/*

 * Copyright 2006-2025 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

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/evp.h>

#include <openssl/objects.h>

#include "crypto/evp.h"

#include "internal/provider.h"

#include "internal/numbers.h" /* includes SIZE_MAX */

#include "internal/common.h"

#include "evp_local.h"

/*

 * If we get the "NULL" md then the name comes back as "UNDEF". We want to use

 * NULL for this.

 */

static const char *canon_mdname(const char *mdname)

{

    if (mdname != NULL && strcmp(mdname, "UNDEF") == 0)

        return NULL;

    return mdname;

}

static int do_sigver_init(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

    const EVP_MD *type, const char *mdname,

    OSSL_LIB_CTX *libctx, const char *props,

    EVP_PKEY *pkey, int ver,

    const OSSL_PARAM params[])

{

    EVP_PKEY_CTX *locpctx = NULL;

    EVP_SIGNATURE *signature = NULL;

    const char *desc;

    EVP_KEYMGMT *tmp_keymgmt = NULL;

    const OSSL_PROVIDER *tmp_prov = NULL;

    const char *supported_sig = NULL;

    char locmdname[80] = ""; /* 80 chars should be enough */

    void *provkey = NULL;

    int ret, iter, reinit = 1;

    if (!evp_md_ctx_free_algctx(ctx))

        return 0;

    if (ctx->pctx == NULL) {

        reinit = 0;

        ctx->pctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, props);

    }

    if (ctx->pctx == NULL)

        return 0;

    EVP_MD_CTX_clear_flags(ctx, EVP_MD_CTX_FLAG_FINALISED);

    locpctx = ctx->pctx;

    ERR_set_mark();

    if (evp_pkey_ctx_is_legacy(locpctx))

        goto notsupported;

    /* do not reinitialize if pkey is set or operation is different */

    if (reinit

        && (pkey != NULL

            || locpctx->operation != (ver ? EVP_PKEY_OP_VERIFYCTX : EVP_PKEY_OP_SIGNCTX)

            || (signature = locpctx->op.sig.signature) == NULL

            || locpctx->op.sig.algctx == NULL))

        reinit = 0;

    if (props == NULL)

        props = locpctx->propquery;

    if (locpctx->pkey == NULL) {

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);

        goto err;

    }

    if (!reinit) {

        evp_pkey_ctx_free_old_ops(locpctx);

    } else {

        if (mdname == NULL && type == NULL)

            mdname = canon_mdname(EVP_MD_get0_name(ctx->reqdigest));

        goto reinitialize;

    }

    /*

     * Try to derive the supported signature from |locpctx->keymgmt|.

     */

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

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

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    supported_sig = evp_keymgmt_util_query_operation_name(locpctx->keymgmt,

        OSSL_OP_SIGNATURE);

    if (supported_sig == NULL) {

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    /*

     * We perform two iterations:

     *

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

     *     the EVP_PKEY_CTX.

     * 2.  Do the provider specific signature fetch, from the same provider

     *     as |ctx->keymgmt|

     *

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

     * signature, 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 = NULL;

        /*

         * 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_SIGNATURE_free(signature);

        EVP_KEYMGMT_free(tmp_keymgmt);

        switch (iter) {

        case 1:

            signature = EVP_SIGNATURE_fetch(locpctx->libctx, supported_sig,

                locpctx->propquery);

            if (signature != NULL)

                tmp_prov = EVP_SIGNATURE_get0_provider(signature);

            break;

        case 2:

            tmp_prov = EVP_KEYMGMT_get0_provider(locpctx->keymgmt);

            signature = evp_signature_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,

                supported_sig, locpctx->propquery);

            if (signature == NULL)

                goto notsupported;

            break;

        }

        if (signature == 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

         * |locpctx->pkey|, but from the provider of the signature method, using

         * the same property query as when fetching the signature method.

