add_key()函数 Unix/Linux
名称
add_key - 添加到内核的密钥管理机制一个键
内容简介
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#include <keyutils.h> key_serial_t add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t keyring); |
描述
add_key() 要求内核给定类型和描述来创建或更新一个键，它的有效载荷plen 长度实例，将它安装到提名 keyringand，返回其序列号。
密钥类型可能会拒绝该数据，如果它是在错误的格式或以其他方式无效。
如果目标的钥匙圈已经包含匹配指定类型和描述，然后，如果密钥类型支持一个键，该键将被更新，而不是创建一个新的密钥，如果没有，将创建一个新的密钥，它将取代链接到现存的核心，从钥匙圈。
目的地钥匙圈序号可能是一个有效的钥匙圈，主调用写入权限，或者它可以是一个特殊的密钥环ID：
| 标签 | 描述 |
|---|---|
| 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. |
密钥类型
有很多可供选择的核心密钥管理代码的密钥类型，而这些可以被指定为这个函数：
| 标签 | 描述 |
|---|---|
| “user” | Keys of the user-defined key type may contain a blob of arbitrary data, and thedescription may be any valid string, though it is preferred that the description be prefixed with a string representing the service to which the key is of interest and a colon (for instance “afs:mykey”). The payload may be empty or NULL for keys of this type. |
| “keyring” | Keyrings are special key types that may contain links to sequences of other keys of any type. If this interface is used to create a keyring, then a NULL payload should be specified, andplen should be zero. |
返回值
成功 add_key() 返回序列号密钥，它创建或更新。错误将返回值-1并且errno将被设置为一个适当的错误。
错误
| 标签 | 描述 |
|---|---|
| ENOKEY | The keyring doesn’t exist. |
| EKEYEXPIRED | The keyring has expired. |
| EKEYREVOKED | The keyring has been revoked. |
| EINVAL | The payload data was invalid. |
| ENOMEM | Insufficient memory to create a key. |
| 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. |
链接
虽然这是一个Linux系统调用，它是在libc中不存在，但可以发现合适的 libkey 工具。链接时，lkey 工具应指定给链接器。
