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openssl/ssl/record/ssl3_record.c
Matt Caswell 2d9f56e999 Ensure TLS padding is added during encryption on the provider side 
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12288)
2020-07-06 09:26:09 +01:00

1936 lines
68 KiB
C
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/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "../ssl_local.h"
#include <openssl/trace.h>
#include <openssl/rand.h>
#include <openssl/core_names.h>
#include "record_local.h"
#include "internal/cryptlib.h"
static const unsigned char ssl3_pad_1[48] = {
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
};
static const unsigned char ssl3_pad_2[48] = {
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
};
/*
* Clear the contents of an SSL3_RECORD but retain any memory allocated
*/
void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
{
unsigned char *comp;
size_t i;
for (i = 0; i < num_recs; i++) {
comp = r[i].comp;
memset(&r[i], 0, sizeof(*r));
r[i].comp = comp;
}
}
void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
{
size_t i;
for (i = 0; i < num_recs; i++) {
OPENSSL_free(r[i].comp);
r[i].comp = NULL;
}
}
void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
{
memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
}
/*
* Peeks ahead into "read_ahead" data to see if we have a whole record waiting
* for us in the buffer.
*/
static int ssl3_record_app_data_waiting(SSL *s)
{
SSL3_BUFFER *rbuf;
size_t left, len;
unsigned char *p;
rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
p = SSL3_BUFFER_get_buf(rbuf);
if (p == NULL)
return 0;
left = SSL3_BUFFER_get_left(rbuf);
if (left < SSL3_RT_HEADER_LENGTH)
return 0;
p += SSL3_BUFFER_get_offset(rbuf);
/*
* We only check the type and record length, we will sanity check version
* etc later
*/
if (*p != SSL3_RT_APPLICATION_DATA)
return 0;
p += 3;
n2s(p, len);
if (left < SSL3_RT_HEADER_LENGTH + len)
return 0;
return 1;
}
int early_data_count_ok(SSL *s, size_t length, size_t overhead, int send)
{
uint32_t max_early_data;
SSL_SESSION *sess = s->session;
/*
* If we are a client then we always use the max_early_data from the
* session/psksession. Otherwise we go with the lowest out of the max early
* data set in the session and the configured max_early_data.
*/
if (!s->server && sess->ext.max_early_data == 0) {
if (!ossl_assert(s->psksession != NULL
&& s->psksession->ext.max_early_data > 0)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_EARLY_DATA_COUNT_OK,
ERR_R_INTERNAL_ERROR);
return 0;
}
sess = s->psksession;
}
if (!s->server)
max_early_data = sess->ext.max_early_data;
else if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED)
max_early_data = s->recv_max_early_data;
else
max_early_data = s->recv_max_early_data < sess->ext.max_early_data
? s->recv_max_early_data : sess->ext.max_early_data;
if (max_early_data == 0) {
SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
return 0;
}
/* If we are dealing with ciphertext we need to allow for the overhead */
max_early_data += overhead;
if (s->early_data_count + length > max_early_data) {
SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
return 0;
}
s->early_data_count += length;
return 1;
}
/*
* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
* will be processed per call to ssl3_get_record. Without this limit an
* attacker could send empty records at a faster rate than we can process and
* cause ssl3_get_record to loop forever.
*/
#define MAX_EMPTY_RECORDS 32
#define SSL2_RT_HEADER_LENGTH 2
/*-
* Call this to get new input records.
* It will return <= 0 if more data is needed, normally due to an error
* or non-blocking IO.
