fdo#87030: Generate a proper PKCS#7 signature

The signature should be in DER-encoded PKCS#7 format and what CryptSignHash()
produces is nothing like that. Luckily CryptSignMessage() is actually almost
easier to use and is capable of doing what we need. This also means that we
won't need any HCRYPTPROV or HCRYPTHASH after all so all the code related to
that can be removed. CryptSignMessage() handles both calculating the hash and
signing it.

One less than ideal issue with CryptSignMessage() is that it needs all the
data to be hashed and signed at the same time, so we need to keep both buffers
around for signing.

It also turns out that we don't need to look up the certificate anew from the
user's certificate store after all.

Now Adobe Reader doesn't complain any longer about the signature's format and
contents.

Change-Id: I25cfb93b516ffa723c6228d068d9ffa8e7cc4790

1 files changed, 35 insertions, 248 deletions

diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index fe260d7117ec..457af31c8873 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -6025,144 +6025,6 @@ OUString WindowsError(DWORD nErrorCode)
     return result;
 }
 
-#if SAL_LOG_INFO
-
-OUString CertificatePropertyName(int nId)
-{
-    switch (nId)
-    {
-    case CERT_ACCESS_STATE_PROP_ID: return OUString("ACCESS_STATE");
-    case CERT_AIA_URL_RETRIEVED_PROP_ID: return OUString("AIA_URL_RETRIEVED");
-    case CERT_ARCHIVED_KEY_HASH_PROP_ID: return OUString("ARCHIVED_KEY_HASH");
-    case CERT_ARCHIVED_PROP_ID: return OUString("ARCHIVED");
-    case CERT_AUTHORITY_INFO_ACCESS_PROP_ID: return OUString("AUTHORITY_INFO_ACCESS");
-    case CERT_AUTH_ROOT_SHA256_HASH_PROP_ID: return OUString("AUTH_ROOT_SHA256_HASH");
-    case CERT_AUTO_ENROLL_PROP_ID: return OUString("AUTO_ENROLL");
-    case CERT_AUTO_ENROLL_RETRY_PROP_ID: return OUString("AUTO_ENROLL_RETRY");
-    case CERT_BACKED_UP_PROP_ID: return OUString("BACKED_UP");
-    case CERT_CA_DISABLE_CRL_PROP_ID: return OUString("CA_DISABLE_CRL");
-    case CERT_CA_OCSP_AUTHORITY_INFO_ACCESS_PROP_ID: return OUString("CA_OCSP_AUTHORITY_INFO_ACCESS");
-    case CERT_CEP_PROP_ID: return OUString("CEP");
-    case CERT_CROSS_CERT_DIST_POINTS_PROP_ID: return OUString("CROSS_CERT_DIST_POINTS");
-    case CERT_CTL_USAGE_PROP_ID: return OUString("CTL_USAGE");
-    case CERT_DATE_STAMP_PROP_ID: return OUString("DATE_STAMP");
-    case CERT_DESCRIPTION_PROP_ID: return OUString("DESCRIPTION");
-    case CERT_DISALLOWED_FILETIME_PROP_ID: return OUString("DISALLOWED_FILETIME");
-    case CERT_EFS_PROP_ID: return OUString("EFS");
-    case CERT_ENROLLMENT_PROP_ID: return OUString("ENROLLMENT");
-    case CERT_EXTENDED_ERROR_INFO_PROP_ID: return OUString("EXTENDED_ERROR_INFO");
-    case CERT_FORTEZZA_DATA_PROP_ID: return OUString("FORTEZZA_DATA");
-    case CERT_FRIENDLY_NAME_PROP_ID: return OUString("FRIENDLY_NAME");
-    case CERT_HASH_PROP_ID: return OUString("HASH");
-    case CERT_HCRYPTPROV_OR_NCRYPT_KEY_HANDLE_PROP_ID: return OUString("HCRYPTPROV_OR_NCRYPT_KEY_HANDLE");
-    case CERT_HCRYPTPROV_TRANSFER_PROP_ID: return OUString("HCRYPTPROV_TRANSFER");
