PACKETise ClientHello processing
Uses the new PACKET code to process the incoming ClientHello including all
extensions etc.
Reviewed-by: Tim Hudson <tjh@openssl.org>
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 47abf2b..c0dd35f 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1756,46 +1756,33 @@
* alert value to send in the event of a non-zero return. returns: 0 on
* success.
*/
-static int tls1_alpn_handle_client_hello(SSL *s, const unsigned char *data,
- unsigned data_len, int *al)
+static int tls1_alpn_handle_client_hello(SSL *s, PACKET *pkt, int *al)
{
- unsigned i;
- unsigned proto_len;
+ unsigned int data_len;
+ unsigned int proto_len;
const unsigned char *selected;
+ unsigned char *data;
unsigned char selected_len;
int r;
if (s->ctx->alpn_select_cb == NULL)
return 0;
- if (data_len < 2)
- goto parse_error;
-
/*
* data should contain a uint16 length followed by a series of 8-bit,
* length-prefixed strings.
*/
- i = ((unsigned)data[0]) << 8 | ((unsigned)data[1]);
- data_len -= 2;
- data += 2;
- if (data_len != i)
+ if (!PACKET_get_net_2(pkt, &data_len)
+ || PACKET_remaining(pkt) != data_len
+ || !PACKET_peek_bytes(pkt, &data, data_len))
goto parse_error;
- if (data_len < 2)
- goto parse_error;
-
- for (i = 0; i < data_len;) {
- proto_len = data[i];
- i++;
-
- if (proto_len == 0)
+ do {
+ if (!PACKET_get_1(pkt, &proto_len)
+ || proto_len == 0
+ || !PACKET_forward(pkt, proto_len))
goto parse_error;
-
- if (i + proto_len < i || i + proto_len > data_len)
- goto parse_error;
-
- i += proto_len;
- }
+ } while (PACKET_remaining(pkt));
r = s->ctx->alpn_select_cb(s, &selected, &selected_len, data, data_len,
s->ctx->alpn_select_cb_arg);
@@ -1830,10 +1817,11 @@
* Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
* 10.8..10.8.3 (which don't work).
*/
-static void ssl_check_for_safari(SSL *s, const unsigned char *data,
- const unsigned char *d, int n)
+static void ssl_check_for_safari(SSL *s, PACKET *pkt)
{
- unsigned short type, size;
+ unsigned int type, size;
+ unsigned char *eblock1, *eblock2;
+
static const unsigned char kSafariExtensionsBlock[] = {
0x00, 0x0a, /* elliptic_curves extension */
0x00, 0x08, /* 8 bytes */
@@ -1860,38 +1848,34 @@
0x02, 0x03, /* SHA-1/ECDSA */
};
- if (data >= (d + n - 2))
+ if (!PACKET_forward(pkt, 2)
+ || !PACKET_get_net_2(pkt, &type)
+ || !PACKET_get_net_2(pkt, &size)
+ || !PACKET_forward(pkt, size))
return;
- data += 2;
-
- if (data > (d + n - 4))
- return;
- n2s(data, type);
- n2s(data, size);
if (type != TLSEXT_TYPE_server_name)
return;
- if (data + size > d + n)
- return;
- data += size;
-
if (TLS1_get_client_version(s) >= TLS1_2_VERSION) {
const size_t len1 = sizeof(kSafariExtensionsBlock);
const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
- if (data + len1 + len2 != d + n)
+ if (!PACKET_get_bytes(pkt, &eblock1, len1)
+ || !PACKET_get_bytes(pkt, &eblock2, len2)
+ || PACKET_remaining(pkt))
return;
- if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
+ if (memcmp(eblock1, kSafariExtensionsBlock, len1) != 0)
return;
- if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
+ if (memcmp(eblock2, kSafariTLS12ExtensionsBlock, len2) != 0)
return;
} else {
const size_t len = sizeof(kSafariExtensionsBlock);
- if (data + len != d + n)
+ if (!PACKET_get_bytes(pkt, &eblock1, len)
+ || PACKET_remaining(pkt))
return;
