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/*
* (C) 1999-2010,2015 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/pubkey.h>
#include <botan/internal/algo_registry.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/bigint.h>
namespace Botan {
namespace {
template<typename T, typename Key>
T* get_pk_op(const std::string& what, const Key& key, const std::string& pad,
const std::string& provider = "")
{
if(T* p = Algo_Registry<T>::global_registry().make(typename T::Spec(key, pad), provider))
return p;
const std::string err = what + " with " + key.algo_name() + "/" + pad + " not supported";
if(!provider.empty())
throw Lookup_Error(err + " with provider " + provider);
else
throw Lookup_Error(err);
}
}
PK_Encryptor_EME::PK_Encryptor_EME(const Public_Key& key,
const std::string& padding,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::Encryption>("Encryption", key, padding, provider));
}
std::vector<byte>
PK_Encryptor_EME::enc(const byte in[], size_t length, RandomNumberGenerator& rng) const
{
return unlock(m_op->encrypt(in, length, rng));
}
size_t PK_Encryptor_EME::maximum_input_size() const
{
return m_op->max_input_bits() / 8;
}
PK_Decryptor_EME::PK_Decryptor_EME(const Private_Key& key, const std::string& padding,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::Decryption>("Decryption", key, padding, provider));
}
secure_vector<byte> PK_Decryptor_EME::dec(const byte msg[], size_t length) const
{
return m_op->decrypt(msg, length);
}
PK_KEM_Encryptor::PK_KEM_Encryptor(const Public_Key& key,
const std::string& param,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::KEM_Encryption>("KEM", key, param, provider));
}
void PK_KEM_Encryptor::encrypt(secure_vector<byte>& out_encapsulated_key,
secure_vector<byte>& out_shared_key,
size_t desired_shared_key_len,
Botan::RandomNumberGenerator& rng,
const uint8_t salt[],
size_t salt_len)
{
m_op->kem_encrypt(out_encapsulated_key,
out_shared_key,
desired_shared_key_len,
rng,
salt,
salt_len);
}
PK_KEM_Decryptor::PK_KEM_Decryptor(const Private_Key& key,
const std::string& param,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::KEM_Decryption>("KEM", key, param, provider));
}
secure_vector<byte> PK_KEM_Decryptor::decrypt(const byte encap_key[],
size_t encap_key_len,
size_t desired_shared_key_len,
const uint8_t salt[],
size_t salt_len)
{
return m_op->kem_decrypt(encap_key, encap_key_len,
desired_shared_key_len,
salt, salt_len);
}
PK_Key_Agreement::PK_Key_Agreement(const Private_Key& key,
const std::string& kdf,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::Key_Agreement>("Key agreement", key, kdf, provider));
}
SymmetricKey PK_Key_Agreement::derive_key(size_t key_len,
const byte in[], size_t in_len,
const byte salt[],
size_t salt_len) const
{
return m_op->agree(key_len, in, in_len, salt, salt_len);
}
namespace {
std::vector<byte> der_encode_signature(const std::vector<byte>& sig, size_t parts)
{
if(sig.size() % parts)
throw Encoding_Error("PK_Signer: strange signature size found");
const size_t SIZE_OF_PART = sig.size() / parts;
std::vector<BigInt> sig_parts(parts);
for(size_t j = 0; j != sig_parts.size(); ++j)
sig_parts[j].binary_decode(&sig[SIZE_OF_PART*j], SIZE_OF_PART);
return DER_Encoder()
.start_cons(SEQUENCE)
.encode_list(sig_parts)
.end_cons()
.get_contents_unlocked();
}
std::vector<byte> der_decode_signature(const byte sig[], size_t len,
size_t part_size, size_t parts)
{
std::vector<byte> real_sig;
BER_Decoder decoder(sig, len);
BER_Decoder ber_sig = decoder.start_cons(SEQUENCE);
size_t count = 0;
while(ber_sig.more_items())
{
BigInt sig_part;
ber_sig.decode(sig_part);
real_sig += BigInt::encode_1363(sig_part, part_size);
++count;
}
if(count != parts)
throw Decoding_Error("PK_Verifier: signature size invalid");
return real_sig;
}
}
PK_Signer::PK_Signer(const Private_Key& key,
const std::string& emsa,
Signature_Format format,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::Signature>("Signing", key, emsa, provider));
m_sig_format = format;
}
void PK_Signer::update(const byte in[], size_t length)
{
m_op->update(in, length);
}
std::vector<byte> PK_Signer::signature(RandomNumberGenerator& rng)
{
const std::vector<byte> plain_sig = unlock(m_op->sign(rng));
const size_t parts = m_op->message_parts();
if(parts == 1 || m_sig_format == IEEE_1363)
return plain_sig;
else if(m_sig_format == DER_SEQUENCE)
return der_encode_signature(plain_sig, parts);
else
throw Encoding_Error("PK_Signer: Unknown signature format " +
std::to_string(m_sig_format));
}
PK_Verifier::PK_Verifier(const Public_Key& key,
const std::string& emsa_name,
Signature_Format format,
const std::string& provider)
{
m_op.reset(get_pk_op<PK_Ops::Verification>("Verification", key, emsa_name, provider));
m_sig_format = format;
}
void PK_Verifier::set_input_format(Signature_Format format)
{
if(m_op->message_parts() == 1 && format != IEEE_1363)
throw Invalid_State("PK_Verifier: This algorithm always uses IEEE 1363");
m_sig_format = format;
}
bool PK_Verifier::verify_message(const byte msg[], size_t msg_length,
const byte sig[], size_t sig_length)
{
update(msg, msg_length);
return check_signature(sig, sig_length);
}
void PK_Verifier::update(const byte in[], size_t length)
{
m_op->update(in, length);
}
bool PK_Verifier::check_signature(const byte sig[], size_t length)
{
try {
if(m_sig_format == IEEE_1363)
{
return m_op->is_valid_signature(sig, length);
}
else if(m_sig_format == DER_SEQUENCE)
{
std::vector<byte> real_sig = der_decode_signature(sig, length,
m_op->message_part_size(),
m_op->message_parts());
return m_op->is_valid_signature(real_sig.data(), real_sig.size());
}
else
throw Decoding_Error("PK_Verifier: Unknown signature format " +
std::to_string(m_sig_format));
}
catch(Invalid_Argument&) { return false; }
}
}
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