How to pass a .pem file with a private key to jsrasign’s KJUR.crypto.Signature.init() method?
In the jsrasign library (https://kjur.github.io/jsrsasign), the KJUR.crypto.Signature.init(key, [pass]) method expects a ‘PEM formatted PKCS#8 plain RSA/ECDSA private key concluding “BEGIN PRIVATE KEY”‘ in the key parameter (see https://kjur.github.io/jsrsasign/api/symbols/KJUR.crypto.Signature.html#init).