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

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

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

         */

        tmp_keymgmt_tofree = tmp_keymgmt = evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,

            EVP_KEYMGMT_get0_name(locpctx->keymgmt),

            locpctx->propquery);

        if (tmp_keymgmt != NULL)

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

                &tmp_keymgmt, locpctx->propquery);

        if (tmp_keymgmt == NULL)

            EVP_KEYMGMT_free(tmp_keymgmt_tofree);

    }

    if (provkey == NULL) {

        EVP_SIGNATURE_free(signature);

        ERR_clear_last_mark();

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    ERR_pop_to_mark();

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

    locpctx->op.sig.signature = signature;

    locpctx->operation = ver ? EVP_PKEY_OP_VERIFYCTX

                             : EVP_PKEY_OP_SIGNCTX;

    locpctx->op.sig.algctx

        = signature->newctx(ossl_provider_ctx(signature->prov), props);

    if (locpctx->op.sig.algctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

reinitialize:

    if (pctx != NULL)

        *pctx = locpctx;

    if (type != NULL) {

        ctx->reqdigest = type;

        if (mdname == NULL)

            mdname = canon_mdname(EVP_MD_get0_name(type));

    } else {

        if (mdname == NULL && !reinit) {

            if (evp_keymgmt_util_get_deflt_digest_name(tmp_keymgmt, provkey,

                    locmdname,

                    sizeof(locmdname))

                > 0) {

                mdname = canon_mdname(locmdname);

            }

        }

        if (mdname != NULL) {

            /*

             * We're about to get a new digest so clear anything associated with

             * an old digest.

             */

            evp_md_ctx_clear_digest(ctx, 1, 0);

            /*

             * This might be requested by a later call to EVP_MD_CTX_get0_md().

             * In that case the "explicit fetch" rules apply for that

             * function (as per man pages), i.e. the ref count is not updated

             * so the EVP_MD should not be used beyond the lifetime of the

             * EVP_MD_CTX.

             */

            ctx->fetched_digest = EVP_MD_fetch(locpctx->libctx, mdname, props);

            if (ctx->fetched_digest != NULL) {

                ctx->digest = ctx->reqdigest = ctx->fetched_digest;

                if (ctx->digest == NULL) {

                    ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

                    goto err;

                }

            }

        }

    }

    desc = signature->description != NULL ? signature->description : "";

    if (ver) {

        if (signature->digest_verify_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

                "%s digest_verify_init:%s", signature->type_name, desc);

            goto err;

        }

        ret = signature->digest_verify_init(locpctx->op.sig.algctx,

            mdname, provkey, params);

    } else {

        if (signature->digest_sign_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

                "%s digest_sign_init:%s", signature->type_name, desc);

            goto err;

        }

        ret = signature->digest_sign_init(locpctx->op.sig.algctx,

            mdname, provkey, params);

    }

    /*

     * If the operation was not a success and no digest was found, an error

     * needs to be raised.

     */

    if (ret > 0 || mdname != NULL) {

        if (ret > 0)

            ret = evp_pkey_ctx_use_cached_data(locpctx);

        EVP_KEYMGMT_free(tmp_keymgmt);

        return ret > 0 ? 1 : 0;

    }

    if (type == NULL) /* This check is redundant but clarifies matters */

        ERR_raise(ERR_LIB_EVP, EVP_R_NO_DEFAULT_DIGEST);

    ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

        ver ? "%s digest_verify_init:%s" : "%s digest_sign_init:%s",

        signature->type_name, desc);

err:

    evp_pkey_ctx_free_old_ops(locpctx);

    locpctx->operation = EVP_PKEY_OP_UNDEFINED;

    EVP_KEYMGMT_free(tmp_keymgmt);

    return 0;

notsupported:

    ERR_pop_to_mark();

    EVP_KEYMGMT_free(tmp_keymgmt);

    ERR_raise_data(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE,

        ver ? "%s digest_verify_init" : "%s digest_sign_init",

        EVP_PKEY_get0_type_name(locpctx->pkey));

    return 0;

}

int EVP_DigestSignInit_ex(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

    const char *mdname, OSSL_LIB_CTX *libctx,

    const char *props, EVP_PKEY *pkey,

    const OSSL_PARAM params[])

{

    return do_sigver_init(ctx, pctx, NULL, mdname, libctx, props, pkey, 0,

        params);

