1KEYCTL_PKEY_ENCRYPT(3) Linux Public-Key Encryption KEYCTL_PKEY_ENCRYPT(3)
2
3
4
6 keyctl_pkey_encrypt, keyctl_pkey_decrypt - Encrypt and decrypt data
7
9 #include <keyutils.h>
10
11 long keyctl_pkey_encrypt(key_serial_t key, const char *info,
12 const void *data, size_t data_len,
13 void *enc, size_t enc_len);
14
15 long keyctl_pkey_decrypt(key_serial_t key, const char *info,
16 const void *enc, size_t enc_len,
17 void *data, size_t data_len);
18
20 keyctl_pkey_encrypt() asks the kernel to use the crypto material
21 attached to a key to encrypt a blob of data and keyctl_pkey_decrypt()
22 asks the kernel to use the key to reverse the operation and recover the
23 original data. Note that these operations may involve the kernel call‐
24 ing out to cryptographic hardware. The caller must have search permis‐
25 sion on a key to be able to use them in this manner.
26
27 When invoking the function, key indicates the key that will provide the
28 cryptographic material and info points to a comma-separated string of
29 "key[=value]" parameters that indicate things like encoding forms and
30 passwords to unlock the key; see asymmetric-key(7) for more informa‐
31 tion.
32
33 data and datalen indicate the address and size of the decrypted data
34 buffer and enc and enclen indicate the address and size of the
35 encrypted data buffer. The encrypt function draws data from the
36 decrypted data buffer and places the output into the encryption buffer.
37 The decrypt function does the reverse, drawing from the encryption buf‐
38 fer and writing into the data buffer.
39
40 keyctl_pkey_query(2) can be called to find out how large the buffers
41 need to be.
42
43 Note that not all asymmetric-type keys will support these operations;
44 further, the operations available may depend on which components of the
45 key material are available: typically encryption only requires the pub‐
46 lic key, but decryption requires the private key as well. Which opera‐
47 tions are supported on a particular key can also be determined using
48 the query function.
49
51 On success keyctl_pkey_encrypt() and keyctl_pkey_decrypt() return the
52 amount of data written into the output buffer. On error, the value -1
53 will be returned and errno will have been set to an appropriate error.
54
56 ENOKEY The key specified is invalid.
57
58 EKEYEXPIRED
59 The key specified has expired.
60
61 EKEYREVOKED
62 The key specified has been revoked.
63
64 EACCES The key exists, but is not searchable by the calling process.
65
66 ENOPKG Some facility needed to complete the requested operation is not
67 available. This is most probably a requested or required digest
68 or encryption algorithm.
69
70 EFAULT Bad address.
71
73 This is a library function that can be found in libkeyutils. When
74 linking, -lkeyutils should be specified to the linker.
75
77 keyctl(1), add_key(2), keyctl(2), keyctl(3), keyctl_pkey_query(3),
78 keyctl_pkey_sign(3), keyrings(7), keyutils(7)
79
80
81
82Linux 8 Nov 2018 KEYCTL_PKEY_ENCRYPT(3)