/* Request a key from userspace * * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * See Documentation/security/keys/request-key.rst */ #include <linux/module.h>#include <linux/sched.h>#include <linux/kmod.h>#include <linux/err.h>#include <linux/keyctl.h>#include <linux/slab.h>#include "internal.h" #define key_negative_timeout 60 /* default timeout on a negative key's existence */ /** * complete_request_key - Complete the construction of a key. * @cons: The key construction record. * @error: The success or failute of the construction. * * Complete the attempt to construct a key. The key will be negated * if an error is indicated. The authorisation key will be revoked * unconditionally. */void complete_request_key(struct key_construction *cons, int error){ kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error); if (error < 0) key_negate_and_link(cons->key, key_negative_timeout, NULL, cons->authkey); else key_revoke(cons->authkey); key_put(cons->key); key_put(cons->authkey); kfree(cons);}EXPORT_SYMBOL(complete_request_key); /* * Initialise a usermode helper that is going to have a specific session * keyring. * * This is called in context of freshly forked kthread before kernel_execve(), * so we can simply install the desired session_keyring at this point. */static int umh_keys_init(struct subprocess_info *info, struct cred *cred){ struct key *keyring = info->data; return install_session_keyring_to_cred(cred, keyring);} /* * Clean up a usermode helper with session keyring. */static void umh_keys_cleanup(struct subprocess_info *info){ struct key *keyring = info->data; key_put(keyring);} /* * Call a usermode helper with a specific session keyring. */static int call_usermodehelper_keys(const char *path, char **argv, char **envp, struct key *session_keyring, int wait){ struct subprocess_info *info; info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, umh_keys_init, umh_keys_cleanup, session_keyring); if (!info) return -ENOMEM; key_get(session_keyring); return call_usermodehelper_exec(info, wait);} /* * Request userspace finish the construction of a key * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" */static int call_sbin_request_key(struct key_construction *cons, const char *op, void *aux){ static char const request_key[] = "/sbin/request-key"; const struct cred *cred = current_cred(); key_serial_t prkey, sskey; struct key *key = cons->key, *authkey = cons->authkey, *keyring, *session; char *argv[9], *envp[3], uid_str[12], gid_str[12]; char key_str[12], keyring_str[3][12]; char desc[20]; int ret, i; kenter("{%d},{%d},%s", key->serial, authkey->serial, op); ret = install_user_keyrings(); if (ret < 0) goto error_alloc; /* allocate a new session keyring */ sprintf(desc, "_req.%u", key->serial); cred = get_current_cred(); keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); put_cred(cred); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error_alloc; } /* attach the auth key to the session keyring */ ret = key_link(keyring, authkey); if (ret < 0) goto error_link; /* record the UID and GID */ sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", cred->thread_keyring ? cred->thread_keyring->serial : 0); prkey = 0; if (cred->process_keyring) prkey = cred->process_keyring->serial; sprintf(keyring_str[1], "%d", prkey); rcu_read_lock(); session = rcu_dereference(cred->session_keyring); if (!session) session = cred->user->session_keyring; sskey = session->serial; rcu_read_unlock(); sprintf(keyring_str[2], "%d", sskey); /* set up a minimal environment */ i = 0; envp[i++] = "HOME=/"; envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; envp[i] = NULL; /* set up the argument list */ i = 0; argv[i++] = (char *)request_key; argv[i++] = (char *) op; argv[i++] = key_str; argv[i++] = uid_str; argv[i++] = gid_str; argv[i++] = keyring_str[0]; argv[i++] = keyring_str[1]; argv[i++] = keyring_str[2]; argv[i] = NULL; /* do it */ ret = call_usermodehelper_keys(request_key, argv, envp, keyring, UMH_WAIT_PROC); kdebug("usermode -> 0x%x", ret); if (ret >= 0) { /* ret is the exit/wait code */ if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || key_validate(key) < 0) ret = -ENOKEY; else /* ignore any errors from userspace if the key was * instantiated */ ret = 0; } error_link: key_put(keyring); error_alloc: complete_request_key(cons, ret); kleave(" = %d", ret); return ret;} /* * Call out to userspace for key construction. * * Program failure is ignored in favour of key status. */static int construct_key(struct