/*
* Given a |secret|; a |label| of length |labellen|; and a |hash| of the
* handshake messages, derive a new secret |outlen| bytes long and store it in
* the location pointed to be |out|. The |hash| value may be NULL. Returns 1 on
* success 0 on failure.
*/
static int tls13_hkdf_expand(SSL *s, const unsigned char *secret,
const unsigned char *label, size_t labellen,
const unsigned char *hash,
unsigned char *out, size_t outlen)
{
const unsigned char label_prefix[] = "TLS 1.3, ";
const EVP_MD *md = ssl_handshake_md(s);
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
int ret;
size_t hkdflabellen;
size_t hashlen;
/*
* 2 bytes for length of whole HkdfLabel + 1 byte for length of combined
* prefix and label + bytes for the label itself + bytes for the hash
*/
unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
+ sizeof(label_prefix) + TLS13_MAX_LABEL_LEN
+ EVP_MAX_MD_SIZE];
WPACKET pkt;
if (pctx == NULL)
return 0;
hashlen = EVP_MD_size(md);
if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
|| !WPACKET_put_bytes_u16(&pkt, outlen)
|| !WPACKET_start_sub_packet_u8(&pkt)
|| !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
|| !WPACKET_memcpy(&pkt, label, labellen)
|| !WPACKET_close(&pkt)
|| !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen)
|| !WPACKET_get_total_written(&pkt, &hkdflabellen)
|| !WPACKET_finish(&pkt)) {
WPACKET_cleanup(&pkt);
return 0;
}
ret = EVP_PKEY_derive_init(pctx) <= 0
|| EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
<= 0
|| EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
|| EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
|| EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
|| EVP_PKEY_derive(pctx, out, &outlen) <= 0;
EVP_PKEY_CTX_free(pctx);
return ret == 0;
}
EXT_RETURN tls_construct_stoc_cryptopro_bug(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
const unsigned char cryptopro_ext[36] = {
0xfd, 0xe8, /* 65000 */
0x00, 0x20, /* 32 bytes length */
0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
};
if (((s->s3->tmp.new_cipher->id & 0xFFFF) != 0x80
&& (s->s3->tmp.new_cipher->id & 0xFFFF) != 0x81)
|| (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG) == 0)
return EXT_RETURN_NOT_SENT;
if (!WPACKET_memcpy(pkt, cryptopro_ext, sizeof(cryptopro_ext))) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_CRYPTOPRO_BUG, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
return EXT_RETURN_SENT;
}
int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
size_t lenbytes)
{
if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
|| !WPACKET_memcpy(pkt, src, len)
|| !WPACKET_close(pkt))
return 0;
return 1;
}
/*
* Add the server's renegotiation binding
*/
int tls_construct_stoc_renegotiate(SSL *s, WPACKET *pkt, int *al)
{
if (!s->s3->send_connection_binding)
return 1;
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_renegotiate)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u8(pkt)
|| !WPACKET_memcpy(pkt, s->s3->previous_client_finished,
s->s3->previous_client_finished_len)
|| !WPACKET_memcpy(pkt, s->s3->previous_server_finished,
s->s3->previous_server_finished_len)
|| !WPACKET_close(pkt)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_RENEGOTIATE, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
/*
* Add the server's renegotiation binding
*/
EXT_RETURN tls_construct_stoc_renegotiate(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
if (!s->s3->send_connection_binding)
return EXT_RETURN_NOT_SENT;
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_renegotiate)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u8(pkt)
|| !WPACKET_memcpy(pkt, s->s3->previous_client_finished,
s->s3->previous_client_finished_len)
|| !WPACKET_memcpy(pkt, s->s3->previous_server_finished,
s->s3->previous_server_finished_len)
|| !WPACKET_close(pkt)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_RENEGOTIATE, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
return EXT_RETURN_SENT;
}
int tls_construct_finished(SSL *s, const char *sender, int slen)
