Excessive allocation of memory in dtls1_preprocess_fragment()

[openssl.git] / ssl / statem / statem_dtls.c

diff --git a/ssl/statem/statem_dtls.c b/ssl/statem/statem_dtls.c
index 7c8437a518b40eae7f0718549736b23d00cd6f82..7e23ad91a134dce4a085cd468b1470c5573df841 100644 (file)
--- a/ssl/statem/statem_dtls.c
+++ b/ssl/statem/statem_dtls.c
@@ -388,6 +388,20 @@ int dtls_get_message(SSL *s, int *mt, unsigned long *len)
     return 1;
 }
 
+/*
+ * dtls1_max_handshake_message_len returns the maximum number of bytes
+ * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
+ * may be greater if the maximum certificate list size requires it.
+ */
+static unsigned long dtls1_max_handshake_message_len(const SSL *s)
+{
+    unsigned long max_len =
+        DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
+    if (max_len < (unsigned long)s->max_cert_list)
+        return s->max_cert_list;
+    return max_len;
+}
+
 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
 {
     size_t frag_off, frag_len, msg_len;
@@ -397,15 +411,16 @@ static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
     frag_len = msg_hdr->frag_len;
 
     /* sanity checking */
-    if ((frag_off + frag_len) > msg_len) {
+    if ((frag_off + frag_len) > msg_len
+            || msg_len > dtls1_max_handshake_message_len(s)) {
         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
         return SSL_AD_ILLEGAL_PARAMETER;
     }
 
     if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
         /*
-         * msg_len is limited to 2^24, but is effectively checked against max
-         * above
+         * msg_len is limited to 2^24, but is effectively checked against
+         * dtls_max_handshake_message_len(s) above
          */
         if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
             SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
@@ -493,20 +508,6 @@ static int dtls1_retrieve_buffered_fragment(SSL *s, int *ok)
         return 0;
 }
 
-/*
- * dtls1_max_handshake_message_len returns the maximum number of bytes
- * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
- * may be greater if the maximum certificate list size requires it.
- */
-static unsigned long dtls1_max_handshake_message_len(const SSL *s)
-{
-    unsigned long max_len =
-        DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
-    if (max_len < (unsigned long)s->max_cert_list)
-        return s->max_cert_list;
-    return max_len;
-}
-
 static int
 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
 {