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/*************************************************
* PKCS #5 PBES1 Source File *
* (C) 1999-2008 The Botan Project *
*************************************************/
#include <botan/pbe_pkcs.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/parsing.h>
#include <botan/lookup.h>
#include <botan/rng.h>
#include <algorithm>
#include <memory>
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()
{
pipe.append(get_cipher(cipher, key, iv, direction));
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)
{
std::auto_ptr<S2K> pbkdf(get_s2k("PBKDF1(" + digest + ")"));
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()
{
iterations = 2048;
salt.create(8);
Global_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");
if(cipher == "DES/CBC" && digest == "MD2")
return (base_pbes1_oid + 1);
else if(cipher == "DES/CBC" && digest == "MD5")
return (base_pbes1_oid + 3);
else if(cipher == "DES/CBC" && digest == "SHA-160")
return (base_pbes1_oid + 10);
else if(cipher == "RC2/CBC" && digest == "MD2")
return (base_pbes1_oid + 4);
else if(cipher == "RC2/CBC" && digest == "MD5")
return (base_pbes1_oid + 6);
else if(cipher == "RC2/CBC" && 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(const std::string& d_algo,
const std::string& c_algo, Cipher_Dir dir) :
direction(dir), digest(deref_alias(d_algo)), cipher(c_algo)
{
std::vector<std::string> cipher_spec = split_on(c_algo, '/');
if(cipher_spec.size() != 2)
throw Invalid_Argument("PBE-PKCS5 v1.5: Invalid cipher spec " + c_algo);
const std::string cipher_algo = deref_alias(cipher_spec[0]);
const std::string cipher_mode = cipher_spec[1];
if(!have_block_cipher(cipher_algo))
throw Algorithm_Not_Found(cipher_algo);
if(!have_hash(digest))
throw Algorithm_Not_Found(digest);
if((cipher_algo != "DES" && cipher_algo != "RC2") || (cipher_mode != "CBC"))
throw Invalid_Argument("PBE-PKCS5 v1.5: Invalid cipher " + cipher);
if(digest != "MD2" && digest != "MD5" && digest != "SHA-160")
throw Invalid_Argument("PBE-PKCS5 v1.5: Invalid digest " + digest);
}
}
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