void bdoc::Signature::checkSignatureValue()
{
X509Cert cert(getSigningCertificate());
const dsig::SignatureMethodType::AlgorithmType&
algorithmType = getSignatureMethodAlgorithmType();
const char* algorithmUri = algorithmType.c_str();
// Get hash method URI from signature method URI.
signatureMethod sm;
hashMethod hm;
safeBuffer hashMethodUri;
if (!XSECmapURIToSignatureMethods(XMLString::transcode(algorithmUri), sm, hm)
|| !hashMethod2URI(hashMethodUri, hm)) {
THROW_STACK_EXCEPTION("Couldn't extract hash method from "
"signature method URI '%s'.", algorithmUri);
}
std::auto_ptr<Digest> calc = Digest::create(hashMethodUri.rawCharBuffer());
std::vector<unsigned char> digest =
calcDigestOnNode(calc.get(), DSIG_NAMESPACE, "SignedInfo");
std::vector<unsigned char> signatureValue = getSignatureValue();
if (!cert.verifySignature(calc->getMethod(), calc->getSize(), digest,
signatureValue)) {
THROW_STACK_EXCEPTION("Signature is not valid.");
}
}
bool DSIGAlgorithmHandlerDefault::appendSignatureHashTxfm(TXFMChain * inputBytes,
const XMLCh * URI,
XSECCryptoKey * key) {
signatureMethod sm;
hashMethod hm;
// Map to internal constants
if (!XSECmapURIToSignatureMethods(URI, sm, hm)) {
safeBuffer sb;
sb.sbTranscodeIn("DSIGAlgorithmHandlerDefault - Unknown URI : ");
sb.sbXMLChCat(URI);
throw XSECException(XSECException::AlgorithmMapperError,
sb.rawXMLChBuffer());
}
// Now append the appropriate hash transform onto the end of the chain
// If this is an HMAC of some kind - this function will add the appropriate key
TXFMBase * htxfm = addHashTxfm(sm, hm, key, inputBytes->getLastTxfm()->getDocument());
inputBytes->appendTxfm(htxfm);
return true;
}
// --------------------------------------------------------------------------------
// Verify
// --------------------------------------------------------------------------------
bool DSIGAlgorithmHandlerDefault::verifyBase64Signature(
TXFMChain * inputBytes,
const XMLCh * URI,
const char * sig,
unsigned int outputLength,
XSECCryptoKey * key) {
signatureMethod sm;
hashMethod hm;
// Map to internal constants
if (!XSECmapURIToSignatureMethods(URI, sm, hm)) {
safeBuffer sb;
sb.sbTranscodeIn("DSIGAlgorithmHandlerDefault - Unknown URI : ");
sb.sbXMLChCat(URI);
throw XSECException(XSECException::AlgorithmMapperError,
sb.rawXMLChBuffer());
}
// Now append the appropriate hash transform onto the end of the chain
// If this is an HMAC of some kind - this function will add the appropriate key
TXFMBase * htxfm = addHashTxfm(sm, hm, key, inputBytes->getLastTxfm()->getDocument());
inputBytes->appendTxfm(htxfm);
unsigned char hash[4096];
int hashLen = inputBytes->getLastTxfm()->readBytes((XMLByte *) hash, 4096);
// Now check the calculated hash
bool sigVfyRet = false;
switch (key->getKeyType()) {
case (XSECCryptoKey::KEY_DSA_PUBLIC) :
case (XSECCryptoKey::KEY_DSA_PAIR) :
if (sm != SIGNATURE_DSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
sigVfyRet = ((XSECCryptoKeyDSA *) key)->verifyBase64Signature(
hash,
hashLen,
(char *) sig,
(unsigned int) strlen(sig));
break;
case (XSECCryptoKey::KEY_RSA_PUBLIC) :
case (XSECCryptoKey::KEY_RSA_PAIR) :
if (sm != SIGNATURE_RSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
sigVfyRet = ((XSECCryptoKeyRSA *) key)->verifySHA1PKCS1Base64Signature(
hash,
hashLen,
sig,
(unsigned int) strlen(sig),
hm);
break;
case (XSECCryptoKey::KEY_EC_PUBLIC) :
case (XSECCryptoKey::KEY_EC_PAIR) :
if (sm != SIGNATURE_ECDSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
sigVfyRet = ((XSECCryptoKeyEC *) key)->verifyBase64SignatureDSA(
hash,
hashLen,
(char *) sig,
(unsigned int) strlen(sig));
break;
case (XSECCryptoKey::KEY_HMAC) :
// Already done - just compare calculated value with read value
// FIX: CVE-2009-0217
if (outputLength > 0 && (outputLength > hashLen || outputLength < 80 || outputLength < hashLen / 2)) {
throw XSECException(XSECException::AlgorithmMapperError,
"HMACOutputLength set to unsafe value.");
}
sigVfyRet = compareBase64StringToRaw(sig,
hash,
hashLen,
outputLength);
break;
default :
throw XSECException(XSECException::AlgorithmMapperError,
"Key found, but don't know how to check the signature using it");
}
return sigVfyRet;
}
unsigned int DSIGAlgorithmHandlerDefault::signToSafeBuffer(
TXFMChain * inputBytes,
const XMLCh * URI,
XSECCryptoKey * key,
unsigned int outputLength,
safeBuffer & result) {
signatureMethod sm;
hashMethod hm;
// Map to internal constants
if (!XSECmapURIToSignatureMethods(URI, sm, hm)) {
safeBuffer sb;
sb.sbTranscodeIn("DSIGAlgorithmHandlerDefault - Unknown URI : ");
sb.sbXMLChCat(URI);
throw XSECException(XSECException::AlgorithmMapperError,
sb.rawXMLChBuffer());
}
// Now append the appropriate hash transform onto the end of the chain
// If this is an HMAC of some kind - this function will add the appropriate key
TXFMBase * htxfm = addHashTxfm(sm, hm, key, inputBytes->getLastTxfm()->getDocument());
inputBytes->appendTxfm(htxfm);
unsigned char hash[4096];
int hashLen = inputBytes->getLastTxfm()->readBytes((XMLByte *) hash, 4096);
// Now check the calculated hash
// For now, use a fixed length buffer, but expand it,
// and detect if the signature size exceeds what we can
// handle.
