Section: Linux Public-Key Encryption (3)
Updated: 8 Nov 2018
keyctl_pkey_encrypt, keyctl_pkey_decrypt - Encrypt and decrypt data
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);
asks the kernel to use the crypto material attached to a key to encrypt a blob
of data and
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
permission on a key to be able to use them in this manner.
When invoking the function,
indicates the key that will provide the cryptographic material and
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.
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.
() and keyctl_pkey_decrypt
return the amount of data written into the output buffer. On error, the value
will be returned and
will have been set to an appropriate error.
The key specified is invalid.
The key specified has expired.
The key specified has been revoked.
The key exists, but is not
by the calling process.
Some facility needed to complete the requested operation is not available.
This is most probably a requested or required digest or encryption algorithm.
This is a library function that can be found in
should be specified to the linker.