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, 5 insertions, 3 deletions

diff --git a/crypto/encryptor_win.cc b/crypto/encryptor_win.cc
index fae1f82..dc59519 100644
--- a/crypto/encryptor_win.cc
+++ b/crypto/encryptor_win.cc
@@ -83,8 +83,10 @@ bool Encryptor::Init(SymmetricKey* key,
 bool Encryptor::Encrypt(const base::StringPiece& plaintext,
                         std::string* ciphertext) {
   DWORD data_len = plaintext.size();
+  CHECK((data_len > 0u) || (mode_ == CBC));
   DWORD total_len = data_len + block_size_;
-  CHECK_GT(total_len, data_len);
+  CHECK_GT(total_len, 0u);
+  CHECK_GT(total_len + 1, data_len);
 
   // CryptoAPI encrypts/decrypts in place.
   char* ciphertext_data = WriteInto(ciphertext, total_len + 1);
@@ -105,8 +107,8 @@ bool Encryptor::Encrypt(const base::StringPiece& plaintext,
 bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
                         std::string* plaintext) {
   DWORD data_len = ciphertext.size();
-  if (data_len == 0 || (data_len + 1) < data_len)
-    return false;
+  CHECK_GT(data_len, 0u);
+  CHECK_GT(data_len + 1, data_len);
 
   // CryptoAPI encrypts/decrypts in place.
   char* plaintext_data = WriteInto(plaintext, data_len + 1);