refactoring sources

Change-Id: Id6d52eee86b706958972e9b345ec0d4d1e488146
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 371 insertions, 0 deletions

diff --git a/src/wgtpkg-xmlsec.c b/src/wgtpkg-xmlsec.c
new file mode 100644
index 0000000..843ea2b
--- /dev/null
+++ b/src/wgtpkg-xmlsec.c
@@ -0,0 +1,371 @@
+/*
+ Copyright 2015 IoT.bzh
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+
+#include <syslog.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <string.h>
+#include <assert.h>
+
+#include <libxml/tree.h>
+#include <xmlsec/xmlsec.h>
+#include <xmlsec/xmltree.h>
+#include <xmlsec/xmldsig.h>
+#include <xmlsec/crypto.h>
+#include <xmlsec/templates.h>
+#include <xmlsec/errors.h>
+#include <xmlsec/io.h>
+
+
+#include "wgtpkg.h"
+
+static int initstatus;
+static int initdone;
+static xmlSecKeysMngrPtr keymgr;
+
+#ifndef CA_ROOT_DIRECTORY
+#define CA_ROOT_DIRECTORY "./ca-certificates"
+#endif
+
+/* checks if a file match  uri (should not be a distributor signature) */
+static int file_match_cb(const char *uri)
+{
+	struct filedesc *fdesc = file_of_name(uri);
+	return fdesc != NULL && fdesc->type == type_file && (fdesc->flags & flag_distributor_signature) == 0;
+}
+
+/* open the file of uri */
+static void *file_open_cb(const char *file)
+{
+	struct filedesc *fdesc;
+	FILE *f;
+
+	fdesc = file_of_name(file);
+	if (fdesc == NULL) {
+		syslog(LOG_ERR, "shouldn't open uri %s", file);
+		return NULL;
+	}
+
+	f = fopen(file, "r");
+	if (f == NULL)
+		syslog(LOG_ERR, "can't open file %s for reading", file);
+	else
+		fdesc->flags |= flag_opened;
+
+	return f;
+}
+
+/* read the opened file */
+static int file_read_cb(void *context, char *buffer, int len)
+{
+	size_t r = fread(buffer, 1, len, (FILE*)context);
+	return r ? (int)r : feof((FILE*)context) ? 0 : - 1;
+}
+
+/* close the opened file */
+static int file_close_cb(void *context)
+{
+	return (int)fclose((FILE*)context);
+}
+
+/* echo an error message */
+static void errors_cb(const char *file, int line, const char *func, const char *errorObject, const char *errorSubject, int reason, const char *msg)
+{
+	syslog(LOG_ERR, "xmlSec error %3d: %s (subject=\"%s\", object=\"%s\")", reason, msg, errorSubject ? errorSubject : "?", errorObject ? errorObject : "?");
+}
+
+/* fills database with trusted keys */
+static int fill_trusted_keys()
+{
+	int err;
+	DIR *dir;
+	struct dirent *ent;
+	char path[PATH_MAX], *e;
+
+	e = stpcpy(path, CA_ROOT_DIRECTORY);
+	dir = opendir(path);
+	if (!dir) {
+		syslog(LOG_ERR, "opendir %s failed in fill_trusted_keys", path);
+		return -1;
+	}
+
+	*e++ = '/';
+	ent = readdir(dir);
+	while (ent != NULL) {
+		if (ent->d_type == DT_REG) {
+			strcpy(e, ent->d_name);
+			err = xmlSecCryptoAppKeysMngrCertLoad(keymgr, path, xmlSecKeyDataFormatPem, xmlSecKeyDataTypeTrusted);
+			if (err < 0) {
+				syslog(LOG_ERR, "xmlSecCryptoAppKeysMngrCertLoadMemory failed for %s", path);
+				closedir(dir);
+				return -1;
+			}
+		}
+		ent = readdir(dir);
+	}
+
+	closedir(dir);
+	return 0;
+	
+}
+
+/* initialisation of access to xmlsec */
+int xmlsec_init()
+{
+
+	if (initdone)
+		goto end;
+
+	initdone = 1;
+	initstatus = -1;
+
+	if(xmlSecInit() < 0) {
+		syslog(LOG_ERR, "xmlSecInit failed.");
+		goto end;
+	}
+
+#ifdef XMLSEC_CRYPTO_DYNAMIC_LOADING
+	if(xmlSecCryptoDLLoadLibrary(XMLSEC_CRYPTO) < 0) {
