Android Question [Solved]Encryption Lib (RSA via OpenSSL/php) -> decryption fails in OpenSSL

[KMatle]

What works:

- Generate RSA keys via php & OpenSSL
- store the keys in a MySQL table
- retrieve the keys and encrypt/decrypt data

On the B4A side:

- retrieve the *same* public key (via php)
- load the key
- encrypt & send a message

Problem:

- I can't decrypt the message via openssl_private_decrypt (message is just "can't decrypt")

mess="Hallo"                     
MessageBytes = Bconv.StringToBytes(mess, "UTF8")
                      
MessageBytesEncrypted = c.encrypt(MessageBytes, ForeignKPG.PublicKey, False)
MessageStringEncrypted=Bconv.StringFromBytes(MessageBytesEncrypted,"UTF8")
MessageStringEncrypted=su.EncodeBase64(MessageBytesEncrypted)
                      
Dim DeCryptM As HttpJob
DeCryptM.Initialize("DeCryptM", Me)
DeCryptM.Download2("http://192.168.178.21/rsa/RSASql.php", _
Array As String("Action", "DeCryptM", "Mess", MessageStringEncrypted ))

Conclusion:

I can en-/decrypt on the serverside. The server-key can be used in b4a's encryption lib. So this must be a encoding/padding thing.

Any ideas?

 

[KMatle]

So now I'm able to load and use both keys generated by OpenSSL into b4a. The secret is (however) that the encryption lib needs a pkcs#8 formated private key.

I can now en-/and decrypt messages (which means the keys are compatible).

Still not possible: Decrypt the message from b4a on my server (will try some things this evening).

Anyway: Any help would be nice. Must be a encoding thing

 

[KMatle]

So now it works .The solution needs some explanation. If someone is interested, I will write a complete tutorial. Anyone?

This will include:

- Create the keys with a script on the server (Xampp)
- Store the keys in a MySql table
- retrieve the keys in b4a via httputils
- use both keys (for a test - private key must be kept secret)
- en-/decript messages
- send them to your server (php script)
- en-/decrypt

 

[DonManfred]

Anyone?

Yes

 

[inakigarm]

Me too !

 

[Jmu5667]

Me too !