gnupg: Scdaemon PKDECRYPT
6.6.6 Decrypting data with a Smartcard
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To decrypt some data the caller should use the command
SETDATA HEXSTRING
to tell 'scdaemon' about the data to be decrypted. The data must be
given in hex notation. The actual decryption is then done using the
command
PKDECRYPT KEYID
where KEYID is the hexified ID of the key to be used.
If the card is aware of the apdding format a status line with padding
information is send before the plaintext data. The key for this status
line is 'PADDING' with the only defined value being 0 and meaning
padding has been removed.