/*

 * Copyright 2020-2023 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 <openssl/core_names.h>

#include <openssl/core_object.h>

#include <openssl/provider.h>

#include <openssl/evp.h>

#include <openssl/ui.h>

#include <openssl/decoder.h>

#include <openssl/safestack.h>

#include <openssl/trace.h>

#include "crypto/evp.h"

#include "crypto/decoder.h"

#include "encoder_local.h"

int OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX *ctx,

    const unsigned char *kstr,

    size_t klen)

{

    return ossl_pw_set_passphrase(&ctx->pwdata, kstr, klen);

}

int OSSL_DECODER_CTX_set_passphrase_ui(OSSL_DECODER_CTX *ctx,

    const UI_METHOD *ui_method,

    void *ui_data)

{

    return ossl_pw_set_ui_method(&ctx->pwdata, ui_method, ui_data);

}

int OSSL_DECODER_CTX_set_pem_password_cb(OSSL_DECODER_CTX *ctx,

    pem_password_cb *cb, void *cbarg)

{

    return ossl_pw_set_pem_password_cb(&ctx->pwdata, cb, cbarg);

}

int OSSL_DECODER_CTX_set_passphrase_cb(OSSL_DECODER_CTX *ctx,

    OSSL_PASSPHRASE_CALLBACK *cb,

    void *cbarg)

{

    return ossl_pw_set_ossl_passphrase_cb(&ctx->pwdata, cb, cbarg);

}

/*

 * Support for OSSL_DECODER_CTX_new_for_pkey:

 * The construct data, and collecting keymgmt information for it

 */

DEFINE_STACK_OF(EVP_KEYMGMT)

struct decoder_pkey_data_st {

    OSSL_LIB_CTX *libctx;

    char *propq;

    int selection;

    STACK_OF(EVP_KEYMGMT) *keymgmts;

    char *object_type; /* recorded object data type, may be NULL */

    void **object; /* Where the result should end up */

};

static int decoder_construct_pkey(OSSL_DECODER_INSTANCE *decoder_inst,

    const OSSL_PARAM *params,

    void *construct_data)

{

    struct decoder_pkey_data_st *data = construct_data;

    OSSL_DECODER *decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);

    void *decoderctx = OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);

    const OSSL_PROVIDER *decoder_prov = OSSL_DECODER_get0_provider(decoder);

    EVP_KEYMGMT *keymgmt = NULL;

    const OSSL_PROVIDER *keymgmt_prov = NULL;

    int i, end;

    /*

     * |object_ref| points to a provider reference to an object, its exact

     * contents entirely opaque to us, but may be passed to any provider

     * function that expects this (such as OSSL_FUNC_keymgmt_load().

     *

     * This pointer is considered volatile, i.e. whatever it points at

     * is assumed to be freed as soon as this function returns.

     */

    void *object_ref = NULL;

    size_t object_ref_sz = 0;

    const OSSL_PARAM *p;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);

    if (p != NULL) {

        char *object_type = NULL;

        if (!OSSL_PARAM_get_utf8_string(p, &object_type, 0))

            return 0;

        OPENSSL_free(data->object_type);

        data->object_type = object_type;

    }

    /*

     * For stuff that should end up in an EVP_PKEY, we only accept an object

     * reference for the moment.  This enforces that the key data itself

     * remains with the provider.

     */

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_REFERENCE);

    if (p == NULL || p->data_type != OSSL_PARAM_OCTET_STRING)

        return 0;

    object_ref = p->data;

    object_ref_sz = p->data_size;

    /*

     * First, we try to find a keymgmt that comes from the same provider as

     * the decoder that passed the params.

