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).

I have a pem file containing such a private key. How do I pass it to the key parameter? Since this parameter cannot be a string, I cannot pass the path to the file.

Thanks in advance!