[xmlsec] Win32 rsa encryption with Aes192 session key crashes
Bundschuh, Goetz
Goetz.Bundschuh at usd.de
Wed Jul 20 02:12:07 PDT 2005
Hi,
I tried to adapt the tutorial example "Using keys manager for encryption."
to work with RSA public keys extracted from certificates in the MS store under
WinXP SP2. I also changed the symmetric algorithm used from 3Des to Aes 192.
While the example worked flawlessly while using OpenSSL and .pem-files, trying
to run it with mscrypto leads to a crash with an access violation during the
xmlSecEncCtxXmlEncrypt() call. My best guess after 2 days of debugging
attempts is that the RSA key extracted from the certificate store is not
correctly added to the Keymanager during the
xmlSecCryptoAppDefaultKeysMngrAdoptKey() call, but I have no clue why.
I use the following Binaries:
xmlsec 1.2.8
libxml2 2.6.19
Thanks in advance,
Goetz
Here's the Code I used:
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <windows.h>
#include <Wincrypt.h>
#define XMLSEC_CRYPTO_DYNAMIC_LOADING
#define XMLSEC_CRYPTO "mscrypto"
#define DEFAULT_CERT 1
#define USER_CERT_STORE_NAME "My"
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#ifndef XMLSEC_NO_XSLT
#include <libxslt/xslt.h>
#endif /* XMLSEC_NO_XSLT */
#include <xmlsec/xmlsec.h>
#include <xmlsec/xmltree.h>
#include <xmlsec/xmlenc.h>
#include <xmlsec/templates.h>
#include <xmlsec/crypto.h>
#include <xmlsec/mscrypto/certkeys.h>
xmlSecKeysMngrPtr load_rsa_keys(char** key_file, HCERTSTORE storeHandle);
int encrypt_file(xmlSecKeysMngrPtr mngr, const char* xml_file, const char*
keyName);
int
main(int argc, char **argv) {
xmlSecKeysMngrPtr mngr;
HCERTSTORE storeHandle = NULL; // Certificate store handle.
char* keyName = NULL;
assert(argv);
if(argc != 2) {
fprintf(stderr, "Error: wrong number of arguments.\n");
fprintf(stderr, "Usage: %s <xml-file>\n", argv[0]);
return(1);
}
if ( !(storeHandle = CertOpenSystemStore(NULL,USER_CERT_STORE_NAME)))
{
fprintf(stderr, "Error: unable to open certificate store\n");
return (NULL);
}
/* 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 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(BAD_CAST XMLSEC_CRYPTO) < 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) envornment variable.\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);
}
/* create keys manager and load keys */
mngr = load_rsa_keys(&keyName, storeHandle);
if(mngr == NULL) {
return(-1);
}
/* we use keyName as key name here */
if(encrypt_file(mngr, argv[1], (const char*)keyName) < 0)
{
xmlSecKeysMngrDestroy(mngr);
return(-1);
}
/* destroy keys manager */
return(0);
}
/**
* load_rsa_keys:
* @keyName: pointer to key name(out).
* @storeHandle handle for Mscrypto store
*
* Creates simple keys manager and loads an RSA key from the first certificate
in the MScrypto-store.
* The caller is responsible for destroing returned keys manager using
* @xmlSecKeysMngrDestroy.
*
* Returns the pointer to newly created keys manager or NULL if an error
* occurs.
*/
xmlSecKeysMngrPtr
load_rsa_keys(char** keyName,
HCERTSTORE storeHandle) {
xmlSecKeysMngrPtr mngr; // Security Manager Pointer
xmlSecKeyPtr key; // Key Pointer
PCCERT_CONTEXT certContext = NULL; // Certificate context
certContext= CertEnumCertificatesInStore(storeHandle, certContext);
/* create and initialize keys manager, we use a simple list based
* keys manager, implement your own xmlSecKeysStore klass if you need
* something more sophisticated
*/
mngr = xmlSecKeysMngrCreate();
if(mngr == NULL)
{
fprintf(stderr, "Error: failed to create keys manager.\n");
return(NULL);
}
if(xmlSecCryptoAppDefaultKeysMngrInit(mngr) < 0)
{
fprintf(stderr, "Error: failed to initialize keys manager.\n");
xmlSecKeysMngrDestroy(mngr);
return(NULL);
}
//Create key from certificate public key data
key = xmlSecKeyCreate();
/* load public RSA key */
xmlSecKeySetValue(key,xmlSecMSCryptoCertAdopt(certContext,
xmlSecKeyDataTypePublic));;
int size =CertGetNameString(certContext,
CERT_NAME_FRIENDLY_DISPLAY_TYPE,
0,
NULL,
NULL,
0);
if(size>0)
{
*keyName = (char *)malloc(size);
CertGetNameString(certContext,
CERT_NAME_FRIENDLY_DISPLAY_TYPE,
0,
NULL,
*keyName,
size);
}
else
{
// cleaning
fprintf(stderr, "Error: reading subject name for certificate failed.\n");
CertFreeCertificateContext(certContext);
xmlSecKeyDestroy(key);
xmlSecKeysMngrDestroy(mngr);
CertCloseStore(storeHandle,0);
return (NULL);
}
/* set key name to the certificate friendly name*/
if(xmlSecKeySetName(key, BAD_CAST *keyName) < 0)
{
fprintf(stderr,"Error: failed to set key name for key from \"%s\"\n",
*keyName);
xmlSecKeyDestroy(key);
xmlSecKeysMngrDestroy(mngr);
return(NULL);
}
/* add key to keys manager, from now on keys manager is responsible
* for destroying key
*/
if(xmlSecCryptoAppDefaultKeysMngrAdoptKey(mngr, key) < 0)
{
fprintf(stderr,"Error: failed to add key from \"%s\" to keys
manager\n", *keyName);
xmlSecKeyDestroy(key);
xmlSecKeysMngrDestroy(mngr);
return(NULL);
}
CertFreeCertificateContext(certContext);
return(mngr);
}
/**
* encrypt_file:
* @mngr: the pointer to keys manager.
