CACertificate.cpp

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/*
Copyright (c) 2000, The JAP-Team
All rights reserved.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
 
  - Redistributions of source code must retain the above copyright notice,
    this list of conditions and the following disclaimer.
 
  - Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation and/or
    other materials provided with the distribution.
 
  - Neither the name of the University of Technology Dresden, Germany nor the names of its contributors
    may be used to endorse or promote products derived from this software without specific
    prior written permission.
 
 
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
*/
 
#include "StdAfx.h"
#if !defined ONLY_LOCAL_PROXY || defined INCLUDE_MIDDLE_MIX
#include "CACertificate.hpp"
#include "CABase64.hpp"
#include "CAUtil.hpp"
#include "CAMsg.hpp"
 
UINT8 * CACertificate::m_spXmlElementName =0;
 
CACertificate::CACertificate()
  {
    m_pCert = NULL;
    m_pSKI = NULL;
    m_pAKI = NULL;
  }
 
CACertificate::CACertificate(X509* x)
  {
    m_pCert = x;
    m_pSKI = NULL;
    m_pAKI = NULL;
    if(m_pCert != NULL)
      {
        m_pSKI = (ASN1_OCTET_STRING*) X509_get_ext_d2i(m_pCert, NID_subject_key_identifier, NULL, NULL);
        m_pAKI = (AUTHORITY_KEYID*) X509_get_ext_d2i (m_pCert, NID_authority_key_identifier, NULL, NULL);
      }
  }
SINT32 CACertificate::setSubjectKeyIdentifier( UINT8* a_value, UINT32 a_valueLen )
{
    SINT32 ret = E_UNKNOWN;
    ASN1_OCTET_STRING* skid = NULL;
 
    skid = ASN1_OCTET_STRING_new();
    if(NULL == skid)   goto end;
 
    ASN1_OCTET_STRING_set(skid, a_value, a_valueLen);
    if( X509_add1_ext_i2d(m_pCert, NID_subject_key_identifier, skid, false, X509V3_ADD_REPLACE) == 1)
    {
      m_pSKI = skid;
      ret = E_SUCCESS;
    }
 
end:
    //ASN1_OCTET_STRING_free(skid);
    return ret;
}
 
 
CACertificate* CACertificate::decode(const DOMNode* n,UINT32 type,const char* passwd)
  {
    const DOMNode* node=n;
    switch(type)
      {
        case CERT_PKCS12:
          while(node!=NULL)
            {
              if(equals(node->getNodeName(),"X509PKCS12"))
                {
                  UINT32 strLen=4096;
                  UINT8* tmpStr=new UINT8[strLen];
                  CACertificate* cert=NULL;
                  if(getDOMElementValue(node,tmpStr,&strLen)!=E_SUCCESS)
                    {
                      delete[] tmpStr;
                      tmpStr = NULL;
                      return NULL;
                    }
                  UINT32 decLen=4096;
                  UINT8* decBuff=new UINT8[decLen];
                  SINT32 ret=CABase64::decode((UINT8*)tmpStr,strLen,decBuff,&decLen);
                  delete[] tmpStr;
                  tmpStr = NULL;
                  if(ret==E_SUCCESS)
                    {
                      cert=decode(decBuff,decLen,CERT_PKCS12,passwd);
                    }
                  delete[] decBuff;
                  decBuff = NULL;
                  return cert;
                }
              node=node->getNextSibling();
            }
        break;
        case  CERT_X509CERTIFICATE:
          while(node!=NULL)
            {
              if(equals(node->getNodeName(),"X509Certificate"))
                {
                  UINT32 strLen=4096;
                  UINT8* tmpStr=new UINT8[strLen];
                  CACertificate* cert=NULL;
                  if(getDOMElementValue(node,tmpStr,&strLen)!=E_SUCCESS)
                    {
                      delete[] tmpStr;
                      tmpStr = NULL;
                      return NULL;
                    }
                  UINT32 decLen=4096;
                  UINT8* decBuff=new UINT8[decLen];
                  SINT32 ret=CABase64::decode((UINT8*)tmpStr,strLen,decBuff,&decLen);
                  delete[] tmpStr;
                  tmpStr = NULL;
                  if(ret==E_SUCCESS)
                    {
                      cert=decode(decBuff,decLen,CERT_DER);
                    }
                  delete[] decBuff;
                  decBuff = NULL;
                  return cert;
                }
              node=node->getNextSibling();
            }
 
