmentation and even interleaving):
* Change cipher spec protocol
* just 1 byte needed, no need for keeping anything stored
* Alert protocol
* 2 bytes needed (AlertLevel, AlertDescription)
* Handshake protocol
* 4 bytes needed (HandshakeType, uint24 length) -- we just have
* to detect unexpected Client Hello and Hello Request messages
* here, anything else is handled by higher layers
* Application data protocol
* none of our business
*/
int ssl3_read_bytes(SSL *s, int type, uint8_t *buf, int len, int peek) {
int al, i, ret;
unsigned int n;
SSL3_RECORD *rr;
void (*cb)(const SSL *ssl, int type2, int val) = NULL;
if ((type && 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;
}
if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment_len > 0) {
/* (partially) satisfy request from storage */
uint8_t *src = s->s3->handshake_fragment;
uint8_t *dst = buf;
unsigned int k;
/* peek == 0 */
n = 0;
while (len > 0 && s->s3->handshake_fragment_len > 0) {
*dst++ = *src++;
len--;
s->s3->handshake_fragment_len--;
n++;
}
/* move any remaining fragment bytes: */
for (k = 0; k < s->s3->handshake_fragment_len; k++) {
s->s3->handshake_fragment[k] = *src++;
}
return n;
}
/* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
/* This may require multiple iterations. False Start will cause
* |s->handshake_func| to signal success one step early, but the handshake
* must be completely finished before other modes are accepted.
*
* TODO(davidben): Move this check up to a higher level. */
while (!s->in_handshake && SSL_in_init(s)) {
assert(type == SSL3_RT_APPLICATION_DATA);
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
start:
s->rwstate = SSL_NOTHING;
/* s->s3->rrec.type - is the type of record
* s->s3->rrec.data - data
* s->s3->rrec.off - offset into 'data' for next read
* s->s3->rrec.length - number of bytes. */
rr = &s->s3->rrec;
/* get new packet if necessary */
if (rr->length == 0) {
ret = ssl3_get_record(s);
if (ret <= 0) {
return ret;
}
}
/* we now have a packet which can be read and processed */
/* |change_cipher_spec is set when we receive a ChangeCipherSpec and reset by
* ssl3_get_finished. */
if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE &&
rr->type != SSL3_RT_ALERT) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
goto f_err;
}
/* If we are expecting a ChangeCipherSpec, it is illegal to receive a
* Handshake record. */
if (rr->type == SSL3_RT_HANDSHAKE && (s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_HANDSHAKE_RECORD_BEFORE_CCS);
goto f_err;
}
/* If the other end has shut down, throw anything we read away (even in
* 'peek' mode) */
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
s->rwstate = SSL_NOTHING;
return 0;
}
if (type != 0 && type == rr->type) {
s->s3->warning_alert_count = 0;
/* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
/* make sure that we are not getting application data when we are doing a
* handshake for the first time */
if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
s->aead_read_ctx == NULL) {
/* TODO(davidben): Is this check redundant with the handshake_func
* check? */
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
/* 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[rr->off]), n);
if (!peek) {
rr->length -= n;
rr->off += n;
if (rr->length == 0) {
rr->off = 0;
/* The record has been consumed, so we may now clear the buffer. */
ssl_read_buffer_discard(s);
}
}
return n;
}
/* Process unexpected records. */
if (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 (s->server || !ssl3_can_renegotiate(s)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* HelloRequests may be fragmented across multiple records. */
const size_t size = sizeof(s->s3->handshake_fragment);
const size_t avail = size - s->s3->handshake_fragment_len;
const size_t todo = (rr->length < avail) ? rr->length : avail;
memcpy(s->s3->handshake_fragment + s->s3->handshake_fragment_len,
&rr->data[rr->off], todo);
rr->off += todo;
rr->length -= todo;
s->s3->handshake_fragment_len += todo;
if (s->s3->handshake_fragment_len < size) {
goto start; /* fragment was too small */
}
/* Parse out and consume a HelloRequest. */
if (s->s3->handshake_fragment[0] != SSL3_MT_HELLO_REQUEST ||
s->s3->handshake_fragment[1] != 0 ||
s->s3->handshake_fragment[2] != 0 ||
s->s3->handshake_fragment[3] != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HELLO_REQUEST);
goto f_err;
}
s->s3->handshake_fragment_len = 0;
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
}
if (!SSL_is_init_finished(s) || !s->s3->initial_handshake_complete) {
/* This cannot happen. If a handshake is in progress, |type| must be
* |SSL3_RT_HANDSHAKE|. */
assert(0);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
/* 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(s)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* Begin a new handshake. */
s->s3->total_renegotiations++;
s->state = SSL_ST_CONNECT;
i = s->handshake_func(s);
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;
}
/* If an alert record, process one alert out of the record. Note that we allow
* a single record to contain multiple alerts. */
if (rr->type == SSL3_RT_ALERT) {
/* Alerts may not be fragmented. */
if (rr->length < 2) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
goto f_err;
}
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_ALERT, &rr->data[rr->off], 2, s,
s->msg_callback_arg);
}
const uint8_t alert_level = rr->data[rr->off++];
const uint8_t alert_descr = rr->data[rr->off++];
rr->length -= 2;
if (s->info_callback != NULL) {
cb = s->info_callback;
} else if (s->ctx->info_callback != NULL) {
cb = s->ctx->info_callback;
}
if (cb != NULL) {
uint16_t alert = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, alert);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3->warn_alert = alert_descr;
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
/* This is a warning but we receive it if we requested renegotiation and
* the peer denied it. Terminate with a fatal alert because if
* application tried to renegotiatie it presumably had a good reason and
* expects it to succeed.
