/*

 * Copyright 2006-2023 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

 */

#include <stdio.h>

#include <stdlib.h>

#include <openssl/objects.h>

#include <openssl/evp.h>

#include "internal/cryptlib.h"

#include "internal/provider.h"

#include "internal/core.h"

#include "crypto/evp.h"

#include "evp_local.h"

static int evp_pkey_asym_cipher_init(EVP_PKEY_CTX *ctx, int operation,

                                     const OSSL_PARAM params[])

{

    int ret = 0;

    void *provkey = NULL;

    EVP_ASYM_CIPHER *cipher = NULL;

    EVP_KEYMGMT *tmp_keymgmt = NULL;

    const OSSL_PROVIDER *tmp_prov = NULL;

    const char *supported_ciph = NULL;

    int iter;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    evp_pkey_ctx_free_old_ops(ctx);

    ctx->operation = operation;

    ERR_set_mark();

    if (evp_pkey_ctx_is_legacy(ctx))

        goto legacy;

    if (ctx->pkey == NULL) {

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);

        goto err;

    }

    /*

     * Try to derive the supported asym cipher from |ctx->keymgmt|.

     */

    if (!ossl_assert(ctx->pkey->keymgmt == NULL

                     || ctx->pkey->keymgmt == ctx->keymgmt)) {

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    supported_ciph

        = evp_keymgmt_util_query_operation_name(ctx->keymgmt,

                                                OSSL_OP_ASYM_CIPHER);

    if (supported_ciph == NULL) {

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    /*

     * We perform two iterations:

     *

     * 1.  Do the normal asym cipher fetch, using the fetching data given by

     *     the EVP_PKEY_CTX.

     * 2.  Do the provider specific asym cipher fetch, from the same provider

     *     as |ctx->keymgmt|

     *

     * We then try to fetch the keymgmt from the same provider as the

     * asym cipher, and try to export |ctx->pkey| to that keymgmt (when

     * this keymgmt happens to be the same as |ctx->keymgmt|, the export

     * is a no-op, but we call it anyway to not complicate the code even

     * more).

     * If the export call succeeds (returns a non-NULL provider key pointer),

     * we're done and can perform the operation itself.  If not, we perform

     * the second iteration, or jump to legacy.

     */

    for (iter = 1, provkey = NULL; iter < 3 && provkey == NULL; iter++) {

        EVP_KEYMGMT *tmp_keymgmt_tofree;

        /*

         * If we're on the second iteration, free the results from the first.

         * They are NULL on the first iteration, so no need to check what

         * iteration we're on.

         */

        EVP_ASYM_CIPHER_free(cipher);

        EVP_KEYMGMT_free(tmp_keymgmt);

        switch (iter) {

        case 1:

            cipher = EVP_ASYM_CIPHER_fetch(ctx->libctx, supported_ciph,

                                           ctx->propquery);

            if (cipher != NULL)

                tmp_prov = EVP_ASYM_CIPHER_get0_provider(cipher);

            break;

        case 2:

            tmp_prov = EVP_KEYMGMT_get0_provider(ctx->keymgmt);

            cipher =

                evp_asym_cipher_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,

                                                supported_ciph, ctx->propquery);

            if (cipher == NULL)

                goto legacy;

            break;

        }

        if (cipher == NULL)

            continue;

        /*

         * Ensure that the key is provided, either natively, or as a cached

         * export.  We start by fetching the keymgmt with the same name as

         * |ctx->pkey|, but from the provider of the asym cipher method, using

         * the same property query as when fetching the asym cipher method.

         * With the keymgmt we found (if we did), we try to export |ctx->pkey|

         * to it (evp_pkey_export_to_provider() is smart enough to only actually

         * export it if |tmp_keymgmt| is different from |ctx->pkey|'s keymgmt)

         */

        tmp_keymgmt_tofree = tmp_keymgmt

            = evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,

                                          EVP_KEYMGMT_get0_name(ctx->keymgmt),

                                          ctx->propquery);

        if (tmp_keymgmt != NULL)

            provkey = evp_pkey_export_to_provider(ctx->pkey, ctx->libctx,

                                                  &tmp_keymgmt, ctx->propquery);

        if (tmp_keymgmt == NULL)

            EVP_KEYMGMT_free(tmp_keymgmt_tofree);

    }

    if (provkey == NULL) {

        EVP_ASYM_CIPHER_free(cipher);

        goto legacy;

    }

    ERR_pop_to_mark();

    /* No more legacy from here down to legacy: */

    ctx->op.ciph.cipher = cipher;

    ctx->op.ciph.algctx = cipher->newctx(ossl_provider_ctx(cipher->prov));

    if (ctx->op.ciph.algctx == NULL) {

        /* The provider key can stay in the cache */

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    switch (operation) {

    case EVP_PKEY_OP_ENCRYPT:

        if (cipher->encrypt_init == NULL) {

            ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

            ret = -2;

            goto err;

        }

        ret = cipher->encrypt_init(ctx->op.ciph.algctx, provkey, params);

        break;

    case EVP_PKEY_OP_DECRYPT:

        if (cipher->decrypt_init == NULL) {

            ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

            ret = -2;

            goto err;

        }

        ret = cipher->decrypt_init(ctx->op.ciph.algctx, provkey, params);

        break;

    default:

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    if (ret <= 0)

        goto err;

    EVP_KEYMGMT_free(tmp_keymgmt);

    return 1;

 legacy:

    /*

     * If we don't have the full support we need with provided methods,

     * let's go see if legacy does.

     */

    ERR_pop_to_mark();

    EVP_KEYMGMT_free(tmp_keymgmt);

    tmp_keymgmt = NULL;

    if (ctx->pmeth == NULL || ctx->pmeth->encrypt == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    switch (ctx->operation) {

    case EVP_PKEY_OP_ENCRYPT:

        if (ctx->pmeth->encrypt_init == NULL)

            return 1;

        ret = ctx->pmeth->encrypt_init(ctx);

        break;

    case EVP_PKEY_OP_DECRYPT:

        if (ctx->pmeth->decrypt_init == NULL)

            return 1;

        ret = ctx->pmeth->decrypt_init(ctx);

        break;

    default:

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        ret = -1;

    }

 err:

    if (ret <= 0) {

        evp_pkey_ctx_free_old_ops(ctx);

        ctx->operation = EVP_PKEY_OP_UNDEFINED;

    }

    EVP_KEYMGMT_free(tmp_keymgmt);

    return ret;

}

int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx)

{

    return evp_pkey_asym_cipher_init(ctx, EVP_PKEY_OP_ENCRYPT, NULL);

}

int EVP_PKEY_encrypt_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])

{

    return evp_pkey_asym_cipher_init(ctx, EVP_PKEY_OP_ENCRYPT, params);

}

int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx,

                     unsigned char *out, size_t *outlen,

                     const unsigned char *in, size_t inlen)

{

    int ret;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    if (ctx->operation != EVP_PKEY_OP_ENCRYPT) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);

        return -1;

    }

    if (ctx->op.ciph.algctx == NULL)

        goto legacy;

    ret = ctx->op.ciph.cipher->encrypt(ctx->op.ciph.algctx, out, outlen,

                                       (out == NULL ? 0 : *outlen), in, inlen);

    return ret;

 legacy:

    if (ctx->pmeth == NULL || ctx->pmeth->encrypt == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    M_check_autoarg(ctx, out, outlen, EVP_F_EVP_PKEY_ENCRYPT)

        return ctx->pmeth->encrypt(ctx, out, outlen, in, inlen);

}

int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx)

{

    return evp_pkey_asym_cipher_init(ctx, EVP_PKEY_OP_DECRYPT, NULL);

}

int EVP_PKEY_decrypt_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])

{

    return evp_pkey_asym_cipher_init(ctx, EVP_PKEY_OP_DECRYPT, params);

}

int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx,

                     unsigned char *out, size_t *outlen,

                     const unsigned char *in, size_t inlen)

{

    int ret;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    if (ctx->operation != EVP_PKEY_OP_DECRYPT) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);

        return -1;

    }

    if (ctx->op.ciph.algctx == NULL)

        goto legacy;

    ret = ctx->op.ciph.cipher->decrypt(ctx->op.ciph.algctx, out, outlen,

                                       (out == NULL ? 0 : *outlen), in, inlen);

    return ret;

 legacy:

    if (ctx->pmeth == NULL || ctx->pmeth->decrypt == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    }

    M_check_autoarg(ctx, out, outlen, EVP_F_EVP_PKEY_DECRYPT)

        return ctx->pmeth->decrypt(ctx, out, outlen, in, inlen);

}

/* decrypt to new buffer of dynamic size, checking any pre-determined size */

int evp_pkey_decrypt_alloc(EVP_PKEY_CTX *ctx, unsigned char **outp,

                           size_t *outlenp, size_t expected_outlen,

                           const unsigned char *in, size_t inlen)

{

    if (EVP_PKEY_decrypt(ctx, NULL, outlenp, in, inlen) <= 0

            || (*outp = OPENSSL_malloc(*outlenp)) == NULL)

        return -1;

    if (EVP_PKEY_decrypt(ctx, *outp, outlenp, in, inlen) <= 0

            || *outlenp == 0

            || (expected_outlen != 0 && *outlenp != expected_outlen)) {

        ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);

