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/*
* PKCS #5 PBES1
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/pbes1.h>
#include <botan/pbkdf1.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/cbc.h>
#include <algorithm>
namespace Botan {
/*
* Encrypt some bytes using PBES1
*/
void PBE_PKCS5v15::write(const byte input[], u32bit length)
{
while(length)
{
u32bit put = std::min(DEFAULT_BUFFERSIZE, length);
pipe.write(input, length);
flush_pipe(true);
length -= put;
}
}
/*
* Start encrypting with PBES1
*/
void PBE_PKCS5v15::start_msg()
{
if(direction == ENCRYPTION)
pipe.append(new CBC_Encryption(block_cipher->clone(),
new PKCS7_Padding,
key, iv));
else
pipe.append(new CBC_Decryption(block_cipher->clone(),
new PKCS7_Padding,
key, iv));
pipe.start_msg();
if(pipe.message_count() > 1)
pipe.set_default_msg(pipe.default_msg() + 1);
}
/*
* Finish encrypting with PBES1
*/
void PBE_PKCS5v15::end_msg()
{
pipe.end_msg();
flush_pipe(false);
pipe.reset();
}
/*
* Flush the pipe
*/
void PBE_PKCS5v15::flush_pipe(bool safe_to_skip)
{
if(safe_to_skip && pipe.remaining() < 64)
return;
SecureVector<byte> buffer(DEFAULT_BUFFERSIZE);
while(pipe.remaining())
{
u32bit got = pipe.read(buffer, buffer.size());
send(buffer, got);
}
}
/*
* Set the passphrase to use
*/
void PBE_PKCS5v15::set_key(const std::string& passphrase)
{
PKCS5_PBKDF1 pbkdf(hash_function->clone());
pbkdf.set_iterations(iterations);
pbkdf.change_salt(salt, salt.size());
SymmetricKey key_and_iv = pbkdf.derive_key(16, passphrase);
key.set(key_and_iv.begin(), 8);
iv.set(key_and_iv.begin() + 8, 8);
}
/*
* Create a new set of PBES1 parameters
*/
void PBE_PKCS5v15::new_params(RandomNumberGenerator& rng)
{
iterations = 2048;
salt.create(8);
rng.randomize(salt, salt.size());
}
/*
* Encode PKCS#5 PBES1 parameters
*/
MemoryVector<byte> PBE_PKCS5v15::encode_params() const
{
return DER_Encoder()
.start_cons(SEQUENCE)
.encode(salt, OCTET_STRING)
.encode(iterations)
.end_cons()
.get_contents();
}
/*
* Decode PKCS#5 PBES1 parameters
*/
void PBE_PKCS5v15::decode_params(DataSource& source)
{
BER_Decoder(source)
.start_cons(SEQUENCE)
.decode(salt, OCTET_STRING)
.decode(iterations)
.verify_end()
.end_cons();
if(salt.size() != 8)
throw Decoding_Error("PBES1: Encoded salt is not 8 octets");
}
/*
* Return an OID for this PBES1 type
*/
OID PBE_PKCS5v15::get_oid() const
{
const OID base_pbes1_oid("1.2.840.113549.1.5");
const std::string cipher = block_cipher->name();
const std::string digest = hash_function->name();
if(cipher == "DES" && digest == "MD2")
return (base_pbes1_oid + 1);
else if(cipher == "DES" && digest == "MD5")
return (base_pbes1_oid + 3);
else if(cipher == "DES" && digest == "SHA-160")
return (base_pbes1_oid + 10);
else if(cipher == "RC2" && digest == "MD2")
return (base_pbes1_oid + 4);
else if(cipher == "RC2" && digest == "MD5")
return (base_pbes1_oid + 6);
else if(cipher == "RC2" && digest == "SHA-160")
return (base_pbes1_oid + 11);
else
throw Internal_Error("PBE-PKCS5 v1.5: get_oid() has run out of options");
}
/*
* PKCS#5 v1.5 PBE Constructor
*/
PBE_PKCS5v15::PBE_PKCS5v15(BlockCipher* cipher,
HashFunction* hash,
Cipher_Dir dir) :
direction(dir), block_cipher(cipher), hash_function(hash)
{
if(cipher->name() != "DES" && cipher->name() != "RC2")
{
throw Invalid_Argument("PBE_PKCS5v1.5: Unknown cipher " +
cipher->name());
}
if(hash->name() != "MD2" && hash->name() != "MD5" &&
hash->name() != "SHA-160")
{
throw Invalid_Argument("PBE_PKCS5v1.5: Unknown hash " +
hash->name());
}
}
PBE_PKCS5v15::~PBE_PKCS5v15()
{
delete block_cipher;
delete hash_function;
}
}
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