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/*
* PKCS #8
* (C) 1999-2010,2014 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/pkcs8.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/alg_id.h>
#include <botan/oids.h>
#include <botan/pem.h>
#include <botan/pbes2.h>
#include <botan/scan_name.h>
#include <botan/internal/pk_algs.h>
namespace Botan {
namespace PKCS8 {
namespace {
/*
* Get info from an EncryptedPrivateKeyInfo
*/
secure_vector<byte> PKCS8_extract(DataSource& source,
AlgorithmIdentifier& pbe_alg_id)
{
secure_vector<byte> key_data;
BER_Decoder(source)
.start_cons(SEQUENCE)
.decode(pbe_alg_id)
.decode(key_data, OCTET_STRING)
.verify_end();
return key_data;
}
/*
* PEM decode and/or decrypt a private key
*/
secure_vector<byte> PKCS8_decode(
DataSource& source,
std::function<std::string ()> get_passphrase,
AlgorithmIdentifier& pk_alg_id)
{
AlgorithmIdentifier pbe_alg_id;
secure_vector<byte> key_data, key;
bool is_encrypted = true;
try {
if(ASN1::maybe_BER(source) && !PEM_Code::matches(source))
key_data = PKCS8_extract(source, pbe_alg_id);
else
{
std::string label;
key_data = PEM_Code::decode(source, label);
if(label == "PRIVATE KEY")
is_encrypted = false;
else if(label == "ENCRYPTED PRIVATE KEY")
{
DataSource_Memory key_source(key_data);
key_data = PKCS8_extract(key_source, pbe_alg_id);
}
else
throw PKCS8_Exception("Unknown PEM label " + label);
}
if(key_data.empty())
throw PKCS8_Exception("No key data found");
}
catch(Decoding_Error& e)
{
throw Decoding_Error("PKCS #8 private key decoding failed: " + std::string(e.what()));
}
try
{
if(is_encrypted)
{
if(OIDS::lookup(pbe_alg_id.oid) != "PBE-PKCS5v20")
throw Exception("Unknown PBE type " + pbe_alg_id.oid.as_string());
key = pbes2_decrypt(key_data, get_passphrase(), pbe_alg_id.parameters);
}
else
key = key_data;
BER_Decoder(key)
.start_cons(SEQUENCE)
.decode_and_check<size_t>(0, "Unknown PKCS #8 version number")
.decode(pk_alg_id)
.decode(key, OCTET_STRING)
.discard_remaining()
.end_cons();
}
catch(std::exception& e)
{
throw Decoding_Error("PKCS #8 private key decoding failed: " + std::string(e.what()));
}
return key;
}
}
/*
* BER encode a PKCS #8 private key, unencrypted
*/
secure_vector<byte> BER_encode(const Private_Key& key)
{
const size_t PKCS8_VERSION = 0;
return DER_Encoder()
.start_cons(SEQUENCE)
.encode(PKCS8_VERSION)
.encode(key.pkcs8_algorithm_identifier())
.encode(key.pkcs8_private_key(), OCTET_STRING)
.end_cons()
.get_contents();
}
/*
* PEM encode a PKCS #8 private key, unencrypted
*/
std::string PEM_encode(const Private_Key& key)
{
return PEM_Code::encode(PKCS8::BER_encode(key), "PRIVATE KEY");
}
namespace {
std::pair<std::string, std::string>
choose_pbe_params(const std::string& pbe_algo, const std::string& key_algo)
{
if(pbe_algo == "")
{
// Defaults:
if(key_algo == "Curve25519" || key_algo == "McEliece")
return std::make_pair("AES-256/GCM", "SHA-512");
else // for everything else (RSA, DSA, ECDSA, GOST, ...)
return std::make_pair("AES-256/CBC", "SHA-256");
}
SCAN_Name request(pbe_algo);
if(request.algo_name() != "PBE-PKCS5v20" || request.arg_count() != 2)
throw Exception("Unsupported PBE " + pbe_algo);
return std::make_pair(request.arg(1), request.arg(0));
}
}
/*
* BER encode a PKCS #8 private key, encrypted
*/
std::vector<byte> BER_encode(const Private_Key& key,
RandomNumberGenerator& rng,
const std::string& pass,
std::chrono::milliseconds msec,
const std::string& pbe_algo)
{
const auto pbe_params = choose_pbe_params(pbe_algo, key.algo_name());
const std::pair<AlgorithmIdentifier, std::vector<byte>> pbe_info =
pbes2_encrypt(PKCS8::BER_encode(key), pass, msec,
pbe_params.first, pbe_params.second, rng);
return DER_Encoder()
.start_cons(SEQUENCE)
.encode(pbe_info.first)
.encode(pbe_info.second, OCTET_STRING)
.end_cons()
.get_contents_unlocked();
}
/*
* PEM encode a PKCS #8 private key, encrypted
*/
std::string PEM_encode(const Private_Key& key,
RandomNumberGenerator& rng,
const std::string& pass,
std::chrono::milliseconds msec,
const std::string& pbe_algo)
{
if(pass == "")
return PEM_encode(key);
return PEM_Code::encode(PKCS8::BER_encode(key, rng, pass, msec, pbe_algo),
"ENCRYPTED PRIVATE KEY");
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(DataSource& source,
RandomNumberGenerator& rng,
std::function<std::string ()> get_pass)
{
AlgorithmIdentifier alg_id;
secure_vector<byte> pkcs8_key = PKCS8_decode(source, get_pass, alg_id);
const std::string alg_name = OIDS::lookup(alg_id.oid);
if(alg_name == "" || alg_name == alg_id.oid.as_string())
throw PKCS8_Exception("Unknown algorithm OID: " +
alg_id.oid.as_string());
return make_private_key(alg_id, pkcs8_key, rng);
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(const std::string& fsname,
RandomNumberGenerator& rng,
std::function<std::string ()> get_pass)
{
DataSource_Stream source(fsname, true);
return PKCS8::load_key(source, rng, get_pass);
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(DataSource& source,
RandomNumberGenerator& rng,
const std::string& pass)
{
return PKCS8::load_key(source, rng, [pass]() { return pass; });
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(const std::string& fsname,
RandomNumberGenerator& rng,
const std::string& pass)
{
return PKCS8::load_key(fsname, rng, [pass]() { return pass; });
}
/*
* Make a copy of this private key
*/
Private_Key* copy_key(const Private_Key& key,
RandomNumberGenerator& rng)
{
DataSource_Memory source(PEM_encode(key));
return PKCS8::load_key(source, rng);
}
}
}
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