// Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#ifndef OPENSSL_HEADER_CRYPTO_EVP_INTERNAL_H

#define OPENSSL_HEADER_CRYPTO_EVP_INTERNAL_H

#include <openssl/evp.h>

#include <array>

#include <openssl/span.h>

#include "../internal.h"

#include "../mem_internal.h"

DECLARE_OPAQUE_STRUCT(evp_pkey_st, EvpPkey)

DECLARE_OPAQUE_STRUCT(evp_pkey_ctx_st, EvpPkeyCtx)

BSSL_NAMESPACE_BEGIN

typedef struct evp_pkey_asn1_method_st EVP_PKEY_ASN1_METHOD;

typedef struct evp_pkey_ctx_method_st EVP_PKEY_CTX_METHOD;

BSSL_NAMESPACE_END

struct evp_pkey_alg_st {

  // method implements operations for this |EVP_PKEY_ALG|.

  const bssl::EVP_PKEY_ASN1_METHOD *method;

};

BSSL_NAMESPACE_BEGIN

enum evp_decode_result_t {

  evp_decode_error = 0,

  evp_decode_ok = 1,

  evp_decode_unsupported = 2,

};

struct evp_pkey_asn1_method_st {

  // pkey_id contains one of the |EVP_PKEY_*| values and corresponds to the OID

  // in the key type's AlgorithmIdentifier.

  int pkey_id;

  uint8_t oid[9];

  uint8_t oid_len;

  const EVP_PKEY_CTX_METHOD *pkey_method;

  // pub_decode decodes |params| and |key| as a SubjectPublicKeyInfo

  // and writes the result into |out|. It returns |evp_decode_ok| on success,

  // and |evp_decode_error| on error, and |evp_decode_unsupported| if the input

  // was not supported by this |EVP_PKEY_ALG|. In case of

  // |evp_decode_unsupported|, it does not add an error to the error queue. May

  // modify |params| and |key|. Callers must make a copy if calling in a loop.

  //

  // |params| is the AlgorithmIdentifier after the OBJECT IDENTIFIER type field,

  // and |key| is the contents of the subjectPublicKey with the leading padding

  // byte checked and removed. Although X.509 uses BIT STRINGs to represent

  // SubjectPublicKeyInfo, every key type defined encodes the key as a byte

  // string with the same conversion to BIT STRING.

  evp_decode_result_t (*pub_decode)(const EVP_PKEY_ALG *alg, EvpPkey *out,

                                    CBS *params, CBS *key);

  // pub_encode encodes |key| as a SubjectPublicKeyInfo and appends the result

  // to |out|. It returns one on success and zero on error.

  int (*pub_encode)(CBB *out, const EvpPkey *key);

  bool (*pub_equal)(const EvpPkey *a, const EvpPkey *b);

  // pub_present returns true iff the |pk| has a public key. (If so, validity

  // is not guaranteed and should be checked separately.)

  bool (*pub_present)(const EvpPkey *pk);

  // priv_decode decodes |params| and |key| as a PrivateKeyInfo and writes the

  // result into |out|.  It returns |evp_decode_ok| on success, and

  // |evp_decode_error| on error, and |evp_decode_unsupported| if the key type

  // was not supported by this |EVP_PKEY_ALG|. In case of

  // |evp_decode_unsupported|, it does not add an error to the error queue. May

  // modify |params| and |key|. Callers must make a copy if calling in a loop.

  //

  // |params| is the AlgorithmIdentifier after the OBJECT IDENTIFIER type field,

  // and |key| is the contents of the OCTET STRING privateKey field.

  evp_decode_result_t (*priv_decode)(const EVP_PKEY_ALG *alg, EvpPkey *out,

                                     CBS *params, CBS *key);

  // priv_encode encodes |key| as a PrivateKeyInfo and appends the result to

  // |out|. It returns one on success and zero on error.

  int (*priv_encode)(CBB *out, const EvpPkey *key);

  // priv_present returns true iff the |pk| has a private key. (If so, validity

  // is not guaranteed and should be checked separately.)

  bool (*priv_present)(const EvpPkey *pk);

  int (*set_priv_raw)(EvpPkey *pkey, const uint8_t *in, size_t len);

  int (*set_priv_seed)(EvpPkey *pkey, const uint8_t *in, size_t len);

  int (*set_pub_raw)(EvpPkey *pkey, const uint8_t *in, size_t len);

  int (*get_priv_raw)(const EvpPkey *pkey, uint8_t *out, size_t *out_len);

  int (*get_priv_seed)(const EvpPkey *pkey, uint8_t *out, size_t *out_len);

  int (*get_pub_raw)(const EvpPkey *pkey, uint8_t *out, size_t *out_len);

  // TODO(davidben): Can these be merged with the functions above? OpenSSL does

  // not implement |EVP_PKEY_get_raw_public_key|, etc., for |EVP_PKEY_EC|, but

  // the distinction seems unimportant. OpenSSL 3.0 has since renamed

  // |EVP_PKEY_get1_tls_encodedpoint| to |EVP_PKEY_get1_encoded_public_key|, and

  // what is the difference between "raw" and an "encoded" public key.

  //

  // One nuisance is the notion of "raw" is slightly ambiguous for EC keys. Is

  // it a DER ECPrivateKey or just the scalar?

  int (*set1_tls_encodedpoint)(EvpPkey *pkey, const uint8_t *in, size_t len);

  size_t (*get1_tls_encodedpoint)(const EvpPkey *pkey, uint8_t **out_ptr);

  // pkey_opaque returns 1 if the |pk| is opaque. Opaque keys are backed by

  // custom implementations which do not expose key material and parameters.

  int (*pkey_opaque)(const EvpPkey *pk);

  int (*pkey_size)(const EvpPkey *pk);

  int (*pkey_bits)(const EvpPkey *pk);

  int (*param_missing)(const EvpPkey *pk);

  int (*param_copy)(EvpPkey *to, const EvpPkey *from);

  bool (*param_equal)(const EvpPkey *a, const EvpPkey *b);

  void (*pkey_free)(EvpPkey *pkey);

} /* EVP_PKEY_ASN1_METHOD */;

class EvpPkey : public evp_pkey_st, public RefCounted<EvpPkey> {

 public:

  EvpPkey();

  // pkey contains a pointer to a structure dependent on |ameth|.

  void *pkey = nullptr;

  // ameth contains a pointer to a method table that determines the key type, or

  // nullptr if the key is empty.

  const bssl::EVP_PKEY_ASN1_METHOD *ameth = nullptr;

 private:

  ~EvpPkey();

  friend RefCounted;

} /* EVP_PKEY */;

#define EVP_PKEY_OP_UNDEFINED 0

#define EVP_PKEY_OP_KEYGEN (1 << 2)

#define EVP_PKEY_OP_SIGN (1 << 3)

#define EVP_PKEY_OP_VERIFY (1 << 4)

#define EVP_PKEY_OP_VERIFYRECOVER (1 << 5)

#define EVP_PKEY_OP_ENCRYPT (1 << 6)

#define EVP_PKEY_OP_DECRYPT (1 << 7)

#define EVP_PKEY_OP_DERIVE (1 << 8)

#define EVP_PKEY_OP_PARAMGEN (1 << 9)

#define EVP_PKEY_OP_TYPE_SIG \

  (EVP_PKEY_OP_SIGN | EVP_PKEY_OP_VERIFY | EVP_PKEY_OP_VERIFYRECOVER)

#define EVP_PKEY_OP_TYPE_CRYPT (EVP_PKEY_OP_ENCRYPT | EVP_PKEY_OP_DECRYPT)

#define EVP_PKEY_OP_TYPE_NOGEN \

  (EVP_PKEY_OP_SIG | EVP_PKEY_OP_CRYPT | EVP_PKEY_OP_DERIVE)

#define EVP_PKEY_OP_TYPE_GEN (EVP_PKEY_OP_KEYGEN | EVP_PKEY_OP_PARAMGEN)

// EVP_PKEY_CTX_ctrl performs |cmd| on |ctx|. The |keytype| and |optype|

// arguments can be -1 to specify that any type and operation are acceptable,

// otherwise |keytype| must match the type of |ctx| and the bits of |optype|

// must intersect the operation flags set on |ctx|.

//

// The |p1| and |p2| arguments depend on the value of |cmd|.

//

// It returns one on success and zero on error.

OPENSSL_EXPORT int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,

                                     int cmd, int p1, void *p2);

#define EVP_PKEY_CTRL_MD 1

#define EVP_PKEY_CTRL_GET_MD 2

// EVP_PKEY_CTRL_PEER_KEY is called with different values of |p1|:

//   0: Is called from |EVP_PKEY_derive_set_peer| and |p2| contains a peer key.

//      If the return value is <= 0, the key is rejected.

//   1: Is called at the end of |EVP_PKEY_derive_set_peer| and |p2| contains a

//      peer key. If the return value is <= 0, the key is rejected.

//   2: Is called with |p2| == NULL to test whether the peer's key was used.

//      (EC)DH always return one in this case.

//   3: Is called with |p2| == NULL to set whether the peer's key was used.

//      (EC)DH always return one in this case. This was only used for GOST.

#define EVP_PKEY_CTRL_PEER_KEY 3

// EVP_PKEY_ALG_CTRL is the base value from which key-type specific ctrl

// commands are numbered.

#define EVP_PKEY_ALG_CTRL 0x1000

#define EVP_PKEY_CTRL_RSA_PADDING (EVP_PKEY_ALG_CTRL + 1)

#define EVP_PKEY_CTRL_GET_RSA_PADDING (EVP_PKEY_ALG_CTRL + 2)

#define EVP_PKEY_CTRL_RSA_PSS_SALTLEN (EVP_PKEY_ALG_CTRL + 3)

#define EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN (EVP_PKEY_ALG_CTRL + 4)

#define EVP_PKEY_CTRL_RSA_KEYGEN_BITS (EVP_PKEY_ALG_CTRL + 5)

#define EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP (EVP_PKEY_ALG_CTRL + 6)

#define EVP_PKEY_CTRL_RSA_OAEP_MD (EVP_PKEY_ALG_CTRL + 7)

#define EVP_PKEY_CTRL_GET_RSA_OAEP_MD (EVP_PKEY_ALG_CTRL + 8)

#define EVP_PKEY_CTRL_RSA_MGF1_MD (EVP_PKEY_ALG_CTRL + 9)

#define EVP_PKEY_CTRL_GET_RSA_MGF1_MD (EVP_PKEY_ALG_CTRL + 10)

#define EVP_PKEY_CTRL_RSA_OAEP_LABEL (EVP_PKEY_ALG_CTRL + 11)

#define EVP_PKEY_CTRL_GET_RSA_OAEP_LABEL (EVP_PKEY_ALG_CTRL + 12)

#define EVP_PKEY_CTRL_EC_PARAMGEN_GROUP (EVP_PKEY_ALG_CTRL + 13)

#define EVP_PKEY_CTRL_HKDF_MODE (EVP_PKEY_ALG_CTRL + 14)

#define EVP_PKEY_CTRL_HKDF_MD (EVP_PKEY_ALG_CTRL + 15)

#define EVP_PKEY_CTRL_HKDF_KEY (EVP_PKEY_ALG_CTRL + 16)

#define EVP_PKEY_CTRL_HKDF_SALT (EVP_PKEY_ALG_CTRL + 17)

#define EVP_PKEY_CTRL_HKDF_INFO (EVP_PKEY_ALG_CTRL + 18)

#define EVP_PKEY_CTRL_DH_PAD (EVP_PKEY_ALG_CTRL + 19)

#define EVP_PKEY_CTRL_SIGNATURE_CONTEXT_STRING (EVP_PKEY_ALG_CTRL + 20)

class EvpPkeyCtx : public evp_pkey_ctx_st {

 public:

  static constexpr bool kAllowUniquePtr = true;

  ~EvpPkeyCtx();

  // Method associated with this operation

  const bssl::EVP_PKEY_CTX_METHOD *pmeth = nullptr;

  // Key: may be nullptr

  bssl::UniquePtr<EvpPkey> pkey;

  // Peer key for key agreement, may be nullptr

  bssl::UniquePtr<EvpPkey> peerkey;

  // operation contains one of the |EVP_PKEY_OP_*| values.

  int operation = EVP_PKEY_OP_UNDEFINED;

  // Algorithm specific data.

  // TODO(davidben): Since a |EVP_PKEY_CTX| never has its type change after

  // creation, this should instead be a base class, with the algorithm-specific

  // data on the subclass, coming from the same allocation.

  void *data = nullptr;

};

struct evp_pkey_ctx_method_st {

  int pkey_id;

  int (*init)(EvpPkeyCtx *ctx);

  int (*copy)(EvpPkeyCtx *dst, EvpPkeyCtx *src);

  void (*cleanup)(EvpPkeyCtx *ctx);

  int (*keygen)(EvpPkeyCtx *ctx, EvpPkey *pkey);

  int (*sign)(EvpPkeyCtx *ctx, uint8_t *sig, size_t *siglen, const uint8_t *tbs,

              size_t tbslen);

  int (*sign_message)(EvpPkeyCtx *ctx, uint8_t *sig, size_t *siglen,

                      const uint8_t *tbs, size_t tbslen);

  int (*verify)(EvpPkeyCtx *ctx, const uint8_t *sig, size_t siglen,

                const uint8_t *tbs, size_t tbslen);

  int (*verify_message)(EvpPkeyCtx *ctx, const uint8_t *sig, size_t siglen,

                        const uint8_t *tbs, size_t tbslen);

  int (*verify_recover)(EvpPkeyCtx *ctx, uint8_t *out, size_t *out_len,

                        const uint8_t *sig, size_t sig_len);

  int (*encrypt)(EvpPkeyCtx *ctx, uint8_t *out, size_t *outlen,

                 const uint8_t *in, size_t inlen);

  int (*decrypt)(EvpPkeyCtx *ctx, uint8_t *out, size_t *outlen,

                 const uint8_t *in, size_t inlen);

  int (*derive)(EvpPkeyCtx *ctx, uint8_t *key, size_t *keylen);

  int (*paramgen)(EvpPkeyCtx *ctx, EvpPkey *pkey);

  int (*ctrl)(EvpPkeyCtx *ctx, int type, int p1, void *p2);

} /* EVP_PKEY_CTX_METHOD */;

extern const EVP_PKEY_CTX_METHOD rsa_pkey_meth;

extern const EVP_PKEY_CTX_METHOD rsa_pss_pkey_meth;

extern const EVP_PKEY_CTX_METHOD ec_pkey_meth;

extern const EVP_PKEY_CTX_METHOD ed25519_pkey_meth;

extern const EVP_PKEY_CTX_METHOD x25519_pkey_meth;

extern const EVP_PKEY_CTX_METHOD hkdf_pkey_meth;

extern const EVP_PKEY_CTX_METHOD dh_pkey_meth;

// evp_pkey_set0 sets |pkey|'s method to |method| and data to |pkey_data|,

// freeing any key that may previously have been configured. This function takes

// ownership of |pkey_data|, which must be of the type expected by |method|.

void evp_pkey_set0(EvpPkey *pkey, const EVP_PKEY_ASN1_METHOD *method,

                   void *pkey_data);

inline auto GetDefaultEVPAlgorithms() {

  // A set of algorithms to use by default in |EVP_parse_public_key| and

  // |EVP_parse_private_key|.

  return std::array{

      EVP_pkey_ec_p224(),

      EVP_pkey_ec_p256(),

      EVP_pkey_ec_p384(),

      EVP_pkey_ec_p521(),

      EVP_pkey_ed25519(),

      EVP_pkey_rsa(),

      EVP_pkey_x25519(),

      EVP_pkey_ml_dsa_44(),

      EVP_pkey_ml_dsa_65(),

      EVP_pkey_ml_dsa_87(),

      // TODO(crbug.com/438761503): Remove DSA from this set, after callers that

      // need DSA pass in |EVP_pkey_dsa| explicitly.

      EVP_pkey_dsa(),

  };

}

BSSL_NAMESPACE_END

#endif  // OPENSSL_HEADER_CRYPTO_EVP_INTERNAL_H