Integrate GPGME into libalpm

Signed-off-by: Dan McGee <dan@archlinux.org>

6 files changed, 282 insertions, 16 deletions

diff --git a/lib/libalpm/Makefile.am b/lib/libalpm/Makefile.am
index 7c411b2c..dc6d8516 100644
--- a/lib/libalpm/Makefile.am
+++ b/lib/libalpm/Makefile.am
@@ -43,6 +43,7 @@ libalpm_la_SOURCES = \
 	package.h package.c \
 	pkghash.h pkghash.c \
 	remove.h remove.c \
+	signing.c signing.h \
 	sync.h sync.c \
 	trans.h trans.c \
 	util.h util.c \
diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 1c8d232e..150730ce 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -246,6 +246,12 @@ off_t alpm_pkg_download_size(pmpkg_t *newpkg);
 alpm_list_t *alpm_pkg_unused_deltas(pmpkg_t *pkg);
 
 /*
+ * Signatures
+ */
+
+int alpm_pkg_check_pgp_signature(pmpkg_t *pkg);
+
+/*
  * Deltas
  */
 
@@ -527,6 +533,7 @@ enum _pmerrno_t {
 	PM_ERR_PKG_INVALID_ARCH,
 	PM_ERR_PKG_REPO_NOT_FOUND,
 	/* Signatures */
+	PM_ERR_SIG_MISSINGDIR,
 	PM_ERR_SIG_INVALID,
 	PM_ERR_SIG_UNKNOWN,
 	/* Deltas */
@@ -543,7 +550,8 @@ enum _pmerrno_t {
 	/* External library errors */
 	PM_ERR_LIBARCHIVE,
 	PM_ERR_LIBCURL,
-	PM_ERR_EXTERNAL_DOWNLOAD
+	PM_ERR_EXTERNAL_DOWNLOAD,
+	PM_ERR_GPGME
 };
 
 extern enum _pmerrno_t pm_errno;
diff --git a/lib/libalpm/error.c b/lib/libalpm/error.c
index 71c058f6..4d4a065c 100644
--- a/lib/libalpm/error.c
+++ b/lib/libalpm/error.c
@@ -116,6 +116,8 @@ const char SYMEXPORT *alpm_strerror(int err)
 		case PM_ERR_PKG_REPO_NOT_FOUND:
 			return _("could not find repository for target");
 		/* Signatures */
+		case PM_ERR_SIG_MISSINGDIR:
+			return _("signature directory not configured correctly");
 		case PM_ERR_SIG_INVALID:
 			return _("invalid PGP signature");
 		case PM_ERR_SIG_UNKNOWN:
@@ -152,6 +154,8 @@ const char SYMEXPORT *alpm_strerror(int err)
 			/* obviously shouldn't get here... */
 			return _("download library error");
 #endif
+		case PM_ERR_GPGME:
+			return _("gpgme error");
 		case PM_ERR_EXTERNAL_DOWNLOAD:
 			return _("error invoking external downloader");
 		/* Unknown error! */
diff --git a/lib/libalpm/signing.c b/lib/libalpm/signing.c
new file mode 100644
index 00000000..27855798
--- /dev/null
+++ b/lib/libalpm/signing.c
@@ -0,0 +1,219 @@
+/*
+ *  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;
+	}
+	fprintf(stdout, "\nsummary=%x\n", gpgsig->summary);
+	fprintf(stdout, "fpr=%s\n", gpgsig->fpr);
+	fprintf(stdout, "status=%d\n", gpgsig->status);
+	fprintf(stdout, "timestamp=%lu\n", gpgsig->timestamp);
+	fprintf(stdout, "wrong_key_usage=%u\n", gpgsig->wrong_key_usage);
+	fprintf(stdout, "pka_trust=%u\n", gpgsig->pka_trust);
+	fprintf(stdout, "chain_model=%u\n", gpgsig->chain_model);
+	fprintf(stdout, "validity=%d\n", gpgsig->validity);
+	fprintf(stdout, "validity_reason=%d\n", gpgsig->validity_reason);
+	fprintf(stdout, "key=%d\n", gpgsig->pubkey_algo);
+	fprintf(stdout, "hash=%d\n", gpgsig->hash_algo);
+
+	if(gpgsig->summary & GPGME_SIGSUM_VALID) {
+		/* good signature, continue */
+	} 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: */
diff --git a/lib/libalpm/signing.h b/lib/libalpm/signing.h
new file mode 100644
index 00000000..bd12de42
--- /dev/null
+++ b/lib/libalpm/signing.h
@@ -0,0 +1,28 @@
+/*
+ *  signing.h
+ *
+ *  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/>.
+ */
+#ifndef _ALPM_SIGNING_H
+#define _ALPM_SIGNING_H
+
+#include "alpm.h"
+
+int _alpm_gpgme_checksig(const char *pkgpath, const pmpgpsig_t *sig);
+
+#endif /* _ALPM_SIGNING_H */
+
+/* vim: set ts=2 sw=2 noet: */
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index e0a86706..5e7cf293 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -50,6 +50,7 @@
 #include "delta.h"
 #include "remove.h"
 #include "diskspace.h"
+#include "signing.h"
 