     */

    end = sk_EVP_KEYMGMT_num(data->keymgmts);

    for (i = 0; i < end; i++) {

        keymgmt = sk_EVP_KEYMGMT_value(data->keymgmts, i);

        keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);

        if (keymgmt_prov == decoder_prov

            && evp_keymgmt_has_load(keymgmt)

            && EVP_KEYMGMT_is_a(keymgmt, data->object_type))

            break;

    }

    if (i < end) {

        /* To allow it to be freed further down */

        if (!EVP_KEYMGMT_up_ref(keymgmt))

            return 0;

    } else if ((keymgmt = EVP_KEYMGMT_fetch(data->libctx,

                    data->object_type,

                    data->propq))

        != NULL) {

        keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);

    }

    if (keymgmt != NULL) {

        EVP_PKEY *pkey = NULL;

        void *keydata = NULL;

        /*

         * If the EVP_KEYMGMT and the OSSL_DECODER are from the

         * same provider, we assume that the KEYMGMT has a key loading

         * function that can handle the provider reference we hold.

         *

         * Otherwise, we export from the decoder and import the

         * result in the keymgmt.

         */

        if (keymgmt_prov == decoder_prov) {

            keydata = evp_keymgmt_load(keymgmt, object_ref, object_ref_sz);

        } else {

            struct evp_keymgmt_util_try_import_data_st import_data;

            import_data.keymgmt = keymgmt;

            import_data.keydata = NULL;

            if (data->selection == 0)

                /* import/export functions do not tolerate 0 selection */

                import_data.selection = OSSL_KEYMGMT_SELECT_ALL;

            else

                import_data.selection = data->selection;

            /*

             * No need to check for errors here, the value of

             * |import_data.keydata| is as much an indicator.

             */

            (void)decoder->export_object(decoderctx,

                object_ref, object_ref_sz,

                &evp_keymgmt_util_try_import,

                &import_data);

            keydata = import_data.keydata;

            import_data.keydata = NULL;

        }

        if (keydata != NULL

            && (pkey = evp_keymgmt_util_make_pkey(keymgmt, keydata)) == NULL)

            evp_keymgmt_freedata(keymgmt, keydata);

        *data->object = pkey;

        /*

         * evp_keymgmt_util_make_pkey() increments the reference count when

         * assigning the EVP_PKEY, so we can free the keymgmt here.

         */

        EVP_KEYMGMT_free(keymgmt);

    }

    /*

     * We successfully looked through, |*ctx->object| determines if we

     * actually found something.

     */

    return (*data->object != NULL);

}

static void decoder_clean_pkey_construct_arg(void *construct_data)

{

    struct decoder_pkey_data_st *data = construct_data;

    if (data != NULL) {

        sk_EVP_KEYMGMT_pop_free(data->keymgmts, EVP_KEYMGMT_free);

        OPENSSL_free(data->propq);

        OPENSSL_free(data->object_type);

        OPENSSL_free(data);

    }

}

static void collect_name(const char *name, void *arg)

{

    STACK_OF(OPENSSL_CSTRING) *names = arg;

    sk_OPENSSL_CSTRING_push(names, name);

}

static void collect_keymgmt(EVP_KEYMGMT *keymgmt, void *arg)

{

    STACK_OF(EVP_KEYMGMT) *keymgmts = arg;

    if (!EVP_KEYMGMT_up_ref(keymgmt) /* ref++ */)

        return;

    if (sk_EVP_KEYMGMT_push(keymgmts, keymgmt) <= 0) {

        EVP_KEYMGMT_free(keymgmt); /* ref-- */

        return;

    }

}

struct collect_decoder_data_st {

    STACK_OF(OPENSSL_CSTRING) *names;

    OSSL_DECODER_CTX *ctx;

    int total;

    unsigned int error_occurred : 1;

};

static void collect_decoder(OSSL_DECODER *decoder, void *arg)

{

    struct collect_decoder_data_st *data = arg;

    size_t i, end_i;

    const OSSL_PROVIDER *prov = OSSL_DECODER_get0_provider(decoder);

    void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);

    if (data->error_occurred)

        return;

    if (data->names == NULL) {

        data->error_occurred = 1;

        return;

    }

    /*

     * Either the caller didn't give a selection, or if they did,

     * the decoder must tell us if it supports that selection to

     * be accepted.  If the decoder doesn't have |does_selection|,

     * it's seen as taking anything.