* When it finishes, |numrpipes| records have been decoded. For each record 'i':
* rr[i].type - is the type of record
* rr[i].data, - data
* rr[i].length, - number of bytes
* Multiple records will only be returned if the record types are all
* SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
* |max_pipelines|
*/
/* used only by ssl3_read_bytes */
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 = 0;
int imac_size;
size_t num_recs = 0, max_recs, j;
PACKET pkt, sslv2pkt;
int is_ktls_left;
SSL_MAC_BUF *macbufs = NULL;
int ret = -1;
rr = RECORD_LAYER_get_rrec(&s->rlayer);
rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
is_ktls_left = (rbuf->left > 0);
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) {
#ifndef OPENSSL_NO_KTLS
if (!BIO_get_ktls_recv(s->rbio))
return rret; /* error or non-blocking */
switch (errno) {
case EBADMSG:
SSLfatal(s, SSL_AD_BAD_RECORD_MAC,
SSL_F_SSL3_GET_RECORD,
SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
break;
case EMSGSIZE:
SSLfatal(s, SSL_AD_RECORD_OVERFLOW,
SSL_F_SSL3_GET_RECORD,
SSL_R_PACKET_LENGTH_TOO_LONG);
break;
case EINVAL:
SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
SSL_F_SSL3_GET_RECORD,
SSL_R_WRONG_VERSION_NUMBER);
break;
default:
break;
}
#endif
return rret;
}
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 && !BIO_get_ktls_recv(s->rbio)) {
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;
}
/*
* KTLS reads full records. If there is any data left,
* then it is from before enabling ktls
*/
if (BIO_get_ktls_recv(s->rbio) && !is_ktls_left)
goto skip_decryption;
/* TODO(size_t): convert this to do size_t properly */
if (s->read_hash != NULL) {
const EVP_MD *tmpmd = EVP_MD_CTX_md(s->read_hash);
if (tmpmd != NULL) {
imac_size = EVP_MD_size(tmpmd);
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;
}
}
/*
* 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;
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;
}
}
/*
* We've handled the mac now - there is no MAC inside the encrypted
* record
*/
mac_size = 0;
}
if (mac_size > 0) {
macbufs = OPENSSL_zalloc(sizeof(*macbufs) * num_recs);
if (macbufs == NULL) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
ERR_R_MALLOC_FAILURE);
return -1;
}
}
enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0, macbufs, mac_size);
/*-
* enc_err is:
* 0: if the record is publicly invalid, or an internal error, or AEAD
* decryption failed, or ETM decryption failed.
* 1: Success or MTE decryption failed (MAC will be randomised)
*/
if (enc_err == 0) {
if (ossl_statem_in_error(s)) {
/* SSLfatal() already got called */
goto end;
}
if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
/*
* Valid early_data that we cannot decrypt will fail here. 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 */
goto end;
}
thisrr->length = 0;
thisrr->read = 1;
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
RECORD_LAYER_reset_read_sequence(&s->rlayer);
ret = 1;
goto end;
}
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
goto end;
}
OSSL_TRACE_BEGIN(TLS) {
BIO_printf(trc_out, "dec %lu\n", (unsigned long)rr[0].length);
BIO_dump_indent(trc_out, rr[0].data, rr[0].length, 4);
} OSSL_TRACE_END(TLS);
/* 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 */
for (j = 0; j < num_recs; j++) {
SSL_MAC_BUF *thismb = &macbufs[j];
thisrr = &rr[j];
i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
if (i == 0 || thismb == NULL || thismb->mac == NULL
|| CRYPTO_memcmp(md, thismb->mac, (size_t)mac_size) != 0)
enc_err = 0;
if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
enc_err = 0;
}
}
if (enc_err == 0) {
if (ossl_statem_in_error(s)) {
/* We already called SSLfatal() */
goto end;
}
/*
* 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);
goto end;
}
skip_decryption:
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);
goto end;
}
if (!ssl3_do_uncompress(s, thisrr)) {
SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
SSL_R_BAD_DECOMPRESSION);
goto end;
}
}
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);
goto end;
}
/* 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);
goto end;
}
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);
goto end;
}
if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH && !BIO_get_ktls_recv(s->rbio)) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_DATA_LENGTH_TOO_LONG);
goto end;
}
/* 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)
