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request_key(2) [suse man page]

REQUEST_KEY(2)						    Linux Key Management Calls						    REQUEST_KEY(2)

NAME
request_key - Request a key from the kernel's key management facility SYNOPSIS
#include <keyutils.h> key_serial_t request_key(const char *type, const char *description, const char *callout_info, key_serial_t keyring); DESCRIPTION
request_key() asks the kernel to find a key of the given type that matches the specified description and, if successful, to attach it to the nominated keyring and to return its serial number. request_key() first recursively searches all the keyrings attached to the calling process in the order thread-specific keyring, process- specific keyring and then session keyring for a matching key. If request_key() is called from a program invoked by request_key() on behalf of some other process to generate a key, then the keyrings of that other process will be searched next, using that other process's UID, GID, groups and security context to control access. The keys in each keyring searched are checked for a match before any child keyrings are recursed into. Only keys that are searchable for the caller may be found, and only searchable keyrings may be searched. If the key is not found then, if callout_info is set, this function will attempt to look further afield. In such a case, the callout_info is passed to a userspace service such as /sbin/request-key to generate the key. If that is unsuccessful also, then an error will be returned, and a temporary negative key will be installed in the nominated keyring. This will expire after a few seconds, but will cause subsequent calls to request_key() to fail until it does. The keyring serial number may be that of a valid keyring to which the caller has write permission, or it may be a special keyring ID: KEY_SPEC_THREAD_KEYRING This specifies the caller's thread-specific keyring. KEY_SPEC_PROCESS_KEYRING This specifies the caller's process-specific keyring. KEY_SPEC_SESSION_KEYRING This specifies the caller's session-specific keyring. KEY_SPEC_USER_KEYRING This specifies the caller's UID-specific keyring. KEY_SPEC_USER_SESSION_KEYRING This specifies the caller's UID-session keyring. If a key is created, no matter whether it's a valid key or a negative key, it will displace any other key of the same type and description from the destination keyring. RETURN VALUE
On success request_key() returns the serial number of the key it found. On error, the value -1 will be returned and errno will have been set to an appropriate error. ERRORS
ENOKEY No matching key was found. EKEYEXPIRED An expired key was found, but no replacement could be obtained. EKEYREVOKED A revoked key was found, but no replacement could be obtained. EKEYREJECTED The attempt to generate a new key was rejected. ENOMEM Insufficient memory to create a key. EINTR The request was interrupted by a signal. EDQUOT The key quota for this user would be exceeded by creating this key or linking it to the keyring. EACCES The keyring wasn't available for modification by the user. LINKING
Although this is a Linux system call, it is not present in libc but can be found rather in libkeyutils. When linking, -lkeyutils should be specified to the linker. SEE ALSO
keyctl(1), add_key(2), keyctl(2), request-key(8) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2010-02-25 REQUEST_KEY(2)

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KEYCTL_SEARCH(3)					    Linux Key Management Calls						  KEYCTL_SEARCH(3)

NAME
keyctl_search - Search a keyring for a key SYNOPSIS
#include <keyutils.h> long keyctl_search(key_serial_t keyring, const char *type, const char *description, key_serial_t destination); DESCRIPTION
keyctl_search() recursively searches the keyring for a key of the specified type and description. If found, the key will be attached to the destination keyring (if given), and its serial number will be returned. The source keyring must grant search permission to the caller, and for a key to be found, it must also grant search permission to the call- er. Child keyrings will be only be recursively searched if they grant search permission to the caller as well. If the destination keyring is zero, no attempt will be made to forge a link to the key, and just the serial number will be returned. If the destination keyring is given, then the link may only be formed if the found key grants the caller link permission and the destina- tion keyring grants the caller write permission. If the search is successful, and if the destination keyring already contains a link to a key that matches the specified type and descrip- tion, then that link will be replaced by a link to the found key. The source keyring and destination keyring serial numbers may be those of valid keyrings to which the caller has appropriate permission, or they may be special keyring IDs: KEY_SPEC_THREAD_KEYRING This specifies the caller's thread-specific keyring. KEY_SPEC_PROCESS_KEYRING This specifies the caller's process-specific keyring. KEY_SPEC_SESSION_KEYRING This specifies the caller's session-specific keyring. KEY_SPEC_USER_KEYRING This specifies the caller's UID-specific keyring. KEY_SPEC_USER_SESSION_KEYRING This specifies the caller's UID-session keyring. RETURN VALUE
On success keyctl_search() returns the serial number of the key it found. On error, the value -1 will be returned and errno will have been set to an appropriate error. ERRORS
ENOKEY One of the keyrings doesn't exist, no key was found by the search, or the only key found by the search was a negative key. ENOTDIR One of the keyrings is a valid key that isn't a keyring. EKEYEXPIRED One of the keyrings has expired, or the only key found was expired. EKEYREVOKED One of the keyrings has been revoked, or the only key found was revoked. ENOMEM Insufficient memory to expand the destination keyring. EDQUOT The key quota for this user would be exceeded by creating a link to the found key in the destination keyring. EACCES The source keyring didn't grant search permission, the destination keyring didn't grant write permission or the found key didn't grant link permission to the caller. LINKING
Although this is a Linux system call, it is not present in libc but can be found rather in libkeyutils. When linking, -lkeyutils should be specified to the linker. SEE ALSO
keyctl(1), add_key(2), keyctl(2), request_key(2), keyctl_get_keyring_ID(3), keyctl_join_session_keyring(3), keyctl_update(3), keyctl_revoke(3), keyctl_chown(3), keyctl_setperm(3), keyctl_describe(3), keyctl_clear(3), keyctl_link(3), keyctl_unlink(3), keyctl_read(3), keyctl_instantiate(3), keyctl_negate(3), keyctl_set_reqkey_keyring(3), keyctl_set_timeout(3), keyctl_assume_authority(3), keyctl_describe_alloc(3), keyctl_read_alloc(3), request-key(8) Linux 4 May 2006 KEYCTL_SEARCH(3)

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