PR: 2658
Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Reviewed by: steve
Support for TLS/DTLS heartbeats.
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 1c0164a..c5c805c 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -114,6 +114,7 @@
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/ocsp.h>
+#include <openssl/rand.h>
#include "ssl_locl.h"
const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
@@ -618,6 +619,20 @@
i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
}
+#ifndef OPENSSL_NO_HEARTBEATS
+ /* Add Heartbeat extension */
+ s2n(TLSEXT_TYPE_heartbeat,ret);
+ s2n(1,ret);
+ /* Set mode:
+ * 1: peer may send requests
+ * 2: peer not allowed to send requests
+ */
+ if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
+ *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
+ else
+ *(ret++) = SSL_TLSEXT_HB_ENABLED;
+#endif
+
#ifndef OPENSSL_NO_NEXTPROTONEG
if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
{
@@ -796,6 +811,20 @@
}
+#ifndef OPENSSL_NO_HEARTBEATS
+ /* Add Heartbeat extension */
+ s2n(TLSEXT_TYPE_heartbeat,ret);
+ s2n(1,ret);
+ /* Set mode:
+ * 1: peer may send requests
+ * 2: peer not allowed to send requests
+ */
+ if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
+ *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
+ else
+ *(ret++) = SSL_TLSEXT_HB_ENABLED;
+#endif
+
#ifndef OPENSSL_NO_NEXTPROTONEG
next_proto_neg_seen = s->s3->next_proto_neg_seen;
s->s3->next_proto_neg_seen = 0;
@@ -840,6 +869,11 @@
s->s3->next_proto_neg_seen = 0;
#endif
+#ifndef OPENSSL_NO_HEARTBEATS
+ s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
+ SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
+#endif
+
if (data >= (d+n-2))
goto ri_check;
n2s(data,len);
@@ -1227,6 +1261,21 @@
else
s->tlsext_status_type = -1;
}
+#ifndef OPENSSL_NO_HEARTBEATS
+ else if (type == TLSEXT_TYPE_heartbeat)
+ {
+ switch(data[0])
+ {
+ case 0x01: /* Client allows us to send HB requests */
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
+ break;
+ case 0x02: /* Client doesn't accept HB requests */
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
+ break;
+ }
+ }
+#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0)
@@ -1312,6 +1361,11 @@
s->s3->next_proto_neg_seen = 0;
#endif
+#ifndef OPENSSL_NO_HEARTBEATS
+ s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
+ SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
+#endif
+
if (data >= (d+n-2))
goto ri_check;
@@ -1478,6 +1532,21 @@
return 0;
renegotiate_seen = 1;
}
+#ifndef OPENSSL_NO_HEARTBEATS
+ else if (type == TLSEXT_TYPE_heartbeat)
+ {
+ switch(data[0])
+ {
+ case 0x01: /* Server allows us to send HB requests */
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
+ break;
+ case 0x02: /* Server doesn't accept HB requests */
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
+ s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
+ break;
+ }
+ }
+#endif
else if (type == TLSEXT_TYPE_use_srtp)
{
if(ssl_parse_serverhello_use_srtp_ext(s, data, size,
@@ -2330,3 +2399,145 @@
}
#endif
+
+#ifndef OPENSSL_NO_HEARTBEATS
+int
+tls1_process_heartbeat(SSL *s)
+ {
+ unsigned char *p = &s->s3->rrec.data[0], *pl;
+ unsigned short hbtype;
+ unsigned int payload;
+ unsigned int padding = 16; /* Use minimum padding */
+
+ /* Read type and payload length first */
+ hbtype = *p++;
+ n2s(p, payload);
+ pl = p;
+
+ if (s->msg_callback)
+ s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
+ &s->s3->rrec.data[0], s->s3->rrec.length,
+ s, s->msg_callback_arg);
+
+ if (hbtype == TLS1_HB_REQUEST)
+ {
+ unsigned char *buffer, *bp;
+ int r;
+
+ /* Allocate memory for the response, size is 1 bytes
+ * message type, plus 2 bytes payload length, plus
+ * payload, plus padding
+ */
+ buffer = OPENSSL_malloc(1 + 2 + payload + padding);
+ bp = buffer;
+
+ /* Enter response type, length and copy payload */
+ *bp++ = TLS1_HB_RESPONSE;
+ s2n(payload, bp);
+ memcpy(bp, pl, payload);
+
+ r = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
+
+ if (r >= 0 && s->msg_callback)
+ s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+ buffer, 3 + payload + padding,
+ s, s->msg_callback_arg);
+
+ OPENSSL_free(buffer);
+
+ if (r < 0)
+ return r;
+ }
+ else if (hbtype == TLS1_HB_RESPONSE)
+ {
+ unsigned int seq;
+
+ /* We only send sequence numbers (2 bytes unsigned int),
+ * and 16 random bytes, so we just try to read the
+ * sequence number */
+ n2s(pl, seq);
+
+ if (payload == 18 && seq == s->tlsext_hb_seq)
+ {
+ s->tlsext_hb_seq++;
+ s->tlsext_hb_pending = 0;
+ }
+ }
+
+ return 0;
+ }
+
+int
+tls1_heartbeat(SSL *s)
+ {
+ unsigned char *buf, *p;
+ int ret;
+ unsigned int payload = 18; /* Sequence number + random bytes */
+ unsigned int padding = 16; /* Use minimum padding */
+
+ /* Only send if peer supports and accepts HB requests... */
+ if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
+ s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
+ {
+ SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
+ return -1;
+ }
+
+ /* ...and there is none in flight yet... */
+ if (s->tlsext_hb_pending)
+ {
+ SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
+ return -1;
+ }
+
+ /* ...and no handshake in progress. */
+ if (SSL_in_init(s) || s->in_handshake)
+ {
+ SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
+ return -1;
+ }
+
+ /* Check if padding is too long, payload and padding
+ * must not exceed 2^14 - 3 = 16381 bytes in total.
+ */
+ OPENSSL_assert(payload + padding <= 16381);
+
+ /* Create HeartBeat message, we just use a sequence number
+ * as payload to distuingish different messages and add
+ * some random stuff.
+ * - Message Type, 1 byte
+ * - Payload Length, 2 bytes (unsigned int)
+ * - Payload, the sequence number (2 bytes uint)
+ * - Payload, random bytes (16 bytes uint)
+ * - Padding
+ */
+ buf = OPENSSL_malloc(1 + 2 + payload + padding);
+ p = buf;
+ /* Message Type */
+ *p++ = TLS1_HB_REQUEST;
+ /* Payload length (18 bytes here) */
+ s2n(payload, p);
+ /* Sequence number */
+ s2n(s->tlsext_hb_seq, p);
+ /* 16 random bytes */
+ RAND_pseudo_bytes(p, 16);
+ p += 16;
+ /* Random padding */
+ RAND_pseudo_bytes(p, padding);
+
+ ret = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
+ if (ret >= 0)
+ {
+ if (s->msg_callback)
+ s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+ buf, 3 + payload + padding,
+ s, s->msg_callback_arg);
+
+ s->tlsext_hb_pending = 1;
+ }
+
+ OPENSSL_free(buf);
+
+ return ret;
+ }
+#endif
