cred_verify.c

/*
 * Copyright (c) 2018 Yubico AB. All rights reserved.
 * Use of this source code is governed by a BSD-style
 * license that can be found in the LICENSE file.
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <fido.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "../openbsd-compat/openbsd-compat.h"
#include "extern.h"

static fido_cred_t *
prepare_cred(FILE *in_f, int type, int flags)
{
	fido_cred_t *cred = NULL;
	struct blob cdh;
	struct blob authdata;
	struct blob id;
	struct blob sig;
	struct blob x5c;
	char *rpid = NULL;
	char *fmt = NULL;
	int r;

	memset(&cdh, 0, sizeof(cdh));
	memset(&authdata, 0, sizeof(authdata));
	memset(&id, 0, sizeof(id));
	memset(&sig, 0, sizeof(sig));
	memset(&x5c, 0, sizeof(x5c));

	r = base64_read(in_f, &cdh);
	r |= string_read(in_f, &rpid);
	r |= string_read(in_f, &fmt);
	r |= base64_read(in_f, &authdata);
	r |= base64_read(in_f, &id);
	r |= base64_read(in_f, &sig);
	if (r < 0)
		errx(1, "input error");

	(void)base64_read(in_f, &x5c);

	if (flags & FLAG_DEBUG) {
		fprintf(stderr, "client data hash:\n");
		xxd(cdh.ptr, cdh.len);
		fprintf(stderr, "relying party id: %s\n", rpid);
		fprintf(stderr, "format: %s\n", fmt);
		fprintf(stderr, "authenticator data:\n");
		xxd(authdata.ptr, authdata.len);
		fprintf(stderr, "credential id:\n");
		xxd(id.ptr, id.len);
		fprintf(stderr, "signature:\n");
		xxd(sig.ptr, sig.len);
		fprintf(stderr, "x509:\n");
		xxd(x5c.ptr, x5c.len);
	}

	if ((cred = fido_cred_new()) == NULL)
		errx(1, "fido_cred_new");

	if ((r = fido_cred_set_type(cred, type)) != FIDO_OK ||
	    (r = fido_cred_set_clientdata_hash(cred, cdh.ptr,
	    cdh.len)) != FIDO_OK ||
	    (r = fido_cred_set_rp(cred, rpid, NULL)) != FIDO_OK ||
	    (r = fido_cred_set_authdata(cred, authdata.ptr,
	    authdata.len)) != FIDO_OK ||
	    (r = fido_cred_set_sig(cred, sig.ptr, sig.len)) != FIDO_OK ||
	    (r = fido_cred_set_fmt(cred, fmt)) != FIDO_OK)
		errx(1, "fido_cred_set: %s", fido_strerr(r));

	if (x5c.ptr != NULL) {
		if ((r = fido_cred_set_x509(cred, x5c.ptr, x5c.len)) != FIDO_OK)
			errx(1, "fido_cred_set_x509: %s", fido_strerr(r));
	}

	if (flags & FLAG_UV) {
		if ((r = fido_cred_set_uv(cred, FIDO_OPT_TRUE)) != FIDO_OK)
			errx(1, "fido_cred_set_uv: %s", fido_strerr(r));
	}
	if (flags & FLAG_HMAC) {
		if ((r = fido_cred_set_extensions(cred,
		    FIDO_EXT_HMAC_SECRET)) != FIDO_OK)
			errx(1, "fido_cred_set_extensions: %s", fido_strerr(r));
	}

	free(cdh.ptr);
	free(authdata.ptr);
	free(id.ptr);
	free(sig.ptr);
	free(x5c.ptr);
	free(rpid);
	free(fmt);

	return (cred);
}

int
cred_verify(int argc, char **argv)
{
	fido_cred_t *cred = NULL;
	char *in_path = NULL;
	char *out_path = NULL;
	FILE *in_f = NULL;
	FILE *out_f = NULL;
	int type = COSE_ES256;
	int flags = 0;
	int cred_prot = -1;
	int ch;
	int r;

	while ((ch = getopt(argc, argv, "c:dhi:o:v")) != -1) {
		switch (ch) {
		case 'c':
			if ((cred_prot = base10(optarg)) < 0)
				errx(1, "-c: invalid argument '%s'", optarg);
			break;
		case 'd':
			flags |= FLAG_DEBUG;
			break;
		case 'h':
			flags |= FLAG_HMAC;
			break;
		case 'i':
			in_path = optarg;
			break;
		case 'o':
			out_path = optarg;
			break;
		case 'v':
			flags |= FLAG_UV;
			break;
		default:
			usage();
		}
	}

	argc -= optind;
	argv += optind;

	if (argc > 1)
		usage();

	in_f = open_read(in_path);
	out_f = open_write(out_path);

	if (argc > 0 && cose_type(argv[0], &type) < 0)
		errx(1, "unknown type %s", argv[0]);

	fido_init((flags & FLAG_DEBUG) ? FIDO_DEBUG : 0);
	cred = prepare_cred(in_f, type, flags);

	if (cred_prot > 0) {
		r = fido_cred_set_prot(cred, cred_prot);
		if (r != FIDO_OK) {
			errx(1, "fido_cred_set_prot: %s", fido_strerr(r));
		}
	}

	if (fido_cred_x5c_ptr(cred) == NULL) {
		if ((r = fido_cred_verify_self(cred)) != FIDO_OK)
			errx(1, "fido_cred_verify_self: %s", fido_strerr(r));
	} else {
		if ((r = fido_cred_verify(cred)) != FIDO_OK)
			errx(1, "fido_cred_verify: %s", fido_strerr(r));
	}

	print_cred(out_f, type, cred);
	fido_cred_free(&cred);

	fclose(in_f);
	fclose(out_f);
	in_f = NULL;
	out_f = NULL;

	exit(0);
}