-    case CERT_IE30_RESERVED_PROP_ID: return OUString("IE30_RESERVED");
-    case CERT_ISSUER_CHAIN_PUB_KEY_CNG_ALG_BIT_LENGTH_PROP_ID: return OUString("ISSUER_CHAIN_PUB_KEY_CNG_ALG_BIT_LENGTH");
-    case CERT_ISSUER_CHAIN_SIGN_HASH_CNG_ALG_PROP_ID: return OUString("ISSUER_CHAIN_SIGN_HASH_CNG_ALG");
-    case CERT_ISSUER_PUBLIC_KEY_MD5_HASH_PROP_ID: return OUString("ISSUER_PUBLIC_KEY_MD5_HASH");
-    case CERT_ISSUER_PUB_KEY_BIT_LENGTH_PROP_ID: return OUString("ISSUER_PUB_KEY_BIT_LENGTH");
-    case CERT_ISSUER_SERIAL_NUMBER_MD5_HASH_PROP_ID: return OUString("ISSUER_SERIAL_NUMBER_MD5_HASH");
-    case CERT_KEY_CONTEXT_PROP_ID: return OUString("KEY_CONTEXT");
-    case CERT_KEY_IDENTIFIER_PROP_ID: return OUString("KEY_IDENTIFIER");
-    case CERT_KEY_PROV_HANDLE_PROP_ID: return OUString("KEY_PROV_HANDLE");
-    case CERT_KEY_PROV_INFO_PROP_ID: return OUString("KEY_PROV_INFO");
-    case CERT_KEY_REPAIR_ATTEMPTED_PROP_ID: return OUString("KEY_REPAIR_ATTEMPTED");
-    case CERT_KEY_SPEC_PROP_ID: return OUString("KEY_SPEC");
-    case CERT_MD5_HASH_PROP_ID: return OUString("MD5_HASH");
-    case CERT_NCRYPT_KEY_HANDLE_PROP_ID: return OUString("NCRYPT_KEY_HANDLE");
-    case CERT_NCRYPT_KEY_HANDLE_TRANSFER_PROP_ID: return OUString("NCRYPT_KEY_HANDLE_TRANSFER");
-    case CERT_NEW_KEY_PROP_ID: return OUString("NEW_KEY");
-    case CERT_NEXT_UPDATE_LOCATION_PROP_ID: return OUString("NEXT_UPDATE_LOCATION");
-    case CERT_NO_AUTO_EXPIRE_CHECK_PROP_ID: return OUString("NO_AUTO_EXPIRE_CHECK");
-    case CERT_NO_EXPIRE_NOTIFICATION_PROP_ID: return OUString("NO_EXPIRE_NOTIFICATION");
-    case CERT_OCSP_CACHE_PREFIX_PROP_ID: return OUString("OCSP_CACHE_PREFIX");
-    case CERT_OCSP_RESPONSE_PROP_ID: return OUString("OCSP_RESPONSE");
-    case CERT_PUBKEY_ALG_PARA_PROP_ID: return OUString("PUBKEY_ALG_PARA");
-    case CERT_PUBKEY_HASH_RESERVED_PROP_ID: return OUString("PUBKEY_HASH_RESERVED");
-    case CERT_PUB_KEY_CNG_ALG_BIT_LENGTH_PROP_ID: return OUString("PUB_KEY_CNG_ALG_BIT_LENGTH");
-    case CERT_PVK_FILE_PROP_ID: return OUString("PVK_FILE");
-    case CERT_RENEWAL_PROP_ID: return OUString("RENEWAL");
-    case CERT_REQUEST_ORIGINATOR_PROP_ID: return OUString("REQUEST_ORIGINATOR");
-    case CERT_ROOT_PROGRAM_CERT_POLICIES_PROP_ID: return OUString("ROOT_PROGRAM_CERT_POLICIES");
-    case CERT_ROOT_PROGRAM_CHAIN_POLICIES_PROP_ID: return OUString("ROOT_PROGRAM_CHAIN_POLICIES");
-    case CERT_ROOT_PROGRAM_NAME_CONSTRAINTS_PROP_ID: return OUString("ROOT_PROGRAM_NAME_CONSTRAINTS");
-    case CERT_SCARD_PIN_ID_PROP_ID: return OUString("SCARD_PIN_ID");
-    case CERT_SCARD_PIN_INFO_PROP_ID: return OUString("SCARD_PIN_INFO");
-    case CERT_SEND_AS_TRUSTED_ISSUER_PROP_ID: return OUString("SEND_AS_TRUSTED_ISSUER");
-    case CERT_SHA256_HASH_PROP_ID: return OUString("SHA256_HASH");
-    case CERT_SIGNATURE_HASH_PROP_ID: return OUString("SIGNATURE_HASH");
-    case CERT_SIGN_HASH_CNG_ALG_PROP_ID: return OUString("SIGN_HASH_CNG_ALG");
-    case CERT_SMART_CARD_DATA_PROP_ID: return OUString("SMART_CARD_DATA");
