jsrsasign
opensource free pure JavaScript cryptographic library supports RSA/RSAPSS/ECDSA/DSA signing/validation, ASN.1, PKCS#1/5/8 private/public key, X.509 certificate, CRL, OCSP, CMS SignedData, TimeStamp and CAdES and JSON Web Signature(JWS)/Token(JWT)/Key(JWK)
eckles
💯 PEM-to-JWK and JWK-to-PEM (and SSH) for ECDSA keys in a lightweight, zero-dependency library focused on perfect universal compatibility.
jodid25519
jodid25519 - Curve 25519-based cryptography
@root/keypairs
Lightweight, Zero-Dependency RSA and EC/ECDSA crypto for Node.js and Browsers
keypairs
Lightweight RSA/ECDSA keypair generation and JWK <-> PEM using node's native RSA and ECDSA support