}

int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

    const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey)

{

    if (!ossl_assert(e == NULL))

        return 0;

    return do_sigver_init(ctx, pctx, type, NULL, NULL, NULL, pkey, 0,

        NULL);

}

int EVP_DigestVerifyInit_ex(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

    const char *mdname, OSSL_LIB_CTX *libctx,

    const char *props, EVP_PKEY *pkey,

    const OSSL_PARAM params[])

{

    return do_sigver_init(ctx, pctx, NULL, mdname, libctx, props, pkey, 1,

        params);

}

int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

    const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey)

{

    if (!ossl_assert(e == NULL))

        return 0;

    return do_sigver_init(ctx, pctx, type, NULL, NULL, NULL, pkey, 1,

        NULL);

}

int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *data, size_t dsize)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    EVP_PKEY_CTX *pctx = ctx->pctx;

    int ret;

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);

        return 0;

    }

    if (pctx == NULL)

        return EVP_DigestUpdate(ctx, data, dsize);

    if (pctx->operation != EVP_PKEY_OP_SIGNCTX

        || pctx->op.sig.algctx == NULL

        || pctx->op.sig.signature == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        return 0;

    }

    signature = pctx->op.sig.signature;

    desc = signature->description != NULL ? signature->description : "";

    if (signature->digest_sign_update == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

            "%s digest_sign_update:%s", signature->type_name, desc);

        return 0;

    }

    ERR_set_mark();

    ret = signature->digest_sign_update(pctx->op.sig.algctx, data, dsize);

    if (ret <= 0 && ERR_count_to_mark() == 0)

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

            "%s digest_sign_update:%s", signature->type_name, desc);

    ERR_clear_last_mark();

    return ret;

}

int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *data, size_t dsize)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    EVP_PKEY_CTX *pctx = ctx->pctx;

    int ret;

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);

        return 0;

    }

    if (pctx == NULL

        || pctx->operation != EVP_PKEY_OP_VERIFYCTX

        || pctx->op.sig.algctx == NULL

        || pctx->op.sig.signature == NULL)

        return EVP_DigestUpdate(ctx, data, dsize);

    signature = pctx->op.sig.signature;

    desc = signature->description != NULL ? signature->description : "";

    if (signature->digest_verify_update == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

            "%s digest_verify_update:%s", signature->type_name, desc);

        return 0;

    }

    ERR_set_mark();

    ret = signature->digest_verify_update(pctx->op.sig.algctx, data, dsize);

    if (ret <= 0 && ERR_count_to_mark() == 0)

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

            "%s digest_verify_update:%s", signature->type_name, desc);

    ERR_clear_last_mark();

    return ret;

}

int EVP_DigestSignFinal(EVP_MD_CTX *ctx, unsigned char *sigret,

    size_t *siglen)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    int r = 0;

    EVP_PKEY_CTX *dctx = NULL, *pctx = ctx->pctx;

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);

        return 0;

    }

    if (pctx == NULL

        || pctx->operation != EVP_PKEY_OP_SIGNCTX

        || pctx->op.sig.algctx == NULL

        || pctx->op.sig.signature == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        return 0;

    }

    signature = pctx->op.sig.signature;

    desc = signature->description != NULL ? signature->description : "";

    if (signature->digest_sign_final == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

            "%s digest_sign_final:%s", signature->type_name, desc);

        return 0;

    }

    if (sigret != NULL && (ctx->flags & EVP_MD_CTX_FLAG_FINALISE) == 0) {

        /* try dup */

        dctx = EVP_PKEY_CTX_dup(pctx);

        if (dctx != NULL)

            pctx = dctx;

    }

    ERR_set_mark();

    r = signature->digest_sign_final(pctx->op.sig.algctx, sigret, siglen,

        sigret == NULL ? 0 : *siglen);

    if (!r && ERR_count_to_mark() == 0)

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

            "%s digest_sign_final:%s", signature->type_name, desc);

    ERR_clear_last_mark();

    if (dctx == NULL && sigret != NULL)

        ctx->flags |= EVP_MD_CTX_FLAG_FINALISED;

    else

        EVP_PKEY_CTX_free(dctx);

    return r;

