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Java Requires Chilkat v11.0.0+

Decrypt a SAML Response

See more Encryption Examples

Demonstrates how to decrypt a SAML response.

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Chilkat2 Java
import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.Http;
import com.chilkatsoft.chilkat2.PrivateKey;
import com.chilkatsoft.chilkat2.Rsa;
import com.chilkatsoft.chilkat2.StringBuilder;
import com.chilkatsoft.chilkat2.Xml;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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:
        Http http = new Http();
        StringBuilder sbSamlResponse = new StringBuilder();
        StringBuilder sbPrivateKeyPem = new StringBuilder();
        try {
            http.quickGetSb("https://chilkatdownload.com/data/samlresponse.xml", sbSamlResponse);
            http.quickGetSb("https://chilkatdownload.com/data/samlresponse_privkey.pem", sbPrivateKeyPem);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Xml xml = new Xml();
        xml.loadSb(sbSamlResponse, true);

        // Load the RSA private key..
        PrivateKey privkey = new PrivateKey();
        try {
            privkey.loadPem(sbPrivateKeyPem.getAsString());
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Prepare an RSA object w/ the private key...
        Rsa rsa = new Rsa();
        try {
            rsa.usePrivateKey(privkey);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // RSA will be used to decrypt the xenc:EncryptedKey
        // The bytes to be decrypted are in xenc:CipherValue (in base64 format)
        String encryptedAesKey = xml.getChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:CipherData|xenc:CipherValue");
        if (encryptedAesKey == null) {
            System.out.println("Encrypted AES key not found.");
            return;
        }

        System.out.println("Encrypted AES key (base64) = " + encryptedAesKey);

        BinData bdAesKey = new BinData();
        bdAesKey.appendEncoded(encryptedAesKey, "base64");

        StringBuilder sbRsaAlg = new StringBuilder();
        sbRsaAlg.append(xml.chilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:EncryptionMethod|(Algorithm)"));
        System.out.println("sbRsaAlg contains: " + sbRsaAlg.getAsString());
        if (sbRsaAlg.contains("rsa-oaep", true)) {
            rsa.setPkcsPadding(false);
        }

        try {
            rsa.decryptBd(bdAesKey, true);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Decrypted AES key (hex) = " + bdAesKey.getEncoded("hex"));

        // Get the encrypted XML (in base64) to be decrypted w/ the AES key.
        String encrypted64 = xml.getChildContent("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:CipherData|xenc:CipherValue");
        if (encrypted64 == null) {
            System.out.println("Encrypted data not found.");
            return;
        }

        BinData bdEncrypted = new BinData();
        bdEncrypted.appendEncoded(encrypted64, "base64");

        // Get the symmetric algorithm:  "http://www.w3.org/2001/04/xmlenc#aes128-cbc"
        // and set the symmetric decrypt properties.
        Crypt2 crypt = new Crypt2();
        StringBuilder sbAlg = new StringBuilder();
        sbAlg.append(xml.chilkatPath("saml2:EncryptedAssertion|xenc:EncryptedData|xenc:EncryptionMethod|(Algorithm)"));
        if (sbAlg.contains("aes128-cbc", true)) {
            crypt.setCryptAlgorithm("aes");
            crypt.setKeyLength(128);
            crypt.setCipherMode("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);
        }

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

        crypt.setEncodedKey(bdAesKey.getEncoded("hex"), "hex");

        // AES decrypt...
        try {
            crypt.decryptBd(bdEncrypted);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the decrypted XML
        String decryptedXml = bdEncrypted.getString("utf-8");
        System.out.println("Decrypted XML:");
        System.out.println(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>

        Xml xmlAssertion = new Xml();
        xmlAssertion.loadXml(decryptedXml);

        // Replace the saml2:EncryptedAssertion XML subtree with the saml2:Assertion XML.
        Xml xmlEncryptedAssertion = xml.findChild("saml2:EncryptedAssertion");
        xmlEncryptedAssertion.swapTree(xmlAssertion);
        xmlEncryptedAssertion.close();

        // The decrypted XML assertion has now replaced the encrypted XML assertion.
        // Examine the fully decrypted XML document:
        System.out.println("Full XML SAML document with decrypted assertion:");
        System.out.println(xml.getXml());
    }
}