CAMultiSignature.cpp

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/*
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/*
 * CAMultiSignature.cpp
 *
 *  Created on: 17.07.2008
 *      Author: zenoxx
 */
#include "StdAfx.h"
#include "CABase64.hpp"
#include "CAUtil.hpp"
#include "xml/DOM_Output.hpp"
#include "CASignature.hpp"
#include "CAMultiSignature.hpp"

CAMultiSignature::CAMultiSignature()
{
  m_signatures = NULL;
  m_sigCount = 0;
  m_xoredID = new UINT8[SHA_DIGEST_LENGTH];
  for(SINT32 i = 0; i<SHA_DIGEST_LENGTH; i++)
  {
    m_xoredID[i] = 0;
  }
}

CAMultiSignature::~CAMultiSignature()
{
  SIGNATURE* tmp;
  while(m_signatures != NULL)
  {
    //delete Signer and CertStore
    delete m_signatures->pSig;
    delete m_signatures->pCerts;
    m_signatures->pCerts = NULL;
    m_signatures->pSig = NULL;
    delete[] m_signatures->pSKI;
    m_signatures->pSKI = NULL;
    //store current pointer
    tmp = m_signatures;
    //go to next signature
    m_signatures = m_signatures->next;
    //delete current signature
    delete tmp;
    tmp = NULL;
  }
}


SINT32 CAMultiSignature::findSKI(const UINT8* a_strSKI)
{
  SIGNATURE* tmp = m_signatures;
  UINT8 tmpSKI[200];
  
  if (tmp == NULL)
  {
    return E_UNKNOWN;
  }
  
  while(tmp != NULL)
  {
    if (getSKI(tmpSKI, 200, tmp->pSKI) == E_SUCCESS &&
      strncmp((char*)a_strSKI, (char*)tmpSKI, strlen((char*)tmpSKI) ) == 0)
    {
      return E_SUCCESS;
    }
    tmp = tmp->next;
  }
  
  if (getSKI(tmpSKI, 200, m_xoredID) == E_SUCCESS &&
    strncmp((char*)a_strSKI, (char*)tmpSKI, strlen((char*)tmpSKI) ) == 0)
  {
    return E_SUCCESS;
  }
  
  return E_NOT_FOUND;
}

SINT32 CAMultiSignature::addSignature(CASignature* a_signature, CACertStore* a_certs, UINT8* a_ski, UINT32 a_skiLen)
{
  if(a_signature == NULL || a_certs == NULL || a_ski == NULL || a_skiLen != SHA_DIGEST_LENGTH)
    return E_UNKNOWN;
  for(SINT32 i=0; i<SHA_DIGEST_LENGTH; i++)
  {
    m_xoredID[i] = m_xoredID[i] ^ a_ski[i];
  }
  SIGNATURE* newSignature = new SIGNATURE;
  newSignature->pSig = a_signature;
  newSignature->pCerts = a_certs;
  newSignature->pSKI = new UINT8[a_skiLen];
  memcpy(newSignature->pSKI, a_ski, a_skiLen);
  newSignature->next = m_signatures;
  m_signatures = newSignature;
  m_sigCount++;
  return E_SUCCESS;
}

SINT32 CAMultiSignature::signXML(UINT8* in,UINT32 inlen,UINT8* out,UINT32* outlen, bool appendCerts)
{
  if(in == NULL || inlen < 1 || out == NULL || outlen == NULL)
    return E_UNKNOWN;

  XERCES_CPP_NAMESPACE::DOMDocument* doc = parseDOMDocument(in, inlen);
  if(doc == NULL)
    return E_UNKNOWN;
  DOMElement* root = doc->getDocumentElement();
  if(signXML(root, appendCerts) != E_SUCCESS)
    return E_UNKNOWN;
  return DOM_Output::dumpToMem(root,out,outlen);
}

SINT32 CAMultiSignature::signXML(DOMNode* node, bool appendCerts)
{
  if(m_sigCount == 0)
  {
    CAMsg::printMsg(LOG_ERR, "Trying to sign a document with no signature-keys set!");
    return E_UNKNOWN;
  }

  //getting the Document an the Node to sign
  XERCES_CPP_NAMESPACE::DOMDocument* doc = NULL;
  DOMNode* elemRoot = NULL;
  if(node->getNodeType() == DOMNode::DOCUMENT_NODE)
  {
    doc = (XERCES_CPP_NAMESPACE::DOMDocument*)node;
    elemRoot = doc->getDocumentElement();
  }
  else
  {
    elemRoot = node;
    doc = node->getOwnerDocument();
  }

