coverity 1462549 Dereference before null check

[openssl.git] / crypto / evp / e_aes_cbc_hmac_sha256.c

diff --git a/crypto/evp/e_aes_cbc_hmac_sha256.c b/crypto/evp/e_aes_cbc_hmac_sha256.c
index bef603a3a5970f06a315bac571edc83e6489916c..72508c9851c6c13cbf2e096d8c08d7687b3354fa 100644 (file)
--- a/crypto/evp/e_aes_cbc_hmac_sha256.c
+++ b/crypto/evp/e_aes_cbc_hmac_sha256.c
@@ -1,26 +1,31 @@
 /*
- * Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2013-2020 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */
 
-#include <openssl/opensslconf.h>
+/*
+ * AES low level APIs are deprecated for public use, but still ok for internal
+ * use where we're using them to implement the higher level EVP interface, as is
+ * the case here.
+ */
+#include "internal/deprecated.h"
 
 #include <stdio.h>
 #include <string.h>
-
-
+#include <openssl/opensslconf.h>
 #include <openssl/evp.h>
 #include <openssl/objects.h>
 #include <openssl/aes.h>
 #include <openssl/sha.h>
 #include <openssl/rand.h>
-#include "modes_lcl.h"
-#include "internal/constant_time_locl.h"
-#include "internal/evp_int.h"
+#include "internal/cryptlib.h"
+#include "crypto/modes.h"
+#include "internal/constant_time.h"
+#include "crypto/evp.h"
 
 typedef struct {
     AES_KEY ks;
@@ -38,7 +43,6 @@ typedef struct {
         defined(__x86_64)       || defined(__x86_64__)  || \
         defined(_M_AMD64)       || defined(_M_X64)      )
 
-extern unsigned int OPENSSL_ia32cap_P[];
 # define AESNI_CAPABLE   (1<<(57-32))
 
 int aesni_set_encrypt_key(const unsigned char *userKey, int bits,
@@ -453,10 +457,12 @@ static int aesni_cbc_hmac_sha256_cipher(EVP_CIPHER_CTX *ctx,
          * to identify it and avoid stitch invocation. So that after we
          * establish that current CPU supports AVX, we even see if it's
          * either even XOP-capable Bulldozer-based or GenuineIntel one.
+         * But SHAEXT-capable go ahead...
          */
-        if (OPENSSL_ia32cap_P[1] & (1 << (60 - 32)) && /* AVX? */
-            ((OPENSSL_ia32cap_P[1] & (1 << (43 - 32))) /* XOP? */
-             | (OPENSSL_ia32cap_P[0] & (1<<30))) &&    /* "Intel CPU"? */
+        if (((OPENSSL_ia32cap_P[2] & (1 << 29)) ||         /* SHAEXT? */
+             ((OPENSSL_ia32cap_P[1] & (1 << (60 - 32))) && /* AVX? */
+              ((OPENSSL_ia32cap_P[1] & (1 << (43 - 32)))   /* XOP? */
+               | (OPENSSL_ia32cap_P[0] & (1 << 30))))) &&  /* "Intel CPU"? */
             plen > (sha_off + iv) &&
             (blocks = (plen - (sha_off + iv)) / SHA256_CBLOCK)) {
             SHA256_Update(&key->md, in + iv, sha_off);
@@ -538,12 +544,17 @@ static int aesni_cbc_hmac_sha256_cipher(EVP_CIPHER_CTX *ctx,
             maxpad |= (255 - maxpad) >> (sizeof(maxpad) * 8 - 8);
             maxpad &= 255;
 
-            ret &= constant_time_ge(maxpad, pad);
+            mask = constant_time_ge(maxpad, pad);
+            ret &= mask;
+            /*
+             * If pad is invalid then we will fail the above test but we must
+             * continue anyway because we are in constant time code. However,
+             * we'll use the maxpad value instead of the supplied pad to make
+             * sure we perform well defined pointer arithmetic.
+             */
+            pad = constant_time_select(mask, pad, maxpad);
 
             inp_len = len - (SHA256_DIGEST_LENGTH + pad + 1);
-            mask = (0 - ((inp_len - len) >> (sizeof(inp_len) * 8 - 1)));
-            inp_len &= mask;
-            ret &= (int)mask;
 
             key->aux.tls_aad[plen - 2] = inp_len >> 8;
             key->aux.tls_aad[plen - 1] = inp_len;
@@ -788,6 +799,8 @@ static int aesni_cbc_hmac_sha256_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
                 key->payload_length = len;
                 if ((key->aux.tls_ver =
                      p[arg - 4] << 8 | p[arg - 3]) >= TLS1_1_VERSION) {
+                    if (len < AES_BLOCK_SIZE)
+                        return 0;
                     len -= AES_BLOCK_SIZE;
                     p[arg - 2] = len >> 8;
                     p[arg - 1] = len;