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/*
* signing.c
*
* Copyright (c) 2008-2011 Pacman Development Team <pacman-dev@archlinux.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 of the License, 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <locale.h> /* setlocale() */
#include <gpgme.h>
/* libalpm */
#include "signing.h"
#include "package.h"
#include "util.h"
#include "log.h"
#include "alpm.h"
#define CHECK_ERR(void) do { \
if(err != GPG_ERR_NO_ERROR) { goto error; } \
} while(0)
static int gpgme_init(void)
{
static int init = 0;
const char *version;
gpgme_error_t err;
gpgme_engine_info_t enginfo;
ALPM_LOG_FUNC;
if(init) {
/* we already successfully initialized the library */
return 0;
}
if(!alpm_option_get_signaturedir()) {
RET_ERR(PM_ERR_SIG_MISSINGDIR, 1);
}
/* calling gpgme_check_version() returns the current version and runs
* some internal library setup code */
version = gpgme_check_version(NULL);
_alpm_log(PM_LOG_DEBUG, "GPGME version: %s\n", version);
gpgme_set_locale(NULL, LC_CTYPE, setlocale(LC_CTYPE, NULL));
#ifdef LC_MESSAGES
gpgme_set_locale(NULL, LC_MESSAGES, setlocale(LC_MESSAGES, NULL));
#endif
/* NOTE:
* The GPGME library installs a SIGPIPE signal handler automatically if
* the default signal hander is in use. The only time we set a handler
* for SIGPIPE is in dload.c, and we reset it when we are done. Given that
* we do this, we can let GPGME do its automagic. However, if we install
* a library-wide SIGPIPE handler, we will have to be careful.
*/
/* check for OpenPGP support (should be a no-brainer, but be safe) */
err = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
CHECK_ERR();
/* set and check engine information */
err = gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP, NULL,
alpm_option_get_signaturedir());
CHECK_ERR();
err = gpgme_get_engine_info(&enginfo);
CHECK_ERR();
_alpm_log(PM_LOG_DEBUG, "GPGME engine info: file=%s, home=%s\n",
enginfo->file_name, enginfo->home_dir);
init = 1;
return 0;
error:
_alpm_log(PM_LOG_ERROR, _("GPGME error: %s\n"), gpgme_strerror(err));
RET_ERR(PM_ERR_GPGME, 1);
}
/**
* Check the PGP package signature for the given package file.
* @param pkgpath the full path to a package file
* @param sig PGP signature data in raw form (already decoded)
* @return a int value : 0 (valid), 1 (invalid), -1 (an error occured)
*/
int _alpm_gpgme_checksig(const char *pkgpath, const pmpgpsig_t *sig)
{
int ret = 0;
gpgme_error_t err;
gpgme_ctx_t ctx;
gpgme_data_t pkgdata, sigdata;
gpgme_verify_result_t result;
gpgme_signature_t gpgsig;
FILE *pkgfile = NULL, *sigfile = NULL;
ALPM_LOG_FUNC;
if(!sig || !sig->rawdata) {
RET_ERR(PM_ERR_SIG_UNKNOWN, -1);
}
if(!pkgpath || access(pkgpath, R_OK) != 0) {
RET_ERR(PM_ERR_PKG_NOT_FOUND, -1);
}
if(gpgme_init()) {
/* pm_errno was set in gpgme_init() */
return -1;
}
_alpm_log(PM_LOG_DEBUG, "checking package signature for %s\n", pkgpath);
memset(&ctx, 0, sizeof(ctx));
