Forge: Ed25519 signature verification accepts small-order public keys

Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.3, ed25519.verify() decodes a public key in crypto_sign_open() without rejecting small-order points or their non-canonical encodings. With S = 0 and a small-order R value, an attacker who can choose the public key can produce signatures that verify for many messages, or all messages with the identity key, without a private key. This can defeat proof-of-possession, attribution, non-repudiation, or deduplication checks that rely on a signature being bound to the message. Keys produced by normal Ed25519 key generation are not small-order, so applications that verify only trusted or internally generated public keys are not affected. This issue is fixed in version 1.4.3.