  //check if there are already Signatures and if so remove them first...
  DOMNode* tmpSignature = NULL;
  while(getDOMChildByName(elemRoot, "Signature", tmpSignature, false) == E_SUCCESS)
  {
    DOMNode* n = elemRoot->removeChild(tmpSignature);
    if (n != NULL)
    {
      n->release();
      n = NULL;
    }
  }
  //get SHA1-Digest
  UINT32 len = 0;
  UINT8* canonicalBuff = DOM_Output::makeCanonical(elemRoot, &len);
  if(canonicalBuff == NULL)
  {
    return E_UNKNOWN;
  }
  UINT8 dgst[SHA_DIGEST_LENGTH];
  SHA1(canonicalBuff, len, dgst);
  delete[] canonicalBuff;
  canonicalBuff = NULL;

  UINT8 digestValue[512];
  len = 512;
  if(CABase64::encode(dgst, SHA_DIGEST_LENGTH, digestValue, &len) != E_SUCCESS)
  {
    return E_UNKNOWN;
  }

  //append a signature for each SIGNATURE element we have
  SIGNATURE* currentSignature = m_signatures;
  UINT32 sigCount = 0;
  for(UINT32 i=0; i<m_sigCount; i++)
  {
    //Creating the Sig-InfoBlock....
    DOMElement* elemSignedInfo = createDOMElement(doc, "SignedInfo");
    DOMElement* elemCanonicalizationMethod = createDOMElement(doc, "CanonicalizationMethod");
    DOMElement* elemSignatureMethod = createDOMElement(doc, "SignatureMethod");
    DOMElement* elemReference = createDOMElement(doc, "Reference");
    elemReference->setAttribute(XMLString::transcode("URI"), XMLString::transcode(""));
    DOMElement* elemDigestMethod = createDOMElement(doc, "DigestMethod");
    if(currentSignature->pSig->isDSA()) //DSA-Signature
    {
      setDOMElementAttribute(elemSignatureMethod, "Algorithm", (UINT8*)DSA_SHA1_REFERENCE);
    }
    else if(currentSignature->pSig->isRSA())
    {
      setDOMElementAttribute(elemSignatureMethod, "Algorithm", (UINT8*)RSA_SHA1_REFERENCE);
    }
#ifdef ECC
    else if(currentSignature->pSig->isECDSA())
    {
      setDOMElementAttribute(elemSignatureMethod, "Algorithm", (UINT8*)ECDSA_SHA1_REFERENCE);
    }
#endif //ECC
    setDOMElementAttribute(elemDigestMethod, "Algorithm", (UINT8*)SHA1_REFERENCE);
    DOMElement* elemDigestValue = createDOMElement(doc, "DigestValue");
    setDOMElementValue(elemDigestValue, digestValue);

    elemSignedInfo->appendChild(elemCanonicalizationMethod);
    elemSignedInfo->appendChild(elemSignatureMethod);
    elemSignedInfo->appendChild(elemReference);
    elemReference->appendChild(elemDigestMethod);
    elemReference->appendChild(elemDigestValue);

    // Signing the SignInfo block....
    canonicalBuff = DOM_Output::makeCanonical(elemSignedInfo,&len);
    if(canonicalBuff==NULL)
    {
      return E_UNKNOWN;
    }

    UINT32 sigLen = currentSignature->pSig->getSignatureSize();
    UINT8* sigBuff=new UINT8[sigLen];
    SINT32 ret = currentSignature->pSig->sign(canonicalBuff, len, sigBuff, &sigLen);
    delete[] canonicalBuff;
    canonicalBuff = NULL;
    if(ret != E_SUCCESS)
    {
      currentSignature = currentSignature->next;
      delete[] sigBuff;
      continue;
    }
    UINT sigSize = 255;
    UINT8 sig[255];
    if(CABase64::encode(sigBuff, sigLen, sig, &sigSize) != E_SUCCESS)
    {
      currentSignature = currentSignature->next;
      delete[] sigBuff;
      continue;
    }

    //Makeing the whole Signature-Block....
    DOMElement* elemSignature = createDOMElement(doc,"Signature");
    DOMElement* elemSignatureValue = createDOMElement(doc,"SignatureValue");
    setDOMElementValue(elemSignatureValue,sig);
    elemSignature->appendChild(elemSignedInfo);
    elemSignature->appendChild(elemSignatureValue);