+		syslog(LOG_ERR, "xmlSecCryptoDLLoadLibrary %s failed.", XMLSEC_CRYPTO);
+		goto end;
+	}
+#endif
+
+	if(xmlSecCryptoAppInit(NULL) < 0) {
+		syslog(LOG_ERR, "xmlSecCryptoAppInit failed.");
+		goto end;
+	}
+
+	if(xmlSecCryptoInit() < 0) {
+		syslog(LOG_ERR, "xmlSecCryptoInit failed.");
+		goto end;
+	}
+
+	xmlSecErrorsSetCallback(errors_cb);
+
+	xmlSecIOCleanupCallbacks();
+	if (xmlSecIORegisterCallbacks(file_match_cb,
+					file_open_cb, file_read_cb, file_close_cb)) {
+		syslog(LOG_ERR, "xmlSecIORegisterCallbacks failed.");
+		goto end;
+	}
+
+	keymgr = xmlSecKeysMngrCreate();
+	if (keymgr == NULL) {
+		syslog(LOG_ERR, "xmlSecKeysMngrCreate failed.");
+		goto end;
+	}
+
+	if(xmlSecCryptoAppDefaultKeysMngrInit(keymgr) < 0) {
+		syslog(LOG_ERR, "xmlSecCryptoAppDefaultKeysMngrInit failed.");
+		goto end;
+	}
+	fill_trusted_keys();
+
+	initstatus = 0;
+end:
+	return initstatus;
+}
+
+/* shuting down accesses to xmlsec */
+void xmlsec_shutdown()
+{
+	xmlSecKeysMngrDestroy(keymgr);
+
+	xmlSecCryptoShutdown();
+	
+	xmlSecCryptoAppShutdown();
+	
+	xmlSecShutdown();
+}
+
+/* verify a signature */
+int xmlsec_verify(xmlNodePtr node)
+{
+	int rc;
+	xmlSecDSigCtxPtr dsigctx;
+
+	assert(initdone && !initstatus);
+
+	dsigctx = xmlSecDSigCtxCreate(keymgr);
+	if (dsigctx == NULL) {
+		syslog(LOG_ERR, "xmlSecDSigCtxCreate failed.");
+		rc = -1;
+	} else {
+		rc = xmlSecDSigCtxVerify(dsigctx, node);
+		if (rc)
+			syslog(LOG_ERR, "xmlSecDSigCtxVerify failed.");
+		else if (dsigctx->status != xmlSecDSigStatusSucceeded) {
+			syslog(LOG_ERR, "invalid signature.");
+			rc = -1;
+		}
+		xmlSecDSigCtxDestroy(dsigctx);
+	}
+
+	return rc;
+}
+
+/* templates for properties of signature files */
+static const struct { const char *id; const char *xml; } properties[2] = {
+	{
+		.id = "AuthorSignature", /* template of properties for author signature */
+		.xml =
+			"<SignatureProperties xmlns:dsp=\"http://www.w3.org/2009/xmldsig-properties\">"
+			 "<SignatureProperty Id=\"profile\" Target=\"#AuthorSignature\">"
+			  "<dsp:Profile URI=\"http://www.w3.org/ns/widgets-digsig#profile\"></dsp:Profile>"
+			 "</SignatureProperty>"
+			 "<SignatureProperty Id=\"role\" Target=\"#AuthorSignature\">"
+			   "<dsp:Role URI=\"http://www.w3.org/ns/widgets-digsig#role-author\"></dsp:Role>"
+			 "</SignatureProperty>"
+			 "<SignatureProperty Id=\"identifier\" Target=\"#AuthorSignature\">"
+			   "<dsp:Identifier></dsp:Identifier>"
+			 "</SignatureProperty>"
+			"</SignatureProperties>"
+	},
+	{
+		.id = "DistributorSignature", /* template of properties for distributor signature */
+		.xml = 
+			"<SignatureProperties xmlns:dsp=\"http://www.w3.org/2009/xmldsig-properties\">"
+			 "<SignatureProperty Id=\"profile\" Target=\"#DistributorSignature\">"
+			  "<dsp:Profile URI=\"http://www.w3.org/ns/widgets-digsig#profile\"></dsp:Profile>"
+			 "</SignatureProperty>"
+			 "<SignatureProperty Id=\"role\" Target=\"#DistributorSignature\">"
+			   "<dsp:Role URI=\"http://www.w3.org/ns/widgets-digsig#role-distributor\"></dsp:Role>"
+			 "</SignatureProperty>"
+			 "<SignatureProperty Id=\"identifier\" Target=\"#DistributorSignature\">"
+			   "<dsp:Identifier></dsp:Identifier>"
+			 "</SignatureProperty>"
+			"</SignatureProperties>"
+	}
+};
+
+/* create a signature of 'index' (0 for author, other values for distributors)