{
int i;
WPACKET pkt;
if (!WPACKET_init(&pkt, s->init_buf)
|| !ssl_set_handshake_header2(s, &pkt, SSL3_MT_FINISHED)) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
i = s->method->ssl3_enc->final_finish_mac(s,
sender, slen,
s->s3->tmp.finish_md);
if (i <= 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
s->s3->tmp.finish_md_len = i;
if (!WPACKET_memcpy(&pkt, s->s3->tmp.finish_md, i)) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
/*
* Copy the finished so we can use it for renegotiation checks
*/
if (!s->server) {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
s->s3->previous_client_finished_len = i;
} else {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
s->s3->previous_server_finished_len = i;
}
if (!ssl_close_construct_packet(s, &pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
return 1;
err:
ossl_statem_set_error(s);
WPACKET_cleanup(&pkt);
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return 0;
}
int tls_construct_finished(SSL *s, WPACKET *pkt)
{
size_t finish_md_len;
const char *sender;
size_t slen;
if (s->server) {
sender = s->method->ssl3_enc->server_finished_label;
slen = s->method->ssl3_enc->server_finished_label_len;
} else {
sender = s->method->ssl3_enc->client_finished_label;
slen = s->method->ssl3_enc->client_finished_label_len;
}
finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
sender, slen,
s->s3->tmp.finish_md);
if (finish_md_len == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
s->s3->tmp.finish_md_len = finish_md_len;
if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, finish_md_len)) {
SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
goto err;
}
/*
* Copy the finished so we can use it for renegotiation checks
*/
if (!s->server) {
OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md,
finish_md_len);
s->s3->previous_client_finished_len = finish_md_len;
} else {
OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md,
finish_md_len);
s->s3->previous_server_finished_len = finish_md_len;
}
return 1;
err:
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return 0;
}
int tls_construct_ctos_srp(SSL *s, WPACKET *pkt, int *al)
{
/* Add SRP username if there is one */
if (s->srp_ctx.login == NULL)
return 1;
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_srp)
/* Sub-packet for SRP extension */
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u8(pkt)
/* login must not be zero...internal error if so */
|| !WPACKET_set_flags(pkt, WPACKET_FLAGS_NON_ZERO_LENGTH)
|| !WPACKET_memcpy(pkt, s->srp_ctx.login,
strlen(s->srp_ctx.login))
|| !WPACKET_close(pkt)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SRP, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
/*
* Given a |secret|; a |label| of length |labellen|; and |data| of length
* |datalen| (e.g. typically a hash of the handshake messages), derive a new
* secret |outlen| bytes long and store it in the location pointed to be |out|.
* The |data| value may be zero length. Any errors will be treated as fatal if
* |fatal| is set. Returns 1 on success 0 on failure.
*/
int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
const unsigned char *label, size_t labellen,
const unsigned char *data, size_t datalen,
unsigned char *out, size_t outlen, int fatal)
{
static const unsigned char label_prefix[] = "tls13 ";
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
int ret;
size_t hkdflabellen;
size_t hashlen;
/*
* 2 bytes for length of derived secret + 1 byte for length of combined
* prefix and label + bytes for the label itself + 1 byte length of hash
* + bytes for the hash itself
*/
unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
+ sizeof(label_prefix) + TLS13_MAX_LABEL_LEN
+ 1 + EVP_MAX_MD_SIZE];
WPACKET pkt;
if (pctx == NULL)
return 0;
if (labellen > TLS13_MAX_LABEL_LEN) {
if (fatal) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
ERR_R_INTERNAL_ERROR);
} else {
/*
* Probably we have been called from SSL_export_keying_material(),
* or SSL_export_keying_material_early().