&& !BIO_get_ktls_recv(s->rbio)) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
SSL_R_DATA_LENGTH_TOO_LONG);
goto end;
}
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);
goto end;
}
} 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 */
goto end;
}
}
RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
ret = 1;
end:
if (macbufs != NULL) {
for (j = 0; j < num_recs; j++) {
if (macbufs[j].alloced)
OPENSSL_free(macbufs[j].mac);
}
OPENSSL_free(macbufs);
}
return ret;
}
int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
{
#ifndef OPENSSL_NO_COMP
int i;
if (rr->comp == NULL) {
rr->comp = (unsigned char *)
OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
}
if (rr->comp == NULL)
return 0;
/* TODO(size_t): Convert this call */
i = COMP_expand_block(ssl->expand, rr->comp,
SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
if (i < 0)
return 0;
else
rr->length = i;
rr->data = rr->comp;
#endif
return 1;
}
int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
{
#ifndef OPENSSL_NO_COMP
int i;
/* TODO(size_t): Convert this call */
i = COMP_compress_block(ssl->compress, wr->data,
(int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
wr->input, (int)wr->length);
if (i < 0)
return 0;
else
wr->length = i;
wr->input = wr->data;
#endif
return 1;
}
/*-
* ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|. Calls SSLfatal on
* internal error, but not otherwise. It is the responsibility of the caller to
* report a bad_record_mac
*
* Returns:
* 0: if the record is publicly invalid, or an internal error
* 1: Success or Mac-then-encrypt decryption failed (MAC will be randomised)
*/
int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending,
SSL_MAC_BUF *mac, size_t macsize)
{
SSL3_RECORD *rec;
EVP_CIPHER_CTX *ds;
size_t l, i;
size_t bs;
const EVP_CIPHER *enc;
rec = inrecs;
/*
* We shouldn't ever be called with more than one record in the SSLv3 case
*/
if (n_recs != 1)
return 0;
if (sending) {
ds = s->enc_write_ctx;
if (s->enc_write_ctx == NULL)
enc = NULL;
else
enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
} else {
ds = s->enc_read_ctx;
if (s->enc_read_ctx == NULL)
enc = NULL;
else
enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
}
if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
memmove(rec->data, rec->input, rec->length);
rec->input = rec->data;
} else {
int provided = (EVP_CIPHER_provider(enc) != NULL);
l = rec->length;
/* TODO(size_t): Convert this call */
bs = EVP_CIPHER_CTX_block_size(ds);
/* COMPRESS */
if ((bs != 1) && sending && !provided) {
/*
* We only do this for legacy ciphers. Provided ciphers add the
* padding on the provider side.
*/
i = bs - (l % bs);
/* we need to add 'i-1' padding bytes */
l += i;
/*
* the last of these zero bytes will be overwritten with the
* padding length.
*/
memset(&rec->input[rec->length], 0, i);
rec->length += i;
rec->input[l - 1] = (unsigned char)(i - 1);
}
if (!sending) {
if (l == 0 || l % bs != 0) {
/* Publicly invalid */
return 0;
}
/* otherwise, rec->length >= bs */
}
if (EVP_CIPHER_provider(enc) != NULL) {
int outlen;
if (!EVP_CipherUpdate(ds, rec->data, &outlen, rec->input,
(unsigned int)l))
return 0;
rec->length = outlen;
if (!sending && mac != NULL) {
/* Now get a pointer to the MAC */
OSSL_PARAM params[2], *p = params;
/* Get the MAC */
mac->alloced = 0;
*p++ = OSSL_PARAM_construct_octet_ptr(OSSL_CIPHER_PARAM_TLS_MAC,
(void **)&mac->mac,
macsize);
*p = OSSL_PARAM_construct_end();
if (!EVP_CIPHER_CTX_get_params(ds, params)) {
/* Shouldn't normally happen */
SSLfatal(s, SSL_AD_INTERNAL_ERROR, 0,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
} else {
/* TODO(size_t): Convert this call */
if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1) {
/* Shouldn't happen */
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, 0, ERR_R_INTERNAL_ERROR);
return 0;
}
if (!sending)
return ssl3_cbc_remove_padding_and_mac(&rec->length,
rec->orig_len,
rec->data,
(mac != NULL) ? &mac->mac : NULL,
(mac != NULL) ? &mac->alloced : NULL,
bs,
macsize,
s->ctx->libctx);
}
}
return 1;
}
#define MAX_PADDING 256
/*-
* tls1_enc encrypts/decrypts |n_recs| in |recs|. Calls SSLfatal on internal
* error, but not otherwise. It is the responsibility of the caller to report
* a bad_record_mac - if appropriate (DTLS just drops the record).
*
* Returns:
* 0: if the record is publicly invalid, or an internal error, or AEAD
* decryption failed, or Encrypt-then-mac decryption failed.