      }
    return NULL;
  }
 
CACertificate* CACertificate::decode(const UINT8* const buff,UINT32 bufflen,UINT32 type,const char* const passwd)
  {
    if(buff==NULL)
      return NULL;
    X509* tmpCert=NULL;
    EVP_PKEY* tmpKey=NULL;
    SINT32 ret=-1;
    const UINT8* tmp=buff;
    switch(type)
      {
        case CERT_DER:
          tmp=buff;
          #if OPENSSL_VERSION_NUMBER  > 0x009070CfL
            tmpCert=d2i_X509(NULL,&tmp,bufflen);
          #else
            tmpCert=d2i_X509(NULL,(UINT8**)&tmp,bufflen);
          #endif
        break;
        case CERT_PKCS12:
          PKCS12* tmpPKCS12;
          #if OPENSSL_VERSION_NUMBER  > 0x009070CfL
            tmpPKCS12=d2i_PKCS12(NULL,&tmp,bufflen);
          #else
            tmpPKCS12=d2i_PKCS12(NULL,(UINT8**)&tmp,bufflen);
          #endif
          /*Note: Basically we are not interested in the private keys here - but still we need cannot supply
           *NULL for that parameter, as OpenSSL 1.0.0. would not work in that case*/
          ret=PKCS12_parse(tmpPKCS12,passwd,&tmpKey,&tmpCert,NULL);
          PKCS12_free(tmpPKCS12);
          EVP_PKEY_free(tmpKey);
          if(ret!=1)
            {
              return NULL;
            }
        break;
        case CERT_XML_X509CERTIFICATE:
          XERCES_CPP_NAMESPACE::DOMDocument* doc=parseDOMDocument(buff,bufflen);
          if(doc == NULL)
          {
            return NULL;
          }
          DOMElement* root=doc->getDocumentElement();
          if(root==NULL||!equals(root->getNodeName(),"X509Certificate"))
          {
            return NULL;
          }
          UINT8* tmpBuff=new UINT8[bufflen];
          UINT32 tmpBuffSize=bufflen;
          if(getDOMElementValue(root,tmpBuff,&tmpBuffSize)==E_SUCCESS)
            {
              ret=CABase64::decode(tmpBuff,tmpBuffSize,tmpBuff,&tmpBuffSize);
            }
          tmp=tmpBuff;
          if(ret==E_SUCCESS)
            {
              #if OPENSSL_VERSION_NUMBER  > 0x009070CfL
                tmpCert=d2i_X509(NULL,&tmp,tmpBuffSize);
              #else
                tmpCert=d2i_X509(NULL,(UINT8**)&tmp,tmpBuffSize);
              #endif
            }
          delete[] tmpBuff;
          tmpBuff = NULL;
          break;
      }
    if(tmpCert == NULL)
    {
      return NULL;
    }
    return new CACertificate(tmpCert);
  }
 
SINT32 CACertificate::encode(UINT8* buff,UINT32* bufflen,UINT32 type) const
  {
    if(m_pCert==NULL||buff==NULL||bufflen==NULL)
      return E_UNKNOWN;
    int i=0;
    UINT8* tmp=buff;
    switch(type)
      {
        case CERT_DER:
          i=i2d_X509(m_pCert,&tmp);
          if(i==0)
            return E_UNKNOWN;
          *bufflen=i;
        break;
        case CERT_XML_X509CERTIFICATE:
        #define X509_CERTIFICATE_TAGNAME_LEN 17
          memcpy(buff,"<X509Certificate>",X509_CERTIFICATE_TAGNAME_LEN); //we start with '<X509Certificate>'
          tmp+=X509_CERTIFICATE_TAGNAME_LEN;
          i=i2d_X509(m_pCert,&tmp); //now we need DER
          if(i==0)
            return E_UNKNOWN;
          CABase64::encode( buff+X509_CERTIFICATE_TAGNAME_LEN,i,
                            buff+X509_CERTIFICATE_TAGNAME_LEN,bufflen); //now we have it converted to Base64
          memcpy( buff+X509_CERTIFICATE_TAGNAME_LEN+*bufflen,
                  "</X509Certificate>",X509_CERTIFICATE_TAGNAME_LEN+1); //we end it with '</X509Certificate>'
          *bufflen+=2*X509_CERTIFICATE_TAGNAME_LEN+1;
        break;
        default:
          return E_UNKNOWN;
      }
    return E_SUCCESS;
  }
 
SINT32 CACertificate::encode(DOMElement* & elemRoot,XERCES_CPP_NAMESPACE::DOMDocument* doc) const
  {
    elemRoot=createDOMElement(doc,"X509Certificate");
    UINT8 buff[2048]; //TODO: Very bad --> looks like easy buffer overflow... [donn't care at the moment...]
    UINT8* tmp=buff;
    int i=i2d_X509(m_pCert,&tmp); //now we need DER
    UINT32 bufflen=2048;
    CABase64::encode(buff,i,buff,&bufflen); //now we have it converted to Base64
    buff[bufflen]=0;
    setDOMElementValue(elemRoot,buff);
    return E_SUCCESS;
  }
 