- if (memcmp(data, kSafariExtensionsBlock, len) != 0)
+ if (memcmp(eblock1, kSafariExtensionsBlock, len) != 0)
return;
}
@@ -1899,13 +1883,12 @@
}
#endif /* !OPENSSL_NO_EC */
-static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p,
- unsigned char *d, int n, int *al)
+static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al)
{
- unsigned short type;
- unsigned short size;
- unsigned short len;
- unsigned char *data = *p;
+ unsigned int type;
+ unsigned int size;
+ unsigned int len;
+ unsigned char *data;
int renegotiate_seen = 0;
s->servername_done = 0;
@@ -1923,8 +1906,8 @@
#ifndef OPENSSL_NO_EC
if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
- ssl_check_for_safari(s, data, d, n);
-#endif /* !OPENSSL_NO_EC */
+ ssl_check_for_safari(s, pkt);
+# endif /* !OPENSSL_NO_EC */
/* Clear any signature algorithms extension received */
OPENSSL_free(s->s3->tmp.peer_sigalgs);
@@ -1940,27 +1923,26 @@
s->srtp_profile = NULL;
- if (data == d + n)
+ if (PACKET_remaining(pkt) == 0)
goto ri_check;
- if (data > (d + n - 2))
+ if (!PACKET_get_net_2(pkt, &len))
goto err;
- n2s(data, len);
+ while (PACKET_get_net_2(pkt, &type) && PACKET_get_net_2(pkt, &size)) {
+ PACKET subpkt;
- if (data > (d + n - len))
- goto err;
-
- while (data <= (d + n - 4)) {
- n2s(data, type);
- n2s(data, size);
-
- if (data + size > (d + n))
+ if (!PACKET_peek_bytes(pkt, &data, size))
goto err;
+
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 0, type, data, size, s->tlsext_debug_arg);
+
+ if (!PACKET_get_sub_packet(pkt, &subpkt, size))
+ goto err;
+
if (type == TLSEXT_TYPE_renegotiate) {
- if (!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
+ if (!ssl_parse_clienthello_renegotiate_ext(s, &subpkt, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
@@ -1992,23 +1974,18 @@
else if (type == TLSEXT_TYPE_server_name) {
unsigned char *sdata;
- int servname_type;
- int dsize;
+ unsigned int servname_type;
+ unsigned int dsize;
+ PACKET ssubpkt;
- if (size < 2)
- goto err;
- n2s(data, dsize);
- size -= 2;
- if (dsize > size)
+ if (!PACKET_get_net_2(&subpkt, &dsize)
+ || !PACKET_get_sub_packet(&subpkt, &ssubpkt, dsize))
goto err;
- sdata = data;
- while (dsize > 3) {
- servname_type = *(sdata++);
- n2s(sdata, len);
- dsize -= 3;
-
- if (len > dsize)
+ while (PACKET_remaining(&ssubpkt) > 3) {
+ if (!PACKET_get_1(&ssubpkt, &servname_type)
+ || !PACKET_get_net_2(&ssubpkt, &len)
+ || PACKET_remaining(&ssubpkt) < len)
goto err;
if (s->servername_done == 0)
@@ -2027,7 +2004,13 @@
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
- memcpy(s->session->tlsext_hostname, sdata, len);
+ if (!PACKET_copy_bytes(&ssubpkt,
+ (unsigned char *)s->session
+ ->tlsext_hostname,
+ len)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
s->session->tlsext_hostname[len] = '\0';
if (strlen(s->session->tlsext_hostname) != len) {
OPENSSL_free(s->session->tlsext_hostname);
@@ -2037,48 +2020,55 @@
}
s->servername_done = 1;
- } else
+ } else {
+ if (!PACKET_get_bytes(&ssubpkt, &sdata, len)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
s->servername_done = s->session->tlsext_hostname
&& strlen(s->session->tlsext_hostname) == len
&& strncmp(s->session->tlsext_hostname,
(char *)sdata, len) == 0;
+ }
break;
default:
break;
}
-
- dsize -= len;
}
- if (dsize != 0)
+ /* We shouldn't have any bytes left */
+ if (PACKET_remaining(&ssubpkt))