key *key, const void *callout_info, size_t callout_len, void *aux, struct key *dest_keyring){ struct key_construction *cons; request_key_actor_t actor; struct key *authkey; int ret; kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); cons = kmalloc(sizeof(*cons), GFP_KERNEL); if (!cons) return -ENOMEM; /* allocate an authorisation key */ authkey = request_key_auth_new(key, callout_info, callout_len, dest_keyring); if (IS_ERR(authkey)) { kfree(cons); ret = PTR_ERR(authkey); authkey = NULL; } else { cons->authkey = key_get(authkey); cons->key = key_get(key); /* make the call */ actor = call_sbin_request_key; if (key->type->request_key) actor = key->type->request_key; ret = actor(cons, "create", aux); /* check that the actor called complete_request_key() prior to * returning an error */ WARN_ON(ret < 0 && !test_bit(KEY_FLAG_REVOKED, &authkey->flags)); key_put(authkey); } kleave(" = %d", ret); return ret;} /* * Get the appropriate destination keyring for the request. * * The keyring selected is returned with an extra reference upon it which the * caller must release. */static void construct_get_dest_keyring(struct key **_dest_keyring){ struct request_key_auth *rka; const struct cred *cred = current_cred(); struct key *dest_keyring = *_dest_keyring, *authkey; kenter("%p", dest_keyring); /* find the appropriate keyring */ if (dest_keyring) { /* the caller supplied one */ key_get(dest_keyring); } else { /* use a default keyring; falling through the cases until we * find one that we actually have */ switch (cred->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: if (cred->request_key_auth) { authkey = cred->request_key_auth; down_read(&authkey->sem); rka = authkey->payload.data[0]; if (!test_bit(KEY_FLAG_REVOKED, &authkey->flags)) dest_keyring = key_get(rka->dest_keyring); up_read(&authkey->sem); if (dest_keyring) break; } case KEY_REQKEY_DEFL_THREAD_KEYRING: dest_keyring = key_get(cred->thread_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: dest_keyring = key_get(cred->process_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_SESSION_KEYRING: rcu_read_lock(); dest_keyring = key_get( rcu_dereference(cred->session_keyring)); rcu_read_unlock(); if (dest_keyring) break; case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: dest_keyring = key_get(cred->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: dest_keyring = key_get(cred->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: default: BUG(); } } *_dest_keyring = dest_keyring; kleave(" [dk %d]", key_serial(dest_keyring)); return;} /* * Allocate a new key in under-construction state and attempt to link it in to * the requested keyring. * * May return a key that's already under construction instead if there was a * race between two thread calling request_key(). */static int construct_alloc_key(struct keyring_search_context *ctx, struct key *dest_keyring, unsigned long flags, struct key_user *user, struct key **_key){ struct assoc_array_edit *edit; struct key *key; key_perm_t perm; key_ref_t key_ref; int ret; kenter("%s,%s,,,", ctx->index_key.type->name, ctx->index_key.description); *_key = NULL; mutex_lock(&user->cons_lock); perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; perm |= KEY_USR_VIEW; if (ctx->index_key.type->read) perm |= KEY_POS_READ; if (ctx->index_key.type == &key_type_keyring || ctx->index_key.type->update) perm |= KEY_POS_WRITE; key = key_alloc(ctx->index_key.type, ctx->index_key.description, ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, perm, flags, NULL); if (IS_ERR(key)) goto alloc_failed; set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); if (dest_keyring) { ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); if (ret < 0) goto link_prealloc_failed; } /* attach the key to the destination keyring under lock, but we do need * to do another check just in case someone beat us to it whilst we * waited for locks */ mutex_lock(&key_construction_mutex); key_ref = search_process_keyrings(ctx); if (!IS_ERR(key_ref)) goto key_already_present; if (dest_keyring) __key_link(key, &edit); mutex_unlock(&key_construction_mutex); if (dest_keyring) __key_link_end(dest_keyring, &ctx->index_key, edit); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); return 0; /* the key is now present - we tell the caller that we found it by * returning -EINPROGRESS */key_already_present: key_put(key); mutex_unlock(&key_construction_mutex); key = key_ref_to_ptr(key_ref); if (dest_keyring) { ret = __key_link_check_live_key(dest_keyring, key); if (ret == 0) __key_link(key, &edit); __key_link_end(dest_keyring, &ctx->index_key, edit); if (ret < 0) goto link_check_failed; } mutex_unlock(&user->cons_lock); *_key = key; kleave(" = -EINPROGRESS [%d]", key_serial(key)); return -EINPROGRESS; link_check_failed: mutex_unlock(&user->cons_lock); key_put(key); kleave(" = %d [linkcheck]", ret); return ret; link_prealloc_failed: mutex_unlock(&user->cons_lock); key_put(key); kleave(" = %d [prelink]", ret); return ret; alloc_failed: mutex_unlock(&user->cons_lock); kleave(" = %ld", PTR_ERR(key)); return PTR_ERR(key);} /* * Commence key construction. */static struct key *construct_key_and_link(struct keyring_search_context *ctx, const char *callout_info, size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags){ struct key_user *user; struct key *key; int ret; kenter(""); if (ctx->index_key.type == &key_type_keyring) return ERR_PTR(-EPERM); user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); construct_get_dest_keyring(&dest_keyring); ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); key_user_put(user); if (ret == 0) { ret = construct_key(key, callout_info, callout_len, aux, dest_keyring); if (ret < 0) { kdebug("cons failed"); goto construction_failed; } } else if (ret == -EINPROGRESS) { ret = 0; } else { goto couldnt_alloc_key; } key_put(dest_keyring); kleave(" = key %d", key_serial(key)); return key; construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key);couldnt_alloc_key: key_put(dest_keyring); kleave(" = %d", ret); return ERR_PTR(ret);} /** * request_key_and_link - Request a key and cache it in a keyring. * @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. * @dest_keyring: Where to cache the key. * @flags: Flags to key_alloc(). * * A key matching the specified criteria is searched for in the process's * keyrings and returned with its usage count incremented if found. Otherwise, * if callout_info is not NULL, a key will be allocated and some service * (probably in userspace) will be asked to instantiate it. * * If successfully found or created, the key will be linked to the destination * keyring if one is provided. * * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKEDLines 1–500 of 727. Load more
/* Request a key from userspace * * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * See Documentation/security/keys/request-key.rst */ #include <linux/module.h> #include <linux/sched.h> #include <linux/kmod.h> #include <linux/err.h> #include <linux/keyctl.h> #include <linux/slab.h> #include "internal.h" #define key_negative_timeout 60 /* default timeout on a negative key's existence */ /** * complete_request_key - Complete the construction of a key. * @cons: The key construction record. * @error: The success or failute of the construction. * * Complete the attempt to construct a key. The key will be negated * if an error is indicated. The authorisation key will be revoked * unconditionally. */ void complete_request_key(struct key_construction *cons, int error) { kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error); if (error < 0) key_negate_and_link(cons->key, key_negative_timeout, NULL, cons->authkey); else key_revoke(cons->authkey); key_put(cons->key); key_put(cons->authkey); kfree(cons); } EXPORT_SYMBOL(complete_request_key); /* * Initialise a usermode helper that is going to have a specific session * keyring. * * This is called in context of freshly forked kthread before kernel_execve(), * so we can simply install the desired session_keyring at this point. */ static int umh_keys_init(struct subprocess_info *info, struct cred *cred) { struct key *keyring = info->data; return install_session_keyring_to_cred(cred, keyring); } /* * Clean up a usermode helper with session keyring. */ static void umh_keys_cleanup(struct subprocess_info *info) { struct key *keyring = info->data; key_put(keyring); } /* * Call a usermode helper with a specific session keyring. */ static int call_usermodehelper_keys(const char *path, char **argv, char **envp, struct key *session_keyring, int wait) { struct subprocess_info *info; info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, umh_keys_init, umh_keys_cleanup, session_keyring); if (!info) return -ENOMEM; key_get(session_keyring); return call_usermodehelper_exec(info, wait); } /* * Request userspace finish the construction of a key * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" */ static int call_sbin_request_key(struct key_construction *cons, const char *op, void *aux) { static char const request_key[] = "/sbin/request-key"; const struct cred *cred = current_cred(); key_serial_t prkey, sskey; struct key *key = cons->key, *authkey = cons->authkey, *keyring, *session; char *argv[9], *envp[3], uid_str[12], gid_str[12]; char key_str[12], keyring_str[3][12]; char desc[20]; int ret, i; kenter("{%d},{%d},%s", key->serial, authkey->serial, op); ret = install_user_keyrings(); if (ret < 0) goto error_alloc; /* allocate a new session keyring */ sprintf(desc, "_req.