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, 1 deletions

diff --git a/crypto/encryptor_openssl.cc b/crypto/encryptor_openssl.cc
index 6513181..cb26e22 100644
--- a/crypto/encryptor_openssl.cc
+++ b/crypto/encryptor_openssl.cc
@@ -73,11 +73,13 @@ bool Encryptor::Init(SymmetricKey* key,
 
 bool Encryptor::Encrypt(const base::StringPiece& plaintext,
                         std::string* ciphertext) {
+  CHECK(!plaintext.empty() || (mode_ == CBC));
   return Crypt(true, plaintext, ciphertext);
 }
 
 bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
                         std::string* plaintext) {
+  CHECK(!ciphertext.empty());
   return Crypt(false, ciphertext, plaintext);
 }
 
@@ -88,7 +90,7 @@ bool Encryptor::Crypt(bool do_encrypt,
   // Work on the result in a local variable, and then only transfer it to
   // |output| on success to ensure no partial data is returned.
   std::string result;
-  output->swap(result);
+  output->clear();
 
   const EVP_CIPHER* cipher = GetCipherForKey(key_);
   DCHECK(cipher);  // Already handled in Init();
@@ -106,6 +108,8 @@ bool Encryptor::Crypt(bool do_encrypt,
 
   // When encrypting, add another block size of space to allow for any padding.
   const size_t output_size = input.size() + (do_encrypt ? iv_.size() : 0);
+  CHECK_GT(output_size, 0u);
+  CHECK_GT(output_size + 1, input.size());
   uint8* out_ptr = reinterpret_cast<uint8*>(WriteInto(&result,
                                                       output_size + 1));
   int out_len;