/*

 * Copyright 2006-2026 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 <openssl/err.h>

#include <stdio.h>

#include <stdlib.h>

#include <openssl/core_names.h>

#include <openssl/objects.h>

#include <openssl/evp.h>

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

#include "internal/cryptlib.h"

#include "internal/provider.h"

#include "internal/core.h"

#include "crypto/evp.h"

#include "evp_local.h"

static void evp_signature_free(void *data)

{

    EVP_SIGNATURE *signature = (EVP_SIGNATURE *)data;

    int i;

    if (signature == NULL)

        return;

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

    if (i > 0)

        return;

    OPENSSL_free(signature->type_name);

    ossl_provider_free(signature->prov);

    CRYPTO_FREE_REF(&signature->refcnt);

    OPENSSL_free(signature);

}

static int evp_signature_up_ref(void *data)

{

    EVP_SIGNATURE *signature = (EVP_SIGNATURE *)data;

    int ref = 0;

    return CRYPTO_UP_REF(&signature->refcnt, &ref);

}

static EVP_SIGNATURE *evp_signature_new(OSSL_PROVIDER *prov)

{

    EVP_SIGNATURE *signature = OPENSSL_zalloc(sizeof(EVP_SIGNATURE));

    if (signature == NULL)

        return NULL;

    if (!CRYPTO_NEW_REF(&signature->refcnt, 1)

        || !ossl_provider_up_ref(prov)) {

        CRYPTO_FREE_REF(&signature->refcnt);

        OPENSSL_free(signature);

        return NULL;

    }

    signature->prov = prov;

    return signature;

}

static void *evp_signature_from_algorithm(int name_id,

    const OSSL_ALGORITHM *algodef,

    OSSL_PROVIDER *prov, int no_store)

{

    const OSSL_DISPATCH *fns = algodef->implementation;

    EVP_SIGNATURE *signature = NULL;

    const char *desc;

    /* Counts newctx / freectx */

    int ctxfncnt = 0;

    /* Counts all init functions  */

    int initfncnt = 0;

    /* Counts all parameter functions */

    int gparamfncnt = 0, sparamfncnt = 0, gmdparamfncnt = 0, smdparamfncnt = 0;

    int valid = 0;

    if ((signature = evp_signature_new(prov)) == NULL) {

        ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);

        goto err;

    }

    signature->name_id = name_id;

    signature->no_store = no_store;

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

        goto err;

    signature->description = algodef->algorithm_description;

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

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

        switch (fns->function_id) {

        case OSSL_FUNC_SIGNATURE_NEWCTX:

            if (signature->newctx != NULL)

                break;

            signature->newctx = OSSL_FUNC_signature_newctx(fns);

            ctxfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SIGN_INIT:

            if (signature->sign_init != NULL)

                break;

            signature->sign_init = OSSL_FUNC_signature_sign_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SIGN:

            if (signature->sign != NULL)

                break;

            signature->sign = OSSL_FUNC_signature_sign(fns);

            break;

        case OSSL_FUNC_SIGNATURE_SIGN_MESSAGE_INIT:

            if (signature->sign_message_init != NULL)

                break;

            signature->sign_message_init

                = OSSL_FUNC_signature_sign_message_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SIGN_MESSAGE_UPDATE:

            if (signature->sign_message_update != NULL)

                break;

            signature->sign_message_update

                = OSSL_FUNC_signature_sign_message_update(fns);

            break;

        case OSSL_FUNC_SIGNATURE_SIGN_MESSAGE_FINAL:

            if (signature->sign_message_final != NULL)

                break;

            signature->sign_message_final

                = OSSL_FUNC_signature_sign_message_final(fns);

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_INIT:

            if (signature->verify_init != NULL)

                break;

            signature->verify_init = OSSL_FUNC_signature_verify_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY:

            if (signature->verify != NULL)

                break;

            signature->verify = OSSL_FUNC_signature_verify(fns);

