/*

 * Copyright (c) 2018-2022, [Ribose Inc](https://www.ribose.com).

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without modification,

 * are permitted provided that the following conditions are met:

 *

 * 1.  Redistributions of source code must retain the above copyright notice,

 *     this list of conditions and the following disclaimer.

 *

 * 2.  Redistributions in binary form must reproduce the above copyright notice,

 *     this list of conditions and the following disclaimer in the documentation

 *     and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef STREAM_SIG_H_

#define STREAM_SIG_H_

#include <stdint.h>

#include <stdbool.h>

#include <sys/types.h>

#include "rnp.h"

#include "stream-common.h"

#include "stream-packet.h"

#include "sig_subpacket.hpp"

#include "sig_material.hpp"

namespace pgp {

namespace pkt {

class Signature {

  private:

    pgp_sig_type_t       type_;

    std::vector<uint8_t> preferred(sigsub::Type type) const;

    void                 set_preferred(const std::vector<uint8_t> &data, sigsub::Type type);

    rnp_result_t         parse_v2v3(pgp_packet_body_t &pkt);

    rnp_result_t         parse_v4up(pgp_packet_body_t &pkt);

    bool                 get_subpkt_len(pgp_packet_body_t &pkt, size_t &len);

    bool                 parse_subpackets(uint8_t *buf, size_t len, bool hashed);

    static bool          version_supported(pgp_version_t version);

    const sigsub::RevocationKey *revoker_subpkt() const noexcept;

  public:

    pgp_version_t version;

    /* common v3 and v4 fields */

    pgp_pubkey_alg_t       palg;

    pgp_hash_alg_t         halg;

    std::array<uint8_t, 2> lbits{};

    std::vector<uint8_t>   hashed_data;

    std::vector<uint8_t>   material_buf; /* raw signature material */

    /* v3 - only fields */

    uint32_t creation_time;

    KeyID    signer{};

    /* common v4, v5 and v6 fields */

    sigsub::List subpkts;

#if defined(ENABLE_CRYPTO_REFRESH)

    /* v6 - only fields */

    std::vector<uint8_t> salt;

#endif

    Signature()

        : type_(PGP_SIG_BINARY), version(PGP_VUNKNOWN), palg(PGP_PKA_NOTHING),

          halg(PGP_HASH_UNKNOWN), creation_time(0){};

    bool operator==(const Signature &src) const;

    bool operator!=(const Signature &src) const;

    /* @brief Get signature's type */

    pgp_sig_type_t

    type() const

    {

        return type_;

    };

    void

    set_type(pgp_sig_type_t atype)

    {

        type_ = atype;

    };

    bool

    is_document() const

    {

        return (type_ == PGP_SIG_BINARY) || (type_ == PGP_SIG_TEXT);

    };

    /** @brief Calculate the unique signature identifier by hashing signature's fields. */

    SigID get_id() const;

    size_t find_subpkt(uint8_t type, bool hashed = true, size_t skip = 0) const;

    size_t find_subpkt(sigsub::Type type, bool hashed = true, size_t skip = 0) const;

    /**

     * @brief Get v4 and up signature's subpacket of the specified type and hashedness.

     * @param stype subpacket type.

     * @param hashed whether subpacket must be in hashed area on in any area.

     * @return pointer to the subpacket, or nullptr if subpacket was not found.

     */

    sigsub::Raw *      get_subpkt(uint8_t stype, bool hashed = true);

    const sigsub::Raw *get_subpkt(uint8_t stype, bool hashed = true) const;

    sigsub::Raw *      get_subpkt(sigsub::Type type, bool hashed = true);

    const sigsub::Raw *get_subpkt(sigsub::Type type, bool hashed = true) const;

    /* @brief Check whether v4 signature has subpacket of the specified type/hashedness */

    bool has_subpkt(uint8_t stype, bool hashed = true) const;

    /* @brief Check whether signature has signing key id (via v3 field, or v4 key id/key fp

     * subpacket) */

    bool has_keyid() const;

    /**

     * @brief Get signer's key id if available. Availability may be checked via has_keyid().

