/*

 * Copyright 1999-2026 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

 */

/* extension creation utilities */

#include <stdio.h>

#include "crypto/ctype.h"

#include "internal/cryptlib.h"

#include <openssl/conf.h>

#include <openssl/x509.h>

#include "crypto/x509.h"

#include <openssl/x509v3.h>

static int v3_check_critical(const char **value);

static int v3_check_generic(const char **value);

static X509_EXTENSION *do_ext_nconf(CONF *conf, X509V3_CTX *ctx, int ext_nid,

    int crit, const char *value);

static X509_EXTENSION *v3_generic_extension(const char *ext, const char *value,

    int crit, int type,

    X509V3_CTX *ctx);

static char *conf_lhash_get_string(void *db, const char *section, const char *value);

static STACK_OF(CONF_VALUE) *conf_lhash_get_section(void *db, const char *section);

static X509_EXTENSION *do_ext_i2d(const X509V3_EXT_METHOD *method,

    int ext_nid, int crit, void *ext_struc);

static unsigned char *generic_asn1(const char *value, X509V3_CTX *ctx,

    long *ext_len);

static X509_EXTENSION *X509V3_EXT_nconf_int(CONF *conf, X509V3_CTX *ctx,

    const char *section,

    const char *name, const char *value)

{

    int crit;

    int ext_type;

    X509_EXTENSION *ret;

    crit = v3_check_critical(&value);

    if ((ext_type = v3_check_generic(&value)))

        return v3_generic_extension(name, value, crit, ext_type, ctx);

    ret = do_ext_nconf(conf, ctx, OBJ_sn2nid(name), crit, value);

    if (!ret) {

        if (section != NULL)

            ERR_raise_data(ERR_LIB_X509V3, X509V3_R_ERROR_IN_EXTENSION,

                "section=%s, name=%s, value=%s",

                section, name, value);

        else

            ERR_raise_data(ERR_LIB_X509V3, X509V3_R_ERROR_IN_EXTENSION,

                "name=%s, value=%s", name, value);

    }

    return ret;

}

X509_EXTENSION *X509V3_EXT_nconf(CONF *conf, X509V3_CTX *ctx, const char *name,

    const char *value)

{

    X509V3_CTX tmpctx;

    if (ctx == NULL) {

        X509V3_set_ctx(&tmpctx, NULL, NULL, NULL, NULL, 0);

        X509V3_set_nconf(&tmpctx, conf);

    }

    return X509V3_EXT_nconf_int(conf, ctx ? ctx : &tmpctx, NULL, name, value);

}

X509_EXTENSION *X509V3_EXT_nconf_nid(CONF *conf, X509V3_CTX *ctx, int ext_nid,

    const char *value)

{

    int crit;

    int ext_type;

    X509V3_CTX tmpctx;

    if (ctx == NULL) {

        X509V3_set_ctx(&tmpctx, NULL, NULL, NULL, NULL, 0);

        X509V3_set_nconf(&tmpctx, conf);

    }

    crit = v3_check_critical(&value);

    if ((ext_type = v3_check_generic(&value)))

        return v3_generic_extension(OBJ_nid2sn(ext_nid),

            value, crit, ext_type, ctx ? ctx : &tmpctx);

    return do_ext_nconf(conf, ctx ? ctx : &tmpctx, ext_nid, crit, value);

}

/* CONF *conf:  Config file    */

/* char *value:  Value    */

static X509_EXTENSION *do_ext_nconf(CONF *conf, X509V3_CTX *ctx, int ext_nid,

    int crit, const char *value)

{

    const X509V3_EXT_METHOD *method;

    X509_EXTENSION *ext;

    STACK_OF(CONF_VALUE) *nval;

    void *ext_struc;

    if (ext_nid == NID_undef) {

        ERR_raise(ERR_LIB_X509V3, X509V3_R_UNKNOWN_EXTENSION_NAME);

        return NULL;

    }

    if ((method = X509V3_EXT_get_nid(ext_nid)) == NULL) {

        ERR_raise(ERR_LIB_X509V3, X509V3_R_UNKNOWN_EXTENSION);

        return NULL;

    }

    /* Now get internal extension representation based on type */

    if (method->v2i) {

        if (*value == '@')

            nval = NCONF_get_section(conf, value + 1);

        else

            nval = X509V3_parse_list(value);

        if (nval == NULL || sk_CONF_VALUE_num(nval) <= 0) {

            ERR_raise_data(ERR_LIB_X509V3, X509V3_R_INVALID_EXTENSION_STRING,

                "name=%s,section=%s", OBJ_nid2sn(ext_nid), value);

            if (*value != '@')

                sk_CONF_VALUE_pop_free(nval, X509V3_conf_free);

            return NULL;