SINT32 CACertificate::getSubjectKeyIdentifier(UINT8* r_ski, UINT32 *r_skiLen)
{
    if (m_pSKI == NULL)
    {
#ifdef DEBUG
        CAMsg::printMsg( LOG_ERR, "Unable to get SKI from Certificate, trying to recover\n");
#endif
        setSubjectKeyIdentifier();
        if(m_pSKI == NULL)
        {
            CAMsg::printMsg( LOG_ERR, "Unable to retrieve 1SKI from Certificate\n");
            return E_UNKNOWN;
        }
#ifdef DEBUG
        else
        {
            CAMsg::printMsg( LOG_ERR, "Recovery SUCCESSFUL!\n");
        }
#endif
    }
    // Get the ASCII string format of the subject key identifier
    UINT8* cSki = (UINT8*)i2s_ASN1_OCTET_STRING( NULL, m_pSKI );
    if ( cSki==NULL )
    {
        CAMsg::printMsg( LOG_ERR, "Unable to convert SKI\n");
        return E_UNKNOWN;
    }
#ifdef DEBUG
    CAMsg::printMsg( LOG_ERR, "getSubjectKeyIdentifier: SKI is %s\n", cSki);
#endif
    removeColons(cSki, strlen((const char*)cSki), r_ski, r_skiLen);
  OPENSSL_free(cSki);
    return E_SUCCESS;
}
 
SINT32 CACertificate::setSubjectKeyIdentifier()
{
    UINT32 len = 0;
    UINT8 sha_hash[SHA_DIGEST_LENGTH];
    X509_pubkey_digest(m_pCert, EVP_sha1(), sha_hash, &len);
    return setSubjectKeyIdentifier( sha_hash, len );
}
 
SINT32 CACertificate::removeColons(const UINT8* a_cSkid, UINT32 a_cSkidLen, UINT8 *&r_ski, UINT32 *r_skiLen)
{
    UINT32 i = 0, j = 0;
    UINT32 tmp = (2*a_cSkidLen)/3 + 2;
    if(*r_skiLen < tmp)
    {
        CAMsg::printMsg( LOG_ERR, "CACertificate::removeColons: Unable to copy SKI to target array, size must at least be %i but is only %i!\n", tmp, *r_skiLen);
        return E_UNKNOWN;
    }
    for(i = 0; i < a_cSkidLen; i++)
    {
        if(i % 3 == 2) {
            j++;
            continue;
        }
        r_ski[i-j] = a_cSkid[i];
    }
    r_ski[i-j] = 0;
    *r_skiLen = i-j;
    return E_SUCCESS;
}
 
SINT32 CACertificate::verify(const CACertificate* a_cert) const
{
  if(a_cert == NULL || a_cert->m_pCert == NULL || m_pCert == NULL)
  {
    return E_UNKNOWN;
  }
  //check validity
  if(!isValid())
  {
    CAMsg::printMsg(LOG_ERR, "Verification Error: Certificate is not valid!\n");
    return E_UNKNOWN;
  }
  //namechaining...
  if(X509_NAME_cmp(X509_get_issuer_name(m_pCert), X509_get_subject_name(a_cert->m_pCert)) != 0)
  {
    CAMsg::printMsg(LOG_ERR, "Verification Error: Names do not match!\n");
    return E_UNKNOWN;
  }
  //keychaining... (only if available)
  if(m_pAKI != NULL && a_cert->m_pSKI != NULL)
  {
    if(ASN1_OCTET_STRING_cmp(m_pAKI->keyid, a_cert->m_pSKI) != 0)
    {
      CAMsg::printMsg(LOG_ERR, "Verification Error: Key Identifiers do not match!\n");
      return E_UNKNOWN;
    }
  }
  //get public key
  EVP_PKEY* pubKey = X509_get_pubkey(a_cert->m_pCert);
  if(pubKey == NULL)
  {
    CAMsg::printMsg(LOG_ERR, "Verification Error: Public Key is NULL!\n");
    return E_UNKNOWN;
  }
  //check if public key and signature algorithm match -> does not work because of openssl bug!
  //SINT32 sigType = X509_get_signature_type(m_pCert);
  /*SINT32 sigType = OBJ_obj2nid((m_pCert)->sig_alg->algorithm);
  SINT32 keyType = EVP_PKEY_type(pubKey->type);
  CAMsg::printMsg(LOG_DEBUG, "sigType is %d and keyType is %d\n", sigType, keyType);
  if((sigType != (NID_dsaWithSHA1 || NID_sha1WithRSAEncryption ||NID_ecdsa_with_SHA1))
      && keyType != EVP_PKEY_DSA) ||
     (sigType == NID_sha1WithRSAEncryption && keyType != EVP_PKEY_RSA) ||
     (sigType == NID_ecdsa_with_SHA1 && keyType != EVP_PKEY_EC))
  {
    CAMsg::printMsg(LOG_ERR, "Verification Error: Signature Algorithm does not match!\n");
    //return E_UNKNOWN;
  }*/
  SINT32 ret = X509_verify(m_pCert, pubKey);
  if(ret == 1)
  {
    CAMsg::printMsg(LOG_DEBUG, "Successfully verified certificate.\n");
    return E_SUCCESS;
  }
  CAMsg::printMsg(LOG_ERR, "Verification Error: Signature is not correct!\n");
  return E_UNKNOWN;
}
 