goto err;
}
#ifndef OPENSSL_NO_SRP
else if (type == TLSEXT_TYPE_srp) {
- if (size == 0 || ((len = data[0])) != (size - 1))
+ if (!PACKET_get_1(&subpkt, &len)
+ || s->srp_ctx.login != NULL)
goto err;
- if (s->srp_ctx.login != NULL)
- goto err;
+
if ((s->srp_ctx.login = OPENSSL_malloc(len + 1)) == NULL)
return -1;
- memcpy(s->srp_ctx.login, &data[1], len);
+ if (!PACKET_copy_bytes(&subpkt, (unsigned char *)s->srp_ctx.login,
+ len))
+ goto err;
s->srp_ctx.login[len] = '\0';
- if (strlen(s->srp_ctx.login) != len)
+ if (strlen(s->srp_ctx.login) != len
+ || PACKET_remaining(&subpkt))
goto err;
}
#endif
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
- unsigned char *sdata = data;
- int ecpointformatlist_length = *(sdata++);
+ unsigned int ecpointformatlist_length;
- if (ecpointformatlist_length != size - 1 ||
- ecpointformatlist_length < 1)
+ if (!PACKET_get_1(&subpkt, &ecpointformatlist_length)
+ || ecpointformatlist_length == 0)
goto err;
+
if (!s->hit) {
OPENSSL_free(s->session->tlsext_ecpointformatlist);
s->session->tlsext_ecpointformatlist = NULL;
@@ -2090,19 +2080,26 @@
}
s->session->tlsext_ecpointformatlist_length =
ecpointformatlist_length;
- memcpy(s->session->tlsext_ecpointformatlist, sdata,
- ecpointformatlist_length);
+ if (!PACKET_copy_bytes(&subpkt,
+ s->session->tlsext_ecpointformatlist,
+ ecpointformatlist_length))
+ goto err;
+ } else if (!PACKET_forward(&subpkt, ecpointformatlist_length)) {
+ goto err;
+ }
+ /* We should have consumed all the bytes by now */
+ if (PACKET_remaining(&subpkt)) {
+ *al = TLS1_AD_DECODE_ERROR;
+ return 0;
}
} else if (type == TLSEXT_TYPE_elliptic_curves) {
- unsigned char *sdata = data;
- int ellipticcurvelist_length = (*(sdata++) << 8);
- ellipticcurvelist_length += (*(sdata++));
+ unsigned int ellipticcurvelist_length;
- if (ellipticcurvelist_length != size - 2 ||
- ellipticcurvelist_length < 1 ||
- /* Each NamedCurve is 2 bytes. */
- ellipticcurvelist_length & 1)
- goto err;
+ /* Each NamedCurve is 2 bytes and we must have at least 1 */
+ if (!PACKET_get_net_2(&subpkt, &ellipticcurvelist_length)
+ || ellipticcurvelist_length == 0
+ || (ellipticcurvelist_length & 1) != 0)
+ goto err;
if (!s->hit) {
if (s->session->tlsext_ellipticcurvelist)
@@ -2116,54 +2113,63 @@
}
s->session->tlsext_ellipticcurvelist_length =
ellipticcurvelist_length;
- memcpy(s->session->tlsext_ellipticcurvelist, sdata,
- ellipticcurvelist_length);
+ if (!PACKET_copy_bytes(&subpkt,
+ s->session->tlsext_ellipticcurvelist,
+ ellipticcurvelist_length))
+ goto err;
+ } else if (!PACKET_forward(&subpkt, ellipticcurvelist_length)) {
+ goto err;
+ }
+ /* We should have consumed all the bytes by now */
+ if (PACKET_remaining(&subpkt)) {
+ goto err;
}
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket) {
- if (s->tls_session_ticket_ext_cb &&
- !s->tls_session_ticket_ext_cb(s, data, size,
- s->tls_session_ticket_ext_cb_arg))
- {
+ if (!PACKET_forward(&subpkt, size)
+ || (s->tls_session_ticket_ext_cb &&
+ !s->tls_session_ticket_ext_cb(s, data, size,
+ s->tls_session_ticket_ext_cb_arg))) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
} else if (type == TLSEXT_TYPE_signature_algorithms) {
- int dsize;
- if (s->s3->tmp.peer_sigalgs || size < 2)
+ unsigned int dsize;
+
+ if (s->s3->tmp.peer_sigalgs
+ || !PACKET_get_net_2(&subpkt, &dsize)
+ || (dsize & 1) != 0
+ || (dsize == 0)
