/*

 * 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 "e_os.h"

#include <string.h>

#include <openssl/core.h>

#include <openssl/core_names.h>

#include <openssl/core_object.h>

#include <openssl/err.h>

#include <openssl/pkcs12.h>

#include <openssl/provider.h>

#include <openssl/decoder.h>

#include <openssl/store.h>

#include "internal/provider.h"

#include "internal/passphrase.h"

#include "crypto/evp.h"

#include "crypto/x509.h"

#include "store_local.h"

#ifndef OSSL_OBJECT_PKCS12

/*

 * The object abstraction doesn't know PKCS#12, but we want to indicate

 * it anyway, so we create our own.  Since the public macros use positive

 * numbers, negative ones should be fine.  They must never slip out from

 * this translation unit anyway.

 */

# define OSSL_OBJECT_PKCS12 -1

#endif

/*

 * ossl_store_handle_load_result() is initially written to be a companion

 * to our 'file:' scheme provider implementation, but has been made generic

 * to serve others as well.

 *

 * This result handler takes any object abstraction (see provider-object(7))

 * and does the best it can with it.  If the object is passed by value (not

 * by reference), the contents are currently expected to be DER encoded.

 * If an object type is specified, that will be respected; otherwise, this

 * handler will guess the contents, by trying the following in order:

 *

 * 1.  Decode it into an EVP_PKEY, using OSSL_DECODER.

 * 2.  Decode it into an X.509 certificate, using d2i_X509 / d2i_X509_AUX.

 * 3.  Decode it into an X.509 CRL, using d2i_X509_CRL.

 * 4.  Decode it into a PKCS#12 structure, using d2i_PKCS12 (*).

 *

 * For the 'file:' scheme implementation, this is division of labor.  Since

 * the libcrypto <-> provider interface currently doesn't support certain

 * structures as first class objects, they must be unpacked from DER here

 * rather than in the provider.  The current exception is asymmetric keys,

 * which can reside within the provider boundary, most of all thanks to

 * OSSL_FUNC_keymgmt_load(), which allows loading the key material by

 * reference.

 */

struct extracted_param_data_st {

    int object_type;

    const char *data_type;

    const char *data_structure;

    const char *utf8_data;

    const void *octet_data;

    size_t octet_data_size;

    const void *ref;

    size_t ref_size;

    const char *desc;

};

static int try_name(struct extracted_param_data_st *, OSSL_STORE_INFO **);

static int try_key(struct extracted_param_data_st *, OSSL_STORE_INFO **,

                   OSSL_STORE_CTX *, const OSSL_PROVIDER *,

                   OSSL_LIB_CTX *, const char *);

static int try_cert(struct extracted_param_data_st *, OSSL_STORE_INFO **,

                    OSSL_LIB_CTX *, const char *);

static int try_crl(struct extracted_param_data_st *, OSSL_STORE_INFO **,

                   OSSL_LIB_CTX *, const char *);

static int try_pkcs12(struct extracted_param_data_st *, OSSL_STORE_INFO **,

                      OSSL_STORE_CTX *, OSSL_LIB_CTX *, const char *);

int ossl_store_handle_load_result(const OSSL_PARAM params[], void *arg)

{

    struct ossl_load_result_data_st *cbdata = arg;

    OSSL_STORE_INFO **v = &cbdata->v;

    OSSL_STORE_CTX *ctx = cbdata->ctx;

    const OSSL_PROVIDER *provider =

        OSSL_STORE_LOADER_get0_provider(ctx->fetched_loader);

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(provider);

    const char *propq = ctx->properties;

    const OSSL_PARAM *p;

    struct extracted_param_data_st helper_data;

    memset(&helper_data, 0, sizeof(helper_data));

    helper_data.object_type = OSSL_OBJECT_UNKNOWN;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_TYPE)) != NULL

        && !OSSL_PARAM_get_int(p, &helper_data.object_type))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);

    if (p != NULL

        && !OSSL_PARAM_get_utf8_string_ptr(p, &helper_data.data_type))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA);

    if (p != NULL

        && !OSSL_PARAM_get_octet_string_ptr(p, &helper_data.octet_data,

                                            &helper_data.octet_data_size)

