BLS library does not properly check secret key Severity: Informational

[shuse2]

Description

The SecretKey.fromBytes method performs some validation on the input, such as ensuring the secret key is non-zero and of correct length. However, the check against the secret key is not done modulo the order of the elliptic curve. Therefore, it is possible for a secret key equivalent to zero to be used if the value of the secret key is a multiple of this elliptic curve order.

https://github.com/ChainSafe/blst-ts/blob/ad0af59d9d01d45ea144b8306f44e45426c5888b/src/lib.ts#L63-L73

Acceptance Criteria

Add checks to all functions making use of the SecretKey.fromBytes function to ensure that the secret key being used for signing and other operations is non-zero modulo the order of the elliptic curve.

Additional Information

Reference: ChainSafe/bls#96