/* $OpenBSD: x509_akey.c,v 1.4 2025/05/10 05:54:39 tb Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 1999.
 */
/* ====================================================================
 * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <string.h>

#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>

#include "err_local.h"
#include "x509_local.h"

static STACK_OF(CONF_VALUE) *i2v_AUTHORITY_KEYID(X509V3_EXT_METHOD *method,
    AUTHORITY_KEYID *akeyid, STACK_OF(CONF_VALUE) *extlist);
static AUTHORITY_KEYID *v2i_AUTHORITY_KEYID(X509V3_EXT_METHOD *method,
    X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *values);

static const X509V3_EXT_METHOD x509v3_ext_authority_key_identifier = {
        .ext_nid = NID_authority_key_identifier,
        .ext_flags = X509V3_EXT_MULTILINE,
        .it = &AUTHORITY_KEYID_it,
        .ext_new = NULL,
        .ext_free = NULL,
        .d2i = NULL,
        .i2d = NULL,
        .i2s = NULL,
        .s2i = NULL,
        .i2v = (X509V3_EXT_I2V)i2v_AUTHORITY_KEYID,
        .v2i = (X509V3_EXT_V2I)v2i_AUTHORITY_KEYID,
        .i2r = NULL,
        .r2i = NULL,
        .usr_data = NULL,
};

const X509V3_EXT_METHOD *
x509v3_ext_method_authority_key_identifier(void)
{
        return &x509v3_ext_authority_key_identifier;
}

static STACK_OF(CONF_VALUE) *
i2v_AUTHORITY_KEYID(X509V3_EXT_METHOD *method, AUTHORITY_KEYID *akeyid,
    STACK_OF(CONF_VALUE) *extlist)
{
        STACK_OF(CONF_VALUE) *free_extlist = NULL;
        char *tmpstr = NULL;

        if (extlist == NULL) {
                if ((free_extlist = extlist = sk_CONF_VALUE_new_null()) == NULL)
                        return NULL;
        }

        if (akeyid->keyid != NULL) {
                if ((tmpstr = hex_to_string(akeyid->keyid->data,
                    akeyid->keyid->length)) == NULL)
                        goto err;
                if (!X509V3_add_value("keyid", tmpstr, &extlist))
                        goto err;
                free(tmpstr);
                tmpstr = NULL;
        }

        if (akeyid->issuer != NULL) {
                if ((extlist = i2v_GENERAL_NAMES(NULL, akeyid->issuer,
                    extlist)) == NULL)
                        goto err;
        }

        if (akeyid->serial != NULL) {
                if ((tmpstr = hex_to_string(akeyid->serial->data,
                    akeyid->serial->length)) == NULL)
                        goto err;
                if (!X509V3_add_value("serial", tmpstr, &extlist))
                        goto err;
                free(tmpstr);
                tmpstr = NULL;
        }

        if (sk_CONF_VALUE_num(extlist) <= 0)
                goto err;

        return extlist;

 err:
        free(tmpstr);
        sk_CONF_VALUE_pop_free(free_extlist, X509V3_conf_free);

        return NULL;
}

/*
 * Currently two options:
 * keyid: use the issuers subject keyid, the value 'always' means its is
 * an error if the issuer certificate doesn't have a key id.
 * issuer: use the issuers cert issuer and serial number. The default is
 * to only use this if keyid is not present. With the option 'always'
 * this is always included.
 */
static AUTHORITY_KEYID *
v2i_AUTHORITY_KEYID(X509V3_EXT_METHOD *method, X509V3_CTX *ctx,
    STACK_OF(CONF_VALUE) *values)
{
        char keyid = 0, issuer = 0;
        int i;
        CONF_VALUE *cnf;
        ASN1_OCTET_STRING *ikeyid = NULL;
        X509_NAME *isname = NULL;
        STACK_OF(GENERAL_NAME) *gens = NULL;
        GENERAL_NAME *gen = NULL;
        ASN1_INTEGER *serial = NULL;
        X509_EXTENSION *ext;
        X509 *cert;
        AUTHORITY_KEYID *akeyid = NULL;

        for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
                cnf = sk_CONF_VALUE_value(values, i);
                if (!strcmp(cnf->name, "keyid")) {
                        keyid = 1;
                        if (cnf->value && !strcmp(cnf->value, "always"))
                                keyid = 2;
                } else if (!strcmp(cnf->name, "issuer")) {
                        issuer = 1;
                        if (cnf->value && !strcmp(cnf->value, "always"))
                                issuer = 2;
                } else {
                        X509V3error(X509V3_R_UNKNOWN_OPTION);
                        ERR_asprintf_error_data("name=%s", cnf->name);
                        return NULL;
                }
        }

        if (!ctx || !ctx->issuer_cert) {
                if (ctx && (ctx->flags == CTX_TEST))
                        return AUTHORITY_KEYID_new();
                X509V3error(X509V3_R_NO_ISSUER_CERTIFICATE);
                return NULL;
        }

        cert = ctx->issuer_cert;

        if (keyid) {
                i = X509_get_ext_by_NID(cert, NID_subject_key_identifier, -1);
                if ((i >= 0)  && (ext = X509_get_ext(cert, i)))
                        ikeyid = X509V3_EXT_d2i(ext);
                if (keyid == 2 && !ikeyid) {
                        X509V3error(X509V3_R_UNABLE_TO_GET_ISSUER_KEYID);
                        return NULL;
                }
        }

        if ((issuer && !ikeyid) || (issuer == 2)) {
                isname = X509_NAME_dup(X509_get_issuer_name(cert));
                serial = ASN1_INTEGER_dup(X509_get_serialNumber(cert));
                if (!isname || !serial) {
                        X509V3error(X509V3_R_UNABLE_TO_GET_ISSUER_DETAILS);
                        goto err;
                }
        }

        if (!(akeyid = AUTHORITY_KEYID_new()))
                goto err;

        if (isname) {
                if (!(gens = sk_GENERAL_NAME_new_null()) ||
                    !(gen = GENERAL_NAME_new()) ||
                    !sk_GENERAL_NAME_push(gens, gen)) {
                        X509V3error(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                gen->type = GEN_DIRNAME;
                gen->d.dirn = isname;
        }

        akeyid->issuer = gens;
        akeyid->serial = serial;
        akeyid->keyid = ikeyid;

        return akeyid;

 err:
        AUTHORITY_KEYID_free(akeyid);
        GENERAL_NAME_free(gen);
        sk_GENERAL_NAME_free(gens);
        X509_NAME_free(isname);
        ASN1_INTEGER_free(serial);
        ASN1_OCTET_STRING_free(ikeyid);
        return NULL;
}