/**
* XML Security Library example: Signing a file with a dynamicaly created template and an X509 certificate.
*
* Signs a file using a dynamicaly created template, key from PEM file and
* an X509 certificate. The signature has one reference with one enveloped
* transform to sign the whole document except the <dsig:Signature/> node
* itself. The key certificate is written in the <dsig:X509Data/> node.
*
* This example was developed and tested with OpenSSL crypto library. The
* certificates management policies for another crypto library may break it.
*
* Usage:
* sign3 <xml-doc> <pem-key>
*
* Example:
* ./sign3 sign3-doc.xml rsakey.pem rsacert.pem > sign3-res.xml
*
* The result signature could be validated using verify3 example:
* ./verify3 sign3-res.xml ca2cert.pem cacert.pem
*
* This is free software; see Copyright file in the source
* distribution for preciese wording.
*
* Copyright (C) 2002-2022 Aleksey Sanin <aleksey@aleksey.com>. All Rights Reserved.
*/
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#ifndef XMLSEC_NO_XSLT
#include <libxslt/xslt.h>
#include <libxslt/security.h>
#endif /* XMLSEC_NO_XSLT */
#include <xmlsec/xmlsec.h>
#include <xmlsec/xmltree.h>
#include <xmlsec/xmldsig.h>
#include <xmlsec/templates.h>
#include <xmlsec/crypto.h>
int sign_file(const char* xml_file, const char* key_file, const char* cert_file);
int
main(int argc, char **argv) {
#ifndef XMLSEC_NO_XSLT
xsltSecurityPrefsPtr xsltSecPrefs = NULL;
#endif /* XMLSEC_NO_XSLT */
assert(argv);
if(argc != 4) {
fprintf(stderr, "Error: wrong number of arguments.\n");
fprintf(stderr, "Usage: %s <xml-file> <key-file> <cert-file>\n", argv[0]);
return(1);
}
/* Init libxml and libxslt libraries */
xmlInitParser();
LIBXML_TEST_VERSION
xmlLoadExtDtdDefaultValue = XML_DETECT_IDS | XML_COMPLETE_ATTRS;
xmlSubstituteEntitiesDefault(1);
#ifndef XMLSEC_NO_XSLT
xmlIndentTreeOutput = 1;
#endif /* XMLSEC_NO_XSLT */
/* Init libxslt */
#ifndef XMLSEC_NO_XSLT
/* disable everything */
xsltSecPrefs = xsltNewSecurityPrefs();
xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_READ_FILE, xsltSecurityForbid);
xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_WRITE_FILE, xsltSecurityForbid);
xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_CREATE_DIRECTORY, xsltSecurityForbid);
xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_READ_NETWORK, xsltSecurityForbid);
xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_WRITE_NETWORK, xsltSecurityForbid);
xsltSetDefaultSecurityPrefs(xsltSecPrefs);
#endif /* XMLSEC_NO_XSLT */
/* Init xmlsec library */
if(xmlSecInit() < 0) {
fprintf(stderr, "Error: xmlsec initialization failed.\n");
return(-1);
}
/* Check loaded library version */
if(xmlSecCheckVersion() != 1) {
fprintf(stderr, "Error: loaded xmlsec library version is not compatible.\n");
return(-1);
}
/* Load default crypto engine if we are supporting dynamic
* loading for xmlsec-crypto libraries. Use the crypto library
* name ("openssl", "nss", etc.) to load corresponding
* xmlsec-crypto library.
*/
#ifdef XMLSEC_CRYPTO_DYNAMIC_LOADING
if(xmlSecCryptoDLLoadLibrary(NULL) < 0) {
fprintf(stderr, "Error: unable to load default xmlsec-crypto library. Make sure\n"
"that you have it installed and check shared libraries path\n"
"(LD_LIBRARY_PATH and/or LTDL_LIBRARY_PATH) environment variables.\n");
return(-1);
}
#endif /* XMLSEC_CRYPTO_DYNAMIC_LOADING */
/* Init crypto library */
if(xmlSecCryptoAppInit(NULL) < 0) {
fprintf(stderr, "Error: crypto initialization failed.\n");
return(-1);
}
/* Init xmlsec-crypto library */
if(xmlSecCryptoInit() < 0) {
fprintf(stderr, "Error: xmlsec-crypto initialization failed.\n");
return(-1);
}
if(sign_file(argv[1], argv[2], argv[3]) < 0) {
return(-1);
}
/* Shutdown xmlsec-crypto library */
xmlSecCryptoShutdown();
/* Shutdown crypto library */
xmlSecCryptoAppShutdown();
/* Shutdown xmlsec library */
xmlSecShutdown();
/* Shutdown libxslt/libxml */
#ifndef XMLSEC_NO_XSLT
xsltFreeSecurityPrefs(xsltSecPrefs);
xsltCleanupGlobals();
#endif /* XMLSEC_NO_XSLT */
xmlCleanupParser();
return(0);
}
/**
* sign_file:
* @xml_file: the XML file name.