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_MESSAGE_INIT:

            if (signature->verify_message_init != NULL)

                break;

            signature->verify_message_init

                = OSSL_FUNC_signature_verify_message_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_MESSAGE_UPDATE:

            if (signature->verify_message_update != NULL)

                break;

            signature->verify_message_update

                = OSSL_FUNC_signature_verify_message_update(fns);

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_MESSAGE_FINAL:

            if (signature->verify_message_final != NULL)

                break;

            signature->verify_message_final

                = OSSL_FUNC_signature_verify_message_final(fns);

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_RECOVER_INIT:

            if (signature->verify_recover_init != NULL)

                break;

            signature->verify_recover_init

                = OSSL_FUNC_signature_verify_recover_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_VERIFY_RECOVER:

            if (signature->verify_recover != NULL)

                break;

            signature->verify_recover

                = OSSL_FUNC_signature_verify_recover(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_SIGN_INIT:

            if (signature->digest_sign_init != NULL)

                break;

            signature->digest_sign_init

                = OSSL_FUNC_signature_digest_sign_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_SIGN_UPDATE:

            if (signature->digest_sign_update != NULL)

                break;

            signature->digest_sign_update

                = OSSL_FUNC_signature_digest_sign_update(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_SIGN_FINAL:

            if (signature->digest_sign_final != NULL)

                break;

            signature->digest_sign_final

                = OSSL_FUNC_signature_digest_sign_final(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_SIGN:

            if (signature->digest_sign != NULL)

                break;

            signature->digest_sign

                = OSSL_FUNC_signature_digest_sign(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_INIT:

            if (signature->digest_verify_init != NULL)

                break;

            signature->digest_verify_init

                = OSSL_FUNC_signature_digest_verify_init(fns);

            initfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_UPDATE:

            if (signature->digest_verify_update != NULL)

                break;

            signature->digest_verify_update

                = OSSL_FUNC_signature_digest_verify_update(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_FINAL:

            if (signature->digest_verify_final != NULL)

                break;

            signature->digest_verify_final

                = OSSL_FUNC_signature_digest_verify_final(fns);

            break;

        case OSSL_FUNC_SIGNATURE_DIGEST_VERIFY:

            if (signature->digest_verify != NULL)

                break;

            signature->digest_verify

                = OSSL_FUNC_signature_digest_verify(fns);

            break;

        case OSSL_FUNC_SIGNATURE_FREECTX:

            if (signature->freectx != NULL)

                break;

            signature->freectx = OSSL_FUNC_signature_freectx(fns);

            ctxfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_DUPCTX:

            if (signature->dupctx != NULL)

                break;

            signature->dupctx = OSSL_FUNC_signature_dupctx(fns);

            break;

        case OSSL_FUNC_SIGNATURE_GET_CTX_PARAMS:

            if (signature->get_ctx_params != NULL)

                break;

            signature->get_ctx_params

                = OSSL_FUNC_signature_get_ctx_params(fns);

            gparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_GETTABLE_CTX_PARAMS:

            if (signature->gettable_ctx_params != NULL)

                break;

            signature->gettable_ctx_params

                = OSSL_FUNC_signature_gettable_ctx_params(fns);

            gparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SET_CTX_PARAMS:

            if (signature->set_ctx_params != NULL)

                break;

            signature->set_ctx_params

                = OSSL_FUNC_signature_set_ctx_params(fns);

            sparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SETTABLE_CTX_PARAMS:

            if (signature->settable_ctx_params != NULL)

                break;

            signature->settable_ctx_params

                = OSSL_FUNC_signature_settable_ctx_params(fns);

            sparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_GET_CTX_MD_PARAMS:

            if (signature->get_ctx_md_params != NULL)

                break;

            signature->get_ctx_md_params

                = OSSL_FUNC_signature_get_ctx_md_params(fns);

            gmdparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_GETTABLE_CTX_MD_PARAMS:

            if (signature->gettable_ctx_md_params != NULL)

                break;

            signature->gettable_ctx_md_params

                = OSSL_FUNC_signature_gettable_ctx_md_params(fns);

            gmdparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SET_CTX_MD_PARAMS:

            if (signature->set_ctx_md_params != NULL)

                break;

