(PowerBuilder) Decrypt a SAML Response

Demonstrates how to decrypt a SAML response.

Note: This example requires Chilkat v9.5.0.76 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Http
oleobject loo_SbSamlResponse
oleobject loo_SbPrivateKeyPem
integer li_Success
oleobject loo_Xml
oleobject loo_Privkey
oleobject loo_Rsa
string ls_EncryptedAesKey
oleobject loo_BdAesKey
oleobject loo_SbRsaAlg
string ls_Encrypted64
oleobject loo_BdEncrypted
oleobject loo_Crypt
oleobject loo_SbAlg
string ls_DecryptedXml
oleobject loo_XmlAssertion
oleobject loo_XmlEncryptedAssertion

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  This example decrypts this SAML response:

//  <?xml version="1.0" encoding="UTF-8" ?>
//  <saml2p:Response Destination="https://deskflow-asp2.com/ubc/ubcdfe.dll/cwlacs" ID="_e4585eaeedbcaf7c24dff7f1ee2499f5" IssueInstant="2018-10-11T17:46:20.727Z" Version="2.0" xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol">
//      <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">https://authentication.stg.id.ubc.ca</saml2:Issuer>
//      <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
//          <ds:SignedInfo>
//              <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//              <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
//              <ds:Reference URI="#_e4585eaeedbcaf7c24dff7f1ee2499f5">
//                  <ds:Transforms>
//                      <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
//                      <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//                  </ds:Transforms>
//                  <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//                  <ds:DigestValue>1ui22tqFyYEOoWI19CMwz4n+ynxNjLDGdTeRMdi60EU=</ds:DigestValue>
//              </ds:Reference>
//          </ds:SignedInfo>
//          <ds:SignatureValue>ROg7FXV6vsp8socVhdo76/i7cRHGGKIveAiScKdujZT0QrHVqIvvbZ/RnwvEMJ9H9i/kJFAQA171
//  		Eo2kDjSdvNFQ/YcKaJUwMtAwT05yVatGV42RZKEf7ME+vpcCTR1LWZdrhat1FWCg1MNQwNWB0EL5
//  		fEP2a4jAcSTB8tFbjTAHsv7IWC39E5RVv99mACYXLa7iGZLtORANZxgYu5qQgmH6pUkI6Z1cpmf+
//  		m9mIjKM6LF0EvLfWOBWL6udZ+GsHPOLjVTJg+1S0xb9FQCYDVW1QhbjSS0icKHKTNNbrsaxllVDY
//  		m4q27YQjRh+XxugPgvsZ61Pxlto8Jbg+6jUlMQ==</ds:SignatureValue>
//          <ds:KeyInfo>
//              <ds:X509Data>
//                  <ds:X509Certificate>MIIDTTCCAjWgAwIBAgIVAJccYyIV6wly8XyddumpgnHMJ2JLMA0GCSqGSIb3DQEBCwUAMCcxJTAj
//  			BgNVBAMMHGF1dGhlbnRpY2F0aW9uLnN0Zy5pZC51YmMuY2EwHhcNMTcwMzAxMTk1NDM0WhcNMzcw
//  			...
//  			xUuh6HuHKIwQqHBz7udxbH3Zbb6jXGDJjiDHt1LRJ8xbVisFIcDlIwsGQQi0HeEJfx4P</ds:X509Certificate>
//              </ds:X509Data>
//          </ds:KeyInfo>
//      </ds:Signature>
//      <saml2p:Status>
//          <saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
//      </saml2p:Status>
//      <saml2:EncryptedAssertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">
//          <xenc:EncryptedData Id="_314d80b9cf02d8eda8d686a6ffd626cf" Type="http://www.w3.org/2001/04/xmlenc#Element" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
//              <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"/>
//              <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
//                  <xenc:EncryptedKey Id="_d7b6da6fb59a627ebb4a96928441ab79" Recipient="https://ubcdfe.deskflow-asp2.com" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
//                      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
//                          <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" xmlns:ds="http://www.w3.org/2000/09/xmldsig#"/>
//                      </xenc:EncryptionMethod>
//                      <ds:KeyInfo>
//                          <ds:X509Data>
//                              <ds:X509Certificate>MIICuzCCAiQCCQD3bpigRnKMSzANBgkqhkiG9w0BAQsFADCBoTELMAkGA1UEBhMCQ0ExEDAOBgNV
//  				BAgMB09udGFyaW8xEDAOBgNVBAcMB1Rvcm9udG8xJjAkBgNVBAoMHVRhY3RpY2FsIEJ1c2luZXNz
//  				...
//  				kVRcHd1UK3q7G8FoykWjdQz/0EoMTfEZ+Md56mLOe48eMUZV2ONZuL1kDCEKw1UwkaDQI4Pf8pzx
//  				82b9rgw9wBDtvu5eFPlUGEGIBw==</ds:X509Certificate>
//                          </ds:X509Data>
//                      </ds:KeyInfo>
//                      <xenc:CipherData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
//                          <xenc:CipherValue>BNHfUOpgdPE5BgpN2VIZIDthMAv1rxk91qVnWyCZOG9bmUKChJtTUqMpndot7VJwYuyKFshkAdnT
//  				D79KGdlSA1xHKcVeZXXzDWglqSyYjzhDCsyOhPaI4HelMFgCLwyFz89uEpUpqlvfl8ol3Am/XnzQ
//  				Vp7V7oS76hocjUI51Qs=</xenc:CipherValue>
//                      </xenc:CipherData>
//                  </xenc:EncryptedKey>
//              </ds:KeyInfo>
//              <xenc:CipherData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
//                  <xenc:CipherValue>R6l7tmbnXrOfBgB8lA3KnwLYsLH5ZO5omQ7Hp5K05atzw2o55xmCXVMYhNneFxMtxUh6raEyHeZX
//  			PTZNgWrvdqc4GYND/R7MhRrJzk9OAq1WyoOXwbtRpwNDwWA4N2IuprPQJbvjVxaw/PesZMZwZqlp
//  			...
//  			zm9zAxahyu8Ooe8M4r3HN2cY0JxxxkZtDiulbnyA+rRtXfBRJtangvFQ4iFAnzM/Yg9hMyW9jcu0
//  			S7FzuRB9ONMxi+nh0IFWgqp+</xenc:CipherValue>
//              </xenc:CipherData>
//          </xenc:EncryptedData>
//      </saml2:EncryptedAssertion>
//  </saml2p:Response>