* @key_file: the PEM private key file name.
* @cert_file: the x509 certificate PEM file.
*
* Signs the @xml_file using private key from @key_file and dynamicaly
* created enveloped signature template. The certificate from @cert_file
* is placed in the <dsig:X509Data/> node.
*
* Returns 0 on success or a negative value if an error occurs.
*/
int
sign_file(const char* xml_file, const char* key_file, const char* cert_file) {
xmlDocPtr doc = NULL;
xmlNodePtr signNode = NULL;
xmlNodePtr refNode = NULL;
xmlNodePtr keyInfoNode = NULL;
xmlNodePtr x509DataNode = NULL;
xmlSecDSigCtxPtr dsigCtx = NULL;
int res = -1;
assert(xml_file);
assert(key_file);
assert(cert_file);
/* load doc file */
doc = xmlParseFile(xml_file);
if ((doc == NULL) || (xmlDocGetRootElement(doc) == NULL)){
fprintf(stderr, "Error: unable to parse file \"%s\"\n", xml_file);
goto done;
}
/* create signature template for RSA-SHA1 enveloped signature */
signNode = xmlSecTmplSignatureCreate(doc, xmlSecTransformExclC14NId,
xmlSecTransformRsaSha1Id, NULL);
if(signNode == NULL) {
fprintf(stderr, "Error: failed to create signature template\n");
goto done;
}
/* add <dsig:Signature/> node to the doc */
xmlAddChild(xmlDocGetRootElement(doc), signNode);
/* add reference */
refNode = xmlSecTmplSignatureAddReference(signNode, xmlSecTransformSha1Id,
NULL, NULL, NULL);
if(refNode == NULL) {
fprintf(stderr, "Error: failed to add reference to signature template\n");
goto done;
}
/* add enveloped transform */
if(xmlSecTmplReferenceAddTransform(refNode, xmlSecTransformEnvelopedId) == NULL) {
fprintf(stderr, "Error: failed to add enveloped transform to reference\n");
goto done;
}
/* add <dsig:KeyInfo/> and <dsig:X509Data/> */
keyInfoNode = xmlSecTmplSignatureEnsureKeyInfo(signNode, NULL);
if(keyInfoNode == NULL) {
fprintf(stderr, "Error: failed to add key info\n");
goto done;
}
x509DataNode = xmlSecTmplKeyInfoAddX509Data(keyInfoNode);
if(x509DataNode == NULL) {
fprintf(stderr, "Error: failed to add X509Data node\n");
goto done;
}
if(xmlSecTmplX509DataAddSubjectName(x509DataNode) == NULL) {
fprintf(stderr, "Error: failed to add X509SubjectName node\n");
goto done;
}
if(xmlSecTmplX509DataAddCertificate(x509DataNode) == NULL) {
fprintf(stderr, "Error: failed to add X509Certificate node\n");
goto done;
}
/* create signature context, we don't need keys manager in this example */
dsigCtx = xmlSecDSigCtxCreate(NULL);
if(dsigCtx == NULL) {
fprintf(stderr,"Error: failed to create signature context\n");
goto done;
}
/* load private key, assuming that there is not password */
dsigCtx->signKey = xmlSecCryptoAppKeyLoadEx(key_file, xmlSecKeyDataTypePrivate, xmlSecKeyDataFormatPem, NULL, NULL, NULL);
if(dsigCtx->signKey == NULL) {
fprintf(stderr,"Error: failed to load private pem key from \"%s\"\n", key_file);
goto done;
}
/* load certificate and add to the key */
if(xmlSecCryptoAppKeyCertLoad(dsigCtx->signKey, cert_file, xmlSecKeyDataFormatPem) < 0) {
fprintf(stderr,"Error: failed to load pem certificate \"%s\"\n", cert_file);
goto done;
}
/* set key name to the file name, this is just an example! */
if(xmlSecKeySetName(dsigCtx->signKey, BAD_CAST key_file) < 0) {
fprintf(stderr,"Error: failed to set key name for key from \"%s\"\n", key_file);
goto done;
}
/* sign the template */
if(xmlSecDSigCtxSign(dsigCtx, signNode) < 0) {
fprintf(stderr,"Error: signature failed\n");
goto done;
}
/* print signed document to stdout */
xmlDocDump(stdout, doc);
/* success */
res = 0;
done:
/* cleanup */
if(dsigCtx != NULL) {
xmlSecDSigCtxDestroy(dsigCtx);
}
if(doc != NULL) {
xmlFreeDoc(doc);
}
return(res);
}