     * @return signer's key id if available, or empty (zero-filled) keyid otherwise.

     */

    KeyID keyid() const noexcept;

    /** @brief Set the signer's key id for the signature being populated. Version should be set

     *         prior of setting key id. */

    void set_keyid(const KeyID &id);

    /**

     * @brief Check whether signature has valid issuer fingerprint subpacket.

     * @return true if there is one, and it can be safely returned via keyfp() method or false

     *         otherwise.

     */

    bool has_keyfp() const;

    /**

     * @brief Get signing key's fingerprint if it is available. Availability may be checked via

     *        has_keyfp() method.

     * @return fingerprint (or empty zero-size fp in case it is unavailable)

     */

    Fingerprint keyfp() const noexcept;

    /** @brief Set signing key's fingerprint. Works only for signatures with version 4 and up,

     *         so version should be set prior to fingerprint. */

    void set_keyfp(const Fingerprint &fp);

    /**

     * @brief Get signature's creation time

     * @return time in seconds since the Jan 1, 1970 UTC. 0 is the default value and returned

     *         even if creation time is not available

     */

    uint32_t creation() const;

    /**

     * @brief Set signature's creation time

     * @param ctime creation time in seconds since the Jan 1, 1970 UTC.

     */

    void set_creation(uint32_t ctime);

    /**

     * @brief Get the signature's expiration time

     * @return expiration time in seconds since the creation time. 0 if signature never

     * expires.

     */

    uint32_t expiration() const;

    /**

     * @brief Set the signature's expiration time

     * @param etime expiration time

     */

    void set_expiration(uint32_t etime);

    /**

     * @brief Get the key expiration time

     * @return expiration time in seconds since the creation time. 0 if key never expires.

     */

    uint32_t key_expiration() const;

    /**

     * @brief Set the key expiration time

     * @param etime expiration time

     */

    void set_key_expiration(uint32_t etime);

    /**

     * @brief Get the key flags

     * @return byte of key flags. If there is no corresponding subpackets then 0 is returned.

     */

    uint8_t key_flags() const;

    /**

     * @brief Set the key flags

     * @param flags byte of key flags

     */

    void set_key_flags(uint8_t flags);

    /**

     * @brief Get the primary user id flag

     * @return true if user id is marked as primary or false otherwise

     */

    bool primary_uid() const;

    /**

     * @brief Set the primary user id flag

     * @param primary true if user id should be marked as primary

     */

    void set_primary_uid(bool primary);

    /** @brief Get preferred symmetric algorithms if any. If there are no ones then empty

     *         vector is returned. */

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

    /** @brief Set the preferred symmetric algorithms. If empty vector is passed then

     *         corresponding subpacket is deleted. */

    void set_preferred_symm_algs(const std::vector<uint8_t> &algs);

    /** @brief Get preferred hash algorithms if any. If there are no ones then empty vector is

     *         returned.*/

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

    /** @brief Set the preferred hash algorithms. If empty vector is passed then corresponding

     *         subpacket is deleted. */

    void set_preferred_hash_algs(const std::vector<uint8_t> &algs);

    /** @brief Get preferred compression algorithms if any. If there are no ones then empty

     *         vector is returned.*/

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

    /** @brief Set the preferred compression algorithms. If empty vector is passed then

     *         corresponding subpacket is deleted. */

    void set_preferred_z_algs(const std::vector<uint8_t> &algs);

#if defined(ENABLE_CRYPTO_REFRESH)

    /** @brief Get preferred AEAD algorithms if any. If there are no ones then empty

     *         vector is returned.*/

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

    /** @brief Set the preferred AEAD algorithms. If empty vector is passed then

     *         corresponding subpacket is deleted. */

    void set_preferred_aead_algs(const std::vector<uint8_t> &algs);

#endif

    /** @brief Get key server preferences flags. If subpacket is not available then 0 is

     *         returned. */

    uint8_t key_server_prefs() const;

    /** @brief Set key server preferences flags. */

    void set_key_server_prefs(uint8_t prefs);

    /** @brief Get preferred key server URI, if available. Otherwise empty string is returned.

     */

    std::string key_server() const;

    /** @brief Set preferred key server URI. If it is empty string then subpacket is deleted if

     *         it is available. */

    void set_key_server(const std::string &uri);

    /** @brief Get trust level, if available. Otherwise will return 0. See RFC 4880, 5.2.3.14.

     *         for the detailed information on trust level and amount.

     */

    uint8_t trust_level() const;

    /** @brief Get trust amount, if available. Otherwise will return 0. See RFC 4880, 5.2.3.14.

     *         for the detailed information on trust level and amount.

     */

    uint8_t trust_amount() const;

    /** @brief Set the trust level and amount. See RFC 4880, 5.2.3.14.

     *         for the detailed information on trust level and amount.

     */

    void set_trust(uint8_t level, uint8_t amount);

    /** @brief check whether signature is revocable. True by default.

     */

    bool revocable() const;

    /** @brief Set the signature's revocability status.

     */

    void set_revocable(bool status);

    /** @brief Get the key/subkey revocation reason in humand-readable form. If there is no

     *         revocation reason subpacket, then empty string will be returned.

     */

    std::string revocation_reason() const;

    /** @brief Get the key/subkey revocation code. If there is no revocation reason subpacket,

     *         then PGP_REVOCATION_NO_REASON will be rerturned. See the RFC 4880, 5.2.3.24 for

     *         the detailed explanation.

     */

    pgp_revocation_type_t revocation_code() const;

    /**

     * @brief Check whether signature has revocation reason and code subpacket.

     */

    bool has_revocation_reason() const;

    /** @brief Set the revocation reason and code for key/subkey revocation signature. See the

     *         RFC 4880, 5.2.3.24 for the detailed explanation.

     */

    void set_revocation_reason(pgp_revocation_type_t code, const std::string &reason);

    uint32_t key_get_features() const;

    /**

     * @brief Check whether signer's key supports certain feature(s). Makes sense only for

     *        self-signature, for more details see the RFC 4880bis, 5.2.3.25. If there is

     *        no corresponding subpacket then false will be returned.

     * @param flags one or more flags, combined via bitwise OR operation.

     * @return true if key is claimed to support all of the features listed in flags, or false

     *         otherwise

     */

    bool key_has_features(uint32_t flags) const;

    /**

     * @brief Set the features supported by the signer's key, makes sense only for

     *        self-signature. For more details see the RFC 4880bis, 5.2.3.25.

     * @param flags one or more flags, combined via bitwise OR operation.

     */

    void set_key_features(uint32_t flags);

    /** @brief Get signer's user id, if available. Otherwise empty string is returned. See the

     *         RFC 4880bis, 5.2.3.23 for details.

     */

    std::string signer_uid() const;

    /**

     * @brief Set the signer's uid, responsible for the signature creation. See the RFC

     *        4880bis, 5.2.3.23 for details.

     */

    void set_signer_uid(const std::string &uid);

    /**

     * @brief Add notation.

     */

    void add_notation(const std::string &         name,

                      const std::vector<uint8_t> &value,

                      bool                        human = true,

                      bool                        critical = false);

    /**

     * @brief Add human-readable notation.

     */

    void add_notation(const std::string &name,

                      const std::string &value,

                      bool               critical = false);

    /**

     * @brief Set the embedded signature.

     * @param esig populated and calculated embedded signature.

     */

    void set_embedded_sig(const Signature &esig);

    /**

     * @brief Check whether signature includes revocation key subpacket.

     */

    bool has_revoker() const noexcept;

    /**

     * @brief Get the revocation key fingerprint, if it is available. Otherwise empty

     * fingerprint will be returned.