 /** Check for new version of pkg in sync repos
  * (only the first occurrence is considered in sync)
@@ -665,32 +666,24 @@ static int apply_deltas(pmtrans_t *trans)
  * should be deleted.
  *
  * @param trans the transaction
- * @param filename the filename of the file to test
+ * @param filename the absolute path of the file to test
  * @param md5sum the expected md5sum of the file
  *
  * @return 0 if the md5sum matched, 1 if not, -1 in case of errors
  */
-static int test_md5sum(pmtrans_t *trans, const char *filename,
+static int test_md5sum(pmtrans_t *trans, const char *filepath,
 		const char *md5sum)
 {
-	char *filepath;
-	int ret;
-
-	filepath = _alpm_filecache_find(filename);
-
-	ret = _alpm_test_md5sum(filepath, md5sum);
-
+	int ret = _alpm_test_md5sum(filepath, md5sum);
 	if(ret == 1) {
 		int doremove = 0;
-		QUESTION(trans, PM_TRANS_CONV_CORRUPTED_PKG, (char *)filename,
+		QUESTION(trans, PM_TRANS_CONV_CORRUPTED_PKG, (char*)filepath,
 				NULL, NULL, &doremove);
 		if(doremove) {
 			unlink(filepath);
 		}
 	}
 
-	FREE(filepath);
-
 	return ret;
 }
 
@@ -800,12 +793,14 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 		for(i = deltas; i; i = i->next) {
 			pmdelta_t *d = alpm_list_getdata(i);
 			const char *filename = alpm_delta_get_filename(d);
+			char *filepath = _alpm_filecache_find(filename);
 			const char *md5sum = alpm_delta_get_md5sum(d);
 
-			if(test_md5sum(trans, filename, md5sum) != 0) {
+			if(test_md5sum(trans, filepath, md5sum) != 0) {
 				errors++;
 				*data = alpm_list_add(*data, strdup(filename));
 			}
+			FREE(filepath);
 		}
 		if(errors) {
 			pm_errno = PM_ERR_DLT_INVALID;
@@ -829,6 +824,7 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 	EVENT(trans, PM_TRANS_EVT_INTEGRITY_START, NULL, NULL);
 
 	errors = 0;
+
 	for(i = trans->add; i; i = i->next, current++) {
 		pmpkg_t *spkg = i->data;
 		int percent = (current * 100) / numtargs;
@@ -839,17 +835,27 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 				numtargs, current);
 
 		const char *filename = alpm_pkg_get_filename(spkg);
+		char *filepath = _alpm_filecache_find(filename);
 		const char *md5sum = alpm_pkg_get_md5sum(spkg);
+		const pmpgpsig_t *pgpsig = alpm_pkg_get_pgpsig(spkg);
 
-		if(test_md5sum(trans, filename, md5sum) != 0) {
+		/* check md5sum first */
+		if(test_md5sum(trans, filepath, md5sum) != 0) {
 			errors++;
 			*data = alpm_list_add(*data, strdup(filename));
+			FREE(filepath);
+			continue;
+		}
+		/* check PGP signature next */
+		if(_alpm_gpgme_checksig(filepath, pgpsig) != 0) {
+			errors++;
+			*data = alpm_list_add(*data, strdup(filename));
+			FREE(filepath);
 			continue;
 		}
 		/* load the package file and replace pkgcache entry with it in the target list */
 		/* TODO: alpm_pkg_get_db() will not work on this target anymore */
 		_alpm_log(PM_LOG_DEBUG, "replacing pkgcache entry with package file for target %s\n", spkg->name);
-		char *filepath = _alpm_filecache_find(filename);
 		pmpkg_t *pkgfile;
 		if(alpm_pkg_load(filepath, 1, &pkgfile) != 0) {
 			_alpm_pkg_free(pkgfile);