//  The sample encrypted SAML response and RSA private key are available online:
loo_Http = create oleobject
li_rc = loo_Http.ConnectToNewObject("Chilkat_9_5_0.Http")
if li_rc < 0 then
    destroy loo_Http
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_SbSamlResponse = create oleobject
li_rc = loo_SbSamlResponse.ConnectToNewObject("Chilkat_9_5_0.StringBuilder")

loo_SbPrivateKeyPem = create oleobject
li_rc = loo_SbPrivateKeyPem.ConnectToNewObject("Chilkat_9_5_0.StringBuilder")

li_Success = loo_Http.QuickGetSb("https://chilkatdownload.com/data/samlresponse.xml",loo_SbSamlResponse)
if li_Success = 1 then
    li_Success = loo_Http.QuickGetSb("https://chilkatdownload.com/data/samlresponse_privkey.pem",loo_SbPrivateKeyPem)
end if

if li_Success <> 1 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    return
end if

loo_Xml = create oleobject
li_rc = loo_Xml.ConnectToNewObject("Chilkat_9_5_0.Xml")

loo_Xml.LoadSb(loo_SbSamlResponse,1)

//  Load the RSA private key..
loo_Privkey = create oleobject
li_rc = loo_Privkey.ConnectToNewObject("Chilkat_9_5_0.PrivateKey")

li_Success = loo_Privkey.LoadPem(loo_SbPrivateKeyPem.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Privkey.LastErrorText
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    return
end if

//  Prepare an RSA object w/ the private key...
loo_Rsa = create oleobject
li_rc = loo_Rsa.ConnectToNewObject("Chilkat_9_5_0.Rsa")

li_Success = loo_Rsa.ImportPrivateKeyObj(loo_Privkey)
if li_Success <> 1 then
    Write-Debug loo_Rsa.LastErrorText
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    destroy loo_Rsa
    return
end if

//  RSA will be used to decrypt the xenc:EncryptedKey
//  The bytes to be decrypted are in xenc:CipherValue (in base64 format)
ls_EncryptedAesKey = loo_Xml.GetChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:CipherData|xenc:CipherValue")
if loo_Xml.LastMethodSuccess <> 1 then
    Write-Debug "Encrypted AES key not found."
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    destroy loo_Rsa
    return
end if

Write-Debug "Encrypted AES key (base64) = " + ls_EncryptedAesKey

loo_BdAesKey = create oleobject
li_rc = loo_BdAesKey.ConnectToNewObject("Chilkat_9_5_0.BinData")

loo_BdAesKey.AppendEncoded(ls_EncryptedAesKey,"base64")

loo_SbRsaAlg = create oleobject
li_rc = loo_SbRsaAlg.ConnectToNewObject("Chilkat_9_5_0.StringBuilder")

loo_SbRsaAlg.Append(loo_Xml.ChilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:EncryptionMethod|(Algorithm)"))
Write-Debug "sbRsaAlg contains: " + loo_SbRsaAlg.GetAsString()
if loo_SbRsaAlg.Contains("rsa-oaep",1) = 1 then
    loo_Rsa.OaepPadding = 1
end if