        }

        ext_struc = method->v2i(method, ctx, nval);

        if (*value != '@')

            sk_CONF_VALUE_pop_free(nval, X509V3_conf_free);

        if (!ext_struc)

            return NULL;

    } else if (method->s2i) {

        if ((ext_struc = method->s2i(method, ctx, value)) == NULL)

            return NULL;

    } else if (method->r2i) {

        if (!ctx->db || !ctx->db_meth) {

            ERR_raise(ERR_LIB_X509V3, X509V3_R_NO_CONFIG_DATABASE);

            return NULL;

        }

        if ((ext_struc = method->r2i(method, ctx, value)) == NULL)

            return NULL;

    } else {

        ERR_raise_data(ERR_LIB_X509V3, X509V3_R_EXTENSION_SETTING_NOT_SUPPORTED,

            "name=%s", OBJ_nid2sn(ext_nid));

        return NULL;

    }

    ext = do_ext_i2d(method, ext_nid, crit, ext_struc);

    if (method->it)

        ASN1_item_free(ext_struc, ASN1_ITEM_ptr(method->it));

    else

        method->ext_free(ext_struc);

    return ext;

}

static X509_EXTENSION *do_ext_i2d(const X509V3_EXT_METHOD *method,

    int ext_nid, int crit, void *ext_struc)

{

    unsigned char *ext_der = NULL;

    int ext_len;

    ASN1_OCTET_STRING *ext_oct = NULL;

    X509_EXTENSION *ext;

    /* Convert internal representation to DER */

    if (method->it) {

        ext_der = NULL;

        ext_len = ASN1_item_i2d(ext_struc, &ext_der, ASN1_ITEM_ptr(method->it));

        if (ext_len < 0) {

            ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);

            goto err;

        }

    } else {

        unsigned char *p;

        ext_len = method->i2d(ext_struc, NULL);

        if (ext_len <= 0) {

            ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);

            goto err;

        }

        if ((ext_der = OPENSSL_malloc(ext_len)) == NULL)

            goto err;

        p = ext_der;

        method->i2d(ext_struc, &p);

    }

    if ((ext_oct = ASN1_OCTET_STRING_new()) == NULL) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);

        goto err;

    }

    ext_oct->data = ext_der;

    ext_der = NULL;

    ext_oct->length = ext_len;

    ext = X509_EXTENSION_create_by_NID(NULL, ext_nid, crit, ext_oct);

    if (!ext) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_X509V3_LIB);

        goto err;

    }

    ASN1_OCTET_STRING_free(ext_oct);

    return ext;

err:

    OPENSSL_free(ext_der);

    ASN1_OCTET_STRING_free(ext_oct);

    return NULL;

}

/* Given an internal structure, nid and critical flag create an extension */

X509_EXTENSION *X509V3_EXT_i2d(int ext_nid, int crit, void *ext_struc)

{

    const X509V3_EXT_METHOD *method;

    if ((method = X509V3_EXT_get_nid(ext_nid)) == NULL) {

        ERR_raise(ERR_LIB_X509V3, X509V3_R_UNKNOWN_EXTENSION);

        return NULL;

    }

    return do_ext_i2d(method, ext_nid, crit, ext_struc);

}

/* Check the extension string for critical flag */

static int v3_check_critical(const char **value)

{

    const char *p = *value;

    if (!CHECK_AND_SKIP_PREFIX(p, "critical,"))

        return 0;

    while (ossl_isspace(*p))

        p++;

    *value = p;

    return 1;

}

/* Check extension string for generic extension and return the type */

static int v3_check_generic(const char **value)

{

    int gen_type = 0;

    const char *p = *value;

    if (CHECK_AND_SKIP_PREFIX(p, "DER:")) {

        gen_type = 1;

    } else if (CHECK_AND_SKIP_PREFIX(p, "ASN1:")) {

        gen_type = 2;

    } else

        return 0;

    while (ossl_isspace(*p))

        p++;

    *value = p;

    return gen_type;

}

/* Create a generic extension: for now just handle DER type */

static X509_EXTENSION *v3_generic_extension(const char *ext, const char *value,

    int crit, int gen_type,

    X509V3_CTX *ctx)

{

    unsigned char *ext_der = NULL;

    long ext_len = 0;

    ASN1_OBJECT *obj = NULL;

    ASN1_OCTET_STRING *oct = NULL;

