How to decrypt EncryptedAssertion manually

Question

I want to decrypt the EncryptedAssertion. I tried with OpenSaml Decrypter but its not working for me.I am getting Failed to decrypt EncryptedData I have already ask that questio

Answer 1

I won't provide you a complete answer but I hope to get you on the right track

You should not just simply decrypt the calue with the private key.

First decrypt the KeyInfo value (unwrap the aes key) using RSA/ECB/PKCS1Padding (according to the provided saml snippet)

It should give you a 256 bit (32 bytes) random key used to encrypt data itself

then use the AES key to decrypt the data . Please note that first bytes (128 bit / 16 bytes, aes block size) is used as IV.

further reading

• https://www.w3.org/TR/2002/REC-xmlenc-core-20021210/Overview.html#sec-Processing-Encryption
• https://gusto77.wordpress.com/2017/10/30/encryption-reference-project/