B4X Requires Chilkat v11.0.0+
B4X
Decrypt a SAML Response
See more Encryption Examples
Demonstrates how to decrypt a SAML response.Chilkat B4X Downloads
Dim success As Boolean = False
' 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:
Dim http As ChilkatHttp
http.Initialize("http")
Dim sbSamlResponse As ChilkatStringBuilder
sbSamlResponse.Initialize
Dim sbPrivateKeyPem As ChilkatStringBuilder
sbPrivateKeyPem.Initialize
success = http.QuickGetSb("https://chilkatdownload.com/data/samlresponse.xml", sbSamlResponse)
If success = True Then
success = http.QuickGetSb("https://chilkatdownload.com/data/samlresponse_privkey.pem", sbPrivateKeyPem)
End If
If success = False Then
Log(http.LastErrorText)
Return
End If
Dim xml As ChilkatXml
xml.Initialize
xml.LoadSb(sbSamlResponse, True)
' Load the RSA private key..
Dim privkey As ChilkatPrivateKey
privkey.Initialize("privkey")
success = privkey.LoadPem(sbPrivateKeyPem.GetAsString)
If success = False Then
Log(privkey.LastErrorText)
Return
End If
' Prepare an RSA object w/ the private key...
Dim rsa As ChilkatRsa
rsa.Initialize
success = rsa.UsePrivateKey(privkey)
If success = False Then
Log(rsa.LastErrorText)
Return
End If
' RSA will be used to decrypt the xenc:EncryptedKey
' The bytes to be decrypted are in xenc:CipherValue (in base64 format)
Dim encryptedAesKey As String = xml.GetChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:CipherData|xenc:CipherValue")
If xml.LastMethodSuccess <> True Then
Log("Encrypted AES key not found.")
Return
End If
Log("Encrypted AES key (base64) = " & encryptedAesKey)
Dim bdAesKey As ChilkatBinData
bdAesKey.Initialize
bdAesKey.AppendEncoded(encryptedAesKey, "base64")
Dim sbRsaAlg As ChilkatStringBuilder
sbRsaAlg.Initialize
sbRsaAlg.Append(xml.ChilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:EncryptionMethod|(Algorithm)"))
Log("sbRsaAlg contains: " & sbRsaAlg.GetAsString)
If sbRsaAlg.Contains("rsa-oaep", True) = True Then
rsa.PkcsPadding = False
End If
success = rsa.DecryptBd(bdAesKey, True)
If success = False Then
Log(rsa.LastErrorText)
Return
End If
Log("Decrypted AES key (hex) = " & bdAesKey.GetEncoded("hex"))
' Get the encrypted XML (in base64) to be decrypted w/ the AES key.
Dim encrypted64 As String = xml.GetChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:CipherData|xenc:CipherValue")
If xml.LastMethodSuccess <> True Then
Log("Encrypted data not found.")
Return
End If
Dim bdEncrypted As ChilkatBinData
bdEncrypted.Initialize
bdEncrypted.AppendEncoded(encrypted64, "base64")
' Get the symmetric algorithm: "http://www.w3.org/2001/04/xmlenc#aes128-cbc"
' and set the symmetric decrypt properties.
Dim crypt As ChilkatCrypt2
crypt.Initialize("crypt")
Dim sbAlg As ChilkatStringBuilder
sbAlg.Initialize
sbAlg.Append(xml.ChilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:EncryptionMethod|(Algorithm)"))
If sbAlg.Contains("aes128-cbc", True) = True Then
crypt.CryptAlgorithm = "aes"
crypt.KeyLength = 128
crypt.CipherMode = "cbc"
' The 1st 16 bytes of the encrypted data are the AES IV.
crypt.SetEncodedIV(bdEncrypted.GetEncodedChunk(0, 16, "hex"), "hex")
bdEncrypted.RemoveChunk(0, 16)
End If
' Other algorithms, key lengths, etc, can be supported by checking for different Algorithm attribute values..
crypt.SetEncodedKey(bdAesKey.GetEncoded("hex"), "hex")
' AES decrypt...
success = crypt.DecryptBd(bdEncrypted)
If success = False Then
Log(crypt.LastErrorText)
Return
End If
' Get the decrypted XML
Dim decryptedXml As String = bdEncrypted.GetString("utf-8")
Log("Decrypted XML:")
Log(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>
Dim xmlAssertion As ChilkatXml
xmlAssertion.Initialize
xmlAssertion.LoadXml(decryptedXml)
' Replace the saml2:EncryptedAssertion XML subtree with the saml2:Assertion XML.
Dim xmlEncryptedAssertion As ChilkatXml = xml.FindChild("saml2:EncryptedAssertion")
xmlEncryptedAssertion.SwapTree(xmlAssertion)
' The decrypted XML assertion has now replaced the encrypted XML assertion.
' Examine the fully decrypted XML document:
Log("Full XML SAML document with decrypted assertion:")
Log(xml.GetXml)