        OPENSSL_clear_free(*outp, *outlenp);

        *outp = NULL;

        return 0;

    }

    return 1;

}

static EVP_ASYM_CIPHER *evp_asym_cipher_new(OSSL_PROVIDER *prov)

{

    EVP_ASYM_CIPHER *cipher = OPENSSL_zalloc(sizeof(EVP_ASYM_CIPHER));

    if (cipher == NULL)

        return NULL;

    if (!CRYPTO_NEW_REF(&cipher->refcnt, 1)) {

        OPENSSL_free(cipher);

        return NULL;

    }

    cipher->prov = prov;

    ossl_provider_up_ref(prov);

    return cipher;

}

static void *evp_asym_cipher_from_algorithm(int name_id,

                                            const OSSL_ALGORITHM *algodef,

                                            OSSL_PROVIDER *prov)

{

    const OSSL_DISPATCH *fns = algodef->implementation;

    EVP_ASYM_CIPHER *cipher = NULL;

    int ctxfncnt = 0, encfncnt = 0, decfncnt = 0;

    int gparamfncnt = 0, sparamfncnt = 0;

    if ((cipher = evp_asym_cipher_new(prov)) == NULL) {

        ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);

        goto err;

    }

    cipher->name_id = name_id;

    if ((cipher->type_name = ossl_algorithm_get1_first_name(algodef)) == NULL)

        goto err;

    cipher->description = algodef->algorithm_description;

    for (; fns->function_id != 0; fns++) {

        switch (fns->function_id) {

        case OSSL_FUNC_ASYM_CIPHER_NEWCTX:

            if (cipher->newctx != NULL)

                break;

            cipher->newctx = OSSL_FUNC_asym_cipher_newctx(fns);

            ctxfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_ENCRYPT_INIT:

            if (cipher->encrypt_init != NULL)

                break;

            cipher->encrypt_init = OSSL_FUNC_asym_cipher_encrypt_init(fns);

            encfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_ENCRYPT:

            if (cipher->encrypt != NULL)

                break;

            cipher->encrypt = OSSL_FUNC_asym_cipher_encrypt(fns);

            encfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_DECRYPT_INIT:

            if (cipher->decrypt_init != NULL)

                break;

            cipher->decrypt_init = OSSL_FUNC_asym_cipher_decrypt_init(fns);

            decfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_DECRYPT:

            if (cipher->decrypt != NULL)

                break;

            cipher->decrypt = OSSL_FUNC_asym_cipher_decrypt(fns);

            decfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_FREECTX:

            if (cipher->freectx != NULL)

                break;

            cipher->freectx = OSSL_FUNC_asym_cipher_freectx(fns);

            ctxfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_DUPCTX:

            if (cipher->dupctx != NULL)

                break;

            cipher->dupctx = OSSL_FUNC_asym_cipher_dupctx(fns);

            break;

        case OSSL_FUNC_ASYM_CIPHER_GET_CTX_PARAMS:

            if (cipher->get_ctx_params != NULL)

                break;

            cipher->get_ctx_params

                = OSSL_FUNC_asym_cipher_get_ctx_params(fns);

            gparamfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_GETTABLE_CTX_PARAMS:

            if (cipher->gettable_ctx_params != NULL)

                break;

            cipher->gettable_ctx_params

                = OSSL_FUNC_asym_cipher_gettable_ctx_params(fns);

            gparamfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_SET_CTX_PARAMS:

            if (cipher->set_ctx_params != NULL)

                break;

            cipher->set_ctx_params

                = OSSL_FUNC_asym_cipher_set_ctx_params(fns);

            sparamfncnt++;

            break;

        case OSSL_FUNC_ASYM_CIPHER_SETTABLE_CTX_PARAMS:

            if (cipher->settable_ctx_params != NULL)

                break;

            cipher->settable_ctx_params

                = OSSL_FUNC_asym_cipher_settable_ctx_params(fns);

            sparamfncnt++;

            break;

        }

    }

    if (ctxfncnt != 2

        || (encfncnt != 0 && encfncnt != 2)

        || (decfncnt != 0 && decfncnt != 2)

        || (encfncnt != 2 && decfncnt != 2)

        || (gparamfncnt != 0 && gparamfncnt != 2)

        || (sparamfncnt != 0 && sparamfncnt != 2)) {

        /*

         * In order to be a consistent set of functions we must have at least

         * a set of context functions (newctx and freectx) as well as a pair of

         * "cipher" functions: (encrypt_init, encrypt) or

         * (decrypt_init decrypt). set_ctx_params and settable_ctx_params are

         * optional, but if one of them is present then the other one must also

         * be present. The same applies to get_ctx_params and

         * gettable_ctx_params. The dupctx function is optional.

