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-rw-r--r--security/nss/lib/ssl/ssl3gthr.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/security/nss/lib/ssl/ssl3gthr.c b/security/nss/lib/ssl/ssl3gthr.c
index 2bcc1d0aa..cf6f4cb33 100644
--- a/security/nss/lib/ssl/ssl3gthr.c
+++ b/security/nss/lib/ssl/ssl3gthr.c
@@ -32,6 +32,7 @@ ssl3_InitGather(sslGather *gs)
gs->readOffset = 0;
gs->dtlsPacketOffset = 0;
gs->dtlsPacket.len = 0;
+ gs->rejectV2Records = PR_FALSE;
status = sslBuffer_Grow(&gs->buf, 4096);
return status;
}
@@ -147,8 +148,11 @@ ssl3_GatherData(sslSocket *ss, sslGather *gs, int flags, ssl2Gather *ssl2gs)
switch (gs->state) {
case GS_HEADER:
/* Check for SSLv2 handshakes. Always assume SSLv3 on clients,
- * support SSLv2 handshakes only when ssl2gs != NULL. */
- if (!ssl2gs || ssl3_isLikelyV3Hello(gs->hdr)) {
+ * support SSLv2 handshakes only when ssl2gs != NULL.
+ * Always assume v3 after we received the first record. */
+ if (!ssl2gs ||
+ ss->gs.rejectV2Records ||
+ ssl3_isLikelyV3Hello(gs->hdr)) {
/* Should have a non-SSLv2 record header in gs->hdr. Extract
* the length of the following encrypted data, and then
* read in the rest of the record into gs->inbuf. */
@@ -183,7 +187,7 @@ ssl3_GatherData(sslSocket *ss, sslGather *gs, int flags, ssl2Gather *ssl2gs)
/* This is the max length for an encrypted SSLv3+ fragment. */
if (!v2HdrLength &&
gs->remainder > (MAX_FRAGMENT_LENGTH + 2048)) {
- SSL3_SendAlert(ss, alert_fatal, unexpected_message);
+ SSL3_SendAlert(ss, alert_fatal, record_overflow);
gs->state = GS_INIT;
PORT_SetError(SSL_ERROR_RX_RECORD_TOO_LONG);
return SECFailure;
@@ -205,13 +209,28 @@ ssl3_GatherData(sslSocket *ss, sslGather *gs, int flags, ssl2Gather *ssl2gs)
* many into the gs->hdr[] buffer. Copy them over into inbuf so
* that we can properly process the hello record later. */
if (v2HdrLength) {
+ /* Reject v2 records that don't even carry enough data to
+ * resemble a valid ClientHello header. */
+ if (gs->remainder < SSL_HL_CLIENT_HELLO_HBYTES) {
+ SSL3_SendAlert(ss, alert_fatal, illegal_parameter);
+ PORT_SetError(SSL_ERROR_RX_MALFORMED_CLIENT_HELLO);
+ return SECFailure;
+ }
+
+ PORT_Assert(lbp);
gs->inbuf.len = 5 - v2HdrLength;
PORT_Memcpy(lbp, gs->hdr + v2HdrLength, gs->inbuf.len);
gs->remainder -= gs->inbuf.len;
lbp += gs->inbuf.len;
}
- break; /* End this case. Continue around the loop. */
+ if (gs->remainder > 0) {
+ break; /* End this case. Continue around the loop. */
+ }
+
+ /* FALL THROUGH if (gs->remainder == 0) as we just received
+ * an empty record and there's really no point in calling
+ * ssl_DefRecv() with buf=NULL and len=0. */
case GS_DATA:
/*
@@ -219,6 +238,10 @@ ssl3_GatherData(sslSocket *ss, sslGather *gs, int flags, ssl2Gather *ssl2gs)
*/
SSL_TRC(10, ("%d: SSL[%d]: got record of %d bytes",
SSL_GETPID(), ss->fd, gs->inbuf.len));
+
+ /* reject any v2 records from now on */
+ ss->gs.rejectV2Records = PR_TRUE;
+
gs->state = GS_INIT;
return 1;
}