    X509_EXTENSION *extension = NULL;

    if ((obj = OBJ_txt2obj(ext, 0)) == NULL) {

        ERR_raise_data(ERR_LIB_X509V3, X509V3_R_EXTENSION_NAME_ERROR,

            "name=%s", ext);

        goto err;

    }

    if (gen_type == 1)

        ext_der = OPENSSL_hexstr2buf(value, &ext_len);

    else if (gen_type == 2)

        ext_der = generic_asn1(value, ctx, &ext_len);

    if (ext_der == NULL) {

        ERR_raise_data(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR,

            "value=%s", value);

        goto err;

    }

    if ((oct = ASN1_OCTET_STRING_new()) == NULL) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);

        goto err;

    }

    oct->data = ext_der;

    oct->length = ext_len;

    ext_der = NULL;

    extension = X509_EXTENSION_create_by_OBJ(NULL, obj, crit, oct);

err:

    ASN1_OBJECT_free(obj);

    ASN1_OCTET_STRING_free(oct);

    OPENSSL_free(ext_der);

    return extension;

}

static unsigned char *generic_asn1(const char *value, X509V3_CTX *ctx,

    long *ext_len)

{

    ASN1_TYPE *typ;

    unsigned char *ext_der = NULL;

    typ = ASN1_generate_v3(value, ctx);

    if (typ == NULL)

        return NULL;

    *ext_len = i2d_ASN1_TYPE(typ, &ext_der);

    ASN1_TYPE_free(typ);

    return ext_der;

}

static void delete_ext(STACK_OF(X509_EXTENSION) *sk, X509_EXTENSION *dext)

{

    int idx;

    const ASN1_OBJECT *obj;

    obj = X509_EXTENSION_get_object(dext);

    while ((idx = X509v3_get_ext_by_OBJ(sk, obj, -1)) >= 0)

        X509_EXTENSION_free(X509v3_delete_ext(sk, idx));

}

/*

 * This is the main function: add a bunch of extensions based on a config

 * file section to an extension STACK. Just check in case sk == NULL.

 * Note that on error new elements may have been added to *sk if sk != NULL.

 */

int X509V3_EXT_add_nconf_sk(CONF *conf, X509V3_CTX *ctx, const char *section,

    STACK_OF(X509_EXTENSION) **sk)

{

    X509_EXTENSION *ext;

    STACK_OF(CONF_VALUE) *nval;

    const CONF_VALUE *val;

    int i, akid = -1, skid = -1;

    X509V3_CTX tmpctx;

    if (ctx == NULL) {

        X509V3_set_ctx(&tmpctx, NULL, NULL, NULL, NULL, 0);

        X509V3_set_nconf(&tmpctx, conf);

        ctx = &tmpctx;

    }

    if ((nval = NCONF_get_section(conf, section)) == NULL)

        return 0;

    for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {

        val = sk_CONF_VALUE_value(nval, i);

        if (strcmp(val->name, "authorityKeyIdentifier") == 0)

            akid = i;

        else if (strcmp(val->name, "subjectKeyIdentifier") == 0)

            skid = i;

    }

    for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {

        val = sk_CONF_VALUE_value(nval, i);

        if (skid > akid && akid >= 0) {

            /* make sure SKID is handled before AKID */

            if (i == akid)

                val = sk_CONF_VALUE_value(nval, skid);

            else if (i == skid)

                val = sk_CONF_VALUE_value(nval, akid);

        }

        if ((ext = X509V3_EXT_nconf_int(conf, ctx, val->section,

                 val->name, val->value))

            == NULL)

            return 0;

        if (sk != NULL) {

            if (ctx->flags == X509V3_CTX_REPLACE)

                delete_ext(*sk, ext);

            if (X509v3_add_ext(sk, ext, -1) == NULL) {

                X509_EXTENSION_free(ext);

                return 0;

            }

        }

        X509_EXTENSION_free(ext);

    }

    if (sk != NULL && sk_X509_EXTENSION_num(*sk) == 0) {

        sk_X509_EXTENSION_free(*sk);

        *sk = NULL;

    }

    return 1;

}

/*

 * Add extensions to a certificate. Just check in case cert == NULL.

 * Note that on error new elements may remain added to cert if cert != NULL.

 */

int X509V3_EXT_add_nconf(CONF *conf, X509V3_CTX *ctx, const char *section,

    X509 *cert)

{

    STACK_OF(X509_EXTENSION) **sk = NULL;

    if (cert != NULL)

        sk = &cert->cert_info.extensions;

    return X509V3_EXT_add_nconf_sk(conf, ctx, section, sk);

}

/*

 * Add extensions to a CRL. Just check in case crl == NULL.

