GnuPG
PHP Manual

Costanti predefinite

GNUPG_SIG_MODE_NORMAL (integer)
GNUPG_SIG_MODE_DETACH (integer)
GNUPG_SIG_MODE_CLEAR (integer)
GNUPG_VALIDITY_UNKNOWN (integer)
GNUPG_VALIDITY_UNDEFINED (integer)
GNUPG_VALIDITY_NEVER (integer)
GNUPG_VALIDITY_MARGINAL (integer)
GNUPG_VALIDITY_FULL (integer)
GNUPG_VALIDITY_ULTIMATE (integer)
GNUPG_PROTOCOL_OpenPGP (integer)
GNUPG_PROTOCOL_CMS (integer)
GNUPG_SIGSUM_VALID (integer)
GNUPG_SIGSUM_GREEN (integer)
GNUPG_SIGSUM_RED (integer)
GNUPG_SIGSUM_KEY_REVOKED (integer)
GNUPG_SIGSUM_KEY_EXPIRED (integer)
GNUPG_SIGSUM_KEY_MISSING (integer)
GNUPG_SIGSUM_SIG_EXPIRED (integer)
GNUPG_SIGSUM_CRL_MISSING (integer)
GNUPG_SIGSUM_CRL_TOO_OLD (integer)
GNUPG_SIGSUM_BAD_POLICY (integer)
GNUPG_SIGSUM_SYS_ERROR (integer)
GNUPG_ERROR_WARNING (integer)
GNUPG_ERROR_EXCEPTION (integer)
GNUPG_ERROR_SILENT (integer)

GnuPG
PHP Manual