Import Key with even parity fails with Parity Exception

[mchhil-incomm]

From jpos google group

https://groups.google.com/g/jpos-users/c/sa8LIIg4ZNQ/m/fFdIxt7rCwAJ

java  -cp bcprov-jdk18on-172.jar -jar /opt/jPOS/jpos/build/install/jpos/jpos-2.1.8-ST-q2.jar -c "smconsole  -jce org.bouncycastle.jce.provider.BouncyCastleProvider  -lmk  lmk.key IK 128 ZPK E61BCE2AF5508A0E8705BC05AE0BC68B 128 ZMK D48177CDD2ED9E43BB607D9BEE21B17F E7472E"

I was getting below error,

  "  <security-module-exception>

      Parity not adjusted

      org.jpos.security.jceadapter.JCEHandlerException: Parity not adjusted"

I am of the opinion, either have a parameter in IK command of the SMConsole to adjust the parity at input and log appropriate info when adjusted.

or

Change decryptDesKey to adjust parity and use it instead of throwing the exception.

jPOS/jpos/src/main/java/org/jpos/security/jceadapter/JCEHandler.java

Lines 186 to 193 in 096227e

	public Key decryptDESKey(short keyLength, byte[] encryptedDESKey, Key encryptingKey, boolean checkParity)
	throws JCEHandlerException {
	byte[] clearKeyBytes = doCryptStuff(encryptedDESKey, encryptingKey, Cipher.DECRYPT_MODE);
	if (checkParity && !Util.isDESParityAdjusted(clearKeyBytes)) {
	throw new JCEHandlerException("Parity not adjusted");
	}
	return formDESKey(keyLength, clearKeyBytes);
	}

encryptDeskey adjusts the parity and uses the adjusted cryptogram.

jPOS/jpos/src/main/java/org/jpos/security/jceadapter/JCEHandler.java

Lines 140 to 145 in 096227e

	public byte[] encryptDESKey(short keyLength, Key clearDESKey, Key encryptingKey) throws JCEHandlerException {
	byte[] clearKeyBytes = extractDESKeyMaterial(keyLength, clearDESKey);
	// enforce correct (odd) parity before encrypting the key
	Util.adjustDESParity(clearKeyBytes);
	return doCryptStuff(clearKeyBytes, encryptingKey, Cipher.ENCRYPT_MODE);
	}

[ar]

The if statement in the decrypt method honors a checkParity parameter. If we always adjust, we'd loose the ability to raise an exception when the input key material is not parity adjusted, which is usually an indication that the key might be not correct.

[mchhil-incomm]

Checkparity is only set by code and is always true. If you are using the console one has no control over it.

Based on my limited knowledge, a Thales hsm will allow even parity keys and adjust it to odd parity.

[ar]

I guess we could add a --no-check-parity parameter to SSM init CLI command.
We can also create an adjustparity command.

Having the ability to early detect bad keys is something I think we should keep.

[mchhil-incomm]

I agree with you.
If the parity exception gets thrown, one has the ability to try and adjust the even parity keys.

[alcarraz]

IMHO, if we are going to auto adjust, because we assume the parity may be evenly adjusted, we should check it is even before adjusting. Otherwise we are just making an error that would show up later and more difficult to understanding. At the very least, we may show a strong warning if adjusting a non even parity key. Be it by implementing a command or by using a flag. Enviado desde mi móvil, disculpas por la brevedad El vie, 20 de ene. de 2023 22:08, Murtuza Chhil ***@***.***> escribió:

…

I agree with you. If the parity exception gets thrown, one has the ability to try and adjust the even parity keys. — Reply to this email directly, view it on GitHub <#509 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA42RO4IOLU2WUC7KPJ3OTTWTNHMPANCNFSM6AAAAAATZ42UWE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[mchhil-incomm]

Adjusting an odd parity key has no impact and returns the same key. If the key before and after adjust parity are same, then that implies it was already odd else it was even.

Logging should add more clarity to what has happened and what has been done.

[alcarraz]

If It was indeed adjusted, but it could just be encrypted under the wrong key or the user trying to use the wrong key or scheme. That's why I would adjust the parity only if the parity was odd adjusted, but display a strong warning or even return an error if it was not adjusted at all. I wonder what Thales does if the parity is not even or odd adjusted. Enviado desde mi móvil, disculpas por la brevedad El sáb, 21 de ene. de 2023 21:00, Murtuza Chhil ***@***.***> escribió:

…

Adjusting an odd parity key has no impact and returns the same key. If the key before and after adjust parity are same, then that implies it was already odd else it was even. Logging should add more clarity to what has happened and what has been done. — Reply to this email directly, view it on GitHub <#509 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA42RO5Z2WP7VO2UTB452TTWTSIE5ANCNFSM6AAAAAATZ42UWE> . You are receiving this because you commented.Message ID: ***@***.***>