in lib/openssl/ssl/record/ssl3_record.c [173:790]
int ssl3_get_record(SSL *s)
{
int enc_err, rret;
int i;
size_t more, n;
SSL3_RECORD *rr, *thisrr;
SSL3_BUFFER *rbuf;
SSL_SESSION *sess;
unsigned char *p;
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int version;
size_t mac_size;
int imac_size;
size_t num_recs = 0, max_recs, j;
PACKET pkt, sslv2pkt;
size_t first_rec_len;
rr = RECORD_LAYER_get_rrec(&s->rlayer);
rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
max_recs = s->max_pipelines;
if (max_recs == 0)
max_recs = 1;
sess = s->session;
do {
thisrr = &rr[num_recs];
/* check if we have the header */
if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
(RECORD_LAYER_get_packet_length(&s->rlayer)
< SSL3_RT_HEADER_LENGTH)) {
size_t sslv2len;
unsigned int type;
rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
SSL3_BUFFER_get_len(rbuf), 0,
num_recs == 0 ? 1 : 0, &n);
if (rret <= 0)
return rret; /* error or non-blocking */
RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
p = RECORD_LAYER_get_packet(&s->rlayer);
if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
RECORD_LAYER_get_packet_length(&s->rlayer))) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
sslv2pkt = pkt;
if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
|| !PACKET_get_1(&sslv2pkt, &type)) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* The first record received by the server may be a V2ClientHello.
*/
if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
&& (sslv2len & 0x8000) != 0
&& (type == SSL2_MT_CLIENT_HELLO)) {
/*
* SSLv2 style record
*
* |num_recs| here will actually always be 0 because
* |num_recs > 0| only ever occurs when we are processing
* multiple app data records - which we know isn't the case here
* because it is an SSLv2ClientHello. We keep it using
* |num_recs| for the sake of consistency
*/
thisrr->type = SSL3_RT_HANDSHAKE;
thisrr->rec_version = SSL2_VERSION;
thisrr->length = sslv2len & 0x7fff;
if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
- SSL2_RT_HEADER_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_PACKET_LENGTH_TOO_LONG);
return -1;
}
if (thisrr->length < MIN_SSL2_RECORD_LEN) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
SSL_R_LENGTH_TOO_SHORT);
return -1;
}
} else {
/* SSLv3+ style record */
if (s->msg_callback)
s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
s->msg_callback_arg);
/* Pull apart the header into the SSL3_RECORD */
if (!PACKET_get_1(&pkt, &type)
|| !PACKET_get_net_2(&pkt, &version)
|| !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
thisrr->type = type;
thisrr->rec_version = version;
/*
* Lets check version. In TLSv1.3 we only check this field
* when encryption is occurring (see later check). For the
* ServerHello after an HRR we haven't actually selected TLSv1.3
* yet, but we still treat it as TLSv1.3, so we must check for
* that explicitly
*/
if (!s->first_packet && !SSL_IS_TLS13(s)
&& s->hello_retry_request != SSL_HRR_PENDING
&& version != (unsigned int)s->version) {
if ((s->version & 0xFF00) == (version & 0xFF00)
&& !s->enc_write_ctx && !s->write_hash) {
if (thisrr->type == SSL3_RT_ALERT) {
/*
* The record is using an incorrect version number,
* but what we've got appears to be an alert. We
* haven't read the body yet to check whether its a
* fatal or not - but chances are it is. We probably
* shouldn't send a fatal alert back. We'll just
* end.
*/
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
return -1;
}
/*
* Send back error using their minor version number :-)
*/
s->version = (unsigned short)version;
}
SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
return -1;
}
if ((version >> 8) != SSL3_VERSION_MAJOR) {
if (RECORD_LAYER_is_first_record(&s->rlayer)) {
/* Go back to start of packet, look at the five bytes
* that we have. */
p = RECORD_LAYER_get_packet(&s->rlayer);
if (strncmp((char *)p, "GET ", 4) == 0 ||
strncmp((char *)p, "POST ", 5) == 0 ||
strncmp((char *)p, "HEAD ", 5) == 0 ||
strncmp((char *)p, "PUT ", 4) == 0) {
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
SSL_R_HTTP_REQUEST);
return -1;
} else if (strncmp((char *)p, "CONNE", 5) == 0) {
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
SSL_R_HTTPS_PROXY_REQUEST);
return -1;
}
/* Doesn't look like TLS - don't send an alert */
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
return -1;
} else {
SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
return -1;
}
}
if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
if (thisrr->type != SSL3_RT_APPLICATION_DATA
&& (thisrr->type != SSL3_RT_CHANGE_CIPHER_SPEC
|| !SSL_IS_FIRST_HANDSHAKE(s))
&& (thisrr->type != SSL3_RT_ALERT
|| s->statem.enc_read_state
!= ENC_READ_STATE_ALLOW_PLAIN_ALERTS)) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
return -1;
}
if (thisrr->rec_version != TLS1_2_VERSION) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
return -1;
}
}
if (thisrr->length >
SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_PACKET_LENGTH_TOO_LONG);
return -1;
}
}
/* now s->rlayer.rstate == SSL_ST_READ_BODY */
}
if (SSL_IS_TLS13(s)) {
if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
return -1;
}
} else {
size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
#ifndef OPENSSL_NO_COMP
/*
* If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
* does not include the compression overhead anyway.