+ || !PACKET_get_bytes(&subpkt, &data, dsize)
+ || PACKET_remaining(&subpkt)
+ || !tls1_save_sigalgs(s, data, dsize)) {
goto err;
- n2s(data, dsize);
- size -= 2;
- if (dsize != size || dsize & 1 || !dsize)
- goto err;
- if (!tls1_save_sigalgs(s, data, dsize))
- goto err;
+ }
} else if (type == TLSEXT_TYPE_status_request) {
+ PACKET ssubpkt;
- if (size < 5)
+ if (!PACKET_get_1(&subpkt,
+ (unsigned int *)&s->tlsext_status_type))
goto err;
- s->tlsext_status_type = *data++;
- size--;
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
const unsigned char *sdata;
- int dsize;
+ unsigned int dsize;
/* Read in responder_id_list */
- n2s(data, dsize);
- size -= 2;
- if (dsize > size)
+ if (!PACKET_get_net_2(&subpkt, &dsize)
+ || !PACKET_get_sub_packet(&subpkt, &ssubpkt, dsize))
goto err;
- while (dsize > 0) {
+
+ while (PACKET_remaining(&ssubpkt)) {
OCSP_RESPID *id;
- int idsize;
- if (dsize < 4)
+ unsigned int idsize;
+
+ if (PACKET_remaining(&ssubpkt) < 4
+ || !PACKET_get_net_2(&ssubpkt, &idsize)
+ || !PACKET_get_bytes(&ssubpkt, &data, idsize)) {
goto err;
- n2s(data, idsize);
- dsize -= 2 + idsize;
- size -= 2 + idsize;
- if (dsize < 0)
- goto err;
+ }
sdata = data;
data += idsize;
id = d2i_OCSP_RESPID(NULL, &sdata, idsize);
@@ -2188,12 +2194,11 @@
}
/* Read in request_extensions */
- if (size < 2)
+ if (!PACKET_get_net_2(&subpkt, &dsize)
+ || !PACKET_get_bytes(&subpkt, &data, dsize)
+ || PACKET_remaining(&subpkt)) {
goto err;
- n2s(data, dsize);
- size -= 2;
- if (dsize != size)
- goto err;
+ }
sdata = data;
if (dsize > 0) {
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
@@ -2212,7 +2217,14 @@
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (type == TLSEXT_TYPE_heartbeat) {
- switch (data[0]) {
+ unsigned int hbtype;
+
+ if (!PACKET_get_1(&subpkt, &hbtype)
+ || PACKET_remaining(&subpkt)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+ switch (hbtype) {
case 0x01: /* Client allows us to send HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
break;
@@ -2253,7 +2265,7 @@
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
s->ctx->alpn_select_cb && s->s3->tmp.finish_md_len == 0) {
- if (tls1_alpn_handle_client_hello(s, data, size, al) != 0)
+ if (tls1_alpn_handle_client_hello(s, &subpkt, al) != 0)
return 0;
#ifndef OPENSSL_NO_NEXTPROTONEG
/* ALPN takes precedence over NPN. */
@@ -2265,7 +2277,7 @@
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
&& type == TLSEXT_TYPE_use_srtp) {
- if (ssl_parse_clienthello_use_srtp_ext(s, data, size, al))
+ if (ssl_parse_clienthello_use_srtp_ext(s, &subpkt, al))
return 0;
}
#endif
@@ -2288,16 +2300,12 @@
if (custom_ext_parse(s, 1, type, data, size, al) <= 0)
return 0;
}
-
- data += size;
}
/* Spurious data on the end */
- if (data != d + n)
+ if (PACKET_remaining(pkt) != 0)
goto err;
- *p = data;
-
ri_check:
/* Need RI if renegotiating */
@@ -2316,12 +2324,11 @@
return 0;
}
-int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
- int n)
+int ssl_parse_clienthello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
custom_ext_init(&s->cert->srv_ext);
- if (ssl_scan_clienthello_tlsext(s, p, d, n, &al) <= 0) {
+ if (ssl_scan_clienthello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
@@ -2934,12 +2941,12 @@
* s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
* Otherwise, s->tlsext_ticket_expected is set to 0.