-    case CERT_SMART_CARD_READER_NON_REMOVABLE_PROP_ID: return OUString("SMART_CARD_READER_NON_REMOVABLE");
-    case CERT_SMART_CARD_READER_PROP_ID: return OUString("SMART_CARD_READER");
-    case CERT_SMART_CARD_ROOT_INFO_PROP_ID: return OUString("SMART_CARD_ROOT_INFO");
-    case CERT_SOURCE_LOCATION_PROP_ID: return OUString("SOURCE_LOCATION");
-    case CERT_SOURCE_URL_PROP_ID: return OUString("SOURCE_URL");
-    case CERT_SUBJECT_DISABLE_CRL_PROP_ID: return OUString("SUBJECT_DISABLE_CRL");
-    case CERT_SUBJECT_INFO_ACCESS_PROP_ID: return OUString("SUBJECT_INFO_ACCESS");
-    case CERT_SUBJECT_NAME_MD5_HASH_PROP_ID: return OUString("SUBJECT_NAME_MD5_HASH");
-    case CERT_SUBJECT_OCSP_AUTHORITY_INFO_ACCESS_PROP_ID: return OUString("SUBJECT_OCSP_AUTHORITY_INFO_ACCESS");
-    case CERT_SUBJECT_PUBLIC_KEY_MD5_HASH_PROP_ID: return OUString("SUBJECT_PUBLIC_KEY_MD5_HASH");
-    case CERT_SUBJECT_PUB_KEY_BIT_LENGTH_PROP_ID: return OUString("SUBJECT_PUB_KEY_BIT_LENGTH");
-    default: return OUString::number(nId);
-    }
-}
-
-void DumpCertContext(PCCERT_CONTEXT pCertContext)
-{
-    DWORD nProperty(0);
-    bool first(true);
-    while ((nProperty = CertEnumCertificateContextProperties(pCertContext, nProperty)) != 0)
-    {
-        if (first)
-            SAL_INFO("vcl.pdfwriter", "Certificate context properties:");
-        first = false;
-        SAL_INFO("vcl.pdfwriter", "  " << CertificatePropertyName(nProperty));
-    }
-}
-
-void DumpCryptProvider(HCRYPTPROV hCryptProv)
-{
-    DWORD nDataLen(0);
-
-    if (!CryptGetProvParam(hCryptProv, PP_ENUMALGS, NULL, &nDataLen, CRYPT_FIRST))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptGetProvParam failed: " << WindowsError(GetLastError()));
-        return;
-    }
-    BYTE *pData = new BYTE[nDataLen];
-    bool first(true);
-    while (true)
-    {
-        DWORD nDataLen2(nDataLen);
-        if (!CryptGetProvParam(hCryptProv, PP_ENUMALGS, pData, &nDataLen2, (first ? CRYPT_FIRST : CRYPT_NEXT)))
-        {
-            if (GetLastError() == ERROR_NO_MORE_ITEMS)
-                break;
-
-            SAL_WARN("vcl.pdfwriter", "CryptGetProvParam failed: " << WindowsError(GetLastError()));
-            delete[] pData;
-            return;
-        }
-        if (first)
-            SAL_INFO("vcl.pdfwriter", "Crypt provider algorithms:");
-
-        PROV_ENUMALGS *pAlg = reinterpret_cast<PROV_ENUMALGS*>(pData);
-        SAL_INFO("vcl.pdfwriter", "  " <<
-                 (GET_ALG_CLASS(pAlg->aiAlgid) == ALG_CLASS_DATA_ENCRYPT ? "ENCRYPT" :
-                  (GET_ALG_CLASS(pAlg->aiAlgid) == ALG_CLASS_HASH ? "HASH" :
-                   (GET_ALG_CLASS(pAlg->aiAlgid) == ALG_CLASS_KEY_EXCHANGE ? "KEY_EXCHANGE" :
-                    (GET_ALG_CLASS(pAlg->aiAlgid) == ALG_CLASS_SIGNATURE ? "SIGNATURE" :
-                     OUString::number(GET_ALG_CLASS(pAlg->aiAlgid), 16))))) <<
-                 " Algid=" << std::hex << pAlg->aiAlgid << std::dec << " BitLen=" << pAlg->dwBitLen << " Name=" << pAlg->szName);
-
-        first = false;
-    }
-
-    delete[] pData;
-}
-#endif
-
 }
 