* 1: Success or Mac-then-encrypt decryption failed (MAC will be randomised)
*/
int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending,
SSL_MAC_BUF *macs, size_t macsize)
{
EVP_CIPHER_CTX *ds;
size_t reclen[SSL_MAX_PIPELINES];
unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
int i, pad = 0, tmpr;
size_t bs, ctr, padnum, loop;
unsigned char padval;
const EVP_CIPHER *enc;
int tlstree_enc = sending ? (s->mac_flags & SSL_MAC_FLAG_WRITE_MAC_TLSTREE)
: (s->mac_flags & SSL_MAC_FLAG_READ_MAC_TLSTREE);
if (n_recs == 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
if (sending) {
if (EVP_MD_CTX_md(s->write_hash)) {
int n = EVP_MD_CTX_size(s->write_hash);
if (!ossl_assert(n >= 0)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
ds = s->enc_write_ctx;
if (s->enc_write_ctx == NULL)
enc = NULL;
else {
int ivlen;
enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
/* For TLSv1.1 and later explicit IV */
if (SSL_USE_EXPLICIT_IV(s)
&& EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
ivlen = EVP_CIPHER_iv_length(enc);
else
ivlen = 0;
if (ivlen > 1) {
for (ctr = 0; ctr < n_recs; ctr++) {
if (recs[ctr].data != recs[ctr].input) {
/*
* we can't write into the input stream: Can this ever
* happen?? (steve)
*/
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
} else if (RAND_bytes_ex(s->ctx->libctx, recs[ctr].input,
ivlen) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
}
}
} else {
if (EVP_MD_CTX_md(s->read_hash)) {
int n = EVP_MD_CTX_size(s->read_hash);
if (!ossl_assert(n >= 0)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
ds = s->enc_read_ctx;
if (s->enc_read_ctx == NULL)
enc = NULL;
else
enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
}
if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
for (ctr = 0; ctr < n_recs; ctr++) {
memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
recs[ctr].input = recs[ctr].data;
}
} else {
int provided = (EVP_CIPHER_provider(enc) != NULL);
bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
if (n_recs > 1) {
if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
& EVP_CIPH_FLAG_PIPELINE)) {
/*
* We shouldn't have been called with pipeline data if the
* cipher doesn't support pipelining
*/
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
SSL_R_PIPELINE_FAILURE);
return 0;
}
}
for (ctr = 0; ctr < n_recs; ctr++) {
reclen[ctr] = recs[ctr].length;
if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
& EVP_CIPH_FLAG_AEAD_CIPHER) {
unsigned char *seq;
seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
: RECORD_LAYER_get_read_sequence(&s->rlayer);
if (SSL_IS_DTLS(s)) {
/* DTLS does not support pipelining */
unsigned char dtlsseq[9], *p = dtlsseq;
s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
memcpy(p, &seq[2], 6);
memcpy(buf[ctr], dtlsseq, 8);
} else {
memcpy(buf[ctr], seq, 8);
for (i = 7; i >= 0; i--) { /* increment */
++seq[i];
if (seq[i] != 0)
break;
}
}
buf[ctr][8] = recs[ctr].type;
buf[ctr][9] = (unsigned char)(s->version >> 8);
buf[ctr][10] = (unsigned char)(s->version);
buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
if (pad <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
if (sending) {
reclen[ctr] += pad;
recs[ctr].length += pad;
}
} else if ((bs != 1) && sending && !provided) {
/*
* We only do this for legacy ciphers. Provided ciphers add the
* padding on the provider side.
*/
padnum = bs - (reclen[ctr] % bs);
/* Add weird padding of up to 256 bytes */
if (padnum > MAX_PADDING) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
/* we need to add 'padnum' padding bytes of value padval */
padval = (unsigned char)(padnum - 1);
for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
recs[ctr].input[loop] = padval;
reclen[ctr] += padnum;
recs[ctr].length += padnum;
}
if (!sending) {
if (reclen[ctr] == 0 || reclen[ctr] % bs != 0) {
/* Publicly invalid */
return 0;
}
}
}
if (n_recs > 1) {
unsigned char *data[SSL_MAX_PIPELINES];
/* Set the output buffers */
for (ctr = 0; ctr < n_recs; ctr++) {
data[ctr] = recs[ctr].data;
}
if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
(int)n_recs, data) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
SSL_R_PIPELINE_FAILURE);
return 0;
}
/* Set the input buffers */
for (ctr = 0; ctr < n_recs; ctr++) {
data[ctr] = recs[ctr].input;
}
if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
(int)n_recs, data) <= 0
|| EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
(int)n_recs, reclen) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
SSL_R_PIPELINE_FAILURE);
return 0;
}
}
if (!SSL_IS_DTLS(s) && tlstree_enc) {
unsigned char *seq;
int decrement_seq = 0;
/*
* When sending, seq is incremented after MAC calculation.
* So if we are in ETM mode, we use seq 'as is' in the ctrl-function.