memset(&sigdata, 0, sizeof(sigdata));
memset(&pkgdata, 0, sizeof(pkgdata));
err = gpgme_new(&ctx);
CHECK_ERR();
/* create our necessary data objects to verify the signature */
/* first the package itself */
pkgfile = fopen(pkgpath, "rb");
if(pkgfile == NULL) {
pm_errno = PM_ERR_PKG_OPEN;
ret = -1;
goto error;
}
err = gpgme_data_new_from_stream(&pkgdata, pkgfile);
CHECK_ERR();
/* next create data object for the signature */
err = gpgme_data_new_from_mem(&sigdata, (char*)sig->rawdata, sig->rawlen, 0);
CHECK_ERR();
/* here's where the magic happens */
err = gpgme_op_verify(ctx, sigdata, pkgdata, NULL);
CHECK_ERR();
result = gpgme_op_verify_result(ctx);
gpgsig = result->signatures;
if (!gpgsig || gpgsig->next) {
_alpm_log(PM_LOG_ERROR, _("Unexpected number of signatures\n"));
ret = -1;
goto error;
}
_alpm_log(PM_LOG_DEBUG, "summary=%x\n", gpgsig->summary);
_alpm_log(PM_LOG_DEBUG, "fpr=%s\n", gpgsig->fpr);
_alpm_log(PM_LOG_DEBUG, "status=%d\n", gpgsig->status);
_alpm_log(PM_LOG_DEBUG, "timestamp=%lu\n", gpgsig->timestamp);
_alpm_log(PM_LOG_DEBUG, "wrong_key_usage=%u\n", gpgsig->wrong_key_usage);
_alpm_log(PM_LOG_DEBUG, "pka_trust=%u\n", gpgsig->pka_trust);
_alpm_log(PM_LOG_DEBUG, "chain_model=%u\n", gpgsig->chain_model);
_alpm_log(PM_LOG_DEBUG, "validity=%d\n", gpgsig->validity);
_alpm_log(PM_LOG_DEBUG, "validity_reason=%d\n", gpgsig->validity_reason);
_alpm_log(PM_LOG_DEBUG, "key=%d\n", gpgsig->pubkey_algo);
_alpm_log(PM_LOG_DEBUG, "hash=%d\n", gpgsig->hash_algo);
if(gpgsig->summary & GPGME_SIGSUM_VALID) {
/* good signature, continue */
_alpm_log(PM_LOG_DEBUG, _("Package %s has a valid signature.\n"),
pkgpath);
} else if(gpgsig->summary & GPGME_SIGSUM_GREEN) {
/* 'green' signature, not sure what to do here */
_alpm_log(PM_LOG_WARNING, _("Package %s has a green signature.\n"),
pkgpath);
} else if(gpgsig->summary & GPGME_SIGSUM_KEY_MISSING) {
pm_errno = PM_ERR_SIG_UNKNOWN;
_alpm_log(PM_LOG_WARNING, _("Package %s has a signature from an unknown key.\n"),
pkgpath);
ret = -1;
} else {
/* we'll capture everything else here */
pm_errno = PM_ERR_SIG_INVALID;
_alpm_log(PM_LOG_ERROR, _("Package %s has an invalid signature.\n"),
pkgpath);
ret = 1;
}
error:
gpgme_data_release(sigdata);
gpgme_data_release(pkgdata);
gpgme_release(ctx);
if(sigfile) {
fclose(sigfile);
}
if(pkgfile) {
fclose(pkgfile);
}
if(err != GPG_ERR_NO_ERROR) {
_alpm_log(PM_LOG_ERROR, _("GPGME error: %s\n"), gpgme_strerror(err));
RET_ERR(PM_ERR_GPGME, -1);
}
return ret;
}
/**
* Check the PGP package signature for the given package file.
* @param pkg the package to check
* @return a int value : 0 (valid), 1 (invalid), -1 (an error occured)
*/
int SYMEXPORT alpm_pkg_check_pgp_signature(pmpkg_t *pkg)
{
ALPM_LOG_FUNC;
ASSERT(pkg != NULL, return 0);
return _alpm_gpgme_checksig(alpm_pkg_get_filename(pkg),
alpm_pkg_get_pgpsig(pkg));
}
/* vim: set ts=2 sw=2 noet: */
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