/*
* request a key (allow async construction)
* - search the process's keyrings
* - check the list of keys being created or updated
* - call out to userspace for a key if supplementary info was provided
*/
struct key *request_key_async(struct key_type *type,
const char *description,
const char *callout_info)
{
return request_key_and_link(type, description, callout_info, NULL,
NULL, KEY_ALLOC_IN_QUOTA);
}
/*
* request a key with auxiliary data for the upcaller (allow async construction)
* - search the process's keyrings
* - check the list of keys being created or updated
* - call out to userspace for a key if supplementary info was provided
*/
struct key *request_key_async_with_auxdata(struct key_type *type,
const char *description,
const char *callout_info,
void *aux)
{
return request_key_and_link(type, description, callout_info, aux,
NULL, KEY_ALLOC_IN_QUOTA);
}
/*
* request a key
* - search the process's keyrings
* - check the list of keys being created or updated
* - call out to userspace for a key if supplementary info was provided
* - waits uninterruptible for creation to complete
*/
struct key *request_key(struct key_type *type,
const char *description,
const char *callout_info)
{
struct key *key;
int ret;
key = request_key_and_link(type, description, callout_info, NULL,
NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
if (ret < 0) {
key_put(key);
return ERR_PTR(ret);
}
}
return key;
}
/**
* request_key_with_auxdata - Request a key with auxiliary data for the upcaller
* @type: The type of key we want.
* @description: The searchable description of the key.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
*
* As for request_key_and_link() except that it does not add the returned key
* to a keyring if found and new keys are always allocated in the user's quota.
*
* Furthermore, it then works as wait_for_key_construction() to wait for the
* completion of keys undergoing construction with a non-interruptible wait.
*/
struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
void *aux)
{
struct key *key;
int ret;
key = request_key_and_link(type, description, callout_info, callout_len,
aux, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
if (ret < 0) {
key_put(key);
return ERR_PTR(ret);
}
}
return key;
}
/*
* Search the process keyrings and keyring trees linked from those for a
* matching key. Keyrings must have appropriate Search permission to be
* searched.
*
* If a key is found, it will be attached to the destination keyring if there's
* one specified and the serial number of the key will be returned.
*
* If no key is found, /sbin/request-key will be invoked if _callout_info is
* non-NULL in an attempt to create a key. The _callout_info string will be
* passed to /sbin/request-key to aid with completing the request. If the
* _callout_info string is "" then it will be changed to "-".
*/
SYSCALL_DEFINE4(request_key, const char __user *, _type,
const char __user *, _description,
const char __user *, _callout_info,
key_serial_t, destringid)
{
struct key_type *ktype;
struct key *key;
key_ref_t dest_ref;
size_t callout_len;
char type[32], *description, *callout_info;
long ret;
/* pull the type into kernel space */
ret = key_get_type_from_user(type, _type, sizeof(type));
if (ret < 0)
goto error;
/* pull the description into kernel space */
description = strndup_user(_description, PAGE_SIZE);
if (IS_ERR(description)) {
ret = PTR_ERR(description);
goto error;
}
/* pull the callout info into kernel space */
callout_info = NULL;
callout_len = 0;
if (_callout_info) {
callout_info = strndup_user(_callout_info, PAGE_SIZE);
if (IS_ERR(callout_info)) {
ret = PTR_ERR(callout_info);
goto error2;
}
callout_len = strlen(callout_info);
}
/* get the destination keyring if specified */
dest_ref = NULL;
if (destringid) {
dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
}
}
/* find the key type */
ktype = key_type_lookup(type);
if (IS_ERR(ktype)) {
ret = PTR_ERR(ktype);
goto error4;
}
/* do the search */
key = request_key_and_link(ktype, description, callout_info,
callout_len, NULL, key_ref_to_ptr(dest_ref),
KEY_ALLOC_IN_QUOTA);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
}
/* wait for the key to finish being constructed */
ret = wait_for_key_construction(key, 1);
if (ret < 0)
goto error6;
ret = key->serial;
error6:
key_put(key);
error5:
key_type_put(ktype);
error4:
key_ref_put(dest_ref);
error3:
kfree(callout_info);
error2:
kfree(description);
error:
return ret;
}
/*
* search the process keyrings for a matching key
* - nested keyrings may also be searched if they have Search permission
* - if a key is found, it will be attached to the destination keyring if
* there's one specified
* - /sbin/request-key will be invoked if _callout_info is non-NULL
* - the _callout_info string will be passed to /sbin/request-key
* - if the _callout_info string is empty, it will be rendered as "-"
* - implements request_key()
*/
asmlinkage long sys_request_key(const char __user *_type,
const char __user *_description,
const char __user *_callout_info,
key_serial_t destringid)
{
struct key_type *ktype;
struct key *key;
key_ref_t dest_ref;
char type[32], *description, *callout_info;
long dlen, ret;
/* pull the type into kernel space */
ret = strncpy_from_user(type, _type, sizeof(type) - 1);
if (ret < 0)
goto error;
type[31] = '\0';
ret = -EPERM;
if (type[0] == '.')
goto error;
/* pull the description into kernel space */
ret = -EFAULT;
dlen = strnlen_user(_description, PAGE_SIZE - 1);
if (dlen <= 0)
goto error;
ret = -EINVAL;
if (dlen > PAGE_SIZE - 1)
goto error;
ret = -ENOMEM;
description = kmalloc(dlen + 1, GFP_KERNEL);
if (!description)
goto error;
ret = -EFAULT;
if (copy_from_user(description, _description, dlen + 1) != 0)
goto error2;
/* pull the callout info into kernel space */
callout_info = NULL;
if (_callout_info) {
ret = -EFAULT;
dlen = strnlen_user(_callout_info, PAGE_SIZE - 1);
if (dlen <= 0)
goto error2;
ret = -EINVAL;
if (dlen > PAGE_SIZE - 1)
goto error2;
ret = -ENOMEM;
callout_info = kmalloc(dlen + 1, GFP_KERNEL);
if (!callout_info)
goto error2;
ret = -EFAULT;
if (copy_from_user(callout_info, _callout_info, dlen + 1) != 0)
goto error3;
}
/* get the destination keyring if specified */
dest_ref = NULL;
if (destringid) {
dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
}
}
/* find the key type */
ktype = key_type_lookup(type);
if (IS_ERR(ktype)) {
ret = PTR_ERR(ktype);
goto error4;
}
/* do the search */
key = request_key_and_link(ktype, description, callout_info,
key_ref_to_ptr(dest_ref));
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
}
ret = key->serial;
key_put(key);
error5:
key_type_put(ktype);
error4:
key_ref_put(dest_ref);
error3:
kfree(callout_info);
error2:
kfree(description);
error:
return ret;
} /* end sys_request_key() */