1KCAPI_AKCIPHER_SIGN(3) Programming Interface KCAPI_AKCIPHER_SIGN(3)
2
3
4
6 kcapi_akcipher_sign - signature generation
7
9 ssize_t kcapi_akcipher_sign(struct kcapi_handle * handle,
10 const uint8_t * in, size_t inlen,
11 uint8_t * out, size_t outlen, int access);
12
14 handle
15 [in] cipher handle
16
17 in
18 [in] message data buffer
19
20 inlen
21 [in] length of in buffer
22
23 out
24 [out] signature data buffer
25
26 outlen
27 [in] length of out buffer
28
29 access
30 [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
31 heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
32 vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
33
35 It is perfectly legal to use the same buffer as the message and
36 signature pointers. That would mean that after the signature generation
37 operation, the message is overwritten with the signature.
38
39 The memory should be aligned at the page boundary using
40 posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
41 boundary, the vmsplice call may not send all data to the kernel.
42
43 If the output size is insufficiently large, -EINVAL is returned. The
44 output buffer must be at least as large as the modululs of the uses
45 key.
46
47 return number of bytes returned by the signature gen operation upon
48 success; a negative errno-style error code if an error occurred
49
51 Stephan Mueller <smueller@chronox.de>
52 Author.
53
55libkcapi Manual 1.3.1 July 2021 KCAPI_AKCIPHER_SIGN(3)