/*

 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*

 * Low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/evp.h>

#include <openssl/encoder.h>

#include <openssl/buffer.h>

#include <openssl/x509.h>

#include <openssl/rsa.h> /* For i2d_RSAPublicKey */

#include <openssl/dsa.h> /* For i2d_DSAPublicKey */

#include <openssl/ec.h> /* For i2o_ECPublicKey */

#include "crypto/asn1.h"

#include "crypto/evp.h"

struct type_and_structure_st {

    const char *output_type;

    const char *output_structure;

};

static int i2d_provided(const EVP_PKEY *a, int selection,

    const struct type_and_structure_st *output_info,

    unsigned char **pp)

{

    int ret;

    for (ret = -1;

        ret == -1 && output_info->output_type != NULL;

        output_info++) {

        /*

         * The i2d_ calls don't take a boundary length for *pp.  However,

         * OSSL_ENCODER_to_data() needs one, so we make one up.  Because

         * OSSL_ENCODER_to_data() decrements this number by the amount of

         * bytes written, we need to calculate the length written further

         * down, when pp != NULL.

         */

        size_t len = INT_MAX;

        int pp_was_NULL = (pp == NULL || *pp == NULL);

        OSSL_ENCODER_CTX *ctx;

        ctx = OSSL_ENCODER_CTX_new_for_pkey(a, selection,

            output_info->output_type,

            output_info->output_structure,

            NULL);

        if (ctx == NULL)

            return -1;

        if (OSSL_ENCODER_to_data(ctx, pp, &len)) {

            if (pp_was_NULL)

                ret = (int)len;

            else

                ret = INT_MAX - (int)len;

        }

        OSSL_ENCODER_CTX_free(ctx);

    }

    if (ret == -1)

        ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_TYPE);

    return ret;

}

int i2d_KeyParams(const EVP_PKEY *a, unsigned char **pp)

{

    if (evp_pkey_is_provided(a)) {

        static const struct type_and_structure_st output_info[] = {

            { "DER", "type-specific" },

            {

                NULL,

            }

        };

        return i2d_provided(a, EVP_PKEY_KEY_PARAMETERS, output_info, pp);

    }

    if (a->ameth != NULL && a->ameth->param_encode != NULL)

        return a->ameth->param_encode(a, pp);

    ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_TYPE);

    return -1;

}

int i2d_KeyParams_bio(BIO *bp, const EVP_PKEY *pkey)

{

    return ASN1_i2d_bio_of(EVP_PKEY, i2d_KeyParams, bp, pkey);

}

static int

i2d_PrivateKey_impl(const EVP_PKEY *a, unsigned char **pp, int traditional)

{

    if (evp_pkey_is_provided(a)) {

        static const struct type_and_structure_st trad_output_info[] = {

            { "DER", "type-specific" },

            { "DER", "PrivateKeyInfo" },

            {

                NULL,

            }

        };

        const struct type_and_structure_st *oi = trad_output_info;

        if (!traditional)

            ++oi;

        return i2d_provided(a, EVP_PKEY_KEYPAIR, oi, pp);

    }

    if (traditional && a->ameth != NULL && a->ameth->old_priv_encode != NULL)

        return a->ameth->old_priv_encode(a, pp);

    if (a->ameth != NULL && a->ameth->priv_encode != NULL) {

        PKCS8_PRIV_KEY_INFO *p8 = EVP_PKEY2PKCS8(a);

        int ret = 0;

        if (p8 != NULL) {

            ret = i2d_PKCS8_PRIV_KEY_INFO(p8, pp);

            PKCS8_PRIV_KEY_INFO_free(p8);

        }

        return ret;

    }

    ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE);

    return -1;

}

int i2d_PrivateKey(const EVP_PKEY *a, unsigned char **pp)

{

    return i2d_PrivateKey_impl(a, pp, 1);

}

int i2d_PKCS8PrivateKey(const EVP_PKEY *a, unsigned char **pp)

{

    return i2d_PrivateKey_impl(a, pp, 0);

}

int i2d_PublicKey(const EVP_PKEY *a, unsigned char **pp)

{

    if (evp_pkey_is_provided(a)) {

        static const struct type_and_structure_st output_info[] = {

            { "DER", "type-specific" },

            { "blob", NULL }, /* for EC */

            {

                NULL,

            }

        };

        return i2d_provided(a, EVP_PKEY_PUBLIC_KEY, output_info, pp);

    }

    switch (EVP_PKEY_get_base_id(a)) {

    case EVP_PKEY_RSA:

        return i2d_RSAPublicKey(EVP_PKEY_get0_RSA(a), pp);

#ifndef OPENSSL_NO_DSA

    case EVP_PKEY_DSA:

        return i2d_DSAPublicKey(EVP_PKEY_get0_DSA(a), pp);

#endif

#ifndef OPENSSL_NO_EC

    case EVP_PKEY_EC:

        return i2o_ECPublicKey(EVP_PKEY_get0_EC_KEY(a), pp);

#endif

    default:

        ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE);

        return -1;

    }

}