/*

* (C) 2017 Daniel Neus

*     2023 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_PSS_PARAMS_H_

#define BOTAN_PSS_PARAMS_H_

#include <botan/asn1_obj.h>

#include <string>

namespace Botan {

/**

* PSS parameters type

*

* Handles encoding/decoding of RSASSA-PSS-params from RFC 3447

*

* Only MGF1 is supported, and the trailer field must 1 (ie the variant

* from IEEE 1363a using a hash identifier is not supported)

*/

class BOTAN_PUBLIC_API(3, 7) PSS_Params final : public ASN1_Object {

   public:

      /**

      * Note that the only valid strings you can pass to this function

      * are values returned by EMSA::name() and these may change in a

      * minor release.

      */

      static PSS_Params from_emsa_name(std::string_view emsa_name);

      PSS_Params(std::string_view hash_fn, size_t salt_len);

      /**

      * Decode an encoded RSASSA-PSS-params

      */

      PSS_Params(std::span<const uint8_t> der);

      const AlgorithmIdentifier& hash_algid() const { return m_hash; }

      const AlgorithmIdentifier& mgf_algid() const { return m_mgf; }

      const AlgorithmIdentifier& mgf_hash_algid() const { return m_mgf_hash; }

      size_t salt_length() const { return m_salt_len; }

      size_t trailer_field() const { return m_trailer_field; }

      std::string hash_function() const { return hash_algid().oid().to_formatted_string(); }

      std::string mgf_function() const { return mgf_algid().oid().to_formatted_string(); }

      std::vector<uint8_t> serialize() const;

      void encode_into(DER_Encoder& to) const override;

   private:

      // We don't currently support uninitialized PSS_Params

      void decode_from(BER_Decoder& from) override;

      AlgorithmIdentifier m_hash;

      AlgorithmIdentifier m_mgf;

      AlgorithmIdentifier m_mgf_hash;

      size_t m_salt_len;

      size_t m_trailer_field;

};

}  // namespace Botan

#endif