 #endif
@@ -6356,140 +6218,67 @@ bool PDFWriterImpl::finalizeSignature()
     // Prepare buffer and calculate PDF file digest
     CHECK_RETURN( (osl::File::E_None == m_aFile.setPos(osl_Pos_Absolut, 0)) );
 
-    HCERTSTORE hCertStore = CertOpenSystemStore(NULL, "MY");
-    if (!hCertStore)
-    {
-        SAL_WARN("vcl.pdfwriter", "CertOpenSystemStore failed: " << WindowsError(GetLastError()));
-        return false;
-    }
-
-    PCCERT_CONTEXT pCertContextFromDER = CertCreateCertificateContext(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, reinterpret_cast<const BYTE*>(n_derArray), n_derLength);
-    if (pCertContextFromDER == NULL)
-    {
-        SAL_WARN("vcl.pdfwriter", "CertCreateCertificateContext failed: " << WindowsError(GetLastError()));
-        return false;
-    }
-
-    PCCERT_CONTEXT pCertContext = CertFindCertificateInStore(hCertStore, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0, CERT_FIND_EXISTING, (const void*) pCertContextFromDER, NULL);
+    PCCERT_CONTEXT pCertContext = CertCreateCertificateContext(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, reinterpret_cast<const BYTE*>(n_derArray), n_derLength);
     if (pCertContext == NULL)
     {
-        SAL_WARN("vcl.pdfwriter", "CertFindCertificateInStore failed: " << WindowsError(GetLastError()));
-        return false;
-    }
-
-    HCRYPTPROV_OR_NCRYPT_KEY_HANDLE hCryptProvOrNCryptKey;
-    DWORD nKeySpec;
-    BOOL bMustFree;
-    if (!CryptAcquireCertificatePrivateKey(pCertContext, CRYPT_ACQUIRE_CACHE_FLAG, NULL, &hCryptProvOrNCryptKey, &nKeySpec, &bMustFree))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptAcquireCertificatePrivateKey failed: " << WindowsError(GetLastError()));
-        CertFreeCertificateContext(pCertContext);
-        return false;
-    }
-    assert(!bMustFree);
-
-    SAL_INFO("vcl.pdfwriter", "Certificate has private key that is " <<
-             (nKeySpec == AT_KEYEXCHANGE ? OUString("for key exchange") :
-              (nKeySpec == AT_SIGNATURE ? OUString("for signatures") :
-               (nKeySpec == CERT_NCRYPT_KEY_SPEC ? OUString("for CNG (Cryptographi API: Next Generation)") :
-                OUString("unknown type (") + OUString::number(nKeySpec, 16) + ")"))));
-
-    DumpCertContext(pCertContext);
-    DumpCryptProvider(hCryptProvOrNCryptKey);
-
-    HCRYPTHASH hHash;
-    if (!CryptCreateHash(hCryptProvOrNCryptKey, CALG_SHA1, 0, 0, &hHash))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptCreateHash failed: " << WindowsError(GetLastError()));
-        CertFreeCertificateContext(pCertContext);
-        return false;
-    }
-
-#if 0
-    DWORD nHashSize;
-    DWORD nHashSizeLen(sizeof(DWORD));
-    if (!CryptGetHashParam(hHash, HP_HASHSIZE, reinterpret_cast<BYTE *>(&nHashSize), &nHashSizeLen, 0))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptGetHashParam failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
-        CryptReleaseContext(hCryptProvider, 0);
-        CertFreeCertificateContext(pCertContext);
+        SAL_WARN("vcl.pdfwriter", "CertCreateCertificateContext failed: " << WindowsError(GetLastError()));
         return false;
     }
 