     */

    if (decoder->does_selection != NULL

        && !decoder->does_selection(provctx, data->ctx->selection))

        return;

    OSSL_TRACE_BEGIN(DECODER)

    {

        BIO_printf(trc_out,

            "(ctx %p) Checking out decoder %p:\n"

            "    %s with %s\n",

            (void *)data->ctx, (void *)decoder,

            OSSL_DECODER_get0_name(decoder),

            OSSL_DECODER_get0_properties(decoder));

    }

    OSSL_TRACE_END(DECODER);

    end_i = sk_OPENSSL_CSTRING_num(data->names);

    for (i = 0; i < end_i; i++) {

        const char *name = sk_OPENSSL_CSTRING_value(data->names, i);

        if (OSSL_DECODER_is_a(decoder, name)) {

            void *decoderctx = NULL;

            OSSL_DECODER_INSTANCE *di = NULL;

            if ((decoderctx = decoder->newctx(provctx)) == NULL) {

                data->error_occurred = 1;

                return;

            }

            if ((di = ossl_decoder_instance_new(decoder, decoderctx)) == NULL) {

                decoder->freectx(decoderctx);

                data->error_occurred = 1;

                return;

            }

            OSSL_TRACE_BEGIN(DECODER)

            {

                BIO_printf(trc_out,

                    "(ctx %p) Checking out decoder %p:\n"

                    "    %s with %s\n",

                    (void *)data->ctx, (void *)decoder,

                    OSSL_DECODER_get0_name(decoder),

                    OSSL_DECODER_get0_properties(decoder));

            }

            OSSL_TRACE_END(DECODER);

            if (!ossl_decoder_ctx_add_decoder_inst(data->ctx, di)) {

                ossl_decoder_instance_free(di);

                data->error_occurred = 1;

                return;

            }

            data->total++;

            /* Success */

            return;

        }

    }

    /* Decoder not suitable - but not a fatal error */

    data->error_occurred = 0;

}

int ossl_decoder_ctx_setup_for_pkey(OSSL_DECODER_CTX *ctx,

    EVP_PKEY **pkey, const char *keytype,

    OSSL_LIB_CTX *libctx,

    const char *propquery)

{

    struct decoder_pkey_data_st *process_data = NULL;

    STACK_OF(OPENSSL_CSTRING) *names = NULL;

    const char *input_type = ctx->start_input_type;

    const char *input_structure = ctx->input_structure;

    int ok = 0;

    int isecoid = 0;

    int i, end;

    if (keytype != NULL

        && (strcmp(keytype, "id-ecPublicKey") == 0

            || strcmp(keytype, "1.2.840.10045.2.1") == 0))

        isecoid = 1;

    OSSL_TRACE_BEGIN(DECODER)

    {

        BIO_printf(trc_out,

            "(ctx %p) Looking for decoders producing %s%s%s%s%s%s\n",

            (void *)ctx,

            keytype != NULL ? keytype : "",

            keytype != NULL ? " keys" : "keys of any type",

            input_type != NULL ? " from " : "",

            input_type != NULL ? input_type : "",

            input_structure != NULL ? " with " : "",

            input_structure != NULL ? input_structure : "");

    }

    OSSL_TRACE_END(DECODER);

    if ((process_data = OPENSSL_zalloc(sizeof(*process_data))) == NULL

        || (propquery != NULL

            && (process_data->propq = OPENSSL_strdup(propquery)) == NULL)

        || (process_data->keymgmts = sk_EVP_KEYMGMT_new_null()) == NULL

        || (names = sk_OPENSSL_CSTRING_new_null()) == NULL) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    process_data->object = (void **)pkey;

    process_data->libctx = libctx;

    process_data->selection = ctx->selection;

    /* First, find all keymgmts to form goals */

    EVP_KEYMGMT_do_all_provided(libctx, collect_keymgmt,

        process_data->keymgmts);

    /* Then, we collect all the keymgmt names */

    end = sk_EVP_KEYMGMT_num(process_data->keymgmts);

    for (i = 0; i < end; i++) {

        EVP_KEYMGMT *keymgmt = sk_EVP_KEYMGMT_value(process_data->keymgmts, i);

        /*

         * If the key type is given by the caller, we only use the matching

         * KEYMGMTs, otherwise we use them all.

