// SPDX-License-Identifier: GPL-2.0-or-later
/* Instantiate a public key crypto key from an X.509 Certificate
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

//#define pr_fmt(fmt) "X.509: "fmt
//#include <linux/module.h>
//#include <linux/kernel.h>
//#include <linux/slab.h>
//#include <keys/asymmetric-subtype.h>
//#include <keys/asymmetric-parser.h>
//#include <keys/system_keyring.h>
//#include <crypto/hash.h>
//#include "asymmetric_keys.h"
//#include "x509_parser.h"

#include "x509_parser.h"
#include "errno.h"
#include "config.h"

#include "../rewrite/Lib.SoulExtraction.rewrite.h"

//
// macro
//

/*
 * Set up the signature parameters in an X.509 certificate.  This involves
 * digesting the signed data and extracting the signature.
 */
// int x509_get_sig_params(struct x509_certificate *cert)
//{
//	struct public_key_signature *sig = cert->sig;
//	struct crypto_shash *tfm;
//	struct shash_desc *desc;
//	size_t desc_size;
//	int ret;
//
//	pr_devel("==>%s()\n", __func__);
//
//	if (!cert->pub->pkey_algo)
//		cert->unsupported_key = true;
//
//	if (!sig->pkey_algo)
//		cert->unsupported_sig = true;
//
//	/* We check the hash if we can - even if we can't then verify it */
//	if (!sig->hash_algo) {
//		cert->unsupported_sig = true;
//		return 0;
//	}
//
//	sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL);
//	if (!sig->s)
//		return -ENOMEM;
//
//	sig->s_size = cert->raw_sig_size;
//
//	/* Allocate the hashing algorithm we're going to need and find out how
//	 * big the hash operational data will be.
//	 */
//	tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
//	if (IS_ERR(tfm)) {
//		if (PTR_ERR(tfm) == -ENOENT) {
//			cert->unsupported_sig = true;
//			return 0;
//		}
//		return PTR_ERR(tfm);
//	}
//
//	desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
//	sig->digest_size = crypto_shash_digestsize(tfm);
//
//	ret = -ENOMEM;
//	sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
//	if (!sig->digest)
//		goto error;
//
//	desc = kzalloc(desc_size, GFP_KERNEL);
//	if (!desc)
//		goto error;
//
//	desc->tfm = tfm;
//
//	ret = crypto_shash_digest(desc, cert->tbs, cert->tbs_size, sig->digest);
//	if (ret < 0)
//		goto error_2;
//
//	ret = is_hash_blacklisted(sig->digest, sig->digest_size, "tbs");
//	if (ret == -EKEYREJECTED) {
//		pr_err("Cert %p is blacklisted\n",
//		       sig->digest_size, sig->digest);
//		cert->blacklisted = true;
//		ret = 0;
//	}
//
// error_2:
//	kfree(desc);
// error:
//	crypto_free_shash(tfm);
//	pr_devel("<==%s() = %d\n", __func__, ret);
//	return ret;
// }

/*
 * Check for self-signedness in an X.509 cert and if found, check the signature
 * immediately if we can.
 */
int
x509_check_for_self_signed(struct x509_certificate *cert)
{
    int ret = 0;

    pr_devel("==>%s()\n", __func__);

    pr_devel("raw_subject_size=%d,raw_issuer_size=%d\n", cert->raw_subject_size, cert->raw_issuer_size);

    /*if (cert->raw_subject_size != cert->raw_issuer_size ||
        memcmp(cert->raw_subject, cert->raw_issuer,
            cert->raw_issuer_size) != 0)
    {

        goto not_self_signed;
    }*/

    if (cert->sig->auth_ids[0] || cert->sig->auth_ids[1])
    {
        /* If the AKID is present it may have one or two parts.  If
         * both are supplied, both must match.
         */
        unsigned char a = asymmetric_key_id_same(cert->skid, cert->sig->auth_ids[1]);
        unsigned char b = asymmetric_key_id_same(cert->id, cert->sig->auth_ids[0]);

        pr_devel(
            "skid=%p,auth_ids[1]=%p,id=%p,auth_ids[0]=%p,a=%d,b=%d\n",
            cert->skid,
            cert->sig->auth_ids[1],
            cert->id,
            cert->sig->auth_ids[0],
            a,
            b);

        if (!a && !b)
        {
            pr_devel("232323232323\n");
            goto not_self_signed;
        }

        ret = -EKEYREJECTED;
        if (((a && !b) || (b && !a)) && cert->sig->auth_ids[0] && cert->sig->auth_ids[1])
        {
            pr_devel("3.3333\n");
            goto out;
        }
    }

    ret = -EKEYREJECTED;
    if (strcmp(cert->pub->pkey_algo, cert->sig->pkey_algo) != 0)
    {
        pr_devel("3.444\n");
        goto out;
    }

