запросить параметры открытого ключа (Query public key parameters)
Имя (Name)
keyctl_pkey_query - Query public key parameters
Синопсис (Synopsis)
#include <keyutils.h>
long keyctl_pkey_query(key_serial_t key, const char *info,
struct keyctl_pkey_query *result);
Описание (Description)
keyctl_pkey_query() queries the public key parameters associated
with a kernel key that supports these operations (typically
asymmetric-type). The caller must have search permission on the
target key to be able to query its parameters.
When invoking the function, key indicates the key to be queried,
info points to a space- or tab-separated string of "key[=value]"
parameters and result points to a buffer in which the result will
be placed.
The parameters that can be used in the info parameter string are
dependent on the type of key. Parameters can specify such things
as encoding types (such as "enc=pkcs1"); see asymmetric-key(7)
for more information.
If successful, the result is written into the following struct:
struct keyctl_pkey_query {
unsigned int supported_ops;
unsigned int key_size;
unsigned short max_data_size;
unsigned short max_sig_size;
unsigned short max_enc_size;
unsigned short max_dec_size;
};
The supported_ops field contains a bitmask of the following
constants:
KEYCTL_SUPPORTS_ENCRYPT
KEYCTL_SUPPORTS_DECRYPT
KEYCTL_SUPPORTS_SIGN
KEYCTL_SUPPORTS_VERIFY
indicating what operations are supported and thus which of the
other keyctl_pkey_*() operations can be used with this key.
The key_size field indicates the number of bits in the key size
and the max_data_size, max_sig_size, max_enc_size and
max_dec_size fields indicate the maximum sizes in bytes of a blob
of data to be signed, a signature blob, a blob to be encrypted
and a blob to be decrypted respectively.
Возвращаемое значение (Return value)
On success keyctl_pkey_query() returns 0. On error, the value -1
will be returned and errno will have been set to an appropriate
error.
Ошибки (Error)
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The key specified has been revoked.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.
Ссылки (Linking)
This is a library function that can be found in libkeyutils.
When linking, -lkeyutils should be specified to the linker.
Смотри также (See also)
keyctl(1), add_key(2), keyctl(2), keyctl(3),
keyctl_pkey_encrypt(3), keyctl_pkey_sign(3), asymmetric-key(7),
keyrings(7), keyutils(7)
