Build, test, and debug regular expressions
Matches a complete PGP-encrypted message block, starting with the '-----BEGIN PGP MESSAGE-----' header followed by optional Charset, Version, or Comment fields, then the Base64 (Radix-64) encoded ciphertext with proper padding and an optional checksum line, ending with the '-----END PGP MESSAGE-----' footer. Useful for validating PGP/GPG encrypted content in email clients, secure messaging apps, and security tooling.