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/*
* (C) 2015 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/emsa.h>
#include <botan/hash.h>
#include <botan/scan_name.h>
#include <botan/exceptn.h>
#if defined(BOTAN_HAS_EMSA1)
#include <botan/emsa1.h>
#endif
#if defined(BOTAN_HAS_EMSA_X931)
#include <botan/emsa_x931.h>
#endif
#if defined(BOTAN_HAS_EMSA_PKCS1)
#include <botan/emsa_pkcs1.h>
#endif
#if defined(BOTAN_HAS_EMSA_PSSR)
#include <botan/pssr.h>
#endif
#if defined(BOTAN_HAS_EMSA_RAW)
#include <botan/emsa_raw.h>
#endif
#if defined(BOTAN_HAS_ISO_9796)
#include <botan/iso9796.h>
#endif
namespace Botan {
AlgorithmIdentifier EMSA::config_for_x509(const Private_Key&,
const std::string&) const
{
throw Not_Implemented("Encoding " + name() + " not supported for signing X509 objects");
}
EMSA* get_emsa(const std::string& algo_spec)
{
SCAN_Name req(algo_spec);
#if defined(BOTAN_HAS_EMSA1)
if(req.algo_name() == "EMSA1" && req.arg_count() == 1)
{
if(auto hash = HashFunction::create(req.arg(0)))
return new EMSA1(hash.release());
}
#endif
#if defined(BOTAN_HAS_EMSA_PKCS1)
if(req.algo_name() == "EMSA_PKCS1" ||
req.algo_name() == "PKCS1v15" ||
req.algo_name() == "EMSA-PKCS1-v1_5" ||
req.algo_name() == "EMSA3")
{
if(req.arg_count() == 2 && req.arg(0) == "Raw")
{
return new EMSA_PKCS1v15_Raw(req.arg(1));
}
else if(req.arg_count() == 1)
{
if(req.arg(0) == "Raw")
{
return new EMSA_PKCS1v15_Raw;
}
else
{
if(auto hash = HashFunction::create(req.arg(0)))
{
return new EMSA_PKCS1v15(hash.release());
}
}
}
}
#endif
#if defined(BOTAN_HAS_EMSA_PSSR)
if(req.algo_name() == "PSS_Raw" ||
req.algo_name() == "PSSR_Raw")
{
if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1")
{
if(auto h = HashFunction::create(req.arg(0)))
{
if(req.arg_count() == 3)
{
const size_t salt_size = req.arg_as_integer(2, 0);
return new PSSR_Raw(h.release(), salt_size);
}
else
{
return new PSSR_Raw(h.release());
}
}
}
}
if(req.algo_name() == "PSS" ||
req.algo_name() == "PSSR" ||
req.algo_name() == "EMSA-PSS" ||
req.algo_name() == "PSS-MGF1" ||
req.algo_name() == "EMSA4")
{
if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1")
{
if(auto h = HashFunction::create(req.arg(0)))
{
if(req.arg_count() == 3)
{
const size_t salt_size = req.arg_as_integer(2, 0);
return new PSSR(h.release(), salt_size);
}
else
{
return new PSSR(h.release());
}
}
}
}
#endif
#if defined(BOTAN_HAS_ISO_9796)
if(req.algo_name() == "ISO_9796_DS2")
{
if(req.arg_count_between(1, 3))
{
if(auto h = HashFunction::create(req.arg(0)))
{
const size_t salt_size = req.arg_as_integer(2, h->output_length());
const bool implicit = req.arg(1, "exp") == "imp";
return new ISO_9796_DS2(h.release(), implicit, salt_size);
}
}
}
//ISO-9796-2 DS 3 is deterministic and DS2 without a salt
if(req.algo_name() == "ISO_9796_DS3")
{
if(req.arg_count_between(1, 2))
{
if(auto h = HashFunction::create(req.arg(0)))
{
const bool implicit = req.arg(1, "exp") == "imp";
return new ISO_9796_DS3(h.release(), implicit);
}
}
}
#endif
#if defined(BOTAN_HAS_EMSA_X931)
if(req.algo_name() == "EMSA_X931" ||
req.algo_name() == "EMSA2" ||
req.algo_name() == "X9.31")
{
if(req.arg_count() == 1)
{
if(auto hash = HashFunction::create(req.arg(0)))
{
return new EMSA_X931(hash.release());
}
}
}
#endif
#if defined(BOTAN_HAS_EMSA_RAW)
if(req.algo_name() == "Raw")
{
if(req.arg_count() == 0)
{
return new EMSA_Raw;
}
else
{
auto hash = HashFunction::create(req.arg(0));
if(hash)
return new EMSA_Raw(hash->output_length());
}
}
#endif
throw Algorithm_Not_Found(algo_spec);
}
std::string hash_for_emsa(const std::string& algo_spec)
{
SCAN_Name emsa_name(algo_spec);
if(emsa_name.arg_count() > 0)
{
const std::string pos_hash = emsa_name.arg(0);
return pos_hash;
}
// If we don't understand what this is return a safe default
#if defined(BOTAN_HAS_SHA2_64)
return "SHA-512";
#else
return "SHA-256";
#endif
}
}