-    assert(nHashSizeLen == sizeof(DWORD));
-    assert(nHashSize == 20);
-#endif
+    boost::scoped_array<char> buffer1(new char[m_nSignatureContentOffset - 1]);
+    sal_uInt64 bytesRead1;
 
-    boost::scoped_array<char> buffer(new char[m_nSignatureContentOffset + 1]);
-    sal_uInt64 bytesRead;
-
-    //FIXME: Check if SHA1 is calculated from the correct byterange
-    if (osl::File::E_None != m_aFile.read(buffer.get(), m_nSignatureContentOffset - 1 , bytesRead) ||
-        bytesRead != (sal_uInt64)m_nSignatureContentOffset - 1)
+    if (osl::File::E_None != m_aFile.read(buffer1.get(), m_nSignatureContentOffset - 1 , bytesRead1) ||
+        bytesRead1 != (sal_uInt64)m_nSignatureContentOffset - 1)
     {
         SAL_WARN("vcl.pdfwriter", "PDF Signing: First buffer read failed!");
-        CryptDestroyHash(hHash);
-        CertFreeCertificateContext(pCertContext);
-        return false;
-    }
-
-    if (!CryptHashData(hHash, reinterpret_cast<const BYTE *>(buffer.get()), bytesRead, 0))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptHashData failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
         CertFreeCertificateContext(pCertContext);
         return false;
     }
 
-    buffer.reset(new char[nLastByteRangeNo + 1]);
+    boost::scoped_array<char> buffer2(new char[nLastByteRangeNo]);
+    sal_uInt64 bytesRead2;
 
     if (osl::File::E_None != m_aFile.setPos(osl_Pos_Absolut, m_nSignatureContentOffset + MAX_SIGNATURE_CONTENT_LENGTH + 1) ||
-        osl::File::E_None != m_aFile.read(buffer.get(), nLastByteRangeNo, bytesRead) ||
-        bytesRead != (sal_uInt64) nLastByteRangeNo)
+        osl::File::E_None != m_aFile.read(buffer2.get(), nLastByteRangeNo, bytesRead2) ||
+        bytesRead2 != (sal_uInt64) nLastByteRangeNo)
     {
         SAL_WARN("vcl.pdfwriter", "PDF Signing: Second buffer read failed!");
-        CryptDestroyHash(hHash);
         CertFreeCertificateContext(pCertContext);
         return false;
     }
 
-    if (!CryptHashData(hHash, reinterpret_cast<const BYTE *>(buffer.get()), bytesRead, 0))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptHashData failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
-        CertFreeCertificateContext(pCertContext);
-        return false;
-    }
+    OString pass = OUStringToOString( m_aContext.SignPassword, RTL_TEXTENCODING_UTF8 );
 
