// SPDX-License-Identifier: GPL-2.0-or-later
/* Parse a Microsoft Individual Code Signing blob
 *
 * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#define pr_fmt(fmt) "MSCODE: "fmt
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/oid_registry.h>
#include <crypto/pkcs7.h>
#include "verify_pefile.h"
#include "mscode.asn1.h"

/*
 * Parse a Microsoft Individual Code Signing blob
 */
int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
                 size_t asn1hdrlen)
{
        struct pefile_context *ctx = _ctx;

        content_data -= asn1hdrlen;
        data_len += asn1hdrlen;
        pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
                 content_data);

        return asn1_ber_decoder(&mscode_decoder, ctx, content_data, data_len);
}

/*
 * Check the content type OID
 */
int mscode_note_content_type(void *context, size_t hdrlen,
                             unsigned char tag,
                             const void *value, size_t vlen)
{
        enum OID oid;

        oid = look_up_OID(value, vlen);
        if (oid == OID__NR) {
                char buffer[50];

                sprint_oid(value, vlen, buffer, sizeof(buffer));
                pr_err("Unknown OID: %s\n", buffer);
                return -EBADMSG;
        }

        /*
         * pesign utility had a bug where it was putting
         * OID_msIndividualSPKeyPurpose instead of OID_msPeImageDataObjId
         * So allow both OIDs.
         */
        if (oid != OID_msPeImageDataObjId &&
            oid != OID_msIndividualSPKeyPurpose) {
                pr_err("Unexpected content type OID %u\n", oid);
                return -EBADMSG;
        }

        return 0;
}

/*
 * Note the digest algorithm OID
 */
int mscode_note_digest_algo(void *context, size_t hdrlen,
                            unsigned char tag,
                            const void *value, size_t vlen)
{
        struct pefile_context *ctx = context;
        char buffer[50];
        enum OID oid;

        oid = look_up_OID(value, vlen);
        switch (oid) {
        case OID_sha1:
                ctx->digest_algo = "sha1";
                break;
        case OID_sha256:
                ctx->digest_algo = "sha256";
                break;
        case OID_sha384:
                ctx->digest_algo = "sha384";
                break;
        case OID_sha512:
                ctx->digest_algo = "sha512";
                break;
        case OID_sha3_256:
                ctx->digest_algo = "sha3-256";
                break;
        case OID_sha3_384:
                ctx->digest_algo = "sha3-384";
                break;
        case OID_sha3_512:
                ctx->digest_algo = "sha3-512";
                break;

        case OID__NR:
                sprint_oid(value, vlen, buffer, sizeof(buffer));
                pr_err("Unknown OID: %s\n", buffer);
                return -EBADMSG;

        default:
                pr_err("Unsupported content type: %u\n", oid);
                return -ENOPKG;
        }

        return 0;
}

/*
 * Note the digest we're guaranteeing with this certificate
 */
int mscode_note_digest(void *context, size_t hdrlen,
                       unsigned char tag,
                       const void *value, size_t vlen)
{
        struct pefile_context *ctx = context;

        ctx->digest = kmemdup(value, vlen, GFP_KERNEL);
        if (!ctx->digest)
                return -ENOMEM;

        ctx->digest_len = vlen;

        return 0;
}