}

int EVP_DigestSign(EVP_MD_CTX *ctx, unsigned char *sigret, size_t *siglen,

    const unsigned char *tbs, size_t tbslen)

{

    EVP_PKEY_CTX *pctx = ctx->pctx;

    int ret;

    if (pctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        return 0;

    }

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);

        return 0;

    }

    if (pctx->operation == EVP_PKEY_OP_SIGNCTX

        && pctx->op.sig.algctx != NULL

        && pctx->op.sig.signature != NULL) {

        EVP_SIGNATURE *signature = pctx->op.sig.signature;

        if (signature->digest_sign != NULL) {

            const char *desc = signature->description != NULL ? signature->description : "";

            if (sigret != NULL)

                ctx->flags |= EVP_MD_CTX_FLAG_FINALISED;

            ERR_set_mark();

            ret = signature->digest_sign(pctx->op.sig.algctx, sigret, siglen,

                sigret == NULL ? 0 : *siglen, tbs, tbslen);

            if (ret <= 0 && ERR_count_to_mark() == 0)

                ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

                    "%s digest_sign:%s", signature->type_name, desc);

            ERR_clear_last_mark();

            return ret;

        }

    }

    if (sigret != NULL && EVP_DigestSignUpdate(ctx, tbs, tbslen) <= 0)

        return 0;

    return EVP_DigestSignFinal(ctx, sigret, siglen);

}

int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig,

    size_t siglen)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    int r = 0;

    EVP_PKEY_CTX *dctx = NULL, *pctx = ctx->pctx;

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);

        return 0;

    }

    if (pctx == NULL

        || pctx->operation != EVP_PKEY_OP_VERIFYCTX

        || pctx->op.sig.algctx == NULL

        || pctx->op.sig.signature == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        return 0;

    }

    signature = pctx->op.sig.signature;

    desc = signature->description != NULL ? signature->description : "";

    if (signature->digest_verify_final == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

            "%s digest_verify_final:%s", signature->type_name, desc);

        return 0;

    }

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISE) == 0) {

        /* try dup */

        dctx = EVP_PKEY_CTX_dup(pctx);

        if (dctx != NULL)

            pctx = dctx;

    }

    ERR_set_mark();

    r = signature->digest_verify_final(pctx->op.sig.algctx, sig, siglen);

    if (!r && ERR_count_to_mark() == 0)

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

            "%s digest_verify_final:%s", signature->type_name, desc);

    ERR_clear_last_mark();

    if (dctx == NULL)

        ctx->flags |= EVP_MD_CTX_FLAG_FINALISED;

    else

        EVP_PKEY_CTX_free(dctx);

    return r;

}

int EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sigret,

    size_t siglen, const unsigned char *tbs, size_t tbslen)

{

    EVP_PKEY_CTX *pctx = ctx->pctx;

    if (pctx == NULL) {

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        return -1;

    }

    if ((ctx->flags & EVP_MD_CTX_FLAG_FINALISED) != 0) {

        ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);

        return 0;

    }

    if (pctx->operation == EVP_PKEY_OP_VERIFYCTX

        && pctx->op.sig.algctx != NULL

        && pctx->op.sig.signature != NULL) {

        if (pctx->op.sig.signature->digest_verify != NULL) {

            EVP_SIGNATURE *signature = pctx->op.sig.signature;

            const char *desc = signature->description != NULL ? signature->description : "";

            int ret;

            ctx->flags |= EVP_MD_CTX_FLAG_FINALISED;

            ERR_set_mark();

            ret = signature->digest_verify(pctx->op.sig.algctx, sigret, siglen, tbs, tbslen);

            if (ret <= 0 && ERR_count_to_mark() == 0)

                ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

                    "%s digest_verify:%s", signature->type_name, desc);

            ERR_clear_last_mark();

            return ret;

        }

    }

    if (EVP_DigestVerifyUpdate(ctx, tbs, tbslen) <= 0)

        return -1;

    return EVP_DigestVerifyFinal(ctx, sigret, siglen);

}