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/*
* PKCS #8
* (C) 1999-2008 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/pkcs8.h>
#include <botan/get_pbe.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/asn1_obj.h>
#include <botan/oids.h>
#include <botan/pem.h>
#include <botan/internal/pk_algs.h>
#include <memory>
namespace Botan {
namespace PKCS8 {
namespace {
/*
* Get info from an EncryptedPrivateKeyInfo
*/
SecureVector<byte> PKCS8_extract(DataSource& source,
AlgorithmIdentifier& pbe_alg_id)
{
SecureVector<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
*/
SecureVector<byte> PKCS8_decode(DataSource& source, const User_Interface& ui,
AlgorithmIdentifier& pk_alg_id)
{
AlgorithmIdentifier pbe_alg_id;
SecureVector<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)
{
throw Decoding_Error("PKCS #8 private key decoding failed");
}
if(!is_encrypted)
key = key_data;
const u32bit MAX_TRIES = 3;
u32bit tries = 0;
while(true)
{
try {
if(MAX_TRIES && tries >= MAX_TRIES)
break;
if(is_encrypted)
{
DataSource_Memory params(pbe_alg_id.parameters);
std::unique_ptr<PBE> pbe(get_pbe(pbe_alg_id.oid, params));
User_Interface::UI_Result result = User_Interface::OK;
const std::string passphrase =
ui.get_passphrase("PKCS #8 private key", source.id(), result);
if(result == User_Interface::CANCEL_ACTION)
break;
pbe->set_key(passphrase);
Pipe decryptor(pbe.release());
decryptor.process_msg(key_data, key_data.size());
key = decryptor.read_all();
}
u32bit version;
BER_Decoder(key)
.start_cons(SEQUENCE)
.decode(version)
.decode(pk_alg_id)
.decode(key, OCTET_STRING)
.discard_remaining()
.end_cons();
if(version != 0)
throw Decoding_Error("PKCS #8: Unknown version number");
break;
}
catch(Decoding_Error)
{
++tries;
}
}
if(key.empty())
throw Decoding_Error("PKCS #8 private key decoding failed");
return key;
}
}
/*
* DER or PEM encode a PKCS #8 private key
*/
void encode(const Private_Key& key, Pipe& pipe, X509_Encoding encoding)
{
std::unique_ptr<PKCS8_Encoder> encoder(key.pkcs8_encoder());
if(!encoder.get())
throw Encoding_Error("PKCS8::encode: Key does not support encoding");
const u32bit PKCS8_VERSION = 0;
SecureVector<byte> contents =
DER_Encoder()
.start_cons(SEQUENCE)
.encode(PKCS8_VERSION)
.encode(encoder->alg_id())
.encode(encoder->key_bits(), OCTET_STRING)
.end_cons()
.get_contents();
if(encoding == PEM)
pipe.write(PEM_Code::encode(contents, "PRIVATE KEY"));
else
pipe.write(contents);
}
/*
* Encode and encrypt a PKCS #8 private key
*/
void encrypt_key(const Private_Key& key,
Pipe& pipe,
RandomNumberGenerator& rng,
const std::string& pass, const std::string& pbe_algo,
X509_Encoding encoding)
{
const std::string DEFAULT_PBE = "PBE-PKCS5v20(SHA-1,AES-128/CBC)";
Pipe raw_key;
raw_key.start_msg();
encode(key, raw_key, RAW_BER);
raw_key.end_msg();
std::unique_ptr<PBE> pbe(get_pbe(((pbe_algo != "") ? pbe_algo : DEFAULT_PBE)));
pbe->new_params(rng);
pbe->set_key(pass);
AlgorithmIdentifier pbe_algid(pbe->get_oid(), pbe->encode_params());
Pipe key_encrytor(pbe.release());
key_encrytor.process_msg(raw_key);
SecureVector<byte> enc_key =
DER_Encoder()
.start_cons(SEQUENCE)
.encode(pbe_algid)
.encode(key_encrytor.read_all(), OCTET_STRING)
.end_cons()
.get_contents();
if(encoding == PEM)
pipe.write(PEM_Code::encode(enc_key, "ENCRYPTED PRIVATE KEY"));
else
pipe.write(enc_key);
}
/*
* PEM encode a PKCS #8 private key
*/
std::string PEM_encode(const Private_Key& key)
{
Pipe pem;
pem.start_msg();
encode(key, pem, PEM);
pem.end_msg();
return pem.read_all_as_string();
}
/*
* Encrypt and PEM encode a PKCS #8 private key
*/
std::string PEM_encode(const Private_Key& key,
RandomNumberGenerator& rng,
const std::string& pass,
const std::string& pbe_algo)
{
if(pass == "")
return PEM_encode(key);
Pipe pem;
pem.start_msg();
encrypt_key(key, pem, rng, pass, pbe_algo, PEM);
pem.end_msg();
return pem.read_all_as_string();
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(DataSource& source,
RandomNumberGenerator& rng,
const User_Interface& ui)
{
AlgorithmIdentifier alg_id;
SecureVector<byte> pkcs8_key = PKCS8_decode(source, ui, 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());
std::unique_ptr<Private_Key> key(get_private_key(alg_name));
if(!key.get())
throw PKCS8_Exception("Unknown PK algorithm/OID: " + alg_name + ", " +
alg_id.oid.as_string());
std::unique_ptr<PKCS8_Decoder> decoder(key->pkcs8_decoder(rng));
if(!decoder.get())
throw Decoding_Error("Key does not support PKCS #8 decoding");
decoder->alg_id(alg_id);
decoder->key_bits(pkcs8_key);
return key.release();
}
/*
* Extract a private key and return it
*/
Private_Key* load_key(const std::string& fsname,
RandomNumberGenerator& rng,
const User_Interface& ui)
{
DataSource_Stream source(fsname, true);
return PKCS8::load_key(source, rng, ui);
}
/*
* 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, User_Interface(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, User_Interface(pass));
}
/*
* Make a copy of this private key
*/
Private_Key* copy_key(const Private_Key& key,
RandomNumberGenerator& rng)
{
Pipe bits;
bits.start_msg();
PKCS8::encode(key, bits);
bits.end_msg();
DataSource_Memory source(bits.read_all());
return PKCS8::load_key(source, rng);
}
}
}
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