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Fix issues caught by existing test cases.
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@fwh-dc
fwh-dc committed Dec 21, 2023
1 parent 4ade8fc commit d6ef7df
Showing 1 changed file with 95 additions and 42 deletions.
137 changes: 95 additions & 42 deletions ssl/d1_lib.c
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Original file line number Diff line number Diff line change
Expand Up @@ -628,7 +628,7 @@ int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)

do {
/* Get a packet */
unsigned int ciphersuites_len;
int legacy_version;

clear_sys_error();
n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH
Expand Down Expand Up @@ -671,8 +671,10 @@ int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
goto end;
}

legacy_version = (versmajor << 8) | versminor;

if (s->msg_callback)
s->msg_callback(0, (versmajor << 8) | versminor, SSL3_RT_HEADER, buf,
s->msg_callback(0, legacy_version, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg);

if (rectype != SSL3_RT_HANDSHAKE) {
Expand Down Expand Up @@ -765,53 +767,110 @@ int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
}

if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
|| !PACKET_get_length_prefixed_1(&msgpayload, &session)
|| !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)
|| !PACKET_get_net_2(&msgpayload, &ciphersuites_len)
|| !PACKET_forward(&msgpayload, ciphersuites_len)) {
|| !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.
*/
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;

}

// Check if this is a DTLSv1.3 record
int is_dtls13_record = PACKET_remaining(&msgpayload) > 0
&& clientvers == DTLS1_2_VERSION;
/*
* If we have a DTLSv1.3 ClientHello the cookie is supplied in an extension
*/
if (clientvers == DTLS1_2_VERSION
&& PACKET_remaining(&cookiepkt) == 0) {
int i;
PACKET extensions;
size_t pre_proc_exts_len;
RAW_EXTENSION *pre_proc_exts, *suppversions;
unsigned int ciphersuites_len, legacy_compressions_len;

int server_accepts_dtls13 = ssl->method->version == DTLS_ANY_VERSION
|| ssl->method->version == DTLS1_3_VERSION;
if (is_dtls13_record) {
if (!server_accepts_dtls13) {
ERR_raise(ERR_LIB_SSL, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
if (PACKET_remaining(&msgpayload) != 0
&& (!PACKET_get_net_2(&msgpayload, &ciphersuites_len)
|| !PACKET_forward(&msgpayload, ciphersuites_len))) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
//DTLSv1.3 records store cookies in an extension
PACKET extensions;
int i;
size_t pre_proc_exts_len;
RAW_EXTENSION *pre_proc_exts, *extension;
PACKET_get_length_prefixed_2(&msgpayload, &extensions);
if (PACKET_remaining(&msgpayload) != 0
&& (!PACKET_get_1(&msgpayload, &legacy_compressions_len)
|| !PACKET_forward(&msgpayload, legacy_compressions_len))) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Now parse the ClientHello extensions.
* Could be empty.
*/
if (PACKET_remaining(&msgpayload) == 0) {
PACKET_null_init(&extensions);
} else {
if (!PACKET_get_length_prefixed_2(&msgpayload, &extensions)
|| PACKET_remaining(&msgpayload) != 0) {
SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
goto end;
}
}

if (!tls_collect_extensions(s, &extensions,
SSL_EXT_CLIENT_HELLO,
&pre_proc_exts, &pre_proc_exts_len,
1)) {
/* SSLfatal already been called */
goto end;
}

for (i = 0; i < pre_proc_exts_len; i++) {
extension = pre_proc_exts + i;
RAW_EXTENSION *extension = pre_proc_exts + i;

if (extension->present
&& extension->type == TLSEXT_TYPE_cookie) {
&& extension->type == TLSEXT_TYPE_cookie) {
size_t cookie_len = PACKET_remaining(&extension->data);

if (!PACKET_get_sub_packet(&extension->data,
&cookiepkt, cookie_len)) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
// TODO: Check that client does offer dtls1.3 in "supported_versions"?
}
}

/*
* Check if client wants DTLSv1.3 because that decides how to
* respond i.e. HelloRetryRequest (DTLSv1.3) or HelloVerifyRequest
* (DTLSv1.2 and below).
*/
suppversions = &pre_proc_exts[TLSEXT_IDX_supported_versions];
if (suppversions->present) {
PACKET versionslist;
unsigned int candidate_vers = 0;
unsigned int best_vers = INT_MAX;
const SSL_METHOD *best_method = NULL;

if (!PACKET_as_length_prefixed_1(&suppversions->data, &versionslist)) {
/* Trailing or invalid data? */
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}

while (PACKET_get_net_2(&versionslist, &candidate_vers)) {
if (DTLS_VERSION_LE(candidate_vers, best_vers))
continue;
if (ssl_version_supported(s, candidate_vers, &best_method))
best_vers = candidate_vers;
}

if (best_vers == DTLS1_3_VERSION) {
s->hello_retry_request = SSL_HRR_PENDING;
}

if (PACKET_remaining(&versionslist) != 0) {
/* Trailing data? */
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
}
}
Expand All @@ -821,9 +880,6 @@ int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
* HelloVerifyRequest or a HelloRetryRequest (DTLSv1.3).
*/
if (PACKET_remaining(&cookiepkt) == 0) {
if (is_dtls13_record && server_accepts_dtls13) {
s->hello_retry_request = SSL_HRR_PENDING;
}
next = LISTEN_SEND_COOKIE_REQUEST;
} else {
/*
Expand Down Expand Up @@ -859,38 +915,35 @@ int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
*/

/* Generate the cookie */
if (ssl->ctx->app_gen_cookie_cb == NULL ||
ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0 ||
cookielen > 255) {
if (ssl->ctx->app_gen_cookie_cb == NULL
|| ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0
|| cookielen > 255) {
ERR_raise(ERR_LIB_SSL, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
/* This is fatal */
ret = -1;
goto end;
}

/* Construct the record and message headers */
if (is_dtls13_record) {
if (s->hello_retry_request == SSL_HRR_PENDING) {
/*
* Record sequence number is always the same as in the
* received ClientHello
*/
if (construct_hello_retry_request(ssl, &wpkt, wbuf, seq,
cookie, cookielen) == 0) {
/* This is fatal */
ret = -1;
goto end;
}
wreclen = construct_hello_retry_request(ssl, &wpkt, wbuf, seq,
cookie, cookielen);
} else {
/*
* Record sequence number is always the same as in the
* received ClientHello
*/
if (construct_hello_verify_request(ssl, &wpkt, wbuf, seq,
cookie, cookielen) == 0) {
/* This is fatal */
ret = -1;
goto end;
}
wreclen = construct_hello_verify_request(ssl, &wpkt, wbuf, seq,
cookie, cookielen);
}
if (wreclen == 0) {
/* This is fatal */
ret = -1;
goto end;
}

if (s->msg_callback)
Expand Down

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