* Otherwise we have to decrease it in the implementation
*/
if (sending && !SSL_WRITE_ETM(s))
decrement_seq = 1;
seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
: RECORD_LAYER_get_read_sequence(&s->rlayer);
if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_TLSTREE, decrement_seq, seq) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
if (provided) {
int outlen;
/* Provided cipher - we do not support pipelining on this path */
if (n_recs > 1) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
if (!EVP_CipherUpdate(ds, recs[0].data, &outlen, recs[0].input,
(unsigned int)reclen[0]))
return 0;
recs[0].length = outlen;
/*
* The length returned from EVP_CipherUpdate above is the actual
* payload length. We need to adjust the data/input ptr to skip over
* any explicit IV
*/
if (!sending) {
if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
recs[0].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
recs[0].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
} else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
recs[0].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
recs[0].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
} else if (bs != 1 && SSL_USE_EXPLICIT_IV(s)) {
recs[0].data += bs;
recs[0].input += bs;
recs[0].orig_len -= bs;
}
/* Now get a pointer to the MAC (if applicable) */
if (macs != NULL) {
OSSL_PARAM params[2], *p = params;
/* Get the MAC */
macs[0].alloced = 0;
*p++ = OSSL_PARAM_construct_octet_ptr(OSSL_CIPHER_PARAM_TLS_MAC,
(void **)&macs[0].mac,
macsize);
*p = OSSL_PARAM_construct_end();
if (!EVP_CIPHER_CTX_get_params(ds, params)) {
/* Shouldn't normally happen */
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
}
} else {
/* Legacy cipher */
/* TODO(size_t): Convert this call */
tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
(unsigned int)reclen[0]);
if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
& EVP_CIPH_FLAG_CUSTOM_CIPHER)
? (tmpr < 0)
: (tmpr == 0)) {
/* AEAD can fail to verify MAC */
return 0;
}
if (!sending) {
/* Adjust the record to remove the explicit IV/MAC/Tag */
if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
for (ctr = 0; ctr < n_recs; ctr++) {
recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
}
} else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
for (ctr = 0; ctr < n_recs; ctr++) {
recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
}
}
for (ctr = 0; ctr < n_recs; ctr++) {
if (bs != 1 && SSL_USE_EXPLICIT_IV(s)) {
if (recs[ctr].length < bs)
return 0;
recs[ctr].data += bs;
recs[ctr].input += bs;
recs[ctr].length -= bs;
recs[ctr].orig_len -= bs;
}
/*
* If using Mac-then-encrypt, then this will succeed but
* with a random MAC if padding is invalid
*/
if (!tls1_cbc_remove_padding_and_mac(&recs[ctr].length,
recs[ctr].orig_len,
recs[ctr].data,
(macs != NULL) ? &macs[ctr].mac : NULL,
(macs != NULL) ? &macs[ctr].alloced
: NULL,
bs,
macsize,
(EVP_CIPHER_flags(enc)
& EVP_CIPH_FLAG_AEAD_CIPHER) != 0,
s->ctx->libctx))
return 0;
}
if (pad) {
for (ctr = 0; ctr < n_recs; ctr++) {
recs[ctr].length -= pad;
}
}
}
}
}
return 1;
}
int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
{
unsigned char *mac_sec, *seq;
const EVP_MD_CTX *hash;
unsigned char *p, rec_char;
size_t md_size;
size_t npad;
int t;
if (sending) {
mac_sec = &(ssl->s3.write_mac_secret[0]);
seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
hash = ssl->write_hash;
} else {
mac_sec = &(ssl->s3.read_mac_secret[0]);
seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
hash = ssl->read_hash;
}
t = EVP_MD_CTX_size(hash);
if (t < 0)
return 0;
md_size = t;
npad = (48 / md_size) * md_size;
if (!sending &&
EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
ssl3_cbc_record_digest_supported(hash)) {
/*
* This is a CBC-encrypted record. We must avoid leaking any
* timing-side channel information about how many blocks of data we
* are hashing because that gives an attacker a timing-oracle.
*/
/*-
* npad is, at most, 48 bytes and that's with MD5:
* 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
*
* With SHA-1 (the largest hash speced for SSLv3) the hash size
* goes up 4, but npad goes down by 8, resulting in a smaller
* total size.