 * Note that on error new elements may remain added to crl if crl != NULL.

 */

int X509V3_EXT_CRL_add_nconf(CONF *conf, X509V3_CTX *ctx, const char *section,

    X509_CRL *crl)

{

    STACK_OF(X509_EXTENSION) **sk = NULL;

    if (crl != NULL)

        sk = &crl->crl.extensions;

    return X509V3_EXT_add_nconf_sk(conf, ctx, section, sk);

}

static int

update_req_extensions(X509_REQ *req, int *pnid, STACK_OF(X509_EXTENSION) *exts)

{

    unsigned char *ext = NULL;

    int ret = 0, loc = -1, extlen = 0;

    if (pnid == NULL || *pnid == NID_undef)

        if ((pnid = X509_REQ_get_extension_nids()) == NULL)

            return 0;

    loc = X509at_get_attr_by_NID(req->req_info.attributes, *pnid, -1);

    if (exts != NULL) {

        extlen = ASN1_item_i2d((const ASN1_VALUE *)exts,

            &ext, ASN1_ITEM_rptr(X509_EXTENSIONS));

        if (extlen <= 0)

            return ret;

    }

    if (loc != -1) {

        X509_ATTRIBUTE *att = X509_REQ_delete_attr(req, loc);

        if (att == NULL)

            goto end;

        X509_ATTRIBUTE_free(att);

    }

    if (sk_X509_EXTENSION_num(exts) > 0)

        ret = X509_REQ_add1_attr_by_NID(req, *pnid, V_ASN1_SEQUENCE, ext, extlen);

    else

        ret = 1;

end:

    OPENSSL_free(ext);

    return ret;

}

/*

 * Add extensions to certificate request. Just check in case req is NULL.

 * Note that on error new elements may remain added to req if req != NULL.

 */

int X509V3_EXT_REQ_add_nconf(CONF *conf, X509V3_CTX *ctx, const char *section,

    X509_REQ *req)

{

    STACK_OF(X509_EXTENSION) *exts = NULL;

    int ret, *pnid = NULL;

    /*

     * Load current extensions if any, so we can replace any duplicates, possibly

     * with nothing in the case of empty AKID/SKID.

     */

    if (req != NULL) {

        for (pnid = X509_REQ_get_extension_nids(); *pnid != NID_undef; pnid++) {

            exts = ossl_x509_req_get1_extensions_by_nid(req, *pnid);

            if (sk_X509_EXTENSION_num(exts) > 0)

                break;

            sk_X509_EXTENSION_free(exts);

            exts = NULL;

        }

    }

    ret = X509V3_EXT_add_nconf_sk(conf, ctx, section, &exts);

    /* Replace original extension list (stack) with updated stack */

    if (ret && req != NULL)

        ret = update_req_extensions(req, pnid, exts);

    sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);

    return ret;

}

/* Config database functions */

char *X509V3_get_string(X509V3_CTX *ctx, const char *name, const char *section)

{

    if (!ctx->db || !ctx->db_meth || !ctx->db_meth->get_string) {

        ERR_raise(ERR_LIB_X509V3, X509V3_R_OPERATION_NOT_DEFINED);

        return NULL;

    }

    return ctx->db_meth->get_string(ctx->db, name, section);

}

STACK_OF(CONF_VALUE) *X509V3_get_section(X509V3_CTX *ctx, const char *section)

{

    if (!ctx->db || !ctx->db_meth || !ctx->db_meth->get_section) {

        ERR_raise(ERR_LIB_X509V3, X509V3_R_OPERATION_NOT_DEFINED);

        return NULL;

    }

    return ctx->db_meth->get_section(ctx->db, section);

}

void X509V3_string_free(X509V3_CTX *ctx, char *str)

{

    if (!str)

        return;

    if (ctx->db_meth->free_string)

        ctx->db_meth->free_string(ctx->db, str);

}

void X509V3_section_free(X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *section)

{

    if (!section)

        return;

    if (ctx->db_meth->free_section)

        ctx->db_meth->free_section(ctx->db, section);

}

static char *nconf_get_string(void *db, const char *section, const char *value)

{

    return NCONF_get_string(db, section, value);

}

static STACK_OF(CONF_VALUE) *nconf_get_section(void *db, const char *section)

{

    return NCONF_get_section(db, section);

}

static X509V3_CONF_METHOD nconf_method = {

    nconf_get_string,

    nconf_get_section,

    NULL,

    NULL

};

void X509V3_set_nconf(X509V3_CTX *ctx, CONF *conf)