            signature->set_ctx_md_params

                = OSSL_FUNC_signature_set_ctx_md_params(fns);

            smdparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_SETTABLE_CTX_MD_PARAMS:

            if (signature->settable_ctx_md_params != NULL)

                break;

            signature->settable_ctx_md_params

                = OSSL_FUNC_signature_settable_ctx_md_params(fns);

            smdparamfncnt++;

            break;

        case OSSL_FUNC_SIGNATURE_QUERY_KEY_TYPES:

            if (signature->query_key_types != NULL)

                break;

            signature->query_key_types

                = OSSL_FUNC_signature_query_key_types(fns);

            break;

        }

    }

    /*

     * 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 set of

     * "signature" functions.  Because there's an overlap between some sets

     * of functions, counters don't always cut it, we must test known

     * combinations.

     * We start by assuming the implementation is valid, and then look for

     * reasons it's not.

     */

    valid = 1;

    /* Start with the ones where counters say enough */

    if (ctxfncnt != 2) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s newctx or freectx:%s", signature->type_name, desc);

        valid = 0;

    }

    if (valid

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

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

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

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

        /*

         * Params functions are optional, but if defined, they must

         * be pairwise complete sets, i.e. a getter must have an

         * associated gettable, etc

         */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s params getter or setter:%s", signature->type_name, desc);

        valid = 0;

    }

    if (valid && initfncnt == 0) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        valid = 0;

    }

    /* Now we check for function combinations */

    if (valid

        && ((signature->sign_init != NULL

                && signature->sign == NULL)

            || (signature->sign_message_init != NULL

                && signature->sign == NULL

                && (signature->sign_message_update == NULL

                    || signature->sign_message_final == NULL)))) {

        /* sign_init function(s) with no signing function?  That's weird */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s signing function:%s", signature->type_name, desc);

        valid = 0;

    }

    if (valid

        && (signature->sign != NULL

            || signature->sign_message_update != NULL

            || signature->sign_message_final != NULL)

        && signature->sign_init == NULL

        && signature->sign_message_init == NULL) {

        /* signing function(s) with no sign_init? That's odd */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s sign_init or sign_message_init:%s", signature->type_name, desc);

        valid = 0;

    }

    if (valid

        && ((signature->verify_init != NULL

                && signature->verify == NULL)

            || (signature->verify_message_init != NULL

                && signature->verify == NULL

                && (signature->verify_message_update == NULL

                    || signature->verify_message_final == NULL)))) {

        /* verify_init function(s) with no verification function?  That's weird */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s verification function:%s", signature->type_name, desc);

        valid = 0;

    }

    if (valid

        && (signature->verify != NULL

            || signature->verify_message_update != NULL

            || signature->verify_message_final != NULL)

        && signature->verify_init == NULL

        && signature->verify_message_init == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "missing %s verify_init or verify_message_init:%s",

            signature->type_name, desc);

        /* verification function(s) with no verify_init? That's odd */

        valid = 0;

    }

    if (valid

        && (signature->verify_recover_init != NULL)

        && (signature->verify_recover == NULL)) {

        /* verify_recover_init function with no verify_recover?  How quaint */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        valid = 0;

    }

    if (valid

        && (signature->digest_sign_init != NULL

            && signature->digest_sign == NULL

            && (signature->digest_sign_update == NULL

                || signature->digest_sign_final == NULL))) {

        /* You can't have a digest_sign_init without *some* performing functions */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        valid = 0;

    }

    if (valid

        && ((signature->digest_verify_init != NULL

            && signature->digest_verify == NULL

            && (signature->digest_verify_update == NULL

                || signature->digest_verify_final == NULL)))) {

        /* You can't have a digest_verify_init without *some* performing functions */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        valid = 0;

    }

    if (!valid)

        goto err;

    if ((signature->digest_sign != NULL

            || signature->digest_sign_update != NULL

            || signature->digest_sign_final != NULL)

        && signature->digest_sign_init == NULL) {

        /* digest signing function(s) with no digest_sign_init? That's odd */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        goto err;

