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

crypto/symmetric_key.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CRYPTO_SYMMETRIC_KEY_H_
 #define CRYPTO_SYMMETRIC_KEY_H_
 #pragma once
 
 #include <string>
 
@@ skipping 17 matching lines @@
   // Defines the algorithm that a key will be used with. See also
   // classs Encrptor.
   enum Algorithm {
     AES,
     HMAC_SHA1,
   };
 
   virtual ~SymmetricKey();
 
   // Generates a random key suitable to be used with |algorithm| and of
-  // |key_size_in_bits| bits.
+  // |key_size_in_bits| bits. |key_size_in_bits| must be a multiple of 8.
   // The caller is responsible for deleting the returned SymmetricKey.
   static SymmetricKey* GenerateRandomKey(Algorithm algorithm,
                                          size_t key_size_in_bits);
 
   // Derives a key from the supplied password and salt using PBKDF2, suitable
   // for use with specified |algorithm|. Note |algorithm| is not the algorithm
-  // used to derive the key from the password. The caller is responsible for
-  // deleting the returned SymmetricKey.
+  // used to derive the key from the password. |key_size_in_bits| must be a
+  // multiple of 8. The caller is responsible for deleting the returned
+  // SymmetricKey.
   static SymmetricKey* DeriveKeyFromPassword(Algorithm algorithm,
                                              const std::string& password,
                                              const std::string& salt,
                                              size_t iterations,
                                              size_t key_size_in_bits);
 
   // Imports an array of key bytes in |raw_key|. This key may have been
   // generated by GenerateRandomKey or DeriveKeyFromPassword and exported with
   // GetRawKey, or via another compatible method. The key must be of suitable
   // size for use with |algorithm|. The caller owns the returned SymmetricKey.
@@ skipping 44 matching lines @@
   // fails with NTE_BAD_KEY/NTE_BAD_LEN
   std::string raw_key_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(SymmetricKey);
 };
 
 }  // namespace crypto
 
 #endif  // CRYPTO_SYMMETRIC_KEY_H_