*/
if (s->expand == NULL)
len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
#endif
if (thisrr->length > len) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
return -1;
}
}
/*
* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
* Calculate how much more data we need to read for the rest of the
* record
*/
if (thisrr->rec_version == SSL2_VERSION) {
more = thisrr->length + SSL2_RT_HEADER_LENGTH
- SSL3_RT_HEADER_LENGTH;
} else {
more = thisrr->length;
}
if (more > 0) {
/* now s->packet_length == SSL3_RT_HEADER_LENGTH */
rret = ssl3_read_n(s, more, more, 1, 0, &n);
if (rret <= 0)
return rret; /* error or non-blocking io */
}
/* set state for later operations */
RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
/*
* At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
* + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
* + thisrr->length and we have that many bytes in s->packet
*/
if (thisrr->rec_version == SSL2_VERSION) {
thisrr->input =
&(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
} else {
thisrr->input =
&(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
}
/*
* ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
* points at thisrr->length bytes, which need to be copied into
* thisrr->data by either the decryption or by the decompression When
* the data is 'copied' into the thisrr->data buffer, thisrr->input will
* be pointed at the new buffer
*/
/*
* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
* thisrr->length bytes of encrypted compressed stuff.
*/
/* decrypt in place in 'thisrr->input' */
thisrr->data = thisrr->input;
thisrr->orig_len = thisrr->length;
/* Mark this record as not read by upper layers yet */
thisrr->read = 0;
num_recs++;
/* we have pulled in a full packet so zero things */
RECORD_LAYER_reset_packet_length(&s->rlayer);
RECORD_LAYER_clear_first_record(&s->rlayer);
} while (num_recs < max_recs
&& thisrr->type == SSL3_RT_APPLICATION_DATA
&& SSL_USE_EXPLICIT_IV(s)
&& s->enc_read_ctx != NULL
&& (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
& EVP_CIPH_FLAG_PIPELINE)
&& ssl3_record_app_data_waiting(s));
if (num_recs == 1
&& thisrr->type == SSL3_RT_CHANGE_CIPHER_SPEC
&& (SSL_IS_TLS13(s) || s->hello_retry_request != SSL_HRR_NONE)
&& SSL_IS_FIRST_HANDSHAKE(s)) {
/*
* CCS messages must be exactly 1 byte long, containing the value 0x01
*/
if (thisrr->length != 1 || thisrr->data[0] != 0x01) {
SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SSL3_GET_RECORD,
SSL_R_INVALID_CCS_MESSAGE);
return -1;
}
/*
* CCS messages are ignored in TLSv1.3. We treat it like an empty
* handshake record
*/
thisrr->type = SSL3_RT_HANDSHAKE;
RECORD_LAYER_inc_empty_record_count(&s->rlayer);
if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
> MAX_EMPTY_RECORDS) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
SSL_R_UNEXPECTED_CCS_MESSAGE);
return -1;
}
thisrr->read = 1;
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
return 1;
}
/*
* If in encrypt-then-mac mode calculate mac from encrypted record. All
* the details below are public so no timing details can leak.
*/
if (SSL_READ_ETM(s) && s->read_hash) {
unsigned char *mac;
/* TODO(size_t): convert this to do size_t properly */
imac_size = EVP_MD_CTX_size(s->read_hash);
if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_LIB_EVP);
return -1;
}
mac_size = (size_t)imac_size;
for (j = 0; j < num_recs; j++) {
thisrr = &rr[j];
if (thisrr->length < mac_size) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
SSL_R_LENGTH_TOO_SHORT);
return -1;
}
thisrr->length -= mac_size;
mac = thisrr->data + thisrr->length;
i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
return -1;
}
}
}
first_rec_len = rr[0].length;
enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
/*-
* enc_err is:
* 0: (in non-constant time) if the record is publicly invalid.
* 1: if the padding is valid
* -1: if the padding is invalid
*/
if (enc_err == 0) {
if (ossl_statem_in_error(s)) {
/* SSLfatal() already got called */
return -1;
}
if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
/*
* Valid early_data that we cannot decrypt might fail here as
* publicly invalid. We treat it like an empty record.
*/
thisrr = &rr[0];
if (!early_data_count_ok(s, thisrr->length,
EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
/* SSLfatal() already called */
return -1;
}
thisrr->length = 0;
thisrr->read = 1;
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
RECORD_LAYER_reset_read_sequence(&s->rlayer);
return 1;
}
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
return -1;
}
#ifdef SSL_DEBUG
printf("dec %lu\n", (unsigned long)rr[0].length);
{
size_t z;
for (z = 0; z < rr[0].length; z++)
printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
}
printf("\n");
#endif
/* r->length is now the compressed data plus mac */
if ((sess != NULL) &&
(s->enc_read_ctx != NULL) &&
(!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
/* s->read_hash != NULL => mac_size != -1 */
unsigned char *mac = NULL;
unsigned char mac_tmp[EVP_MAX_MD_SIZE];
mac_size = EVP_MD_CTX_size(s->read_hash);
if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
for (j = 0; j < num_recs; j++) {
thisrr = &rr[j];
/*
* orig_len is the length of the record before any padding was
* removed. This is public information, as is the MAC in use,
* therefore we can safely process the record in a different amount
* of time if it's too short to possibly contain a MAC.
