Libdigidocpp library offers creating, signing and verification of digitally signed documents, according to XAdES and XML-DSIG standards. Documentation http://open-eid.github.io/libdigidocpp
@peculiar/x509 is an easy to use TypeScript/Javascript library based on @peculiar/asn1-schema that makes generating X.509 Certificates and Certificate Requests as well as validating certificate chains easy
PDF signing utility supporting GPG and Sigstore (Google, GitHub, Microsoft accounts / keyless OIDC) signatures, multi-party signing, making it easy to sign and verify documents without heavyweight PDF signing stacks, making your PDFs authentic, tamper-proof, fully compatible with regular readers; all while costing zero-dollars to use.