* @xml_file: the encryption template file name.
* @keyName: the RSA key name.
*
* Encrypts #xml_file using a dynamicaly created template, a session Aes192
key
* and an RSA key from keys manager.
*
* Returns 0 on success or a negative value if an error occurs.
*/
int
encrypt_file(xmlSecKeysMngrPtr mngr, const char* xml_file, const char*
keyName) {
xmlDocPtr doc = NULL;
xmlNodePtr encDataNode = NULL;
xmlNodePtr keyInfoNode = NULL;
xmlNodePtr encKeyNode = NULL;
xmlNodePtr keyInfoNode2 = NULL;
xmlSecEncCtxPtr encCtx = NULL;
int res = -1;
assert(mngr);
assert(xml_file);
assert(keyName);
/* load template */
doc = xmlParseFile(xml_file);
if ((doc == NULL) || (xmlDocGetRootElement(doc) == NULL))
{
fprintf(stderr, "Error: unable to parse file \"%s\"\n", xml_file);
goto done;
}
/* create encryption template to encrypt XML file and replace
* its content with encryption result */
encDataNode = xmlSecTmplEncDataCreate(doc, xmlSecTransformAes192CbcId,
NULL, xmlSecTypeEncElement, NULL, NULL);
if(encDataNode == NULL) {
fprintf(stderr, "Error: failed to create encryption template\n");
goto done;
}
/* we want to put encrypted data in the <enc:CipherValue/> node */
if(xmlSecTmplEncDataEnsureCipherValue(encDataNode) == NULL) {
fprintf(stderr, "Error: failed to add CipherValue node\n");
goto done;
}
/* add <dsig:KeyInfo/> */
keyInfoNode = xmlSecTmplEncDataEnsureKeyInfo(encDataNode, NULL);
if(keyInfoNode == NULL) {
fprintf(stderr, "Error: failed to add key info\n");
goto done;
}
/* add <enc:EncryptedKey/> to store the encrypted session key */
encKeyNode = xmlSecTmplKeyInfoAddEncryptedKey(keyInfoNode,
xmlSecTransformRsaPkcs1Id,
NULL, NULL, NULL);
if(encKeyNode == NULL)
{
fprintf(stderr, "Error: failed to add key info\n");
goto done;
}
/* we want to put encrypted key in the <enc:CipherValue/> node */
if(xmlSecTmplEncDataEnsureCipherValue(encKeyNode) == NULL)
{
fprintf(stderr, "Error: failed to add CipherValue node\n");
goto done;
}
/* add <dsig:KeyInfo/> and <dsig:KeyName/> nodes to <enc:EncryptedKey/> */
keyInfoNode2 = xmlSecTmplEncDataEnsureKeyInfo(encKeyNode, NULL);
if(keyInfoNode2 == NULL)
{
fprintf(stderr, "Error: failed to add key info\n");
goto done;
}
/* set key name so we can lookup key when needed */
if(xmlSecTmplKeyInfoAddKeyName(keyInfoNode2, (const unsigned
char*)keyName) == NULL) {
fprintf(stderr, "Error: failed to add key name\n");
goto done;
}
/* create encryption context */
encCtx = xmlSecEncCtxCreate(mngr);
if(encCtx == NULL)
{
fprintf(stderr,"Error: failed to create encryption context\n");
goto done;
}
/* generate a Aes192 DES key */
encCtx->encKey = xmlSecKeyGenerate(xmlSecKeyDataAesId, 192,
xmlSecKeyDataTypeSession);
if(encCtx->encKey == NULL) {
fprintf(stderr,"Error: failed to generate session des key\n");
goto done;
}
/* encrypt the data */
if(xmlSecEncCtxXmlEncrypt(encCtx, encDataNode, xmlDocGetRootElement(doc))
< 0) {
fprintf(stderr,"Error: encryption failed\n");
goto done;
}
/* we template is inserted in the doc */
encDataNode = NULL;
/* print encrypted data with document to stdout */
xmlDocDump(stdout, doc);
/* success */
res = 0;
done:
/* cleanup */
if(encCtx != NULL)
{
xmlSecEncCtxDestroy(encCtx);
}
if(encDataNode != NULL) {
xmlFreeNode(encDataNode);
}
if(doc != NULL) {
xmlFreeDoc(doc);
}
return(res);
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3328 bytes
Desc: not available
Url : http://www.aleksey.com/pipermail/xmlsec/attachments/20050720/98bfee47/smime-0002.bin
More information about the xmlsec
mailing list