*/
unsigned char header[75];
size_t j = 0;
memcpy(header + j, mac_sec, md_size);
j += md_size;
memcpy(header + j, ssl3_pad_1, npad);
j += npad;
memcpy(header + j, seq, 8);
j += 8;
header[j++] = rec->type;
header[j++] = (unsigned char)(rec->length >> 8);
header[j++] = (unsigned char)(rec->length & 0xff);
/* Final param == is SSLv3 */
if (ssl3_cbc_digest_record(ssl, hash,
md, &md_size,
header, rec->input,
rec->length + md_size, rec->orig_len,
mac_sec, md_size, 1) <= 0)
return 0;
} else {
unsigned int md_size_u;
/* Chop the digest off the end :-) */
EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
if (md_ctx == NULL)
return 0;
rec_char = rec->type;
p = md;
s2n(rec->length, p);
if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
|| EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
|| EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
|| EVP_DigestUpdate(md_ctx, seq, 8) <= 0
|| EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
|| EVP_DigestUpdate(md_ctx, md, 2) <= 0
|| EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
|| EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
|| EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
|| EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
|| EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
|| EVP_DigestUpdate(md_ctx, md, md_size) <= 0
|| EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
EVP_MD_CTX_free(md_ctx);
return 0;
}
EVP_MD_CTX_free(md_ctx);
}
ssl3_record_sequence_update(seq);
return 1;
}
int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
{
unsigned char *seq;
EVP_MD_CTX *hash;
size_t md_size;
int i;
EVP_MD_CTX *hmac = NULL, *mac_ctx;
unsigned char header[13];
int stream_mac = sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
: (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM);
int tlstree_mac = sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_TLSTREE)
: (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_TLSTREE);
int t;
if (sending) {
seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
hash = ssl->write_hash;
} else {
seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
hash = ssl->read_hash;
}
t = EVP_MD_CTX_size(hash);
if (!ossl_assert(t >= 0))
return 0;
md_size = t;
/* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
if (stream_mac) {
mac_ctx = hash;
} else {
hmac = EVP_MD_CTX_new();
if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash)) {
EVP_MD_CTX_free(hmac);
return 0;
}
mac_ctx = hmac;
}
if (!SSL_IS_DTLS(ssl) && tlstree_mac && EVP_MD_CTX_ctrl(mac_ctx, EVP_MD_CTRL_TLSTREE, 0, seq) <= 0) {
EVP_MD_CTX_free(hmac);
return 0;
}
if (SSL_IS_DTLS(ssl)) {
unsigned char dtlsseq[8], *p = dtlsseq;
s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
memcpy(p, &seq[2], 6);
memcpy(header, dtlsseq, 8);
} else
memcpy(header, seq, 8);
header[8] = rec->type;
header[9] = (unsigned char)(ssl->version >> 8);
header[10] = (unsigned char)(ssl->version);
header[11] = (unsigned char)(rec->length >> 8);
header[12] = (unsigned char)(rec->length & 0xff);
if (!sending && !SSL_READ_ETM(ssl) &&
EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
ssl3_cbc_record_digest_supported(mac_ctx)) {
/*
* This is a CBC-encrypted record. We must avoid leaking any
* timing-side channel information about how many blocks of data we
* are hashing because that gives an attacker a timing-oracle.
*/
/* Final param == not SSLv3 */
if (ssl3_cbc_digest_record(ssl, mac_ctx,
md, &md_size,
header, rec->input,
rec->length + md_size, rec->orig_len,
ssl->s3.read_mac_secret,
ssl->s3.read_mac_secret_size, 0) <= 0) {
EVP_MD_CTX_free(hmac);
return 0;
}
} else {
/* TODO(size_t): Convert these calls */
if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
|| EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
|| EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
EVP_MD_CTX_free(hmac);
return 0;
}
}
EVP_MD_CTX_free(hmac);
OSSL_TRACE_BEGIN(TLS) {
BIO_printf(trc_out, "seq:\n");
BIO_dump_indent(trc_out, seq, 8, 4);
BIO_printf(trc_out, "rec:\n");
BIO_dump_indent(trc_out, rec->data, rec->length, 4);
} OSSL_TRACE_END(TLS);
if (!SSL_IS_DTLS(ssl)) {
for (i = 7; i >= 0; i--) {
++seq[i];
if (seq[i] != 0)
break;
}
}
OSSL_TRACE_BEGIN(TLS) {
BIO_printf(trc_out, "md:\n");
BIO_dump_indent(trc_out, md, md_size, 4);
} OSSL_TRACE_END(TLS);
return 1;
}
int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
{
int i;
int enc_err;
SSL_SESSION *sess;
SSL3_RECORD *rr;
int imac_size;
size_t mac_size = 0;
unsigned char md[EVP_MAX_MD_SIZE];
size_t max_plain_length = SSL3_RT_MAX_PLAIN_LENGTH;
SSL_MAC_BUF macbuf = { NULL, 0 };
int ret = 0;
rr = RECORD_LAYER_get_rrec(&s->rlayer);
sess = s->session;
/*
* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
* and we have that many bytes in s->packet
*/
rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
/*
* ok, we can now read from 's->packet' data into 'rr' rr->input points
* at rr->length bytes, which need to be copied into rr->data by either
* the decryption or by the decompression When the data is 'copied' into
* the rr->data buffer, rr->input will be pointed at the new buffer
*/
/*
* We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
* bytes of encrypted compressed stuff.
