S/MIME

by Linus Rath

End-to-end S/MIME for webmail: sign and encrypt outgoing messages, and automatically verify signatures and decrypt incoming CMS (PKCS#7) mail. Private keys are imported from a PKCS#12 (.p12/.pfx) file, encrypted at rest with a passphrase, and unlocked into non-extractable WebCrypto keys that never leave your browser. Runs in the privileged (same-origin) plugin tier so all cryptography happens locally with bundled pkijs/asn1js.