         * We have to special case SM2 here because of its abuse of the EC OID.

         * The EC OID can be used to identify an EC key or an SM2 key - so if

         * we have seen that OID we try both key types

         */

        if (keytype == NULL

            || EVP_KEYMGMT_is_a(keymgmt, keytype)

            || (isecoid && EVP_KEYMGMT_is_a(keymgmt, "SM2"))) {

            if (!EVP_KEYMGMT_names_do_all(keymgmt, collect_name, names)) {

                ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);

                goto err;

            }

        }

    }

    OSSL_TRACE_BEGIN(DECODER)

    {

        end = sk_OPENSSL_CSTRING_num(names);

        BIO_printf(trc_out,

            "    Found %d keytypes (possibly with duplicates)",

            end);

        for (i = 0; i < end; i++)

            BIO_printf(trc_out, "%s%s",

                i == 0 ? ": " : ", ",

                sk_OPENSSL_CSTRING_value(names, i));

        BIO_printf(trc_out, "\n");

    }

    OSSL_TRACE_END(DECODER);

    /*

     * Finally, find all decoders that have any keymgmt of the collected

     * keymgmt names

     */

    {

        struct collect_decoder_data_st collect_decoder_data = {

            NULL,

        };

        collect_decoder_data.names = names;

        collect_decoder_data.ctx = ctx;

        OSSL_DECODER_do_all_provided(libctx,

            collect_decoder, &collect_decoder_data);

        sk_OPENSSL_CSTRING_free(names);

        names = NULL;

        if (collect_decoder_data.error_occurred)

            goto err;

        OSSL_TRACE_BEGIN(DECODER)

        {

            BIO_printf(trc_out,

                "(ctx %p) Got %d decoders producing keys\n",

                (void *)ctx, collect_decoder_data.total);

        }

        OSSL_TRACE_END(DECODER);

    }

    if (OSSL_DECODER_CTX_get_num_decoders(ctx) != 0) {

        if (!OSSL_DECODER_CTX_set_construct(ctx, decoder_construct_pkey)

            || !OSSL_DECODER_CTX_set_construct_data(ctx, process_data)

            || !OSSL_DECODER_CTX_set_cleanup(ctx,

                decoder_clean_pkey_construct_arg))

            goto err;

        process_data = NULL; /* Avoid it being freed */

    }

    ok = 1;

err:

    decoder_clean_pkey_construct_arg(process_data);

    sk_OPENSSL_CSTRING_free(names);

    return ok;

}

OSSL_DECODER_CTX *

OSSL_DECODER_CTX_new_for_pkey(EVP_PKEY **pkey,

    const char *input_type,

    const char *input_structure,

    const char *keytype, int selection,

    OSSL_LIB_CTX *libctx, const char *propquery)

{

    OSSL_DECODER_CTX *ctx = NULL;

    if ((ctx = OSSL_DECODER_CTX_new()) == NULL) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    OSSL_TRACE_BEGIN(DECODER)

    {

        BIO_printf(trc_out,

            "(ctx %p) Looking for %s decoders with selection %d\n",

            (void *)ctx, keytype, selection);

        BIO_printf(trc_out, "    input type: %s, input structure: %s\n",

            input_type, input_structure);

    }

    OSSL_TRACE_END(DECODER);

    if (OSSL_DECODER_CTX_set_input_type(ctx, input_type)

        && OSSL_DECODER_CTX_set_input_structure(ctx, input_structure)

        && OSSL_DECODER_CTX_set_selection(ctx, selection)

        && ossl_decoder_ctx_setup_for_pkey(ctx, pkey, keytype,

            libctx, propquery)

        && OSSL_DECODER_CTX_add_extra(ctx, libctx, propquery)) {

        OSSL_TRACE_BEGIN(DECODER)

        {

            BIO_printf(trc_out, "(ctx %p) Got %d decoders\n",

                (void *)ctx, OSSL_DECODER_CTX_get_num_decoders(ctx));

        }

        OSSL_TRACE_END(DECODER);

        return ctx;

    }

    OSSL_DECODER_CTX_free(ctx);

    return NULL;

}