    //Append KeyInfo if neccassary
    if(appendCerts)
    {
      //Making KeyInfo-Block
      DOMElement* tmpElemCerts = NULL;
      if(currentSignature->pCerts->encode(tmpElemCerts, doc) == E_SUCCESS && tmpElemCerts != NULL)
      {
        DOMElement* elemKeyInfo = createDOMElement(doc, "KeyInfo");
        elemKeyInfo->appendChild(tmpElemCerts);
        elemSignature->appendChild(elemKeyInfo);
      }
    }
    elemRoot->appendChild(elemSignature);
    sigCount++;

    //goto next Signature
    currentSignature = currentSignature->next;
    delete[] sigBuff;
  }
  if(sigCount > 0)
  {
    //CAMsg::printMsg(LOG_DEBUG, "Appended %d Signature(s) to XML-Structure\n", sigCount);
    return E_SUCCESS;
  }
  return E_UNKNOWN;
}

SINT32 CAMultiSignature::verifyXML(const UINT8* const in,UINT32 inlen, CACertificate* a_cert)
{
  XERCES_CPP_NAMESPACE::DOMDocument* doc = parseDOMDocument(in,inlen);
  if(doc == NULL)
  {
    return E_UNKNOWN;
  }
  DOMElement* root = doc->getDocumentElement();
  if(root == NULL)
  {
    return E_UNKNOWN;
  }
  return CAMultiSignature::verifyXML(root, a_cert);
}

SINT32 CAMultiSignature::verifyXML(DOMNode* root, CACertificate* a_cert)
{
  CASignature* sigVerifier = new CASignature();
  if(sigVerifier->setVerifyKey(a_cert) != E_SUCCESS)
  {
    CAMsg::printMsg(LOG_ERR, "Failed to set verify Key!");
    return E_UNKNOWN;
  }
  UINT8* signatureMethod = sigVerifier->getSignatureMethod();

  UINT32 signatureElementsCount = MAX_SIGNATURE_ELEMENTS;
  DOMNode* signatureElements[MAX_SIGNATURE_ELEMENTS];

  getSignatureElements((DOMElement*)root, signatureElements, &signatureElementsCount);
  CAMsg::printMsg(LOG_DEBUG, "Found %d Signature(s) in XML-Structure\n", signatureElementsCount);

  UINT8 dgst[255];
  UINT32 dgstlen=255;
  UINT8* out = NULL;
  UINT32 outlen;
  bool verified = false;
  //go through all appended Signatures an try to verify them with the given cert
  for(UINT32 i=0; i<signatureElementsCount; i++)
  {
    dgstlen=255;
    CAMsg::printMsg(LOG_DEBUG, "Trying to verify signature %d of %d!\n", i+1, signatureElementsCount);
    DOMNode* elemSignature = signatureElements[i];

