Swift Requires Chilkat v11.0.0+
Swift
Decrypt a SAML Response
See more Encryption Examples
Demonstrates how to decrypt a SAML response.Chilkat Swift Downloads
func chilkatTest() {
var success: Bool = 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:
let http = CkoHttp()!
let sbSamlResponse = CkoStringBuilder()!
let sbPrivateKeyPem = CkoStringBuilder()!
success = http.quickGetSb(url: "https://chilkatdownload.com/data/samlresponse.xml", sbContent: sbSamlResponse)
if success == true {
success = http.quickGetSb(url: "https://chilkatdownload.com/data/samlresponse_privkey.pem", sbContent: sbPrivateKeyPem)
}
if success == false {
print("\(http.lastErrorText!)")
return
}
let xml = CkoXml()!
xml.loadSb(sb: sbSamlResponse, autoTrim: true)
// Load the RSA private key..
let privkey = CkoPrivateKey()!
success = privkey.loadPem(str: sbPrivateKeyPem.getAsString())
if success == false {
print("\(privkey.lastErrorText!)")
return
}
// Prepare an RSA object w/ the private key...
let rsa = CkoRsa()!
success = rsa.usePrivateKey(privKey: privkey)
if success == false {
print("\(rsa.lastErrorText!)")
return
}
// RSA will be used to decrypt the xenc:EncryptedKey
// The bytes to be decrypted are in xenc:CipherValue (in base64 format)
var encryptedAesKey: String? = xml.getChildContent(tagPath: "saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:CipherData|xenc:CipherValue")
if xml.lastMethodSuccess != true {
print("Encrypted AES key not found.")
return
}
print("Encrypted AES key (base64) = \(encryptedAesKey!)")
let bdAesKey = CkoBinData()!
bdAesKey.appendEncoded(encData: encryptedAesKey, encoding: "base64")
let sbRsaAlg = CkoStringBuilder()!
sbRsaAlg.append(value: xml.chilkatPath(cmd: "saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:EncryptionMethod|(Algorithm)"))
print("sbRsaAlg contains: \(sbRsaAlg.getAsString()!)")
if sbRsaAlg.contains(str: "rsa-oaep", caseSensitive: true) == true {
rsa.pkcsPadding = false
}
success = rsa.decryptBd(bd: bdAesKey, usePrivateKey: true)
if success == false {
print("\(rsa.lastErrorText!)")
return
}
print("Decrypted AES key (hex) = \(bdAesKey.getEncoded(encoding: "hex")!)")
// Get the encrypted XML (in base64) to be decrypted w/ the AES key.
var encrypted64: String? = xml.getChildContent(tagPath: "saml2:EncryptedAssertion|xenc:EncryptedData|xenc:CipherData|xenc:CipherValue")
if xml.lastMethodSuccess != true {
print("Encrypted data not found.")
return
}
let bdEncrypted = CkoBinData()!
bdEncrypted.appendEncoded(encData: encrypted64, encoding: "base64")
// Get the symmetric algorithm: "http://www.w3.org/2001/04/xmlenc#aes128-cbc"
// and set the symmetric decrypt properties.
let crypt = CkoCrypt2()!
let sbAlg = CkoStringBuilder()!
sbAlg.append(value: xml.chilkatPath(cmd: "saml2:EncryptedAssertion|xenc:EncryptedData|xenc:EncryptionMethod|(Algorithm)"))
if sbAlg.contains(str: "aes128-cbc", caseSensitive: true) == true {
crypt.cryptAlgorithm = "aes"
crypt.keyLength = 128
crypt.cipherMode = "cbc"
// The 1st 16 bytes of the encrypted data are the AES IV.
crypt.setEncodedIV(ivStr: bdEncrypted.getEncodedChunk(offset: 0, numBytes: 16, encoding: "hex"), encoding: "hex")
bdEncrypted.removeChunk(offset: 0, numBytes: 16)
}
// Other algorithms, key lengths, etc, can be supported by checking for different Algorithm attribute values..
crypt.setEncodedKey(keyStr: bdAesKey.getEncoded(encoding: "hex"), encoding: "hex")
// AES decrypt...
success = crypt.decryptBd(bd: bdEncrypted)
if success == false {
print("\(crypt.lastErrorText!)")
return
}
// Get the decrypted XML
var decryptedXml: String? = bdEncrypted.getString(charset: "utf-8")
print("Decrypted XML:")
print("\(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>
let xmlAssertion = CkoXml()!
xmlAssertion.load(xmlData: decryptedXml)
// Replace the saml2:EncryptedAssertion XML subtree with the saml2:Assertion XML.
var xmlEncryptedAssertion: CkoXml? = xml.findChild(tagPath: "saml2:EncryptedAssertion")
xmlEncryptedAssertion!.swapTree(tree: xmlAssertion)
xmlEncryptedAssertion = nil
// The decrypted XML assertion has now replaced the encrypted XML assertion.
// Examine the fully decrypted XML document:
print("Full XML SAML document with decrypted assertion:")
print("\(xml.getXml()!)")
}