%u", key->serial); cred = get_current_cred(); keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); put_cred(cred); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error_alloc; } /* attach the auth key to the session keyring */ ret = key_link(keyring, authkey); if (ret < 0) goto error_link; /* record the UID and GID */ sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", cred->thread_keyring ? cred->thread_keyring->serial : 0); prkey = 0; if (cred->process_keyring) prkey = cred->process_keyring->serial; sprintf(keyring_str[1], "%d", prkey); rcu_read_lock(); session = rcu_dereference(cred->session_keyring); if (!session) session = cred->user->session_keyring; sskey = session->serial; rcu_read_unlock(); sprintf(keyring_str[2], "%d", sskey); /* set up a minimal environment */ i = 0; envp[i++] = "HOME=/"; envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; envp[i] = NULL; /* set up the argument list */ i = 0; argv[i++] = (char *)request_key; argv[i++] = (char *) op; argv[i++] = key_str; argv[i++] = uid_str; argv[i++] = gid_str; argv[i++] = keyring_str[0]; argv[i++] = keyring_str[1]; argv[i++] = keyring_str[2]; argv[i] = NULL; /* do it */ ret = call_usermodehelper_keys(request_key, argv, envp, keyring, UMH_WAIT_PROC); kdebug("usermode -> 0x%x", ret); if (ret >= 0) { /* ret is the exit/wait code */ if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || key_validate(key) < 0) ret = -ENOKEY; else /* ignore any errors from userspace if the key was * instantiated */ ret = 0; } error_link: key_put(keyring); error_alloc: complete_request_key(cons, ret); kleave(" = %d", ret); return ret; } /* * Call out to userspace for key construction. * * Program failure is ignored in favour of key status. */ static int construct_key(struct key *key, const void *callout_info, size_t callout_len, void *aux, struct key *dest_keyring) { struct key_construction *cons; request_key_actor_t actor; struct key *authkey; int ret; kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); cons = kmalloc(sizeof(*cons), GFP_KERNEL); if (!cons) return -ENOMEM; /* allocate an authorisation key */ authkey = request_key_auth_new(key, callout_info, callout_len, dest_keyring); if (IS_ERR(authkey)) { kfree(cons); ret = PTR_ERR(authkey); authkey = NULL; } else { cons->authkey = key_get(authkey); cons->key = key_get(key); /* make the call */ actor = call_sbin_request_key; if (key->type->request_key) actor = key->type->request_key; ret = actor(cons, "create", aux); /* check that the actor called complete_request_key() prior to * returning an error */ WARN_ON(ret < 0 && !test_bit(KEY_FLAG_REVOKED, &authkey->flags)); key_put(authkey); } kleave(" = %d", ret); return ret; } /* * Get the appropriate destination keyring for the request. * * The keyring selected is returned with an extra reference upon it which the * caller must release. */ static void construct_get_dest_keyring(struct key **_dest_keyring) { struct request_key_auth *rka; const struct cred *cred = current_cred(); struct key *dest_keyring = *_dest_keyring, *authkey; kenter("%p", dest_keyring); /* find the appropriate keyring */ if (dest_keyring) { /* the caller supplied one */ key_get(dest_keyring); } else { /* use a default keyring; falling through the cases until we * find one that we actually have */ switch (cred->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: if (cred->request_key_auth) { authkey = cred->request_key_auth; down_read(&authkey->sem); rka = authkey->payload.data[0]; if (!test_bit(KEY_FLAG_REVOKED, &authkey->flags)) dest_keyring = key_get(rka->dest_keyring); up_read(&authkey->sem); if (dest_keyring) break; } case KEY_REQKEY_DEFL_THREAD_KEYRING: dest_keyring = key_get(cred->thread_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: dest_keyring = key_get(cred->process_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_SESSION_KEYRING: rcu_read_lock(); dest_keyring = key_get( rcu_dereference(cred->session_keyring)); rcu_read_unlock(); if (dest_keyring) break; case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: dest_keyring = key_get(cred->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: dest_keyring = key_get(cred->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: default: BUG(); } } *_dest_keyring = dest_keyring; kleave(" [dk %d]", key_serial(dest_keyring)); return; } /* * Allocate a new key in under-construction state and attempt to link it in to * the requested keyring. * * May return a key that's already under construction instead if there was a * race between two thread calling request_key(). */ static int construct_alloc_key(struct keyring_search_context *ctx, struct key *dest_keyring, unsigned long flags, struct key_user *user, struct key **_key) { struct assoc_array_edit *edit; struct key *key; key_perm_t perm; key_ref_t key_ref; int ret; kenter("%s,%s,,,", ctx->index_key.type->name, ctx->index_key.description); *_key = NULL; mutex_lock(&user->cons_lock); perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; perm |= KEY_USR_VIEW; if (ctx->index_key.type->read) perm |= KEY_POS_READ; if (ctx->index_key.type == &key_type_keyring || ctx->index_key.type->update) perm |= KEY_POS_WRITE; key = key_alloc(ctx->index_key.type, ctx->index_key.description, ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, perm, flags, NULL); if (IS_ERR(key)) goto alloc_failed; set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); if (dest_keyring) { ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); if (ret < 0) goto link_prealloc_failed; } /* attach the key to the destination keyring under lock, but we do need * to do another check just in case someone beat us to it whilst we * waited for locks */ mutex_lock(&key_construction_mutex); key_ref = search_process_keyrings(ctx); if (!IS_ERR(key_ref)) goto key_already_present; if (dest_keyring) __key_link(key, &edit); mutex_unlock(&key_construction_mutex); if (dest_keyring) __key_link_end(dest_keyring, &ctx->index_key, edit); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); return 0; /* the key is now present - we tell the caller that we found it by * returning -EINPROGRESS */ key_already_present: key_put(key); mutex_unlock(&key_construction_mutex); key = key_ref_to_ptr(key_ref); if (dest_keyring) { ret = __key_link_check_live_key(dest_keyring, key); if (ret == 0) __key_link(key, &edit); __key_link_end(dest_keyring, &ctx->index_key, edit); if (ret < 0) goto link_check_failed; } mutex_unlock(&user->cons_lock); *_key = key; kleave(" = -EINPROGRESS [%d]", key_serial(key)); return -EINPROGRESS; link_check_failed: mutex_unlock(&user->cons_lock); key_put(key); kleave(" = %d [linkcheck]", ret); return ret; link_prealloc_failed: mutex_unlock(&user->cons_lock); key_put(key); kleave(" = %d [prelink]", ret); return ret; alloc_failed: mutex_unlock(&user->cons_lock); kleave(" = %ld", PTR_ERR(key)); return PTR_ERR(key); } /* * Commence key construction. */ static struct key *construct_key_and_link(struct keyring_search_context *ctx, const char *callout_info, size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags) { struct key_user *user; struct key *key; int ret; kenter(""); if (ctx->index_key.type == &key_type_keyring) return ERR_PTR(-EPERM); user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); construct_get_dest_keyring(&dest_keyring); ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); key_user_put(user); if (ret == 0) { ret = construct_key(key, callout_info, callout_len, aux, dest_keyring); if (ret < 0) { kdebug("cons failed"); goto construction_failed; } } else if (ret == -EINPROGRESS) { ret = 0; } else { goto couldnt_alloc_key; } key_put(dest_keyring); kleave(" = key %d", key_serial(key)); return key; construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key); couldnt_alloc_key: key_put(dest_keyring); kleave(" = %d", ret); return ERR_PTR(ret); } /** * request_key_and_link - Request a key and cache it in a keyring. * @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. * @dest_keyring: Where to cache the key. * @flags: Flags to key_alloc(). * * A key matching the specified criteria is searched for in the process's * keyrings and returned with its usage count incremented if found. Otherwise, * if callout_info is not NULL, a key will be allocated and some service * (probably in userspace) will be asked to instantiate it. * * If successfully found or created, the key will be linked to the destination * keyring if one is provided. * * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED