ake string_util::WriteInto() DCHECK() that the supplied |length_with_null| > 1, meaning that the without-'\0' string is non-empty. This replaces the conditional code added recently that makes this case return NULL. It's easier to understand if it's simply an error to call WriteInto() in this case at all.

Add DCHECK()s or conditionals as appropriate to callers in order to ensure this assertion holds.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/8418034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112005 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 11 insertions, 7 deletions

diff --git a/crypto/symmetric_key_openssl.cc b/crypto/symmetric_key_openssl.cc
index 1d1ad23..899a942 100644
--- a/crypto/symmetric_key_openssl.cc
+++ b/crypto/symmetric_key_openssl.cc
@@ -24,10 +24,10 @@ SymmetricKey::~SymmetricKey() {
 SymmetricKey* SymmetricKey::GenerateRandomKey(Algorithm algorithm,
                                               size_t key_size_in_bits) {
   DCHECK_EQ(AES, algorithm);
-  int key_size_in_bytes = key_size_in_bits / 8;
-  DCHECK_EQ(static_cast<int>(key_size_in_bits), key_size_in_bytes * 8);
+  size_t key_size_in_bytes = key_size_in_bits / 8;
+  DCHECK_EQ(key_size_in_bits, key_size_in_bytes * 8);
 
-  if (key_size_in_bits == 0)
+  if (key_size_in_bytes == 0)
     return NULL;
 
   OpenSSLErrStackTracer err_tracer(FROM_HERE);
@@ -35,7 +35,7 @@ SymmetricKey* SymmetricKey::GenerateRandomKey(Algorithm algorithm,
   uint8* key_data =
       reinterpret_cast<uint8*>(WriteInto(&key->key_, key_size_in_bytes + 1));
 
-  int rv = RAND_bytes(key_data, key_size_in_bytes);
+  int rv = RAND_bytes(key_data, static_cast<int>(key_size_in_bytes));
   return rv == 1 ? key.release() : NULL;
 }
 
@@ -46,8 +46,11 @@ SymmetricKey* SymmetricKey::DeriveKeyFromPassword(Algorithm algorithm,
                                                   size_t iterations,
                                                   size_t key_size_in_bits) {
   DCHECK(algorithm == AES || algorithm == HMAC_SHA1);
-  int key_size_in_bytes = key_size_in_bits / 8;
-  DCHECK_EQ(static_cast<int>(key_size_in_bits), key_size_in_bytes * 8);
+  size_t key_size_in_bytes = key_size_in_bits / 8;
+  DCHECK_EQ(key_size_in_bits, key_size_in_bytes * 8);
+
+  if (key_size_in_bytes == 0)
+    return NULL;
 
   OpenSSLErrStackTracer err_tracer(FROM_HERE);
   scoped_ptr<SymmetricKey> key(new SymmetricKey);
@@ -56,7 +59,8 @@ SymmetricKey* SymmetricKey::DeriveKeyFromPassword(Algorithm algorithm,
   int rv = PKCS5_PBKDF2_HMAC_SHA1(password.data(), password.length(),
                                   reinterpret_cast<const uint8*>(salt.data()),
                                   salt.length(), iterations,
-                                  key_size_in_bytes, key_data);
+                                  static_cast<int>(key_size_in_bytes),
+                                  key_data);
   return rv == 1 ? key.release() : NULL;
 }