NAME

       keyctl_pkey_encrypt, keyctl_pkey_decrypt - Encrypt and decrypt data

SYNOPSIS

       #include <keyutils.h>

       long keyctl_pkey_encrypt(key_serial_t key, const char *info,
                                const void *data, size_t data_len,
                                void *enc, size_t enc_len);

       long keyctl_pkey_decrypt(key_serial_t key, const char *info,
                                const void *enc, size_t enc_len,
                                void *data, size_t data_len);

DESCRIPTION

       keyctl_pkey_encrypt()  asks  the kernel to use the crypto material attached to a key to encrypt a blob of
       data and keyctl_pkey_decrypt() asks the kernel to use the key to reverse the operation  and  recover  the
       original  data.  Note that these operations may involve the kernel calling out to cryptographic hardware.
       The caller must have search permission on a key to be able to use them in this manner.

       When invoking the function, key indicates the key that will provide the cryptographic material  and  info
       points  to  a comma-separated string of "key[=value]" parameters that indicate things like encoding forms
       and passwords to unlock the key; see asymmetric-key(7) for more information.

       data and datalen indicate the address and size of the decrypted data buffer and enc and  enclen  indicate
       the  address  and  size of the encrypted data buffer.  The encrypt function draws data from the decrypted
       data buffer and places the output into the encryption buffer.  The decrypt  function  does  the  reverse,
       drawing from the encryption buffer and writing into the data buffer.

       keyctl_pkey_query(2) can be called to find out how large the buffers need to be.

       Note  that  not all asymmetric-type keys will support these operations; further, the operations available
       may depend on which components of the key material are available: typically encryption only requires  the
       public  key,  but  decryption  requires  the  private  key  as well.  Which operations are supported on a
       particular key can also be determined using the query function.

RETURN VALUE

       On success keyctl_pkey_encrypt() and keyctl_pkey_decrypt() return the amount of  data  written  into  the
       output  buffer.   On  error, the value -1 will be returned and errno will have been set to an appropriate
       error.

ERRORS

       ENOKEY The key specified is invalid.

       EKEYEXPIRED
              The key specified has expired.

       EKEYREVOKED
              The key specified has been revoked.

       EACCES The key exists, but is not searchable by the calling process.

       ENOPKG Some facility needed to complete the requested operation is not available.  This is most  probably
              a requested or required digest or encryption algorithm.

       EFAULT Bad address.

LINKING

       This  is  a  library  function  that  can  be  found  in libkeyutils.  When linking, -lkeyutils should be
       specified to the linker.

SEE ALSO

       keyctl(1), add_key(2), keyctl(2), keyctl(3), keyctl_pkey_query(3), keyctl_pkey_sign(3), keyrings(7),
       keyutils(7)