    if(elemSignature == NULL)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: signature element is NULL\n");
      continue;
    }
    DOMNode* elemSigInfo;
    getDOMChildByName(elemSignature, "SignedInfo", elemSigInfo);
    if(elemSigInfo == NULL)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: signed info is NULL\n");
      continue;
    }
    //check if SignatureMethod fits...
    DOMNode* elemSigMethod;
    getDOMChildByName(elemSigInfo, "SignatureMethod", elemSigMethod);
    UINT32 algLen = 255;
    UINT8 algorithm[255];
    getDOMElementAttribute(elemSigMethod, (const char*)"Algorithm", algorithm, &algLen);
    //if signatureMethod is set check if its equal
    if(signatureMethod != NULL &&
        strncmp((const char*)algorithm, (const char*)signatureMethod, algLen) != E_SUCCESS)
    {
      CAMsg::printMsg(LOG_DEBUG, "Did NOT find matching SignatureMethods: %s and %s!\n", signatureMethod, algorithm);
      continue;
    }
    DOMNode* elemSigValue;
    getDOMChildByName(elemSignature, "SignatureValue", elemSigValue);
    if(elemSigValue == NULL)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: signature value is NULL\n");
      continue;
    }
    DOMNode* elemReference;
    getDOMChildByName(elemSigInfo, "Reference", elemReference);
    if(elemReference == NULL)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: signature reference is NULL\n");
      continue;
    }
    DOMNode* elemDigestValue;
    getDOMChildByName(elemReference, "DigestValue", elemDigestValue);
    if(elemDigestValue == NULL)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: digest value is NULL\n");
      continue;
    }
    if(getDOMElementValue(elemDigestValue,dgst,&dgstlen)!=E_SUCCESS)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: could not get digest value from XML\n");
      continue;
    }
    if(CABase64::decode(dgst,dgstlen,dgst,&dgstlen)!=E_SUCCESS)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: could not decode digest value\n");
      continue;
    }
    if(dgstlen!=SHA_DIGEST_LENGTH)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: digest is %d long, should be %d\n", dgstlen, SHA_DIGEST_LENGTH);
      continue;
    }
    UINT32 tmpSiglen = 255;
    UINT8 tmpSig[255];
    if(getDOMElementValue(elemSigValue,tmpSig,&tmpSiglen)!=E_SUCCESS)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: could not get signature value from XML\n");
      continue;
    }
    if(CABase64::decode(tmpSig,tmpSiglen,tmpSig,&tmpSiglen)!=E_SUCCESS)
    {
      CAMsg::printMsg(LOG_DEBUG, "Error: could not decode signature value\n");
      continue;
    }
    outlen = 5000;
    out = new UINT8[outlen];
    if(DOM_Output::makeCanonical(elemSigInfo, out, &outlen) == E_SUCCESS)
    {
      if(sigVerifier->verify(out, outlen, tmpSig, tmpSiglen) == E_SUCCESS)
      {
        CAMsg::printMsg(LOG_DEBUG, "Signature verification successful!\n");
        verified = true;
        break;
      }
    }
    CAMsg::printMsg(LOG_WARNING, "Signature verification not successful!\n");
    delete[] out;
    out = NULL;
    continue;
  }
  if(verified)
  {
    //the signature could be verified, now check digestValue
    //first remove Signature-nodes from root and store them
    DOMNode* removedSignatures[MAX_SIGNATURE_ELEMENTS];

    for(UINT32 i=0; i<signatureElementsCount; i++)
    {
      removedSignatures[i] = root->removeChild(signatureElements[i]);
      if(removedSignatures[i] == NULL)
      {
        //TODO do what? Verification will most likely fail, so just log the error for the moment
        CAMsg::printMsg(LOG_ERR, "Error removing signature-element %d of %d from Root-Node\n", i+1, signatureElementsCount);
      }
    }

    outlen = 5000;
    DOM_Output::makeCanonical(root, out, &outlen);

    //append Signature-nodes again
    for(UINT32 i=0; i<signatureElementsCount; i++)
    {
      if(removedSignatures[i] != NULL)
      {
        root->appendChild(removedSignatures[i]);
      }
    }

    UINT8 newDgst[SHA_DIGEST_LENGTH];
    SHA1(out, outlen, newDgst);
    delete[] out;
    out = NULL;
    for(int i=0; i<SHA_DIGEST_LENGTH; i++)
    {
      if(newDgst[i] != dgst[i])
      {
        CAMsg::printMsg(LOG_ERR, "Error checking XML-Signature DigestValue!\n");
        return E_UNKNOWN;
      }
    }
    return E_SUCCESS;
  }
  CAMsg::printMsg(LOG_ERR, "XML-Signature could not be verified!\n");
  return E_UNKNOWN;
}
SINT32 CAMultiSignature::sign(UINT8* in,UINT32 inlen,UINT8* sig,UINT32* siglen)
{
  if(m_sigCount < 1)
  {
    return E_UNKNOWN;
  }
  return m_signatures->pSig->sign(in, inlen, sig, siglen);
}

SINT32 CAMultiSignature::getSKI(UINT8* out, UINT32 outlen, const UINT8* a_ski)
{
  UINT8* tmp = (UINT8*) hex_to_string((unsigned char*)a_ski, SHA_DIGEST_LENGTH);
  UINT32 len=outlen;
  if (CACertificate::removeColons(tmp, strlen((const char*)tmp), out, &len) != E_SUCCESS)
  {
    OPENSSL_free(tmp);
    return E_UNKNOWN;
  }
  OPENSSL_free(tmp);
  strtrim(out);
  return E_SUCCESS;
}

SINT32 CAMultiSignature::getXORofSKIs(UINT8* out, UINT32 outlen)
{
  return getSKI(out, outlen, m_xoredID);
}