*
* In future we might have a renegotiation where we don't care if the
* peer refused it where we carry on. */
else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
s->s3->warning_alert_count++;
if (s->s3->warning_alert_count > kMaxWarningAlerts) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_WARNING_ALERTS);
goto f_err;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
SSL_CTX_remove_session(s->ctx, s->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
if (s->shutdown & SSL_SENT_SHUTDOWN) {
/* close_notify has been sent, so discard all records other than alerts. */
rr->length = 0;
goto start;
}
if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
/* 'Change Cipher Spec' is just a single byte, so we know exactly what the
* record payload has to look like */
if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC);
goto f_err;
}
/* Check we have a cipher to change to */
if (s->s3->tmp.new_cipher == NULL) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
if (!(s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
s->s3->flags &= ~SSL3_FLAGS_EXPECT_CCS;
rr->length = 0;
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s,
s->msg_callback_arg);
}
s->s3->change_cipher_spec = 1;
if (!ssl3_do_change_cipher_spec(s)) {
goto err;
} else {
goto start;
}
}
/* We already handled these. */
assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT &&
rr->type != SSL3_RT_HANDSHAKE);
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
return -1;
}
/* 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_CHANGE_CIPHER_SPEC (when ssl3_read_change_cipher_spec calls us)
* - SSL3_RT_APPLICATION_DATA (when ssl3_read_app_data calls us)
* - 0 (during a shutdown, no data has to be returned)
*
* 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;
void (*cb)(const SSL *ssl, int type, int value) = NULL;
if ((type && type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE &&
type != SSL3_RT_CHANGE_CIPHER_SPEC) ||
(peek && type != SSL3_RT_APPLICATION_DATA)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
start:
ssl->rwstate = SSL_NOTHING;
/* 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 the other end has shut down, throw anything we read away (even in
* 'peek' mode) */
if (ssl->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
ssl->rwstate = SSL_NOTHING;
return 0;
}
if (type != 0 && type == rr->type) {
ssl->s3->warning_alert_count = 0;
/* Make sure that we are not getting application data when we are doing a
* handshake for the first time. */
if (SSL_in_init(ssl) && type == SSL3_RT_APPLICATION_DATA &&
ssl->s3->aead_read_ctx == NULL) {
/* TODO(davidben): Is this check redundant with the handshake_func
* check? */
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
/* 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;
if (ssl->msg_callback) {
ssl->msg_callback(0, ssl->version, SSL3_RT_HANDSHAKE, kHelloRequest,
sizeof(kHelloRequest), ssl, ssl->msg_callback_arg);
}
if (!SSL_is_init_finished(ssl) || !ssl->s3->initial_handshake_complete) {
/* This cannot happen. If a handshake is in progress, |type| must be
* |SSL3_RT_HANDSHAKE|. */
assert(0);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
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;
}
/* If an alert record, process one alert out of the record. Note that we allow
* a single record to contain multiple alerts. */
if (rr->type == SSL3_RT_ALERT) {
/* Alerts may not be fragmented. */
if (rr->length < 2) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
goto f_err;
}
if (ssl->msg_callback) {
ssl->msg_callback(0, ssl->version, SSL3_RT_ALERT, rr->data, 2, ssl,
ssl->msg_callback_arg);
}
const uint8_t alert_level = rr->data[0];
const uint8_t alert_descr = rr->data[1];
rr->length -= 2;
rr->data += 2;
if (ssl->info_callback != NULL) {
cb = ssl->info_callback;
} else if (ssl->ctx->info_callback != NULL) {
cb = ssl->ctx->info_callback;
}
if (cb != NULL) {
uint16_t alert = (alert_level << 8) | alert_descr;
cb(ssl, SSL_CB_READ_ALERT, alert);
}
if (alert_level == SSL3_AL_WARNING) {
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
ssl->s3->clean_shutdown = 1;
ssl->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
/* This is a warning but we receive it if we requested renegotiation and
* the peer denied it. Terminate with a fatal alert because if
* application tried to renegotiatie it presumably had a good reason and
* expects it to succeed.
*
* In future we might have a renegotiation where we don't care if the
* peer refused it where we carry on. */
else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
ssl->s3->warning_alert_count++;
if (ssl->s3->warning_alert_count > kMaxWarningAlerts) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_WARNING_ALERTS);
goto f_err;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
ssl->rwstate = SSL_NOTHING;
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
ssl->shutdown |= SSL_RECEIVED_SHUTDOWN;
SSL_CTX_remove_session(ssl->ctx, ssl->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
if (ssl->shutdown & SSL_SENT_SHUTDOWN) {
/* close_notify has been sent, so discard all records other than alerts. */
rr->length = 0;
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);
err:
return -1;
}
/* 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;
}
/* Return up to 'len' payload bytes received in 'type' records.
