xof.cpp

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/*
* Extendable Output Function Base Class
* (C) 2023 Jack Lloyd
*     2023 Fabian Albert, René Meusel - Rohde & Schwarz Cybersecurity
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/xof.h>
#include <botan/internal/scan_name.h>
 
#if defined(BOTAN_HAS_SHAKE_XOF)
   #include <botan/internal/shake_xof.h>
#endif
 
#include <botan/exceptn.h>
#include <botan/internal/fmt.h>
 
namespace Botan {
 
//static
std::unique_ptr<XOF> XOF::create(std::string_view algo_spec, std::string_view provider) {
   const SCAN_Name req(algo_spec);
 
   if(!provider.empty() && provider != "base") {
      return nullptr;  // unknown provider
   }
 
#if defined(BOTAN_HAS_SHAKE_XOF)
   if(req.algo_name() == "SHAKE-128" && req.arg_count() == 0) {
      return std::make_unique<SHAKE_128_XOF>();
   }
   if(req.algo_name() == "SHAKE-256" && req.arg_count() == 0) {
      return std::make_unique<SHAKE_256_XOF>();
   }
#endif
 
   return nullptr;
}
 
//static
std::unique_ptr<XOF> XOF::create_or_throw(std::string_view algo_spec, std::string_view provider) {
   if(auto xof = XOF::create(algo_spec, provider)) {
      return xof;
   }
   throw Lookup_Error("XOF", algo_spec, provider);
}
 
// static
std::vector<std::string> XOF::providers(std::string_view algo_spec) {
   return probe_providers_of<XOF>(algo_spec, {"base"});
}
 
std::string XOF::provider() const {
   return "base";
}
 
void XOF::start(std::span<const uint8_t> salt, std::span<const uint8_t> key) {
   if(!key_spec().valid_keylength(key.size())) {
      throw Invalid_Key_Length(name(), key.size());
   }
 
   if(!valid_salt_length(salt.size())) {
      throw Invalid_Argument(fmt("{} cannot accept a salt length of {}", name(), salt.size()));
   }
 
   m_xof_started = true;
   start_msg(salt, key);
}
 
void XOF::start_msg(std::span<const uint8_t> salt, std::span<const uint8_t> key) {
   BOTAN_UNUSED(salt, key);
}
 
}  // namespace Botan