Perform signing operation, return detached signature(s)
$ffi
$data
$keys_fp
$options
ffi
The FFI object returned by rnp_ffi_create.
data
Data to be signed.
keys_fp
Array with key fingerprints. At least one key must be provided. Keys should be present in ffi.
options
An associative array with options.
"armor"
"hash"
"creation_time"
"expiration_time"
Detached signature(s) data on success失敗した場合に false を返します.
false