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/*
* X.509 Public Key
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/x509_key.h>
#include <botan/filters.h>
#include <botan/asn1_obj.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/pem.h>
#include <botan/internal/pk_algs.h>
#include <memory>
namespace Botan {
namespace X509 {
/*
* DER or PEM encode a X.509 public key
*/
void encode(const Public_Key& key, Pipe& pipe, X509_Encoding encoding)
{
MemoryVector<byte> der =
DER_Encoder()
.start_cons(SEQUENCE)
.encode(key.algorithm_identifier())
.encode(key.x509_subject_public_key(), BIT_STRING)
.end_cons()
.get_contents();
if(encoding == PEM)
pipe.write(PEM_Code::encode(der, "PUBLIC KEY"));
else
pipe.write(der);
}
/*
* PEM encode a X.509 public key
*/
std::string PEM_encode(const Public_Key& key)
{
Pipe pem;
pem.start_msg();
encode(key, pem, PEM);
pem.end_msg();
return pem.read_all_as_string();
}
/*
* Extract a public key and return it
*/
Public_Key* load_key(DataSource& source)
{
try {
AlgorithmIdentifier alg_id;
MemoryVector<byte> key_bits;
if(ASN1::maybe_BER(source) && !PEM_Code::matches(source))
{
BER_Decoder(source)
.start_cons(SEQUENCE)
.decode(alg_id)
.decode(key_bits, BIT_STRING)
.verify_end()
.end_cons();
}
else
{
DataSource_Memory ber(
PEM_Code::decode_check_label(source, "PUBLIC KEY")
);
BER_Decoder(ber)
.start_cons(SEQUENCE)
.decode(alg_id)
.decode(key_bits, BIT_STRING)
.verify_end()
.end_cons();
}
if(key_bits.empty())
throw Decoding_Error("X.509 public key decoding failed");
return make_public_key(alg_id, key_bits);
}
catch(Decoding_Error)
{
throw Decoding_Error("X.509 public key decoding failed");
}
}
/*
* Extract a public key and return it
*/
Public_Key* load_key(const std::string& fsname)
{
DataSource_Stream source(fsname, true);
return X509::load_key(source);
}
/*
* Extract a public key and return it
*/
Public_Key* load_key(const MemoryRegion<byte>& mem)
{
DataSource_Memory source(mem);
return X509::load_key(source);
}
/*
* Make a copy of this public key
*/
Public_Key* copy_key(const Public_Key& key)
{
Pipe bits;
bits.start_msg();
X509::encode(key, bits, RAW_BER);
bits.end_msg();
DataSource_Memory source(bits.read_all());
return X509::load_key(source);
}
/*
* Find the allowable key constraints
*/
Key_Constraints find_constraints(const Public_Key& pub_key,
Key_Constraints limits)
{
const std::string name = pub_key.algo_name();
u32bit constraints = 0;
if(name == "DH" || name == "ECDH")
constraints |= KEY_AGREEMENT;
if(name == "RSA" || name == "ElGamal")
constraints |= KEY_ENCIPHERMENT | DATA_ENCIPHERMENT;
if(name == "RSA" || name == "RW" || name == "NR" ||
name == "DSA" || name == "ECDSA")
constraints |= DIGITAL_SIGNATURE | NON_REPUDIATION;
if(limits)
constraints &= limits;
return Key_Constraints(constraints);
}
}
}
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