         */

        ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);

        goto err;

    }

    return cipher;

 err:

    EVP_ASYM_CIPHER_free(cipher);

    return NULL;

}

void EVP_ASYM_CIPHER_free(EVP_ASYM_CIPHER *cipher)

{

    int i;

    if (cipher == NULL)

        return;

    CRYPTO_DOWN_REF(&cipher->refcnt, &i);

    if (i > 0)

        return;

    OPENSSL_free(cipher->type_name);

    ossl_provider_free(cipher->prov);

    CRYPTO_FREE_REF(&cipher->refcnt);

    OPENSSL_free(cipher);

}

int EVP_ASYM_CIPHER_up_ref(EVP_ASYM_CIPHER *cipher)

{

    int ref = 0;

    CRYPTO_UP_REF(&cipher->refcnt, &ref);

    return 1;

}

OSSL_PROVIDER *EVP_ASYM_CIPHER_get0_provider(const EVP_ASYM_CIPHER *cipher)

{

    return cipher->prov;

}

EVP_ASYM_CIPHER *EVP_ASYM_CIPHER_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,

                                       const char *properties)

{

    return evp_generic_fetch(ctx, OSSL_OP_ASYM_CIPHER, algorithm, properties,

                             evp_asym_cipher_from_algorithm,

                             (int (*)(void *))EVP_ASYM_CIPHER_up_ref,

                             (void (*)(void *))EVP_ASYM_CIPHER_free);

}

EVP_ASYM_CIPHER *evp_asym_cipher_fetch_from_prov(OSSL_PROVIDER *prov,

                                                 const char *algorithm,

                                                 const char *properties)

{

    return evp_generic_fetch_from_prov(prov, OSSL_OP_ASYM_CIPHER,

                                       algorithm, properties,

                                       evp_asym_cipher_from_algorithm,

                                       (int (*)(void *))EVP_ASYM_CIPHER_up_ref,

                                       (void (*)(void *))EVP_ASYM_CIPHER_free);

}

int EVP_ASYM_CIPHER_is_a(const EVP_ASYM_CIPHER *cipher, const char *name)

{

    return evp_is_a(cipher->prov, cipher->name_id, NULL, name);

}

int evp_asym_cipher_get_number(const EVP_ASYM_CIPHER *cipher)

{

    return cipher->name_id;

}

const char *EVP_ASYM_CIPHER_get0_name(const EVP_ASYM_CIPHER *cipher)

{

    return cipher->type_name;

}

const char *EVP_ASYM_CIPHER_get0_description(const EVP_ASYM_CIPHER *cipher)

{

    return cipher->description;

}

void EVP_ASYM_CIPHER_do_all_provided(OSSL_LIB_CTX *libctx,

                                     void (*fn)(EVP_ASYM_CIPHER *cipher,

                                                void *arg),

                                     void *arg)

{

    evp_generic_do_all(libctx, OSSL_OP_ASYM_CIPHER,

                       (void (*)(void *, void *))fn, arg,

                       evp_asym_cipher_from_algorithm,

                       (int (*)(void *))EVP_ASYM_CIPHER_up_ref,

                       (void (*)(void *))EVP_ASYM_CIPHER_free);

}

int EVP_ASYM_CIPHER_names_do_all(const EVP_ASYM_CIPHER *cipher,

                                 void (*fn)(const char *name, void *data),

                                 void *data)

{

    if (cipher->prov != NULL)

        return evp_names_do_all(cipher->prov, cipher->name_id, fn, data);

    return 1;

}

const OSSL_PARAM *EVP_ASYM_CIPHER_gettable_ctx_params(const EVP_ASYM_CIPHER *cip)

{

    void *provctx;

    if (cip == NULL || cip->gettable_ctx_params == NULL)

        return NULL;

    provctx = ossl_provider_ctx(EVP_ASYM_CIPHER_get0_provider(cip));

    return cip->gettable_ctx_params(NULL, provctx);

}

const OSSL_PARAM *EVP_ASYM_CIPHER_settable_ctx_params(const EVP_ASYM_CIPHER *cip)

{

    void *provctx;

    if (cip == NULL || cip->settable_ctx_params == NULL)

        return NULL;

    provctx = ossl_provider_ctx(EVP_ASYM_CIPHER_get0_provider(cip));

    return cip->settable_ctx_params(NULL, provctx);

}