    }

    if ((signature->digest_verify != NULL

            || signature->digest_verify_update != NULL

            || signature->digest_verify_final != NULL)

        && signature->digest_verify_init == NULL) {

        /* digest verification function(s) with no digest_verify_init? That's odd */

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

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

        goto err;

    }

    if ((signature->sign_message_update == NULL) != (signature->sign_message_final == NULL)) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "only one of %s message signing update and final available:%s",

            signature->type_name, desc);

        goto err;

    }

    if ((signature->verify_message_update == NULL) != (signature->verify_message_final == NULL)) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "only one of %s message verification update and final available:%s",

            signature->type_name, desc);

        goto err;

    }

    if ((signature->digest_sign_update == NULL) != (signature->digest_sign_final == NULL)) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "only one of %s digest signing update and final available:%s",

            signature->type_name, desc);

        goto err;

    }

    if ((signature->digest_verify_update == NULL) != (signature->digest_verify_final == NULL)) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS,

            "only one of %s digest verification update and final available:%s",

            signature->type_name, desc);

        goto err;

    }

    return signature;

err:

    evp_signature_free(signature);

    return NULL;

}

void EVP_SIGNATURE_free(EVP_SIGNATURE *signature)

{

#ifdef OPENSSL_NO_CACHED_FETCH

    evp_signature_free(signature);

#else

    if (signature != NULL && (signature->no_store != 0))

        evp_signature_free(signature);

#endif

}

int EVP_SIGNATURE_up_ref(EVP_SIGNATURE *signature)

{

#ifdef OPENSSL_NO_CACHED_FETCH

    return evp_signature_up_ref(signature);

#else

    if (signature->no_store != 0)

        return evp_signature_up_ref(signature);

    return 1;

#endif

}

OSSL_PROVIDER *EVP_SIGNATURE_get0_provider(const EVP_SIGNATURE *signature)

{

    return signature->prov;

}

EVP_SIGNATURE *EVP_SIGNATURE_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,

    const char *properties)

{

    return evp_generic_fetch(ctx, OSSL_OP_SIGNATURE, algorithm, properties,

        evp_signature_from_algorithm,

        evp_signature_up_ref,

        evp_signature_free);

}

EVP_SIGNATURE *evp_signature_fetch_from_prov(OSSL_PROVIDER *prov,

    const char *algorithm,

    const char *properties)

{

    return evp_generic_fetch_from_prov(prov, OSSL_OP_SIGNATURE,

        algorithm, properties,

        evp_signature_from_algorithm,

        evp_signature_up_ref,

        evp_signature_free);

}

int EVP_SIGNATURE_is_a(const EVP_SIGNATURE *signature, const char *name)

{

    return signature != NULL

        && evp_is_a(signature->prov, signature->name_id, NULL, name);

}

int EVP_SIGNATURE_has_message_update(const EVP_SIGNATURE *signature)

{

    return signature->verify_message_update != NULL

        && signature->sign_message_update != NULL;

}

int evp_signature_get_number(const EVP_SIGNATURE *signature)

{

    return signature->name_id;

}

const char *EVP_SIGNATURE_get0_name(const EVP_SIGNATURE *signature)

{

    return signature->type_name;

}

const char *EVP_SIGNATURE_get0_description(const EVP_SIGNATURE *signature)

{

    return signature->description;

}

void EVP_SIGNATURE_do_all_provided(OSSL_LIB_CTX *libctx,

    void (*fn)(EVP_SIGNATURE *signature,

        void *arg),

    void *arg)

{

    struct EVP_SIGNATURE_do_all_provided_thunk t;

    t.fn = fn;

    t.arg = arg;

    evp_generic_do_all(libctx, OSSL_OP_SIGNATURE,

        EVP_SIGNATURE_do_all_provided_thunk, &t,

        evp_signature_from_algorithm,

        evp_signature_up_ref,

        evp_signature_free);

}

int EVP_SIGNATURE_names_do_all(const EVP_SIGNATURE *signature,

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

    void *data)

{

    if (signature->prov != NULL)

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

    return 1;