+using the private 'key' (filename) and the certificates 'certs' (filenames)
+as trusted chain */
+xmlDocPtr xmlsec_create(int index, const char *key, const char **certs)
+{
+	unsigned int i, fc, mask;
+	struct filedesc *fdesc;
+	xmlNodePtr sign, obj, ref, kinfo, props;
+	xmlDocPtr doc;
+	int rc;
+	xmlSecDSigCtxPtr dsigctx;
+
+	assert(initdone && !initstatus);
+
+	/* create the document */
+	doc = xmlNewDoc("1.0");
+	if (doc == NULL) {
+		syslog(LOG_ERR, "xmlNewDoc failed");
+		goto error;
+	}
+
+	/* create the root signature node */
+	sign = xmlSecTmplSignatureCreate(doc, xmlSecTransformInclC14N11Id, xmlSecTransformRsaSha256Id, properties[!!index].id);
+	if (sign == NULL) {
+		syslog(LOG_ERR, "xmlSecTmplSignatureCreate failed");
+		goto error2;
+	}
+	xmlDocSetRootElement(doc, sign);
+
+	/* create the object and its reference */
+	obj = xmlSecTmplSignatureAddObject(sign, "prop", NULL, NULL);
+	if (obj == NULL) {
+		syslog(LOG_ERR, "xmlSecTmplSignatureAddObject failed");
+		goto error2;
+	}
+	rc = xmlParseBalancedChunkMemory(doc, NULL, NULL, 0, properties[!!index].xml, &props);
+	if (rc) {
+		syslog(LOG_ERR, "xmlParseBalancedChunkMemory failed");
+		goto error2;
+	}
+	if (NULL == xmlAddChild(obj, props)) {
+		syslog(LOG_ERR, "filling object node failed");
+		xmlFreeNode(obj);
+		goto error2;
+	}
+
+	/* create references to files */
+	mask = index ? flag_distributor_signature : flag_signature;
+	fc = file_count();
+	for (i = 0 ; i < fc ; i++) {
+		fdesc = file_of_index(i);
+		if (fdesc->type == type_file && (fdesc->flags & mask) == 0) {
+			ref = xmlSecTmplSignatureAddReference(sign, xmlSecTransformSha256Id, NULL, fdesc->name, NULL);
+			if (ref == NULL) {
+				syslog(LOG_ERR, "creation of reference to %s failed", fdesc->name);
+				goto error2;
+			}
+		}
+	}
+
+	/* create reference to object having properties */
+	ref =  xmlSecTmplSignatureAddReference(sign, xmlSecTransformSha256Id, NULL, "#prop", NULL);
+	if (ref == NULL) {
+		syslog(LOG_ERR, "creation of reference to #prop failed");
+		goto error2;
+	}
+	if (NULL == xmlSecTmplReferenceAddTransform(ref, xmlSecTransformInclC14N11Id)) {
+		syslog(LOG_ERR, "setting transform reference to #prop failed");
+		goto error2;
+	}
+
+	/* adds the X509 data */
+	kinfo = xmlSecTmplSignatureEnsureKeyInfo(sign, NULL);
+	if (kinfo == NULL) {
+		syslog(LOG_ERR, "xmlSecTmplSignatureEnsureKeyInfo failed");
+		goto error2;
+	}
+	if (NULL == xmlSecTmplKeyInfoAddX509Data(kinfo)) {
+		syslog(LOG_ERR, "xmlSecTmplKeyInfoAddX509Data failed");
+		goto error2;
+	}
+
+	/* sign now */
+	dsigctx = xmlSecDSigCtxCreate(keymgr);
+	if (dsigctx == NULL) {
+		syslog(LOG_ERR, "xmlSecDSigCtxCreate failed.");
+		goto error3;
+	}
+	dsigctx->signKey = xmlSecCryptoAppKeyLoad(key, xmlSecKeyDataFormatPem, NULL, NULL, NULL);
+	if (dsigctx->signKey == NULL) {
+		syslog(LOG_ERR, "loading key %s failed.", key);
+		goto error3;
+	}
+	while (*certs) {
+		if(xmlSecCryptoAppKeyCertLoad(dsigctx->signKey, *certs, xmlSecKeyDataFormatPem) < 0) {
+			syslog(LOG_ERR, "loading certificate %s failed.", *certs);
+			goto error3;
+		}
+		certs++;
+	}
+	if(xmlSecDSigCtxSign(dsigctx, sign) < 0) {
+		syslog(LOG_ERR, "signing the document failed.");
+		goto error3;
+	}
+	xmlSecDSigCtxDestroy(dsigctx);
+	return doc;
+
+error3:
+	xmlSecDSigCtxDestroy(dsigctx);
+error2:
+	xmlFreeDoc(doc);
+error:
+	return NULL;
+}
+