char b64Buf[MAXB64BUFSIZE];
unsigned int b64Len;
safeBuffer b64SB;
switch (key->getKeyType()) {
case (XSECCryptoKey::KEY_DSA_PRIVATE) :
case (XSECCryptoKey::KEY_DSA_PAIR) :
if (sm != SIGNATURE_DSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
b64Len = ((XSECCryptoKeyDSA *) key)->signBase64Signature(
hash,
hashLen,
(char *) b64Buf,
MAXB64BUFSIZE);
if (b64Len <= 0) {
throw XSECException(XSECException::AlgorithmMapperError,
"Unknown error occured during a DSA Signing operation");
}
else if (b64Len >= MAXB64BUFSIZE) {
throw XSECException(XSECException::AlgorithmMapperError,
"DSA Signing operation exceeded size of buffer");
}
if (b64Buf[b64Len-1] == '\n')
b64Buf[b64Len-1] = '\0';
else
b64Buf[b64Len] = '\0';
break;
case (XSECCryptoKey::KEY_RSA_PRIVATE) :
case (XSECCryptoKey::KEY_RSA_PAIR) :
if (sm != SIGNATURE_RSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
b64Len = ((XSECCryptoKeyRSA *) key)->signSHA1PKCS1Base64Signature(
hash,
hashLen,
(char *) b64Buf,
MAXB64BUFSIZE,
hm);
if (b64Len <= 0) {
throw XSECException(XSECException::AlgorithmMapperError,
"Unknown error occured during a RSA Signing operation");
}
else if (b64Len >= MAXB64BUFSIZE) {
throw XSECException(XSECException::AlgorithmMapperError,
"RSA Signing operation exceeded size of buffer");
}
// Clean up some "funnies" and make sure the string is NULL terminated
if (b64Buf[b64Len-1] == '\n')
b64Buf[b64Len-1] = '\0';
else
b64Buf[b64Len] = '\0';
break;
case (XSECCryptoKey::KEY_EC_PRIVATE) :
case (XSECCryptoKey::KEY_EC_PAIR) :
if (sm != SIGNATURE_ECDSA) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
b64Len = ((XSECCryptoKeyEC *) key)->signBase64SignatureDSA(
hash,
hashLen,
(char *) b64Buf,
MAXB64BUFSIZE);
if (b64Len <= 0) {
throw XSECException(XSECException::AlgorithmMapperError,
"Unknown error occured during an ECDSA Signing operation");
}
else if (b64Len >= MAXB64BUFSIZE) {
throw XSECException(XSECException::AlgorithmMapperError,
"ECDSA Signing operation exceeded size of buffer");
}
if (b64Buf[b64Len-1] == '\n')
b64Buf[b64Len-1] = '\0';
else
b64Buf[b64Len] = '\0';
break;
case (XSECCryptoKey::KEY_HMAC) :
if (sm != SIGNATURE_HMAC) {
throw XSECException(XSECException::AlgorithmMapperError,
"Key type does not match <SignedInfo> signature type");
}
// Signature already created, so just translate to base 64 and enter string
// FIX: CVE-2009-0217
if (outputLength > 0 && (outputLength > hashLen || outputLength < 80 || outputLength < hashLen / 2)) {
throw XSECException(XSECException::AlgorithmMapperError,
"HMACOutputLength set to unsafe value.");
}
convertRawToBase64String(b64SB,
hash,
hashLen,
outputLength);
strncpy(b64Buf, (char *) b64SB.rawBuffer(), MAXB64BUFSIZE);
break;
default :
throw XSECException(XSECException::AlgorithmMapperError,
"Key found, but don't know how to sign the document using it");
}
result = b64Buf;
return (unsigned int) strlen(b64Buf);
}