        && !OSSL_PARAM_get_utf8_string_ptr(p, &helper_data.utf8_data))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_STRUCTURE);

    if (p != NULL

        && !OSSL_PARAM_get_utf8_string_ptr(p, &helper_data.data_structure))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_REFERENCE);

    if (p != NULL && !OSSL_PARAM_get_octet_string_ptr(p, &helper_data.ref,

                                                      &helper_data.ref_size))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DESC);

    if (p != NULL && !OSSL_PARAM_get_utf8_string_ptr(p, &helper_data.desc))

        return 0;

    /*

     * The helper functions return 0 on actual errors, otherwise 1, even if

     * they didn't fill out |*v|.

     */

    ERR_set_mark();

    if (*v == NULL && !try_name(&helper_data, v))

        goto err;

    ERR_pop_to_mark();

    ERR_set_mark();

    if (*v == NULL && !try_key(&helper_data, v, ctx, provider, libctx, propq))

        goto err;

    ERR_pop_to_mark();

    ERR_set_mark();

    if (*v == NULL && !try_cert(&helper_data, v, libctx, propq))

        goto err;

    ERR_pop_to_mark();

    ERR_set_mark();

    if (*v == NULL && !try_crl(&helper_data, v, libctx, propq))

        goto err;

    ERR_pop_to_mark();

    ERR_set_mark();

    if (*v == NULL && !try_pkcs12(&helper_data, v, ctx, libctx, propq))

        goto err;

    ERR_pop_to_mark();

    if (*v == NULL)

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_UNSUPPORTED);

    return (*v != NULL);

 err:

    ERR_clear_last_mark();

    return 0;

}

static int try_name(struct extracted_param_data_st *data, OSSL_STORE_INFO **v)

{

    if (data->object_type == OSSL_OBJECT_NAME) {

        char *newname = NULL, *newdesc = NULL;

        if (data->utf8_data == NULL)

            return 0;

        if ((newname = OPENSSL_strdup(data->utf8_data)) == NULL

            || (data->desc != NULL

                && (newdesc = OPENSSL_strdup(data->desc)) == NULL)

            || (*v = OSSL_STORE_INFO_new_NAME(newname)) == NULL) {

            OPENSSL_free(newname);

            OPENSSL_free(newdesc);

            return 0;

        }

        OSSL_STORE_INFO_set0_NAME_description(*v, newdesc);

    }

    return 1;

}

/*

 * For the rest of the object types, the provider code may not know what

 * type of data it gave us, so we may need to figure that out on our own.

 * Therefore, we do check for OSSL_OBJECT_UNKNOWN everywhere below, and

 * only return 0 on error if the object type is known.

 */

static EVP_PKEY *try_key_ref(struct extracted_param_data_st *data,

                             OSSL_STORE_CTX *ctx,

                             const OSSL_PROVIDER *provider,

                             OSSL_LIB_CTX *libctx, const char *propq)

{

    EVP_PKEY *pk = NULL;

    EVP_KEYMGMT *keymgmt = NULL;

    void *keydata = NULL;

    int try_fallback = 2;

    /* If we have an object reference, we must have a data type */

    if (data->data_type == NULL)

        return 0;

    keymgmt = EVP_KEYMGMT_fetch(libctx, data->data_type, propq);

    ERR_set_mark();

    while (keymgmt != NULL && keydata == NULL && try_fallback-- > 0) {

        /*

         * There are two possible cases

         *

         * 1.  The keymgmt is from the same provider as the loader,

         *     so we can use evp_keymgmt_load()

         * 2.  The keymgmt is from another provider, then we must

         *     do the export/import dance.