bool CACertificate::isValid() const
{
#ifdef __BUILD_AS_SHADOW_PLUGIN__
//if the build the Mix as a plugin for the shadow simulator, we do not test certificate validity, because
//the shadow simulator uses it own time base make this checks kind of usesless / break the simulation
return true;
 
#endif //D__BUILD_AS_SHADOW_PLUGIN__
#if  OPENSSL_VERSION_NUMBER > 0x100020cfL
  const ASN1_TIME* pValidNotBefore=X509_get0_notBefore(m_pCert);
  const ASN1_TIME* pValidNotAfter=X509_get0_notAfter(m_pCert);
#else
  ASN1_TIME* pValidNotBefore=X509_get_notBefore(m_pCert);
  ASN1_TIME* pValidNotAfter=X509_get_notAfter(m_pCert);
#endif
  if(X509_cmp_current_time( pValidNotBefore) <0 && X509_cmp_current_time(pValidNotAfter) >0)
    {
      return true;
    }
  //check if certificate is valid within grace period of two months
  time_t now = time(NULL);    //get current time;
  tm* time = new tm;
  time = gmtime_r(&now, time);  //convert time to modifiable format
  if(time->tm_mon < 2)      //go back two months in time
  {
    time->tm_mon = time->tm_mon+10;
    time->tm_year = time->tm_year-1;
  }
  else
  {
    time->tm_mon = time->tm_mon-2;
  }
  time_t ttiq  = mktime(time);    //convert time back to time_t and check again
  delete time;
  time = NULL;
  if(X509_cmp_time( pValidNotBefore, &ttiq) <0 && X509_cmp_time(pValidNotAfter, &ttiq) >0)
    {
      CAMsg::printMsg(LOG_WARNING, "Certificate is only valid within grace period of two months!\n");
      return true;
    }
  return false;
}
 
SINT32 CACertificate::getRawSubjectKeyIdentifier(UINT8* r_ski, UINT32* r_skiLen)
{
  if (m_pSKI == NULL)
  {
    setSubjectKeyIdentifier();
    if(m_pSKI == NULL)
    {
      CAMsg::printMsg( LOG_ERR, "Unable to retrieve raw SKI from Certificate\n");
      return E_UNKNOWN;
        }
 
  }
  if(*r_skiLen < (UINT32) m_pSKI->length)
  {
    CAMsg::printMsg( LOG_ERR, "Unable to copy SKI to target array, size must at least be %i but is only %i!\n", m_pSKI->length, r_skiLen );
    return E_UNKNOWN;
  }
  *r_skiLen = m_pSKI->length;
  for(SINT32 i=0; i<m_pSKI->length; i++)
  {
    r_ski[i] = m_pSKI->data[i];
  }
  return E_SUCCESS;
}
 
SINT32 CACertificate::getAuthorityKeyIdentifier(UINT8* r_aki, UINT32* r_akiLen) const
{
  if(m_pAKI == NULL)
  {
    return E_UNKNOWN;
  }
 
  ASN1_OCTET_STRING* pKeyID = NULL;
  pKeyID = m_pAKI->keyid;
  if(pKeyID == NULL)
  {
    return E_UNKNOWN;
  }
 
  // Get the ASCII string format of the authority key identifier
  UINT8* cKeyID = (UINT8*)i2s_ASN1_OCTET_STRING(NULL, pKeyID);
  if (cKeyID == NULL)
  {
    return E_UNKNOWN;
  }
  removeColons(cKeyID, strlen((const char*)cKeyID), r_aki, r_akiLen);
  OPENSSL_free(cKeyID);
  return E_SUCCESS;
}
 
 
#endif //ONLY_LOCAL_PROXY