{

    if (ctx == NULL)

        return;

    ctx->db_meth = &nconf_method;

    ctx->db = conf;

}

void X509V3_set_ctx(X509V3_CTX *ctx, X509 *issuer, X509 *subject, X509_REQ *req,

    X509_CRL *crl, int flags)

{

    if (ctx == NULL)

        return;

    ctx->flags = flags;

    ctx->issuer_cert = issuer;

    ctx->subject_cert = subject;

    ctx->subject_req = req;

    ctx->crl = crl;

    ctx->db_meth = NULL;

    ctx->db = NULL;

    ctx->issuer_pkey = NULL;

}

/* For API backward compatibility, this is separate from X509V3_set_ctx() */

int X509V3_set_issuer_pkey(X509V3_CTX *ctx, EVP_PKEY *pkey)

{

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (ctx->subject_cert == NULL && pkey != NULL) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

    ctx->issuer_pkey = pkey;

    return 1;

}

/* Old conf compatibility functions */

X509_EXTENSION *X509V3_EXT_conf(LHASH_OF(CONF_VALUE) *conf, X509V3_CTX *ctx,

    const char *name, const char *value)

{

    CONF *ctmp;

    X509_EXTENSION *ret;

    if ((ctmp = NCONF_new(NULL)) == NULL)

        return NULL;

    CONF_set_nconf(ctmp, conf);

    ret = X509V3_EXT_nconf(ctmp, ctx, name, value);

    CONF_set_nconf(ctmp, NULL);

    NCONF_free(ctmp);

    return ret;

}

X509_EXTENSION *X509V3_EXT_conf_nid(LHASH_OF(CONF_VALUE) *conf,

    X509V3_CTX *ctx, int ext_nid, const char *value)

{

    CONF *ctmp;

    X509_EXTENSION *ret;

    if ((ctmp = NCONF_new(NULL)) == NULL)

        return NULL;

    CONF_set_nconf(ctmp, conf);

    ret = X509V3_EXT_nconf_nid(ctmp, ctx, ext_nid, value);

    CONF_set_nconf(ctmp, NULL);

    NCONF_free(ctmp);

    return ret;

}

static char *conf_lhash_get_string(void *db, const char *section, const char *value)

{

    return CONF_get_string(db, section, value);

}

static STACK_OF(CONF_VALUE) *conf_lhash_get_section(void *db, const char *section)

{

    return CONF_get_section(db, section);

}

static X509V3_CONF_METHOD conf_lhash_method = {

    conf_lhash_get_string,

    conf_lhash_get_section,

    NULL,

    NULL

};

void X509V3_set_conf_lhash(X509V3_CTX *ctx, LHASH_OF(CONF_VALUE) *lhash)

{

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_X509V3, ERR_R_PASSED_NULL_PARAMETER);

        return;

    }

    ctx->db_meth = &conf_lhash_method;

    ctx->db = lhash;

}

int X509V3_EXT_add_conf(LHASH_OF(CONF_VALUE) *conf, X509V3_CTX *ctx,

    const char *section, X509 *cert)

{

    CONF *ctmp;

    int ret;

    if ((ctmp = NCONF_new(NULL)) == NULL)

        return 0;

    CONF_set_nconf(ctmp, conf);

    ret = X509V3_EXT_add_nconf(ctmp, ctx, section, cert);

    CONF_set_nconf(ctmp, NULL);

    NCONF_free(ctmp);

    return ret;

}

/* Same as above but for a CRL */

int X509V3_EXT_CRL_add_conf(LHASH_OF(CONF_VALUE) *conf, X509V3_CTX *ctx,

    const char *section, X509_CRL *crl)

{

    CONF *ctmp;

    int ret;

    if ((ctmp = NCONF_new(NULL)) == NULL)

        return 0;

    CONF_set_nconf(ctmp, conf);

    ret = X509V3_EXT_CRL_add_nconf(ctmp, ctx, section, crl);

    CONF_set_nconf(ctmp, NULL);

    NCONF_free(ctmp);

    return ret;

}

/* Add extensions to certificate request */

int X509V3_EXT_REQ_add_conf(LHASH_OF(CONF_VALUE) *conf, X509V3_CTX *ctx,

    const char *section, X509_REQ *req)

{

    CONF *ctmp;

    int ret;

    if ((ctmp = NCONF_new(NULL)) == NULL)

        return 0;

    CONF_set_nconf(ctmp, conf);

    ret = X509V3_EXT_REQ_add_nconf(ctmp, ctx, section, req);

    CONF_set_nconf(ctmp, NULL);

    NCONF_free(ctmp);

    return ret;

}