* 'type' is one of the following:
*
* - SSL3_RT_HANDSHAKE (when dtls1_get_message calls us)
* - SSL3_RT_CHANGE_CIPHER_SPEC (when dtls1_read_change_cipher_spec calls us)
* - SSL3_RT_APPLICATION_DATA (when dtls1_read_app_data calls us)
*
* If we don't have stored data to work from, read a DTLS 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) and out of records. */
int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) {
int al, i, ret;
unsigned int n;
SSL3_RECORD *rr;
void (*cb)(const SSL *ssl, int type, int value) = NULL;
if ((type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE &&
type != SSL3_RT_CHANGE_CIPHER_SPEC) ||
(peek && type != SSL3_RT_APPLICATION_DATA)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
if (!s->in_handshake && SSL_in_init(s)) {
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
start:
s->rwstate = SSL_NOTHING;
/* s->s3->rrec.type - is the type of record
* s->s3->rrec.data - data
* s->s3->rrec.off - offset into 'data' for next read
* s->s3->rrec.length - number of bytes. */
rr = &s->s3->rrec;
/* Check for timeout */
if (DTLSv1_handle_timeout(s) > 0) {
goto start;
}
/* get new packet if necessary */
if (rr->length == 0) {
ret = dtls1_get_record(s);
if (ret <= 0) {
ret = dtls1_read_failed(s, ret);
/* anything other than a timeout is an error */
if (ret <= 0) {
return ret;
} else {
goto start;
}
}
}
/* we now have a packet which can be read and processed */
/* If the other end has shut down, throw anything we read away (even in
* 'peek' mode) */
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
s->rwstate = SSL_NOTHING;
return 0;
}
if (type == rr->type) {
/* Make sure that we are not getting application data when we
* are doing a handshake for the first time. */
if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
(s->aead_read_ctx == NULL)) {
/* TODO(davidben): Is this check redundant with the handshake_func
* check? */
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
/* 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(s);
}
}
return n;
}
/* If we get here, then type != rr->type. */
/* If an alert record, process one alert out of the record. Note that we allow
* a single record to contain multiple alerts. */
if (rr->type == SSL3_RT_ALERT) {
/* Alerts may not be fragmented. */
if (rr->length < 2) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
goto f_err;
}
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_ALERT, rr->data, 2, s,
s->msg_callback_arg);
}
const uint8_t alert_level = rr->data[0];
const uint8_t alert_descr = rr->data[1];
rr->length -= 2;
rr->data += 2;
if (s->info_callback != NULL) {
cb = s->info_callback;
} else if (s->ctx->info_callback != NULL) {
cb = s->ctx->info_callback;
}
if (cb != NULL) {
uint16_t alert = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, alert);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3->warn_alert = alert_descr;
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
SSL_CTX_remove_session(s->ctx, s->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
/* Cross-epoch records are discarded, but we may receive out-of-order
* application data between ChangeCipherSpec and Finished or a ChangeCipherSpec
* before the appropriate point in the handshake. Those must be silently
* discarded.
*
* However, only allow the out-of-order records in the correct epoch.
* Application data must come in the encrypted epoch, and ChangeCipherSpec in
* the unencrypted epoch (we never renegotiate). Other cases fall through and
* fail with a fatal error. */
if ((rr->type == SSL3_RT_APPLICATION_DATA && s->aead_read_ctx != NULL) ||
(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC && s->aead_read_ctx == NULL)) {
rr->length = 0;
goto start;
}
if (rr->type == SSL3_RT_HANDSHAKE) {
if (type != SSL3_RT_APPLICATION_DATA) {
/* Out-of-order handshake record while looking for ChangeCipherSpec. Drop
* it silently. */
assert(type == SSL3_RT_CHANGE_CIPHER_SPEC);
rr->length = 0;
goto start;
}
/* Parse the first fragment header to determine if this is a pre-CCS or
* post-CCS handshake record. DTLS resets handshake message numbers on each
* handshake, so renegotiations and retransmissions are ambiguous. */
if (rr->length < DTLS1_HM_HEADER_LENGTH) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
goto f_err;
}
struct hm_header_st msg_hdr;
dtls1_get_message_header(rr->data, &msg_hdr);
if (msg_hdr.type == SSL3_MT_FINISHED) {
if (msg_hdr.frag_off == 0) {
/* Retransmit our last flight of messages. If the peer sends the second
* Finished, they may not have received ours. Only do this for the
* first fragment, in case the Finished was fragmented. */
if (dtls1_check_timeout_num(s) < 0) {
return -1;
}
dtls1_retransmit_buffered_messages(s);
}
rr->length = 0;
goto start;
}
/* Otherwise, this is a pre-CCS handshake message from an unsupported
* renegotiation attempt. Fall through to the error path. */
}
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
}