*/
if (thisrr->orig_len < mac_size ||
/* CBC records must have a padding length byte too. */
(EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
thisrr->orig_len < mac_size + 1)) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
SSL_R_LENGTH_TOO_SHORT);
return -1;
}
if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
/*
* We update the length so that the TLS header bytes can be
* constructed correctly but we need to extract the MAC in
* constant time from within the record, without leaking the
* contents of the padding bytes.
*/
mac = mac_tmp;
if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
thisrr->length -= mac_size;
} else {
/*
* In this case there's no padding, so |rec->orig_len| equals
* |rec->length| and we checked that there's enough bytes for
* |mac_size| above.
*/
thisrr->length -= mac_size;
mac = &thisrr->data[thisrr->length];
}
i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
if (i == 0 || mac == NULL
|| CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
enc_err = -1;
if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
enc_err = -1;
}
}
if (enc_err < 0) {
if (ossl_statem_in_error(s)) {
/* We already called SSLfatal() */
return -1;
}
if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
/*
* We assume this is unreadable early_data - we treat it like an
* empty record
*/
/*
* The record length may have been modified by the mac check above
* so we use the previously saved value
*/
if (!early_data_count_ok(s, first_rec_len,
EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
/* SSLfatal() already called */
return -1;
}
thisrr = &rr[0];
thisrr->length = 0;
thisrr->read = 1;
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
RECORD_LAYER_reset_read_sequence(&s->rlayer);
return 1;
}
/*
* A separate 'decryption_failed' alert was introduced with TLS 1.0,
* SSL 3.0 only has 'bad_record_mac'. But unless a decryption
* failure is directly visible from the ciphertext anyway, we should
* not reveal which kind of error occurred -- this might become
* visible to an attacker (e.g. via a logfile)
*/
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
return -1;
}
for (j = 0; j < num_recs; j++) {
thisrr = &rr[j];
/* thisrr->length is now just compressed */
if (s->expand != NULL) {
if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_COMPRESSED_LENGTH_TOO_LONG);
return -1;
}
if (!ssl3_do_uncompress(s, thisrr)) {
SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
SSL_R_BAD_DECOMPRESSION);
return -1;
}
}
if (SSL_IS_TLS13(s)
&& s->enc_read_ctx != NULL
&& thisrr->type != SSL3_RT_ALERT) {
size_t end;
if (thisrr->length == 0
|| thisrr->type != SSL3_RT_APPLICATION_DATA) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
SSL_R_BAD_RECORD_TYPE);
return -1;
}
/* Strip trailing padding */
for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
end--)
continue;
thisrr->length = end;
thisrr->type = thisrr->data[end];
if (thisrr->type != SSL3_RT_APPLICATION_DATA
&& thisrr->type != SSL3_RT_ALERT
&& thisrr->type != SSL3_RT_HANDSHAKE) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
SSL_R_BAD_RECORD_TYPE);
return -1;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
&thisrr->data[end], 1, s, s->msg_callback_arg);
}
/*
* TLSv1.3 alert and handshake records are required to be non-zero in
* length.
*/
if (SSL_IS_TLS13(s)
&& (thisrr->type == SSL3_RT_HANDSHAKE
|| thisrr->type == SSL3_RT_ALERT)
&& thisrr->length == 0) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
SSL_R_BAD_LENGTH);
return -1;
}
if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_DATA_LENGTH_TOO_LONG);
return -1;
}
/* If received packet overflows current Max Fragment Length setting */
if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
&& thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_DATA_LENGTH_TOO_LONG);
return -1;
}
thisrr->off = 0;
/*-
* So at this point the following is true
* thisrr->type is the type of record
* thisrr->length == number of bytes in record
* thisrr->off == offset to first valid byte
* thisrr->data == where to take bytes from, increment after use :-).
*/
/* just read a 0 length packet */
if (thisrr->length == 0) {
RECORD_LAYER_inc_empty_record_count(&s->rlayer);
if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
> MAX_EMPTY_RECORDS) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
SSL_R_RECORD_TOO_SMALL);
return -1;
}
} else {
RECORD_LAYER_reset_empty_record_count(&s->rlayer);
}
}
if (s->early_data_state == SSL_EARLY_DATA_READING) {
thisrr = &rr[0];
if (thisrr->type == SSL3_RT_APPLICATION_DATA
&& !early_data_count_ok(s, thisrr->length, 0, 0)) {
/* SSLfatal already called */
return -1;
}
}
RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
return 1;
}