         */

        if (EVP_KEYMGMT_get0_provider(keymgmt) == provider) {

            /* no point trying fallback here */

            try_fallback = 0;

            keydata = evp_keymgmt_load(keymgmt, data->ref, data->ref_size);

        } else {

            struct evp_keymgmt_util_try_import_data_st import_data;

            OSSL_FUNC_store_export_object_fn *export_object =

                ctx->fetched_loader->p_export_object;

            import_data.keymgmt = keymgmt;

            import_data.keydata = NULL;

            import_data.selection = OSSL_KEYMGMT_SELECT_ALL;

            if (export_object != NULL) {

                /*

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

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

                 */

                (void)export_object(ctx->loader_ctx,

                                    data->ref, data->ref_size,

                                    &evp_keymgmt_util_try_import,

                                    &import_data);

            }

            keydata = import_data.keydata;

        }

        if (keydata == NULL && try_fallback > 0) {

            EVP_KEYMGMT_free(keymgmt);

            keymgmt = evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)provider,

                                                  data->data_type, propq);

            if (keymgmt != NULL) {

                ERR_pop_to_mark();

                ERR_set_mark();

            }

        }

    }

    if (keydata != NULL) {

        ERR_pop_to_mark();

        pk = evp_keymgmt_util_make_pkey(keymgmt, keydata);

    } else {

        ERR_clear_last_mark();

    }

    EVP_KEYMGMT_free(keymgmt);

    return pk;

}

static EVP_PKEY *try_key_value(struct extracted_param_data_st *data,

                               OSSL_STORE_CTX *ctx,

                               OSSL_PASSPHRASE_CALLBACK *cb, void *cbarg,

                               OSSL_LIB_CTX *libctx, const char *propq)

{

    EVP_PKEY *pk = NULL;

    OSSL_DECODER_CTX *decoderctx = NULL;

    const unsigned char *pdata = data->octet_data;

    size_t pdatalen = data->octet_data_size;

    int selection = 0;

    switch (ctx->expected_type) {

    case 0:

        break;

    case OSSL_STORE_INFO_PARAMS:

        selection = OSSL_KEYMGMT_SELECT_ALL_PARAMETERS;

        break;

    case OSSL_STORE_INFO_PUBKEY:

        selection =

            OSSL_KEYMGMT_SELECT_PUBLIC_KEY

            | OSSL_KEYMGMT_SELECT_ALL_PARAMETERS;

        break;

    case OSSL_STORE_INFO_PKEY:

        selection = OSSL_KEYMGMT_SELECT_ALL;

        break;

    default:

        return NULL;

    }

    decoderctx =

        OSSL_DECODER_CTX_new_for_pkey(&pk, NULL, data->data_structure,

                                      data->data_type, selection, libctx,

                                      propq);

    (void)OSSL_DECODER_CTX_set_passphrase_cb(decoderctx, cb, cbarg);

    /* No error if this couldn't be decoded */

    (void)OSSL_DECODER_from_data(decoderctx, &pdata, &pdatalen);

    OSSL_DECODER_CTX_free(decoderctx);

    return pk;

}

typedef OSSL_STORE_INFO *store_info_new_fn(EVP_PKEY *);

static EVP_PKEY *try_key_value_legacy(struct extracted_param_data_st *data,

                                      store_info_new_fn **store_info_new,

                                      OSSL_STORE_CTX *ctx,

                                      OSSL_PASSPHRASE_CALLBACK *cb, void *cbarg,

                                      OSSL_LIB_CTX *libctx, const char *propq)

{

    EVP_PKEY *pk = NULL;

    const unsigned char *der = data->octet_data, *derp;

    long der_len = (long)data->octet_data_size;

    /* Try PUBKEY first, that's a real easy target */

    if (ctx->expected_type == 0

        || ctx->expected_type == OSSL_STORE_INFO_PUBKEY) {

        derp = der;

        pk = d2i_PUBKEY_ex(NULL, &derp, der_len, libctx, propq);

        if (pk != NULL)

            *store_info_new = OSSL_STORE_INFO_new_PUBKEY;

    }

    /* Try private keys next */

    if (pk == NULL

        && (ctx->expected_type == 0

            || ctx->expected_type == OSSL_STORE_INFO_PKEY)) {

        unsigned char *new_der = NULL;