}

const OSSL_PARAM *EVP_SIGNATURE_gettable_ctx_params(const EVP_SIGNATURE *sig)

{

    void *provctx;

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

        return NULL;

    provctx = ossl_provider_ctx(EVP_SIGNATURE_get0_provider(sig));

    return sig->gettable_ctx_params(NULL, provctx);

}

const OSSL_PARAM *EVP_SIGNATURE_settable_ctx_params(const EVP_SIGNATURE *sig)

{

    void *provctx;

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

        return NULL;

    provctx = ossl_provider_ctx(EVP_SIGNATURE_get0_provider(sig));

    return sig->settable_ctx_params(NULL, provctx);

}

static int evp_pkey_signature_init(EVP_PKEY_CTX *ctx, EVP_SIGNATURE *signature,

    int operation, const OSSL_PARAM params[])

{

    const char *desc;

    int ret = 0;

    void *provkey = NULL;

    EVP_KEYMGMT *tmp_keymgmt = NULL;

    const OSSL_PROVIDER *tmp_prov = NULL;

    const char *supported_sig = NULL;

    int iter;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);

        return -1;

    }

    evp_pkey_ctx_free_old_ops(ctx);

    ctx->operation = operation;

    if (signature != NULL) {

        /*

         * It's important to figure out what the key type should be, and if

         * that is what we have in ctx.

         */

        EVP_KEYMGMT *tmp_keymgmt_tofree = NULL;

        if (ctx->pkey == NULL) {

            ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);

            goto err;

        }

        /*

         * 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 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 |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_prov = EVP_SIGNATURE_get0_provider(signature);

        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)

            goto end;

        /*

         * Check that the signature matches the given key.  This is not

         * designed to work with legacy keys, so has to be done after we've

         * ensured that the key is at least exported to a provider (above).

         */

        if (signature->query_key_types != NULL) {

            /* This is expected to be a NULL-terminated array */

            const char **keytypes;

            keytypes = signature->query_key_types();

            for (; *keytypes != NULL; keytypes++)

                if (EVP_PKEY_CTX_is_a(ctx, *keytypes))

                    break;

            if (*keytypes == NULL) {

                ERR_raise(ERR_LIB_EVP, EVP_R_SIGNATURE_TYPE_AND_KEY_TYPE_INCOMPATIBLE);

                ret = -2;

                goto end;

            }

        } else {

            /*

             * Fallback 1:

             * check if the keytype is the same as the signature algorithm name

             */

            const char *keytype = EVP_KEYMGMT_get0_name(ctx->keymgmt);

            int ok = EVP_SIGNATURE_is_a(signature, keytype);

            /*

             * Fallback 2:

             * query the pkey for a default signature algorithm name, and check

             * if it matches the signature implementation

             */

            if (!ok) {

                const char *signame

                    = evp_keymgmt_util_query_operation_name(ctx->keymgmt,

                        OSSL_OP_SIGNATURE);

                ok = EVP_SIGNATURE_is_a(signature, signame);

            }

            /* If none of the fallbacks helped, we're lost */

            if (!ok) {

                ERR_raise(ERR_LIB_EVP, EVP_R_SIGNATURE_TYPE_AND_KEY_TYPE_INCOMPATIBLE);

                ret = -2;

                goto end;

            }

        }

        if (!EVP_SIGNATURE_up_ref(signature))

            goto err;

    } else {

        /* Without a pre-fetched signature, it must be figured out somehow */

        ERR_set_mark();

        if (evp_pkey_ctx_is_legacy(ctx))

            goto notsupported;

        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 signature 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_sig

            = evp_keymgmt_util_query_operation_name(ctx->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; 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);

            signature = NULL;

            EVP_KEYMGMT_free(tmp_keymgmt);

            tmp_keymgmt = NULL;

            switch (iter) {

            case 1:

                signature = EVP_SIGNATURE_fetch(ctx->libctx, supported_sig, ctx->propquery);

                if (signature != NULL)

                    tmp_prov = EVP_SIGNATURE_get0_provider(signature);

                break;

            case 2:

                tmp_prov = EVP_KEYMGMT_get0_provider(ctx->keymgmt);

                signature = evp_signature_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,

                    supported_sig, ctx->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 |ctx->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 |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_SIGNATURE_free(signature);

            goto notsupported;