*/
SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
}
EVP_PKEY_CTX_free(pctx);
return 0;
}
hashlen = EVP_MD_size(md);
if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
|| !WPACKET_put_bytes_u16(&pkt, outlen)
|| !WPACKET_start_sub_packet_u8(&pkt)
|| !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
|| !WPACKET_memcpy(&pkt, label, labellen)
|| !WPACKET_close(&pkt)
|| !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
|| !WPACKET_get_total_written(&pkt, &hkdflabellen)
|| !WPACKET_finish(&pkt)) {
EVP_PKEY_CTX_free(pctx);
WPACKET_cleanup(&pkt);
if (fatal)
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
ERR_R_INTERNAL_ERROR);
else
SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
return 0;
}
ret = EVP_PKEY_derive_init(pctx) <= 0
|| EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
<= 0
|| EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
|| EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
|| EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
|| EVP_PKEY_derive(pctx, out, &outlen) <= 0;
EVP_PKEY_CTX_free(pctx);
if (ret != 0) {
if (fatal)
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
ERR_R_INTERNAL_ERROR);
else
SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
}
return ret == 0;
}
int DTLSv1_listen(SSL *s, BIO_ADDR *client)
{
int next, n, ret = 0, clearpkt = 0;
unsigned char cookie[DTLS1_COOKIE_LENGTH];
unsigned char seq[SEQ_NUM_SIZE];
const unsigned char *data;
unsigned char *buf;
size_t fragoff, fraglen, msglen;
unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
BIO *rbio, *wbio;
BUF_MEM *bufm;
BIO_ADDR *tmpclient = NULL;
PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
/* Ensure there is no state left over from a previous invocation */
if (!SSL_clear(s))
return -1;
ERR_clear_error();
rbio = SSL_get_rbio(s);
wbio = SSL_get_wbio(s);
if (!rbio || !wbio) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);
return -1;
}
/*
* We only peek at incoming ClientHello's until we're sure we are going to
* to respond with a HelloVerifyRequest. If its a ClientHello with a valid
* cookie then we leave it in the BIO for accept to handle.
*/
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
/*
* Note: This check deliberately excludes DTLS1_BAD_VER because that version
* requires the MAC to be calculated *including* the first ClientHello
* (without the cookie). Since DTLSv1_listen is stateless that cannot be
* supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
* SSL_accept)
*/
if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
return -1;
}
if (s->init_buf == NULL) {
if ((bufm = BUF_MEM_new()) == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
return -1;
}
if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) {
BUF_MEM_free(bufm);
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
return -1;
}
s->init_buf = bufm;
}
buf = (unsigned char *)s->init_buf->data;
do {
/* Get a packet */
clear_sys_error();
/*
* Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
* + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
* the record header as well, but we do here. We've set up init_buf to
* be the standard size for simplicity. In practice we shouldn't ever
* receive a ClientHello as long as this. If we do it will get dropped
* in the record length check below.
*/
n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
if (n <= 0) {
if (BIO_should_retry(rbio)) {
/* Non-blocking IO */
goto end;
}
return -1;
}
/* If we hit any problems we need to clear this packet from the BIO */
clearpkt = 1;
if (!PACKET_buf_init(&pkt, buf, n)) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* Parse the received record. If there are any problems with it we just
* dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
* resilient in the face of invalid records (e.g., invalid formatting,
* length, MAC, etc.). In general, invalid records SHOULD be silently
* discarded, thus preserving the association; however, an error MAY be
* logged for diagnostic purposes."
*/
/* this packet contained a partial record, dump it */
if (n < DTLS1_RT_HEADER_LENGTH) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
/* Get the record header */
if (!PACKET_get_1(&pkt, &rectype)
|| !PACKET_get_1(&pkt, &versmajor)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (rectype != SSL3_RT_HANDSHAKE) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/*
* Check record version number. We only check that the major version is
* the same.
