PACKETise ServerHello processing
Process ServerHello messages using the PACKET API
Reviewed-by: Tim Hudson <tjh@openssl.org>
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index f004288..95b4fb6 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -2344,28 +2344,23 @@
* elements of zero length are allowed and the set of elements must exactly
* fill the length of the block.
*/
-static char ssl_next_proto_validate(unsigned char *d, unsigned len)
+static char ssl_next_proto_validate(PACKET *pkt)
{
- unsigned int off = 0;
+ unsigned int len;
- while (off < len) {
- if (d[off] == 0)
+ while (PACKET_remaining(pkt)) {
+ if (!PACKET_get_1(pkt, &len)
+ || !PACKET_forward(pkt, len))
return 0;
- off += d[off];
- off++;
}
- return off == len;
+ return 1;
}
#endif
-static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p,
- unsigned char *d, int n, int *al)
+static int ssl_scan_serverhello_tlsext(SSL *s, PACKET *pkt, int *al)
{
- unsigned short length;
- unsigned short type;
- unsigned short size;
- unsigned char *data = *p;
+ unsigned int length, type, size;
int tlsext_servername = 0;
int renegotiate_seen = 0;
@@ -2385,27 +2380,27 @@
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
#endif
- if (data >= (d + n - 2))
+ if (!PACKET_get_net_2(pkt, &length))
goto ri_check;
- n2s(data, length);
- if (data + length != d + n) {
+ if (PACKET_remaining(pkt) != length) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
- while (data <= (d + n - 4)) {
- n2s(data, type);
- n2s(data, size);
+ while (PACKET_get_net_2(pkt, &type) && PACKET_get_net_2(pkt, &size)) {
+ unsigned char *data;
+ PACKET spkt;
- if (data + size > (d + n))
+ if (!PACKET_get_sub_packet(pkt, &spkt, size)
+ || !PACKET_peek_bytes(&spkt, &data, size))
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size, s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_renegotiate) {
- if (!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
+ if (!ssl_parse_serverhello_renegotiate_ext(s, &spkt, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
@@ -2418,10 +2413,9 @@
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
- unsigned char *sdata = data;
- int ecpointformatlist_length = *(sdata++);
-
- if (ecpointformatlist_length != size - 1) {
+ unsigned int ecpointformatlist_length;
+ if (!PACKET_get_1(&spkt, &ecpointformatlist_length)
+ || ecpointformatlist_length != size - 1) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
@@ -2435,8 +2429,13 @@
}
s->session->tlsext_ecpointformatlist_length =
ecpointformatlist_length;
- memcpy(s->session->tlsext_ecpointformatlist, sdata,
- ecpointformatlist_length);
+ if (!PACKET_copy_bytes(&spkt,
+ s->session->tlsext_ecpointformatlist,
+ ecpointformatlist_length)) {
+ *al = TLS1_AD_DECODE_ERROR;
+ return 0;
+ }
+
}
}
#endif /* OPENSSL_NO_EC */
@@ -2472,14 +2471,13 @@
s->s3->tmp.finish_md_len == 0) {
unsigned char *selected;
unsigned char selected_len;
-
/* We must have requested it. */
if (s->ctx->next_proto_select_cb == NULL) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The data must be valid */
- if (!ssl_next_proto_validate(data, size)) {
+ if (!ssl_next_proto_validate(&spkt)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
@@ -2504,31 +2502,21 @@
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation) {
unsigned len;
-
/* We must have requested it. */
if (s->alpn_client_proto_list == NULL) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
- if (size < 4) {
- *al = TLS1_AD_DECODE_ERROR;
- return 0;
- }
/*-
* The extension data consists of:
* uint16 list_length
* uint8 proto_length;
* uint8 proto[proto_length];
*/
- len = data[0];
- len <<= 8;
- len |= data[1];
- if (len != (unsigned)size - 2) {
- *al = TLS1_AD_DECODE_ERROR;
- return 0;
- }
- len = data[2];
- if (len != (unsigned)size - 3) {
+ if (!PACKET_get_net_2(&spkt, &len)
+ || PACKET_remaining(&spkt) != len
+ || !PACKET_get_1(&spkt, &len)
+ || PACKET_remaining(&spkt) != len) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
@@ -2538,12 +2526,20 @@
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
- memcpy(s->s3->alpn_selected, data + 3, len);
+ if (!PACKET_copy_bytes(&spkt, s->s3->alpn_selected, len)) {
+ *al = TLS1_AD_DECODE_ERROR;
+ return 0;
+ }
s->s3->alpn_selected_len = len;
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (type == TLSEXT_TYPE_heartbeat) {
- switch (data[0]) {
+ unsigned int hbtype;
+ if (!PACKET_get_1(&spkt, &hbtype)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+ switch (hbtype) {
case 0x01: /* Server allows us to send HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
break;
@@ -2559,7 +2555,7 @@
#endif
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
- if (ssl_parse_serverhello_use_srtp_ext(s, data, size, al))
+ if (ssl_parse_serverhello_use_srtp_ext(s, &spkt, al))
return 0;
}
#endif
@@ -2581,11 +2577,9 @@
*/
else if (custom_ext_parse(s, 0, type, data, size, al) <= 0)
return 0;
-
- data += size;
}
- if (data != d + n) {
+ if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
@@ -2605,8 +2599,6 @@
}
}
- *p = data;
-
ri_check:
/*
@@ -2887,13 +2879,12 @@
}
}
-int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
- int n)
+int ssl_parse_serverhello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
if (s->version < SSL3_VERSION)
return 1;
- if (ssl_scan_serverhello_tlsext(s, p, d, n, &al) <= 0) {
+ if (ssl_scan_serverhello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
