1ADD_KEY(2) Linux Key Management Calls ADD_KEY(2)
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6 add_key - Add a key to the kernel's key management facility
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9 #include <keyutils.h>
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11 key_serial_t add_key(const char *type, const char *description,
12 const void *payload, size_t plen, key_serial_t keyring);
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15 add_key() asks the kernel to create or update a key of the given type
16 and description, instantiate it with the payload of length plen, and to
17 attach it to the nominated keyring and to return its serial number.
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19 The key type may reject the data if it's in the wrong format or in some
20 other way invalid.
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22 If the destination keyring already contains a key that matches the
23 specified type and description then, if the key type supports it, that
24 key will be updated rather than a new key being created; if not, a new
25 key will be created and it will displace the link to the extant key
26 from the keyring.
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28 The destination keyring serial number may be that of a valid keyring to
29 which the caller has write permission, or it may be a special keyring
30 ID:
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32 KEY_SPEC_THREAD_KEYRING
33 This specifies the caller's thread-specific keyring.
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35 KEY_SPEC_PROCESS_KEYRING
36 This specifies the caller's process-specific keyring.
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38 KEY_SPEC_SESSION_KEYRING
39 This specifies the caller's session-specific keyring.
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41 KEY_SPEC_USER_KEYRING
42 This specifies the caller's UID-specific keyring.
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44 KEY_SPEC_USER_SESSION_KEYRING
45 This specifies the caller's UID-session keyring.
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48 There are a number of key types available in the core key management
49 code, and these can be specified to this function:
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51 “user” Keys of the user-defined key type may contain a blob of arbi‐
52 trary data, and the description may be any valid string, though
53 it is preferred that the description be prefixed with a string
54 representing the service to which the key is of interest and a
55 colon (for instance “afs:mykey”). The payload may be empty or
56 NULL for keys of this type.
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58 “keyring”
59 Keyrings are special key types that may contain links to
60 sequences of other keys of any type. If this interface is used
61 to create a keyring, then a NULL payload should be specified,
62 and plen should be zero.
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65 On success add_key() returns the serial number of the key it created or
66 updated. On error, the value -1 will be returned and errno will have
67 been set to an appropriate error.
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70 ENOKEY The keyring doesn't exist.
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72 EKEYEXPIRED
73 The keyring has expired.
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75 EKEYREVOKED
76 The keyring has been revoked.
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78 EINVAL The payload data was invalid.
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80 ENOMEM Insufficient memory to create a key.
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82 EDQUOT The key quota for this user would be exceeded by creating this
83 key or linking it to the keyring.
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85 EACCES The keyring wasn't available for modification by the user.
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88 Although this is a Linux system call, it is not present in libc but can
89 be found rather in libkeyutils. When linking, -lkeyutils should be
90 specified to the linker.
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93 keyctl(1), keyctl(2), request_key(2)
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97Linux 4 May 2006 ADD_KEY(2)