/*

 * Copyright 2020-2022 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.h>

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/core_object.h>

#include <openssl/asn1.h>

#include <openssl/err.h>

#include <openssl/objects.h>

#include <openssl/pkcs12.h>

#include <openssl/x509.h>

#include <openssl/proverr.h>

#include "internal/asn1.h"

#include "internal/sizes.h"

#include "prov/bio.h"

#include "prov/implementations.h"

#include "endecoder_local.h"

static OSSL_FUNC_decoder_newctx_fn epki2pki_newctx;

static OSSL_FUNC_decoder_freectx_fn epki2pki_freectx;

static OSSL_FUNC_decoder_decode_fn epki2pki_decode;

/*

 * Context used for EncryptedPrivateKeyInfo to PrivateKeyInfo decoding.

 */

struct epki2pki_ctx_st {

    PROV_CTX *provctx;

};

static void *epki2pki_newctx(void *provctx)

{

    struct epki2pki_ctx_st *ctx = OPENSSL_zalloc(sizeof(*ctx));

    if (ctx != NULL)

        ctx->provctx = provctx;

    return ctx;

}

static void epki2pki_freectx(void *vctx)

{

    struct epki2pki_ctx_st *ctx = vctx;

    OPENSSL_free(ctx);

}

/*

 * The selection parameter in epki2pki_decode() is not used by this function

 * because it's not relevant just to decode EncryptedPrivateKeyInfo to

 * PrivateKeyInfo.

 */

static int epki2pki_decode(void *vctx, OSSL_CORE_BIO *cin, int selection,

                           OSSL_CALLBACK *data_cb, void *data_cbarg,

                           OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)

{

    struct epki2pki_ctx_st *ctx = vctx;

    BUF_MEM *mem = NULL;

    unsigned char *der = NULL;

    const unsigned char *pder = NULL;

    long der_len = 0;

    X509_SIG *p8 = NULL;

    PKCS8_PRIV_KEY_INFO *p8inf = NULL;

    const X509_ALGOR *alg = NULL;

    BIO *in = ossl_bio_new_from_core_bio(ctx->provctx, cin);

    int ok = 0;

    if (in == NULL)

        return 0;

    ok = (asn1_d2i_read_bio(in, &mem) >= 0);

    BIO_free(in);

    /* We return "empty handed".  This is not an error. */

    if (!ok)

        return 1;

    pder = der = (unsigned char *)mem->data;

    der_len = (long)mem->length;

    OPENSSL_free(mem);

    ok = 1;                      /* Assume good */

    ERR_set_mark();

    if ((p8 = d2i_X509_SIG(NULL, &pder, der_len)) != NULL) {

        char pbuf[1024];

        size_t plen = 0;

        ERR_clear_last_mark();

        if (!pw_cb(pbuf, sizeof(pbuf), &plen, NULL, pw_cbarg)) {

            ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_GET_PASSPHRASE);

            ok = 0;

        } else {

            const ASN1_OCTET_STRING *oct;

            unsigned char *new_der = NULL;

            int new_der_len = 0;

            X509_SIG_get0(p8, &alg, &oct);

            if (!PKCS12_pbe_crypt_ex(alg, pbuf, plen,

                                     oct->data, oct->length,

                                     &new_der, &new_der_len, 0,

                                     PROV_LIBCTX_OF(ctx->provctx), NULL)) {

                ok = 0;

            } else {

                OPENSSL_free(der);

                der = new_der;

                der_len = new_der_len;

            }

            alg = NULL;

        }

        X509_SIG_free(p8);

    } else {

        ERR_pop_to_mark();

    }

    ERR_set_mark();

    pder = der;

    p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &pder, der_len);

    ERR_pop_to_mark();

    if (p8inf != NULL && PKCS8_pkey_get0(NULL, NULL, NULL, &alg, p8inf)) {

        /*

         * We have something and recognised it as PrivateKeyInfo, so let's

         * pass all the applicable data to the callback.

         */

        char keytype[OSSL_MAX_NAME_SIZE];

        OSSL_PARAM params[5], *p = params;

        int objtype = OSSL_OBJECT_PKEY;

        OBJ_obj2txt(keytype, sizeof(keytype), alg->algorithm, 0);

        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,

                                                keytype, 0);

        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,

                                                "PrivateKeyInfo", 0);

        *p++ = OSSL_PARAM_construct_octet_string(OSSL_OBJECT_PARAM_DATA,

                                                 der, der_len);

        *p++ = OSSL_PARAM_construct_int(OSSL_OBJECT_PARAM_TYPE, &objtype);

        *p = OSSL_PARAM_construct_end();

        ok = data_cb(params, data_cbarg);

    }

    PKCS8_PRIV_KEY_INFO_free(p8inf);

    OPENSSL_free(der);

    return ok;

}

const OSSL_DISPATCH ossl_EncryptedPrivateKeyInfo_der_to_der_decoder_functions[] = {

    { OSSL_FUNC_DECODER_NEWCTX, (void (*)(void))epki2pki_newctx },

    { OSSL_FUNC_DECODER_FREECTX, (void (*)(void))epki2pki_freectx },

    { OSSL_FUNC_DECODER_DECODE, (void (*)(void))epki2pki_decode },

    { 0, NULL }

};