        X509_SIG *p8 = NULL;

        PKCS8_PRIV_KEY_INFO *p8info = NULL;

        /* See if it's an encrypted PKCS#8 and decrypt it. */

        derp = der;

        p8 = d2i_X509_SIG(NULL, &derp, der_len);

        if (p8 != NULL) {

            char pbuf[PEM_BUFSIZE];

            size_t plen = 0;

            if (!cb(pbuf, sizeof(pbuf), &plen, NULL, cbarg)) {

                ERR_raise(ERR_LIB_OSSL_STORE, OSSL_STORE_R_BAD_PASSWORD_READ);

            } else {

                const X509_ALGOR *alg = NULL;

                const ASN1_OCTET_STRING *oct = NULL;

                int len = 0;

                X509_SIG_get0(p8, &alg, &oct);

                /*

                 * No need to check the returned value, |new_der|

                 * will be NULL on error anyway.

                 */

                PKCS12_pbe_crypt(alg, pbuf, plen,

                                 oct->data, oct->length,

                                 &new_der, &len, 0);

                der_len = len;

                der = new_der;

            }

            X509_SIG_free(p8);

        }

        /*

         * If the encrypted PKCS#8 couldn't be decrypted,

         * |der| is NULL

         */

        if (der != NULL) {

            /* Try to unpack an unencrypted PKCS#8, that's easy */

            derp = der;

            p8info = d2i_PKCS8_PRIV_KEY_INFO(NULL, &derp, der_len);

            if (p8info != NULL) {

                pk = EVP_PKCS82PKEY_ex(p8info, libctx, propq);

                PKCS8_PRIV_KEY_INFO_free(p8info);

            }

        }

        if (pk != NULL)

            *store_info_new = OSSL_STORE_INFO_new_PKEY;

        OPENSSL_free(new_der);

    }

    return pk;

}

static int try_key(struct extracted_param_data_st *data, OSSL_STORE_INFO **v,

                   OSSL_STORE_CTX *ctx, const OSSL_PROVIDER *provider,

                   OSSL_LIB_CTX *libctx, const char *propq)

{

    store_info_new_fn *store_info_new = NULL;

    if (data->object_type == OSSL_OBJECT_UNKNOWN

        || data->object_type == OSSL_OBJECT_PKEY) {

        EVP_PKEY *pk = NULL;

        /* Prefer key by reference than key by value */

        if (data->object_type == OSSL_OBJECT_PKEY && data->ref != NULL) {

            pk = try_key_ref(data, ctx, provider, libctx, propq);

            /*

             * If for some reason we couldn't get a key, it's an error.

             * It indicates that while decoders could make a key reference,

             * the keymgmt somehow couldn't handle it, or doesn't have a

             * OSSL_FUNC_keymgmt_load function.

             */

            if (pk == NULL)

                return 0;

        } else if (data->octet_data != NULL) {

            OSSL_PASSPHRASE_CALLBACK *cb = ossl_pw_passphrase_callback_dec;

            void *cbarg = &ctx->pwdata;

            pk = try_key_value(data, ctx, cb, cbarg, libctx, propq);

            /*

             * Desperate last maneuver, in case the decoders don't support

             * the data we have, then we try on our own to at least get an

             * engine provided legacy key.

             * This is the same as der2key_decode() does, but in a limited

             * way and within the walls of libcrypto.

             */

            if (pk == NULL)

                pk = try_key_value_legacy(data, &store_info_new, ctx,

                                          cb, cbarg, libctx, propq);

        }

        if (pk != NULL) {

            data->object_type = OSSL_OBJECT_PKEY;

            if (store_info_new == NULL) {

                /*

                 * We determined the object type for OSSL_STORE_INFO, which

                 * makes an explicit difference between an EVP_PKEY with just

                 * (domain) parameters and an EVP_PKEY with actual key

                 * material.

                 * The logic is that an EVP_PKEY with actual key material

                 * always has the public half.

