opkg-lede/libopkg/opkg_pathfinder.c

/* vi: set noexpandtab sw=4 sts=4: */
/* opkg_pathfinder.c - the opkg package management system

   Copyright (C) 2009 Camille Moncelier <moncelier@devlife.org>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
*/
#include "config.h"

#include <openssl/ssl.h>
#include <libpathfinder.h>
#include <stdlib.h>
#if defined(HAVE_SSLCURL)
#include <curl/curl.h>
#endif

#include "libbb/libbb.h"
#include "opkg_message.h"

#if defined(HAVE_SSLCURL) || defined(HAVE_OPENSSL)
/*
 *      This callback is called instead of X509_verify_cert to perform path
 *      validation on a certificate using pathfinder.
 *
 */
static int pathfinder_verify_callback(X509_STORE_CTX * ctx, void *arg)
{
	char *errmsg;
	const char *hex = "0123456789ABCDEF";
	size_t size = i2d_X509(ctx->cert, NULL);
	unsigned char *keybuf, *iend;
	iend = keybuf = xmalloc(size);
	i2d_X509(ctx->cert, &iend);
	char *certdata_str = xmalloc(size * 2 + 1);
	unsigned char *cp = keybuf;
	char *certdata_str_i = certdata_str;
	while (cp < iend) {
		unsigned char ch = *cp++;
		*certdata_str_i++ = hex[(ch >> 4) & 0xf];
		*certdata_str_i++ = hex[ch & 0xf];
	}
	*certdata_str_i = 0;
	free(keybuf);

	const char *policy = "2.5.29.32.0";	// anyPolicy
	int validated =
	    pathfinder_dbus_verify(certdata_str, policy, 0, 0, &errmsg);

	if (!validated)
		opkg_msg(ERROR, "Path verification failed: %s.\n", errmsg);

	free(certdata_str);
	free(errmsg);

	return validated;
}
#endif

#if defined(HAVE_OPENSSL)
int pkcs7_pathfinder_verify_signers(PKCS7 * p7)
{
	STACK_OF(X509) * signers;
	int i, ret = 1;		/* signers are verified by default */

	signers = PKCS7_get0_signers(p7, NULL, 0);

	for (i = 0; i < sk_X509_num(signers); i++) {
		X509_STORE_CTX ctx = {
			.cert = sk_X509_value(signers, i),
		};

		if (!pathfinder_verify_callback(&ctx, NULL)) {
			/* Signer isn't verified ! goto jail; */
			ret = 0;
			break;
		}
	}

	sk_X509_free(signers);
	return ret;
}
#endif

#if defined(HAVE_SSLCURL)
CURLcode curl_ssl_ctx_function(CURL * curl, void *sslctx, void *parm)
{

	SSL_CTX *ctx = (SSL_CTX *) sslctx;
	SSL_CTX_set_cert_verify_callback(ctx, pathfinder_verify_callback, parm);

	return CURLE_OK;
}
#endif