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/*
* Keypair Checks
* (C) 1999-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/keypair.h>
#include <botan/pubkey.h>
namespace Botan {
namespace KeyPair {
/*
* Check an encryption key pair for consistency
*/
bool encryption_consistency_check(RandomNumberGenerator& rng,
const Private_Key& key,
const std::string& padding)
{
PK_Encryptor_EME encryptor(key, padding);
PK_Decryptor_EME decryptor(key, padding);
/*
Weird corner case, if the key is too small to encrypt anything at
all. This can happen with very small RSA keys with PSS
*/
if(encryptor.maximum_input_size() == 0)
return true;
SecureVector<byte> plaintext =
rng.random_vec(encryptor.maximum_input_size() - 1);
SecureVector<byte> ciphertext = encryptor.encrypt(plaintext, rng);
if(ciphertext == plaintext)
return false;
SecureVector<byte> decrypted = decryptor.decrypt(ciphertext);
return (plaintext == decrypted);
}
/*
* Check a signature key pair for consistency
*/
bool signature_consistency_check(RandomNumberGenerator& rng,
const Private_Key& key,
const std::string& padding)
{
PK_Signer signer(key, padding);
PK_Verifier verifier(key, padding);
SecureVector<byte> message = rng.random_vec(16);
SecureVector<byte> signature;
try
{
signature = signer.sign_message(message, rng);
}
catch(Encoding_Error)
{
return false;
}
if(!verifier.verify_message(message, signature))
return false;
// Now try to check a corrupt signature, ensure it does not succeed
++message[0];
if(verifier.verify_message(message, signature))
return false;
return true;
}
}
}
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