                 */

                if (evp_keymgmt_util_has(pk, OSSL_KEYMGMT_SELECT_PRIVATE_KEY))

                    store_info_new = OSSL_STORE_INFO_new_PKEY;

                else if (evp_keymgmt_util_has(pk,

                                              OSSL_KEYMGMT_SELECT_PUBLIC_KEY))

                    store_info_new = OSSL_STORE_INFO_new_PUBKEY;

                else

                    store_info_new = OSSL_STORE_INFO_new_PARAMS;

            }

            *v = store_info_new(pk);

        }

        if (*v == NULL)

            EVP_PKEY_free(pk);

    }

    return 1;

}

static int try_cert(struct extracted_param_data_st *data, OSSL_STORE_INFO **v,

                    OSSL_LIB_CTX *libctx, const char *propq)

{

    if (data->object_type == OSSL_OBJECT_UNKNOWN

        || data->object_type == OSSL_OBJECT_CERT) {

        /*

         * In most cases, we can try to interpret the serialized

         * data as a trusted cert (X509 + X509_AUX) and fall back

         * to reading it as a normal cert (just X509), but if

         * |data_type| (the PEM name) specifically declares it as a

         * trusted cert, then no fallback should be engaged.

         * |ignore_trusted| tells if the fallback can be used (1)

         * or not (0).

         */

        int ignore_trusted = 1;

        X509 *cert = X509_new_ex(libctx, propq);

        if (cert == NULL)

            return 0;

        /* If we have a data type, it should be a PEM name */

        if (data->data_type != NULL

            && (OPENSSL_strcasecmp(data->data_type, PEM_STRING_X509_TRUSTED) == 0))

            ignore_trusted = 0;

        if (d2i_X509_AUX(&cert, (const unsigned char **)&data->octet_data,

                         data->octet_data_size) == NULL

            && (!ignore_trusted

                || d2i_X509(&cert, (const unsigned char **)&data->octet_data,

                            data->octet_data_size) == NULL)) {

            X509_free(cert);

            cert = NULL;

        }

        if (cert != NULL) {

            /* We determined the object type */

            data->object_type = OSSL_OBJECT_CERT;

            *v = OSSL_STORE_INFO_new_CERT(cert);

            if (*v == NULL)

                X509_free(cert);

        }

    }

    return 1;

}

static int try_crl(struct extracted_param_data_st *data, OSSL_STORE_INFO **v,

                   OSSL_LIB_CTX *libctx, const char *propq)

{

    if (data->object_type == OSSL_OBJECT_UNKNOWN

        || data->object_type == OSSL_OBJECT_CRL) {

        X509_CRL *crl;

        crl = d2i_X509_CRL(NULL, (const unsigned char **)&data->octet_data,

                           data->octet_data_size);

        if (crl != NULL)

            /* We determined the object type */

            data->object_type = OSSL_OBJECT_CRL;

        if (crl != NULL && !ossl_x509_crl_set0_libctx(crl, libctx, propq)) {

            X509_CRL_free(crl);

            crl = NULL;

        }

        if (crl != NULL)

            *v = OSSL_STORE_INFO_new_CRL(crl);

        if (*v == NULL)

            X509_CRL_free(crl);

    }

    return 1;

}

static int try_pkcs12(struct extracted_param_data_st *data, OSSL_STORE_INFO **v,

                      OSSL_STORE_CTX *ctx,

                      OSSL_LIB_CTX *libctx, const char *propq)

{

    int ok = 1;

    /* There is no specific object type for PKCS12 */

    if (data->object_type == OSSL_OBJECT_UNKNOWN) {

        /* Initial parsing */

        PKCS12 *p12;

        p12 = d2i_PKCS12(NULL, (const unsigned char **)&data->octet_data,

                         data->octet_data_size);

        if (p12 != NULL) {

            char *pass = NULL;

            char tpass[PEM_BUFSIZE + 1];

            size_t tpass_len;

            EVP_PKEY *pkey = NULL;

            X509 *cert = NULL;