*/
-int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
- const unsigned char *limit, SSL_SESSION **ret)
+int tls1_process_ticket(SSL *s, PACKET *pkt, unsigned char *session_id,
+ int len, SSL_SESSION **ret)
{
- /* Point after session ID in client hello */
- const unsigned char *p = session_id + len;
- unsigned short i;
+ unsigned int i;
+ size_t bookmark = 0;
+ int retv = -1;
*ret = NULL;
s->tlsext_ticket_expected = 0;
@@ -2950,46 +2957,60 @@
*/
if (!tls_use_ticket(s))
return 0;
- if ((s->version <= SSL3_VERSION) || !limit)
+ if ((s->version <= SSL3_VERSION))
return 0;
- if (p >= limit)
+
+ if (!PACKET_get_bookmark(pkt, &bookmark)) {
return -1;
+ }
+
/* Skip past DTLS cookie */
if (SSL_IS_DTLS(s)) {
- i = *(p++);
- p += i;
- if (p >= limit)
- return -1;
+ if (!PACKET_get_1(pkt, &i)
+ || !PACKET_forward(pkt, i)) {
+ retv = -1;
+ goto end;
+ }
}
- /* Skip past cipher list */
- n2s(p, i);
- p += i;
- if (p >= limit)
- return -1;
- /* Skip past compression algorithm list */
- i = *(p++);
- p += i;
- if (p > limit)
- return -1;
+ /* Skip past cipher list and compression algorithm list */
+ if (!PACKET_get_net_2(pkt, &i)
+ || !PACKET_forward(pkt, i)
+ || !PACKET_get_1(pkt, &i)
+ || !PACKET_forward(pkt, i)) {
+ retv = -1;
+ goto end;
+ }
+
/* Now at start of extensions */
- if ((p + 2) >= limit)
- return 0;
- n2s(p, i);
- while ((p + 4) <= limit) {
- unsigned short type, size;
- n2s(p, type);
- n2s(p, size);
- if (p + size > limit)
- return 0;
+ if (!PACKET_get_net_2(pkt, &i)) {
+ retv = 0;
+ goto end;
+ }
+ while (PACKET_remaining (pkt) >= 4) {
+ unsigned int type, size;
+
+ if (!PACKET_get_net_2(pkt, &type)
+ || !PACKET_get_net_2(pkt, &size)) {
+ /* Shouldn't ever happen */
+ retv = -1;
+ goto end;
+ }
+ if (PACKET_remaining(pkt) < size) {
+ retv = 0;
+ goto end;
+ }
if (type == TLSEXT_TYPE_session_ticket) {
int r;
+ unsigned char *etick;
+
if (size == 0) {
/*
* The client will accept a ticket but doesn't currently have
* one.
*/
s->tlsext_ticket_expected = 1;
- return 1;
+ retv = 1;
+ goto end;
}
if (s->tls_session_secret_cb) {
/*
@@ -2998,25 +3019,39 @@
* abbreviated handshake based on external mechanism to
* calculate the master secret later.
*/
- return 2;
+ retv = 2;
+ goto end;
}
- r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
+ if (!PACKET_get_bytes(pkt, &etick, size)) {
+ /* Shouldn't ever happen */
+ retv = -1;
+ goto end;
+ }
+ r = tls_decrypt_ticket(s, etick, size, session_id, len, ret);
switch (r) {
case 2: /* ticket couldn't be decrypted */
s->tlsext_ticket_expected = 1;
- return 2;
+ retv = 2;
+ break;
case 3: /* ticket was decrypted */
- return r;
+ retv = r;
+ break;
case 4: /* ticket decrypted but need to renew */
s->tlsext_ticket_expected = 1;
- return 3;
+ retv = 3;
+ break;
default: /* fatal error */
- return -1;
+ retv = -1;
+ break;
}
+ goto end;
}
- p += size;
}
- return 0;
+ retv = 0;
+end:
+ if (!PACKET_goto_bookmark(pkt, bookmark))
+ return -1;
+ return retv;
}
/*-