*/
if (versmajor != DTLS1_VERSION_MAJOR) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
goto end;
}
if (!PACKET_forward(&pkt, 1)
/* Save the sequence number: 64 bits, with top 2 bytes = epoch */
|| !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
|| !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* We allow data remaining at the end of the packet because there could
* be a second record (but we ignore it)
*/
/* This is an initial ClientHello so the epoch has to be 0 */
if (seq[0] != 0 || seq[1] != 0) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Get a pointer to the raw message for the later callback */
data = PACKET_data(&msgpkt);
/* Finished processing the record header, now process the message */
if (!PACKET_get_1(&msgpkt, &msgtype)
|| !PACKET_get_net_3_len(&msgpkt, &msglen)
|| !PACKET_get_net_2(&msgpkt, &msgseq)
|| !PACKET_get_net_3_len(&msgpkt, &fragoff)
|| !PACKET_get_net_3_len(&msgpkt, &fraglen)
|| !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
|| PACKET_remaining(&msgpkt) != 0) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (msgtype != SSL3_MT_CLIENT_HELLO) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Message sequence number can only be 0 or 1 */
if (msgseq > 2) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
goto end;
}
/*
* We don't support fragment reassembly for ClientHellos whilst
* listening because that would require server side state (which is
* against the whole point of the ClientHello/HelloVerifyRequest
* mechanism). Instead we only look at the first ClientHello fragment
* and require that the cookie must be contained within it.
*/
if (fragoff != 0 || fraglen > msglen) {
/* Non initial ClientHello fragment (or bad fragment) */
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
fraglen + DTLS1_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Verify client version is supported
*/
if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
s->method->version != DTLS_ANY_VERSION) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
goto end;
}
if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
|| !PACKET_get_length_prefixed_1(&msgpayload, &session)
|| !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
/*
* Could be malformed or the cookie does not fit within the initial
* ClientHello fragment. Either way we can't handle it.
*/
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Check if we have a cookie or not. If not we need to send a
* HelloVerifyRequest.
*/
if (PACKET_remaining(&cookiepkt) == 0) {
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/*
* We have a cookie, so lets check it.
*/
if (s->ctx->app_verify_cookie_cb == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
/* This is fatal */
return -1;
}
if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
(unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
/*
* We treat invalid cookies in the same was as no cookie as
* per RFC6347
*/
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/* Cookie verification succeeded */
next = LISTEN_SUCCESS;
}
}
if (next == LISTEN_SEND_VERIFY_REQUEST) {
WPACKET wpkt;
unsigned int version;
size_t wreclen;
/*
* There was no cookie in the ClientHello so we need to send a
* HelloVerifyRequest. If this fails we do not worry about trying
* to resend, we just drop it.
*/
/*
* Dump the read packet, we don't need it any more. Ignore return
* value
*/
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
/* Generate the cookie */
if (s->ctx->app_gen_cookie_cb == NULL ||
s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
cookielen > 255) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
/* This is fatal */
return -1;
}
/*
* Special case: for hello verify request, client version 1.0 and we
* haven't decided which version to use yet send back using version
* 1.0 header: otherwise some clients will ignore it.
*/
version = (s->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
: s->version;
/* Construct the record and message headers */
if (!WPACKET_init(&wpkt, s->init_buf)
|| !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
|| !WPACKET_put_bytes_u16(&wpkt, version)
/*
* Record sequence number is always the same as in the
* received ClientHello
*/
|| !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
/* End of record, start sub packet for message */
|| !WPACKET_start_sub_packet_u16(&wpkt)
/* Message type */
|| !WPACKET_put_bytes_u8(&wpkt,
DTLS1_MT_HELLO_VERIFY_REQUEST)
/*
* Message length - doesn't follow normal TLS convention:
* the length isn't the last thing in the message header.
* We'll need to fill this in later when we know the
* length. Set it to zero for now
*/
|| !WPACKET_put_bytes_u24(&wpkt, 0)
/*
* Message sequence number is always 0 for a
* HelloVerifyRequest
*/
|| !WPACKET_put_bytes_u16(&wpkt, 0)
/*
* We never fragment a HelloVerifyRequest, so fragment
* offset is 0
*/
|| !WPACKET_put_bytes_u24(&wpkt, 0)
/*
* Fragment length is the same as message length, but
* this *is* the last thing in the message header so we
* can just start a sub-packet. No need to come back
* later for this one.