*/
/* check is not needed I believe */
if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
return 0;
}
/* decrypt in place in 'rr->input' */
rr->data = rr->input;
rr->orig_len = rr->length;
/* TODO(size_t): convert this to do size_t properly */
if (s->read_hash != NULL) {
const EVP_MD *tmpmd = EVP_MD_CTX_md(s->read_hash);
if (tmpmd != NULL) {
imac_size = EVP_MD_size(tmpmd);
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;
}
}
if (SSL_READ_ETM(s) && s->read_hash) {
unsigned char *mac;
if (rr->orig_len < mac_size) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_LENGTH_TOO_SHORT);
return 0;
}
rr->length -= mac_size;
mac = rr->data + rr->length;
i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
return 0;
}
/*
* We've handled the mac now - there is no MAC inside the encrypted
* record
*/
mac_size = 0;
}
enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0, &macbuf, mac_size);
/*-
* enc_err is:
* 0: if the record is publicly invalid, or an internal error, or AEAD
* decryption failed, or ETM decryption failed.
* 1: Success or MTE decryption failed (MAC will be randomised)
*/
if (enc_err == 0) {
if (ossl_statem_in_error(s)) {
/* SSLfatal() got called */
goto end;
}
/* For DTLS we simply ignore bad packets. */
rr->length = 0;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto end;
}
OSSL_TRACE_BEGIN(TLS) {
BIO_printf(trc_out, "dec %zd\n", rr->length);
BIO_dump_indent(trc_out, rr->data, rr->length, 4);
} OSSL_TRACE_END(TLS);
/* r->length is now the compressed data plus mac */
if ((sess != NULL) && !SSL_READ_ETM(s) &&
(s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
/* s->read_hash != NULL => mac_size != -1 */
i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
if (i == 0 || macbuf.mac == NULL
|| CRYPTO_memcmp(md, macbuf.mac, mac_size) != 0)
enc_err = 0;
if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
enc_err = 0;
}
if (enc_err == 0) {
/* decryption failed, silently discard message */
rr->length = 0;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto end;
}
/* r->length is now just compressed */
if (s->expand != NULL) {
if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_COMPRESSED_LENGTH_TOO_LONG);
goto end;
}
if (!ssl3_do_uncompress(s, rr)) {
SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE,
SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
goto end;
}
}
/* use current Max Fragment Length setting if applicable */
if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session))
max_plain_length = GET_MAX_FRAGMENT_LENGTH(s->session);
/* send overflow if the plaintext is too long now it has passed MAC */
if (rr->length > max_plain_length) {
SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_DATA_LENGTH_TOO_LONG);
goto end;
}
rr->off = 0;
/*-
* So at this point the following is true
* ssl->s3.rrec.type is the type of record
* ssl->s3.rrec.length == number of bytes in record
* ssl->s3.rrec.off == offset to first valid byte
* ssl->s3.rrec.data == where to take bytes from, increment
* after use :-).
*/
/* we have pulled in a full packet so zero things */
RECORD_LAYER_reset_packet_length(&s->rlayer);
/* Mark receipt of record. */
dtls1_record_bitmap_update(s, bitmap);
ret = 1;
end:
if (macbuf.alloced)
OPENSSL_free(macbuf.mac);
return ret;
}
/*
* Retrieve a buffered record that belongs to the current epoch, i.e. processed
*/
#define dtls1_get_processed_record(s) \
dtls1_retrieve_buffered_record((s), \
&(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
/*-
* Call this to get a new input record.
* It will return <= 0 if more data is needed, normally due to an error
* or non-blocking IO.
* When it finishes, one packet has been decoded and can be found in
* ssl->s3.rrec.type - is the type of record
* ssl->s3.rrec.data - data
* ssl->s3.rrec.length - number of bytes
*/
/* used only by dtls1_read_bytes */
int dtls1_get_record(SSL *s)
{
int ssl_major, ssl_minor;
int rret;
size_t more, n;
SSL3_RECORD *rr;
unsigned char *p = NULL;
unsigned short version;
DTLS1_BITMAP *bitmap;
unsigned int is_next_epoch;
rr = RECORD_LAYER_get_rrec(&s->rlayer);
again:
/*
* The epoch may have changed. If so, process all the pending records.
* This is a non-blocking operation.