    /*ret = public_key_verify_signature(cert->pub, cert->sig);
    if (ret < 0) {
        if (ret == -ENOPKG) {
            cert->unsupported_sig = TRUE;
            ret = 0;
        }
        goto out;
    }*/

    pr_devel("Cert Self-signature verified");
    cert->self_signed = TRUE;

out:
    pr_devel("<==%s() = %d\n", __func__, ret);
    return ret;

not_self_signed:
    pr_devel("<==%s() = 0 [not]\n", __func__);
    return 0;
}

/*
 * Attempt to parse a data blob for a key as an X509 certificate.
 */
// static int x509_key_preparse(struct key_preparsed_payload *prep)
//{
//	struct asymmetric_key_ids *kids;
//	struct x509_certificate *cert;
//	const char *q;
//	size_t srlen, sulen;
//	char *desc = NULL, *p;
//	int ret;
//
//	cert = x509_cert_parse(prep->data, prep->datalen);
//	if (IS_ERR(cert))
//		return PTR_ERR(cert);
//
//	pr_devel("Cert Issuer: %s\n", cert->issuer);
//	pr_devel("Cert Subject: %s\n", cert->subject);
//
//	if (cert->unsupported_key) {
//		ret = -ENOPKG;
//		goto error_free_cert;
//	}
//
//	pr_devel("Cert Key Algo: %s\n", cert->pub->pkey_algo);
//	pr_devel("Cert Valid period: %lld-%lld\n", cert->valid_from, cert->valid_to);
//
//	cert->pub->id_type = "X509";
//
//	if (cert->unsupported_sig) {
//		public_key_signature_free(cert->sig);
//		cert->sig = NULL;
//	} else {
//		pr_devel("Cert Signature: %s + %s\n",
//			 cert->sig->pkey_algo, cert->sig->hash_algo);
//	}
//
//	/* Don't permit addition of blacklisted keys */
//	ret = -EKEYREJECTED;
//	if (cert->blacklisted)
//		goto error_free_cert;
//
//	/* Propose a description */
//	sulen = strlen(cert->subject);
//	if (cert->raw_skid) {
//		srlen = cert->raw_skid_size;
//		q = cert->raw_skid;
//	} else {
//		srlen = cert->raw_serial_size;
//		q = cert->raw_serial;
//	}
//
//	ret = -ENOMEM;
//	desc = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL);
//	if (!desc)
//		goto error_free_cert;
//	p = memcpy(desc, cert->subject, sulen);
//	p += sulen;
//	*p++ = ':';
//	*p++ = ' ';
//	p = bin2hex(p, q, srlen);
//	*p = 0;
//
//	kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
//	if (!kids)
//		goto error_free_desc;
//	kids->id[0] = cert->id;
//	kids->id[1] = cert->skid;
//
//	/* We're pinning the module by being linked against it */
//	__module_get(public_key_subtype.owner);
//	prep->payload.data[asym_subtype] = &public_key_subtype;
//	prep->payload.data[asym_key_ids] = kids;
//	prep->payload.data[asym_crypto] = cert->pub;
//	prep->payload.data[asym_auth] = cert->sig;
//	prep->description = desc;
//	prep->quotalen = 100;
//
//	/* We've finished with the certificate */
//	cert->pub = NULL;
//	cert->id = NULL;
//	cert->skid = NULL;
//	cert->sig = NULL;
//	desc = NULL;
//	ret = 0;
//
// error_free_desc:
//	kfree(desc);
// error_free_cert:
//	x509_free_certificate(cert);
//	return ret;
// }

// static struct asymmetric_key_parser x509_key_parser = {
//	.owner	= THIS_MODULE,
//	.name	= "x509",
//	.parse	= x509_key_preparse,
// };

/*
 * Module stuff
 */
// static int __init x509_key_init(void)
//{
//	return register_asymmetric_key_parser(&x509_key_parser);
// }
//
// static void __exit x509_key_exit(void)
//{
//	unregister_asymmetric_key_parser(&x509_key_parser);
// }
//
// module_init(x509_key_init);
// module_exit(x509_key_exit);
//
// MODULE_DESCRIPTION("X.509 certificate parser");
// MODULE_AUTHOR("Red Hat, Inc.");
// MODULE_LICENSE("GPL");