evp: prevent underflow in base64 decoding

[openssl.git] / ssl / t1_lib.c

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index f671d1d9c321e8b5edc542ca8e82cd744926e9c7..bddffd92cc045ae920d63e6e140c78b4d96c3425 100644 (file)
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -342,19 +342,11 @@ static unsigned char tls12_sigalgs[] = {
 #ifndef OPENSSL_NO_SHA
        tlsext_sigalg(TLSEXT_hash_sha1)
 #endif
-#ifndef OPENSSL_NO_MD5
-       tlsext_sigalg_rsa(TLSEXT_hash_md5)
-#endif
 };
 
 int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
        {
        size_t slen = sizeof(tls12_sigalgs);
-#ifdef OPENSSL_FIPS
-       /* If FIPS mode don't include MD5 which is last */
-       if (FIPS_mode())
-               slen -= 2;
-#endif
        if (p)
                memcpy(p, tls12_sigalgs, slen);
        return (int)slen;
@@ -670,6 +662,36 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
                 }
 #endif
 
+#ifdef TLSEXT_TYPE_padding
+       /* Add padding to workaround bugs in F5 terminators.
+        * See https://tools.ietf.org/html/draft-agl-tls-padding-03
+        *
+        * NB: because this code works out the length of all existing
+        * extensions it MUST always appear last.
+        */
+       {
+       int hlen = ret - (unsigned char *)s->init_buf->data;
+       /* The code in s23_clnt.c to build ClientHello messages includes the
+        * 5-byte record header in the buffer, while the code in s3_clnt.c does
+        * not. */
+       if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
+               hlen -= 5;
+       if (hlen > 0xff && hlen < 0x200)
+               {
+               hlen = 0x200 - hlen;
+               if (hlen >= 4)
+                       hlen -= 4;
+               else
+                       hlen = 0;
+
+               s2n(TLSEXT_TYPE_padding, ret);
+               s2n(hlen, ret);
+               memset(ret, 0, hlen);
+               ret += hlen;
+               }
+       }
+#endif
+
        if ((extdatalen = ret-p-2)== 0) 
                return p;
 
@@ -947,7 +969,7 @@ static void ssl_check_for_safari(SSL *s, const unsigned char *data, const unsign
 
        s->s3->is_probably_safari = 1;
 }
-#endif /* OPENSSL_NO_EC */
+#endif /* !OPENSSL_NO_EC */
 
 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
        {
@@ -972,7 +994,7 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 #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 */
+#endif /* !OPENSSL_NO_EC */
 
        if (data >= (d+n-2))
                goto ri_check;
@@ -1269,7 +1291,7 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
                                }
                        }
                else if (type == TLSEXT_TYPE_status_request &&
-                        s->version != DTLS1_VERSION && s->ctx->tlsext_status_cb)
+                        s->version != DTLS1_VERSION)
                        {
                
                        if (size < 5) 
@@ -2452,14 +2474,6 @@ const EVP_MD *tls12_get_hash(unsigned char hash_alg)
        {
        switch(hash_alg)
                {
-#ifndef OPENSSL_NO_MD5
-               case TLSEXT_hash_md5:
-#ifdef OPENSSL_FIPS
-               if (FIPS_mode())
-                       return NULL;
-#endif
-               return EVP_md5();
-#endif
 #ifndef OPENSSL_NO_SHA
                case TLSEXT_hash_sha1:
                return EVP_sha1();
@@ -2574,16 +2588,20 @@ tls1_process_heartbeat(SSL *s)
        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);
 
+       /* Read type and payload length first */
+       if (1 + 2 + 16 > s->s3->rrec.length)
+               return 0; /* silently discard */
+       hbtype = *p++;
+       n2s(p, payload);
+       if (1 + 2 + payload + 16 > s->s3->rrec.length)
+               return 0; /* silently discard per RFC 6520 sec. 4 */
+       pl = p;
+
        if (hbtype == TLS1_HB_REQUEST)
                {
                unsigned char *buffer, *bp;