*/
if (!dtls1_process_buffered_records(s)) {
/* SSLfatal() already called */
return -1;
}
/* if we're renegotiating, then there may be buffered records */
if (dtls1_get_processed_record(s))
return 1;
/* get something from the wire */
/* check if we have the header */
if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
(RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
/* read timeout is handled by dtls1_read_bytes */
if (rret <= 0) {
/* SSLfatal() already called if appropriate */
return rret; /* error or non-blocking */
}
/* this packet contained a partial record, dump it */
if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
DTLS1_RT_HEADER_LENGTH) {
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
p = RECORD_LAYER_get_packet(&s->rlayer);
if (s->msg_callback)
s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
s, s->msg_callback_arg);
/* Pull apart the header into the DTLS1_RECORD */
rr->type = *(p++);
ssl_major = *(p++);
ssl_minor = *(p++);
version = (ssl_major << 8) | ssl_minor;
/* sequence number is 64 bits, with top 2 bytes = epoch */
n2s(p, rr->epoch);
memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
p += 6;
n2s(p, rr->length);
rr->read = 0;
/*
* Lets check the version. We tolerate alerts that don't have the exact
* version number (e.g. because of protocol version errors)
*/
if (!s->first_packet && rr->type != SSL3_RT_ALERT) {
if (version != s->version) {
/* unexpected version, silently discard */
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
}
if ((version & 0xff00) != (s->version & 0xff00)) {
/* wrong version, silently discard record */
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
/* record too long, silently discard it */
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
/* If received packet overflows own-client Max Fragment Length setting */
if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
&& rr->length > GET_MAX_FRAGMENT_LENGTH(s->session) + SSL3_RT_MAX_ENCRYPTED_OVERHEAD) {
/* record too long, silently discard it */
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
/* now s->rlayer.rstate == SSL_ST_READ_BODY */
}
/* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
if (rr->length >
RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
/* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
more = rr->length;
rret = ssl3_read_n(s, more, more, 1, 1, &n);
/* this packet contained a partial record, dump it */
if (rret <= 0 || n != more) {
if (ossl_statem_in_error(s)) {
/* ssl3_read_n() called SSLfatal() */
return -1;
}
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
/*
* now n == rr->length, and s->packet_length ==
* DTLS1_RT_HEADER_LENGTH + rr->length
*/
}
/* set state for later operations */
RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
/* match epochs. NULL means the packet is dropped on the floor */
bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
if (bitmap == NULL) {
rr->length = 0;
RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
goto again; /* get another record */
}
#ifndef OPENSSL_NO_SCTP
/* Only do replay check if no SCTP bio */
if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
#endif
/* Check whether this is a repeat, or aged record. */
/*
* TODO: Does it make sense to have replay protection in epoch 0 where
* we have no integrity negotiated yet?
*/
if (!dtls1_record_replay_check(s, bitmap)) {
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
goto again; /* get another record */
}
#ifndef OPENSSL_NO_SCTP
}
#endif
/* just read a 0 length packet */
if (rr->length == 0) {
rr->read = 1;
goto again;
}
/*
* If this record is from the next epoch (either HM or ALERT), and a
* handshake is currently in progress, buffer it since it cannot be
* processed at this time.
*/
if (is_next_epoch) {
if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
if (dtls1_buffer_record (s,
&(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
rr->seq_num) < 0) {
/* SSLfatal() already called */
return -1;
}
}
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer);
goto again;
}
if (!dtls1_process_record(s, bitmap)) {
if (ossl_statem_in_error(s)) {
/* dtls1_process_record() called SSLfatal */
return -1;
}
rr->length = 0;
rr->read = 1;
RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
goto again; /* get another record */
}
return 1;
}
int dtls_buffer_listen_record(SSL *s, size_t len, unsigned char *seq, size_t off)
{
SSL3_RECORD *rr;
rr = RECORD_LAYER_get_rrec(&s->rlayer);
memset(rr, 0, sizeof(SSL3_RECORD));
rr->length = len;
rr->type = SSL3_RT_HANDSHAKE;
memcpy(rr->seq_num, seq, sizeof(rr->seq_num));
rr->off = off;
s->rlayer.packet = RECORD_LAYER_get_rbuf(&s->rlayer)->buf;
s->rlayer.packet_length = DTLS1_RT_HEADER_LENGTH + len;
rr->data = s->rlayer.packet + DTLS1_RT_HEADER_LENGTH;
if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
SSL3_RECORD_get_seq_num(s->rlayer.rrec)) <= 0) {
/* SSLfatal() already called */
return 0;
}
return 1;
}
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