        }

        ERR_pop_to_mark();

    }

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

    ctx->op.sig.signature = signature;

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

    ctx->op.sig.algctx = signature->newctx(ossl_provider_ctx(signature->prov), ctx->propquery);

    if (ctx->op.sig.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_SIGN:

        if (signature->sign_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

            ret = -2;

            goto err;

        }

        ret = signature->sign_init(ctx->op.sig.algctx, provkey, params);

        break;

    case EVP_PKEY_OP_SIGNMSG:

        if (signature->sign_message_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

            ret = -2;

            goto err;

        }

        ret = signature->sign_message_init(ctx->op.sig.algctx, provkey, params);

        break;

    case EVP_PKEY_OP_VERIFY:

        if (signature->verify_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

            ret = -2;

            goto err;

        }

        ret = signature->verify_init(ctx->op.sig.algctx, provkey, params);

        break;

    case EVP_PKEY_OP_VERIFYMSG:

        if (signature->verify_message_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

            ret = -2;

            goto err;

        }

        ret = signature->verify_message_init(ctx->op.sig.algctx, provkey, params);

        break;

    case EVP_PKEY_OP_VERIFYRECOVER:

        if (signature->verify_recover_init == NULL) {

            ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

            ret = -2;

            goto err;

        }

        ret = signature->verify_recover_init(ctx->op.sig.algctx, provkey, params);

        break;

    default:

        ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);

        goto err;

    }

    if (ret <= 0) {

        signature->freectx(ctx->op.sig.algctx);

        ctx->op.sig.algctx = NULL;

        goto err;

    }

    goto end;

notsupported:

    /*

     * 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;

    ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

    return -2;

end:

#ifndef FIPS_MODULE

    if (ret > 0)

        ret = evp_pkey_ctx_use_cached_data(ctx);

#endif

    EVP_KEYMGMT_free(tmp_keymgmt);

    return ret;

err:

    evp_pkey_ctx_free_old_ops(ctx);

    ctx->operation = EVP_PKEY_OP_UNDEFINED;

    EVP_KEYMGMT_free(tmp_keymgmt);

    return ret;

}

int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx)

{

    return evp_pkey_signature_init(ctx, NULL, EVP_PKEY_OP_SIGN, NULL);

}

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

{

    return evp_pkey_signature_init(ctx, NULL, EVP_PKEY_OP_SIGN, params);

}

int EVP_PKEY_sign_init_ex2(EVP_PKEY_CTX *ctx,

    EVP_SIGNATURE *algo, const OSSL_PARAM params[])

{

    return evp_pkey_signature_init(ctx, algo, EVP_PKEY_OP_SIGN, params);

}

int EVP_PKEY_sign_message_init(EVP_PKEY_CTX *ctx,

    EVP_SIGNATURE *algo, const OSSL_PARAM params[])

{

    return evp_pkey_signature_init(ctx, algo, EVP_PKEY_OP_SIGNMSG, params);

}

int EVP_PKEY_sign_message_update(EVP_PKEY_CTX *ctx,

    const unsigned char *in, size_t inlen)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    int ret;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);

        return -1;

    }

    if (ctx->operation != EVP_PKEY_OP_SIGNMSG) {

        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);

        return -1;

    }

    signature = ctx->op.sig.signature;

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

    if (signature->sign_message_update == NULL) {

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_NOT_SUPPORTED,

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

        return -2;

    }

    ret = signature->sign_message_update(ctx->op.sig.algctx, in, inlen);

    if (ret <= 0)

        ERR_raise_data(ERR_LIB_EVP, EVP_R_PROVIDER_SIGNATURE_FAILURE,

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

    return ret;

}

int EVP_PKEY_sign_message_final(EVP_PKEY_CTX *ctx,

    unsigned char *sig, size_t *siglen)

{

    EVP_SIGNATURE *signature;

    const char *desc;

    int ret;

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);