            STACK_OF(X509) *chain = NULL;

            data->object_type = OSSL_OBJECT_PKCS12;

            ok = 0;              /* Assume decryption or parse error */

            if (!PKCS12_mac_present(p12)

                || PKCS12_verify_mac(p12, NULL, 0)) {

                pass = NULL;

            } else if (PKCS12_verify_mac(p12, "", 0)) {

                pass = "";

            } else {

                static char prompt_info[] = "PKCS12 import pass phrase";

                OSSL_PARAM pw_params[] = {

                    OSSL_PARAM_utf8_string(OSSL_PASSPHRASE_PARAM_INFO,

                                           prompt_info,

                                           sizeof(prompt_info) - 1),

                    OSSL_PARAM_END

                };

                if (!ossl_pw_get_passphrase(tpass, sizeof(tpass) - 1,

                                            &tpass_len,

                                            pw_params, 0, &ctx->pwdata)) {

                    ERR_raise(ERR_LIB_OSSL_STORE,

                              OSSL_STORE_R_PASSPHRASE_CALLBACK_ERROR);

                    goto p12_end;

                }

                pass = tpass;

                /*

                 * ossl_pw_get_passphrase() does not NUL terminate but

                 * we must do it for PKCS12_parse()

                 */

                pass[tpass_len] = '\0';

                if (!PKCS12_verify_mac(p12, pass, tpass_len)) {

                    ERR_raise_data(ERR_LIB_OSSL_STORE,

                                   OSSL_STORE_R_ERROR_VERIFYING_PKCS12_MAC,

                                   tpass_len == 0 ? "empty password" :

                                   "maybe wrong password");

                    goto p12_end;

                }

            }

            if (PKCS12_parse(p12, pass, &pkey, &cert, &chain)) {

                STACK_OF(OSSL_STORE_INFO) *infos = NULL;

                OSSL_STORE_INFO *osi_pkey = NULL;

                OSSL_STORE_INFO *osi_cert = NULL;

                OSSL_STORE_INFO *osi_ca = NULL;

                ok = 1;          /* Parsing went through correctly! */

                if ((infos = sk_OSSL_STORE_INFO_new_null()) != NULL) {

                    if (pkey != NULL) {

                        if ((osi_pkey = OSSL_STORE_INFO_new_PKEY(pkey)) != NULL

                            /* clearing pkey here avoids case distinctions */

                            && (pkey = NULL) == NULL

                            && sk_OSSL_STORE_INFO_push(infos, osi_pkey) != 0)

                            osi_pkey = NULL;

                        else

                            ok = 0;

                    }

                    if (ok && cert != NULL) {

                        if ((osi_cert = OSSL_STORE_INFO_new_CERT(cert)) != NULL

                            /* clearing cert here avoids case distinctions */

                            && (cert = NULL) == NULL

                            && sk_OSSL_STORE_INFO_push(infos, osi_cert) != 0)

                            osi_cert = NULL;

                        else

                            ok = 0;

                    }

                    while (ok && sk_X509_num(chain) > 0) {

                        X509 *ca = sk_X509_value(chain, 0);

                        if ((osi_ca = OSSL_STORE_INFO_new_CERT(ca)) != NULL

                            && sk_X509_shift(chain) != NULL

                            && sk_OSSL_STORE_INFO_push(infos, osi_ca) != 0)

                            osi_ca = NULL;

                        else

                            ok = 0;

                    }

                }

                EVP_PKEY_free(pkey);

                X509_free(cert);

                sk_X509_pop_free(chain, X509_free);

                OSSL_STORE_INFO_free(osi_pkey);

                OSSL_STORE_INFO_free(osi_cert);

                OSSL_STORE_INFO_free(osi_ca);

                if (!ok) {

                    sk_OSSL_STORE_INFO_pop_free(infos, OSSL_STORE_INFO_free);

                    infos = NULL;

                }

                ctx->cached_info = infos;

            }

         p12_end:

            OPENSSL_cleanse(tpass, sizeof(tpass));

            PKCS12_free(p12);

        }

        *v = sk_OSSL_STORE_INFO_shift(ctx->cached_info);

    }

    return ok;

}