//  Note: The DecryptBd method is introduced in Chilkat v9.5.0.76
li_Success = loo_Rsa.DecryptBd(loo_BdAesKey,1)
if li_Success <> 1 then
    Write-Debug loo_Rsa.LastErrorText
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    destroy loo_Rsa
    destroy loo_BdAesKey
    destroy loo_SbRsaAlg
    return
end if

Write-Debug "Decrypted AES key (hex) = " + loo_BdAesKey.GetEncoded("hex")

//  Get the encrypted XML (in base64) to be decrypted w/ the AES key.
ls_Encrypted64 = loo_Xml.GetChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:CipherData|xenc:CipherValue")
if loo_Xml.LastMethodSuccess <> 1 then
    Write-Debug "Encrypted data not found."
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    destroy loo_Rsa
    destroy loo_BdAesKey
    destroy loo_SbRsaAlg
    return
end if

loo_BdEncrypted = create oleobject
li_rc = loo_BdEncrypted.ConnectToNewObject("Chilkat_9_5_0.BinData")

loo_BdEncrypted.AppendEncoded(ls_Encrypted64,"base64")

//  Get the symmetric algorithm:  "http://www.w3.org/2001/04/xmlenc#aes128-cbc"
//  and set the symmetric decrypt properties.
loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat_9_5_0.Crypt2")

loo_SbAlg = create oleobject
li_rc = loo_SbAlg.ConnectToNewObject("Chilkat_9_5_0.StringBuilder")

loo_SbAlg.Append(loo_Xml.ChilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:EncryptionMethod|(Algorithm)"))
if loo_SbAlg.Contains("aes128-cbc",1) = 1 then
    loo_Crypt.CryptAlgorithm = "aes"
    loo_Crypt.KeyLength = 128
    loo_Crypt.CipherMode = "cbc"
    //  The 1st 16 bytes of the encrypted data are the AES IV.
    loo_Crypt.SetEncodedIV(loo_BdEncrypted.GetEncodedChunk(0,16,"hex"),"hex")
    loo_BdEncrypted.RemoveChunk(0,16)
end if

//  Other algorithms, key lengths, etc, can be supported by checking for different Algorithm attribute values..

loo_Crypt.SetEncodedKey(loo_BdAesKey.GetEncoded("hex"),"hex")

//  AES decrypt...
li_Success = loo_Crypt.DecryptBd(loo_BdEncrypted)
if li_Success <> 1 then
    Write-Debug loo_Crypt.LastErrorText
    destroy loo_Http
    destroy loo_SbSamlResponse
    destroy loo_SbPrivateKeyPem
    destroy loo_Xml
    destroy loo_Privkey
    destroy loo_Rsa
    destroy loo_BdAesKey
    destroy loo_SbRsaAlg
    destroy loo_BdEncrypted
    destroy loo_Crypt
    destroy loo_SbAlg
    return
end if

//  Get the decrypted XML
ls_DecryptedXml = loo_BdEncrypted.GetString("utf-8")
Write-Debug "Decrypted XML:"
Write-Debug ls_DecryptedXml

//  The decrypted XML looks like this:

//  <saml2:Assertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" ID="_226e565c548db7986d165d7d969b48b4" IssueInstant="2018-10-11T17:46:20.727Z" Version="2.0">
//  ...
//  ...
//  ...
//  </saml2:Assertion>

loo_XmlAssertion = create oleobject
li_rc = loo_XmlAssertion.ConnectToNewObject("Chilkat_9_5_0.Xml")

loo_XmlAssertion.LoadXml(ls_DecryptedXml)

//  Replace the saml2:EncryptedAssertion XML subtree with the saml2:Assertion XML.
loo_XmlEncryptedAssertion = loo_Xml.FindChild("saml2:EncryptedAssertion")
loo_XmlEncryptedAssertion.SwapTree(loo_XmlAssertion)
destroy loo_XmlEncryptedAssertion

//  The decrypted XML assertion has now replaced the encrypted XML assertion.
//  Examine the fully decrypted XML document:
Write-Debug "Full XML SAML document with decrypted assertion:"
Write-Debug loo_Xml.GetXml()


destroy loo_Http
destroy loo_SbSamlResponse
destroy loo_SbPrivateKeyPem
destroy loo_Xml
destroy loo_Privkey
destroy loo_Rsa
destroy loo_BdAesKey
destroy loo_SbRsaAlg
destroy loo_BdEncrypted
destroy loo_Crypt
destroy loo_SbAlg
destroy loo_XmlAssertion