Make string_util::WriteInto() DCHECK() that the supplied |length_with_null| > 1, meaning that the...

crypto/encryptor_openssl.cc

Index: crypto/encryptor_openssl.cc
===================================================================
--- crypto/encryptor_openssl.cc	(revision 111826)
+++ crypto/encryptor_openssl.cc	(working copy)
@@ -73,11 +73,13 @@
 
 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 @@
   // 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 @@
 
   // 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;