-#if 0 // We don't actually need the hash bytes
-    unsigned char aHash[20];
-    if (!CryptGetHashParam(hHash, HP_HASHVAL, aHash, &nHashSize, 0))
-    {
-        SAL_WARN("vcl.pdfwriter", "CryptGetHashParam failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
-        CryptReleaseContext(hCryptProvider, 0);
-        CertFreeCertificateContext(pCertContext);
-        return false;
-    }
+    CRYPT_SIGN_MESSAGE_PARA aPara;
 
-    if (nHashSize != 20)
+    memset(&aPara, 0, sizeof(aPara));
+    aPara.cbSize = sizeof(aPara);
+    aPara.dwMsgEncodingType = PKCS_7_ASN_ENCODING | X509_ASN_ENCODING;
+    aPara.pSigningCert = pCertContext;
+    aPara.HashAlgorithm.pszObjId = szOID_RSA_SHA1RSA;
+    aPara.HashAlgorithm.Parameters.cbData = 0;
+    aPara.cMsgCert = 1;
+    aPara.rgpMsgCert = &pCertContext;
+
+    const BYTE *aBuffers[] =
+        { reinterpret_cast<BYTE*>(buffer1.get()), reinterpret_cast<BYTE*>(buffer2.get()) };
+    DWORD aBufferLens[] =
+        { bytesRead1, bytesRead2 };
+    assert(SAL_N_ELEMENTS(aBuffers) == SAL_N_ELEMENTS(aBufferLens));
+
+    DWORD nSigLen(0);
+
+    if (!CryptSignMessage(&aPara, TRUE, SAL_N_ELEMENTS(aBuffers), aBuffers, aBufferLens, NULL, &nSigLen))
     {
-        SAL_WARN("vcl.pdfwriter", "CryptGetHashParam returned unexpected size hash value: " << nHashSize);
-        CryptDestroyHash(hHash);
-        CryptReleaseContext(hCryptProvider, 0);
+        SAL_WARN("vcl.pdfwriter", "CryptSignMessage failed: " << WindowsError(GetLastError()));
         CertFreeCertificateContext(pCertContext);
         return false;
     }
-#endif
-
-    OString pass = OUStringToOString( m_aContext.SignPassword, RTL_TEXTENCODING_UTF8 );
 
-    DWORD nSigLen(0);
-    if (!CryptSignHash(hHash, nKeySpec, NULL, 0, NULL, &nSigLen))
+    if (nSigLen*2 > MAX_SIGNATURE_CONTENT_LENGTH)
     {
-        SAL_WARN("vcl.pdfwriter", "CryptSignHash failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
+        SAL_WARN("vcl.pdfwriter", "Signature requires more space (" << nSigLen*2 << ") than we reserved (" << MAX_SIGNATURE_CONTENT_LENGTH << ")");
         CertFreeCertificateContext(pCertContext);
         return false;
     }
@@ -6497,16 +6286,14 @@ bool PDFWriterImpl::finalizeSignature()
     SAL_INFO("vcl.pdfwriter", "Signature size is " << nSigLen << " bytes");
 
     boost::scoped_array<BYTE> pSig(new BYTE[nSigLen]);
-    if (!CryptSignHash(hHash, nKeySpec, NULL, 0, pSig.get(), &nSigLen))
+    if (!CryptSignMessage(&aPara, TRUE, SAL_N_ELEMENTS(aBuffers), aBuffers, aBufferLens, pSig.get(), &nSigLen))
     {
-        SAL_WARN("vcl.pdfwriter", "CryptSignHash failed: " << WindowsError(GetLastError()));
-        CryptDestroyHash(hHash);
+        SAL_WARN("vcl.pdfwriter", "CryptSignMessage failed: " << WindowsError(GetLastError()));
         CertFreeCertificateContext(pCertContext);
         return false;
     }
 
     // Release resources
-    CryptDestroyHash(hHash);
     CertFreeCertificateContext(pCertContext);
 
     OStringBuffer cms_hexbuffer;