From 687eaf27a7e4bdfc58dd455e2566b915a7a25c20 Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Thu, 26 Feb 2015 11:53:55 +0000
Subject: [PATCH] Fix missing return value checks.

Fixed various missing return value checks in ssl3_send_newsession_ticket.
Also a mem leak on error.

Reviewed-by: Richard Levitte <levitte@openssl.org>
---
 ssl/s3_srvr.c | 79 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 30 deletions(-)

diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 48dee1016c..39c1574eb4 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -3256,14 +3256,16 @@ int ssl3_send_server_certificate(SSL *s)
 /* send a new session ticket (not necessarily for a new session) */
 int ssl3_send_newsession_ticket(SSL *s)
 {
+    unsigned char *senc = NULL;
+    EVP_CIPHER_CTX ctx;
+    HMAC_CTX hctx;
+
     if (s->state == SSL3_ST_SW_SESSION_TICKET_A) {
-        unsigned char *p, *senc, *macstart;
+        unsigned char *p, *macstart;
         const unsigned char *const_p;
         int len, slen_full, slen;
         SSL_SESSION *sess;
         unsigned int hlen;
-        EVP_CIPHER_CTX ctx;
-        HMAC_CTX hctx;
         SSL_CTX *tctx = s->initial_ctx;
         unsigned char iv[EVP_MAX_IV_LENGTH];
         unsigned char key_name[16];
@@ -3274,32 +3276,38 @@ int ssl3_send_newsession_ticket(SSL *s)
          * Some length values are 16 bits, so forget it if session is too
          * long
          */
-        if (slen_full > 0xFF00)
+        if (slen_full == 0 || slen_full > 0xFF00)
             return -1;
         senc = OPENSSL_malloc(slen_full);
         if (!senc)
             return -1;
+
+        EVP_CIPHER_CTX_init(&ctx);
+        HMAC_CTX_init(&hctx);
+
         p = senc;
-        i2d_SSL_SESSION(s->session, &p);
+        if (!i2d_SSL_SESSION(s->session, &p))
+            goto err;
 
         /*
          * create a fresh copy (not shared with other threads) to clean up
          */
         const_p = senc;
         sess = d2i_SSL_SESSION(NULL, &const_p, slen_full);
-        if (sess == NULL) {
-            OPENSSL_free(senc);
-            return -1;
-        }
+        if (sess == NULL)
+            goto err;
         sess->session_id_length = 0; /* ID is irrelevant for the ticket */
 
         slen = i2d_SSL_SESSION(sess, NULL);
-        if (slen > slen_full) { /* shouldn't ever happen */
-            OPENSSL_free(senc);
-            return -1;
+        if (slen == 0 || slen > slen_full) { /* shouldn't ever happen */
+            SSL_SESSION_free(sess);
+            goto err;
         }
         p = senc;
-        i2d_SSL_SESSION(sess, &p);
+        if (!i2d_SSL_SESSION(sess, &p)) {
+            SSL_SESSION_free(sess);
+            goto err;
+        }
         SSL_SESSION_free(sess);
 
         /*-
@@ -3313,26 +3321,26 @@ int ssl3_send_newsession_ticket(SSL *s)
         if (!BUF_MEM_grow(s->init_buf,
                           SSL_HM_HEADER_LENGTH(s) + 22 + EVP_MAX_IV_LENGTH +
                           EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE + slen))
-            return -1;
+            goto err;
+
         p = ssl_handshake_start(s);
-        EVP_CIPHER_CTX_init(&ctx);
-        HMAC_CTX_init(&hctx);
         /*
          * Initialize HMAC and cipher contexts. If callback present it does
          * all the work otherwise use generated values from parent ctx.
          */
         if (tctx->tlsext_ticket_key_cb) {
             if (tctx->tlsext_ticket_key_cb(s, key_name, iv, &ctx,
-                                           &hctx, 1) < 0) {
-                OPENSSL_free(senc);
-                return -1;
-            }
+                                           &hctx, 1) < 0)
+                goto err;
         } else {
-            RAND_pseudo_bytes(iv, 16);
-            EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
-                               tctx->tlsext_tick_aes_key, iv);
-            HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
-                         EVP_sha256(), NULL);
+            if (RAND_bytes(iv, 16) <= 0)
+                goto err;
+            if (!EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
+                                    tctx->tlsext_tick_aes_key, iv))
+                goto err;
+            if (!HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
+                              EVP_sha256(), NULL))
+                goto err;
             memcpy(key_name, tctx->tlsext_tick_key_name, 16);
         }
 
@@ -3353,14 +3361,19 @@ int ssl3_send_newsession_ticket(SSL *s)
         memcpy(p, iv, EVP_CIPHER_CTX_iv_length(&ctx));
         p += EVP_CIPHER_CTX_iv_length(&ctx);
         /* Encrypt session data */
-        EVP_EncryptUpdate(&ctx, p, &len, senc, slen);
+        if (!EVP_EncryptUpdate(&ctx, p, &len, senc, slen))
+            goto err;
         p += len;
-        EVP_EncryptFinal(&ctx, p, &len);
+        if (!EVP_EncryptFinal(&ctx, p, &len))
+            goto err;
         p += len;
-        EVP_CIPHER_CTX_cleanup(&ctx);
 
-        HMAC_Update(&hctx, macstart, p - macstart);
-        HMAC_Final(&hctx, p, &hlen);
+        if (!HMAC_Update(&hctx, macstart, p - macstart))
+            goto err;
+        if (!HMAC_Final(&hctx, p, &hlen))
+            goto err;
+
+        EVP_CIPHER_CTX_cleanup(&ctx);
         HMAC_CTX_cleanup(&hctx);
 
         p += hlen;
@@ -3377,6 +3390,12 @@ int ssl3_send_newsession_ticket(SSL *s)
 
     /* SSL3_ST_SW_SESSION_TICKET_B */
     return ssl_do_write(s);
+ err:
+    if (senc)
+        OPENSSL_free(senc);
+    EVP_CIPHER_CTX_cleanup(&ctx);
+    HMAC_CTX_cleanup(&hctx);
+    return -1;
 }
 
 int ssl3_send_cert_status(SSL *s)
-- 
2.34.1