*/
|| !WPACKET_start_sub_packet_u24(&wpkt)
/* Create the actual HelloVerifyRequest body */
|| !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
/* Close message body */
|| !WPACKET_close(&wpkt)
/* Close record body */
|| !WPACKET_close(&wpkt)
|| !WPACKET_get_total_written(&wpkt, &wreclen)
|| !WPACKET_finish(&wpkt)) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
WPACKET_cleanup(&wpkt);
/* This is fatal */
return -1;
}
/*
* Fix up the message len in the message header. Its the same as the
* fragment len which has been filled in by WPACKET, so just copy
* that. Destination for the message len is after the record header
* plus one byte for the message content type. The source is the
* last 3 bytes of the message header
*/
memcpy(&buf[DTLS1_RT_HEADER_LENGTH + 1],
&buf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
3);
if (s->msg_callback)
s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
if ((tmpclient = BIO_ADDR_new()) == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
goto end;
}
/*
* This is unnecessary if rbio and wbio are one and the same - but
* maybe they're not. We ignore errors here - some BIOs do not
* support this.
*/
if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
(void)BIO_dgram_set_peer(wbio, tmpclient);
}
BIO_ADDR_free(tmpclient);
tmpclient = NULL;
/* TODO(size_t): convert this call */
if (BIO_write(wbio, buf, wreclen) < (int)wreclen) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
return -1;
}
if (BIO_flush(wbio) <= 0) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
return -1;
}
}
} while (next != LISTEN_SUCCESS);
/*
* Set expected sequence numbers to continue the handshake.
*/
s->d1->handshake_read_seq = 1;
s->d1->handshake_write_seq = 1;
s->d1->next_handshake_write_seq = 1;
DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);
/*
* We are doing cookie exchange, so make sure we set that option in the
* SSL object
*/
SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
/*
* Tell the state machine that we've done the initial hello verify
* exchange
*/
ossl_statem_set_hello_verify_done(s);
/*
* Some BIOs may not support this. If we fail we clear the client address
*/
if (BIO_dgram_get_peer(rbio, client) <= 0)
BIO_ADDR_clear(client);
ret = 1;
clearpkt = 0;
end:
BIO_ADDR_free(tmpclient);
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
if (clearpkt) {
/* Dump this packet. Ignore return value */
BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
}
return ret;
}
/*
* Request custom extension data from the application and add to the return
* buffer.
*/
int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx,
int maxversion, int *al)
{
custom_ext_methods *exts = &s->cert->custext;
custom_ext_method *meth;
size_t i;
for (i = 0; i < exts->meths_count; i++) {
const unsigned char *out = NULL;
size_t outlen = 0;
meth = exts->meths + i;
if (!should_add_extension(s, meth->context, context, maxversion))
continue;
if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
| SSL_EXT_TLS1_3_SERVER_HELLO
| SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
| SSL_EXT_TLS1_3_CERTIFICATE
| SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
/* Only send extensions present in ClientHello. */
if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
continue;
}
/*
* We skip it if the callback is absent - except for a ClientHello where
* we add an empty extension.
*/
if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
continue;
if (meth->add_cb != NULL) {
int cb_retval = meth->add_cb(s, meth->ext_type, context, &out,
&outlen, x, chainidx, al,
meth->add_arg);
if (cb_retval < 0)
return 0; /* error */
if (cb_retval == 0)
continue; /* skip this extension */
}
if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
|| !WPACKET_start_sub_packet_u16(pkt)
|| (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
|| !WPACKET_close(pkt)) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
/*
* We can't send duplicates: code logic should prevent this.
*/
if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
/*
* Indicate extension has been sent: this is both a sanity check to
* ensure we don't send duplicate extensions and indicates that it
* is not an error if the extension is present in ServerHello.
*/
meth->ext_flags |= SSL_EXT_FLAG_SENT;
}
if (meth->free_cb != NULL)
meth->free_cb(s, meth->ext_type, context, out, meth->add_arg);
}
return 1;
}