     */

    Fingerprint revoker() const noexcept;

    /**

     * @brief Set the revocation key.

     *

     * @param revoker revoker's key packet.

     */

    void set_revoker(const rnp::Key &revoker, bool sensitive = false);

    /**

     * @brief Add subpacket to v4 and up signature

     * @param sub pointer to the subpacket object.

     * @param replace replace already existing subpacket of the specified type if any

     * @return reference to the subpacket structure or throws an exception

     */

    void add_subpkt(std::unique_ptr<sigsub::Raw> &&sub, bool replace = true);

    /**

     * @brief Remove signature's subpacket

     * @param idx Index of the subpacket in list.

     */

    void remove_subpkt(size_t idx);

    /**

     * @brief Check whether signature packet matches one-pass signature packet.

     * @param onepass reference to the read one-pass signature packet

     * @return true if sig corresponds to onepass or false otherwise

     */

    bool matches_onepass(const pgp_one_pass_sig_t &onepass) const;

    /**

     * @brief Parse signature body (i.e. without checking the packet header).

     *

     * @param pkt packet body with data.

     * @return RNP_SUCCESS or error code if failed. May also throw an exception.

     */

    rnp_result_t parse(pgp_packet_body_t &pkt);

    /**

     * @brief Parse signature packet from source.

     *

     * @param src source with data.

     * @return RNP_SUCCESS or error code if failed. May also throw an exception.

     */

    rnp_result_t parse(pgp_source_t &src);

    /**

     * @brief Parse signature material, stored in the signature in raw.

     *

     * @param material on success parsed material will be stored here.

     * @return true on success or false otherwise. May also throw an exception.

     */

    std::unique_ptr<SigMaterial> parse_material() const;

    /**

     * @brief Write signature to the destination. May throw an exception.

     */

    void                 write(pgp_dest_t &dst, bool hdr = true) const;

    std::vector<uint8_t> write(bool hdr = true) const;

    /**

     * @brief Write the signature material's raw representation. May throw an exception.

     *

     * @param material populated signature material.

     */

    void write_material(const SigMaterial &material);

    /**

     * @brief Fill signature's hashed data. This includes all the fields from signature which

     * are hashed after the previous document or key fields.

     */

    void fill_hashed_data();

};

using Signatures = std::vector<Signature>;

} // namespace pkt

} // namespace pgp

/**

 * @brief Hash key packet. Used in signatures and v4 fingerprint calculation.

 *        Throws exception on error.

 * @param key key packet, must be populated

 * @param hash initialized hash context

 * @param pgpver for fingerprint calculation, the key version is required,

 * otherwise the signature version is required

 */

void signature_hash_key(const pgp_key_pkt_t &key, rnp::Hash &hash, pgp_version_t pgpver);

void signature_hash_userid(const pgp_userid_pkt_t &uid, rnp::Hash &hash, pgp_version_t sigver);

std::unique_ptr<rnp::Hash> signature_hash_certification(const pgp::pkt::Signature &sig,

                                                        const pgp_key_pkt_t &      key,

                                                        const pgp_userid_pkt_t &   userid);

std::unique_ptr<rnp::Hash> signature_hash_binding(const pgp::pkt::Signature &sig,

                                                  const pgp_key_pkt_t &      key,

                                                  const pgp_key_pkt_t &      subkey);

std::unique_ptr<rnp::Hash> signature_hash_direct(const pgp::pkt::Signature &sig,

                                                 const pgp_key_pkt_t &      key);

/**

 * @brief Parse stream with signatures to the signatures list.

 *        Can handle binary or armored stream with signatures, including stream with multiple

 * armored signatures.

 *

 * @param src signatures stream, cannot be NULL.

 * @param sigs on success parsed signature structures will be put here.

 * @return RNP_SUCCESS or error code otherwise.

 */

rnp_result_t process_pgp_signatures(pgp_source_t &src, pgp::pkt::Signatures &sigs);

#endif