diff options
Diffstat (limited to 'net/rxrpc/ar-key.c')
-rw-r--r-- | net/rxrpc/ar-key.c | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c new file mode 100644 index 00000000000..7e049ff6ae6 --- /dev/null +++ b/net/rxrpc/ar-key.c @@ -0,0 +1,334 @@ +/* RxRPC key management + * + * Copyright (C) 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. + * + * RxRPC keys should have a description of describing their purpose: + * "afs@CAMBRIDGE.REDHAT.COM> + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/key.h> +#include <linux/crypto.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <keys/rxrpc-type.h> +#include <keys/user-type.h> +#include "ar-internal.h" + +static int rxrpc_instantiate(struct key *, const void *, size_t); +static int rxrpc_instantiate_s(struct key *, const void *, size_t); +static void rxrpc_destroy(struct key *); +static void rxrpc_destroy_s(struct key *); +static void rxrpc_describe(const struct key *, struct seq_file *); + +/* + * rxrpc defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_rxrpc = { + .name = "rxrpc", + .instantiate = rxrpc_instantiate, + .match = user_match, + .destroy = rxrpc_destroy, + .describe = rxrpc_describe, +}; + +EXPORT_SYMBOL(key_type_rxrpc); + +/* + * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the + * description and an 8-byte decryption key as the payload + */ +struct key_type key_type_rxrpc_s = { + .name = "rxrpc_s", + .instantiate = rxrpc_instantiate_s, + .match = user_match, + .destroy = rxrpc_destroy_s, + .describe = rxrpc_describe, +}; + +/* + * instantiate an rxrpc defined key + * data should be of the form: + * OFFSET LEN CONTENT + * 0 4 key interface version number + * 4 2 security index (type) + * 6 2 ticket length + * 8 4 key expiry time (time_t) + * 12 4 kvno + * 16 8 session key + * 24 [len] ticket + * + * if no data is provided, then a no-security key is made + */ +static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen) +{ + const struct rxkad_key *tsec; + struct rxrpc_key_payload *upayload; + size_t plen; + u32 kver; + int ret; + + _enter("{%x},,%zu", key_serial(key), datalen); + + /* handle a no-security key */ + if (!data && datalen == 0) + return 0; + + /* get the key interface version number */ + ret = -EINVAL; + if (datalen <= 4 || !data) + goto error; + memcpy(&kver, data, sizeof(kver)); + data += sizeof(kver); + datalen -= sizeof(kver); + + _debug("KEY I/F VERSION: %u", kver); + + ret = -EKEYREJECTED; + if (kver != 1) + goto error; + + /* deal with a version 1 key */ + ret = -EINVAL; + if (datalen < sizeof(*tsec)) + goto error; + + tsec = data; + if (datalen != sizeof(*tsec) + tsec->ticket_len) + goto error; + + _debug("SCIX: %u", tsec->security_index); + _debug("TLEN: %u", tsec->ticket_len); + _debug("EXPY: %x", tsec->expiry); + _debug("KVNO: %u", tsec->kvno); + _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x", + tsec->session_key[0], tsec->session_key[1], + tsec->session_key[2], tsec->session_key[3], + tsec->session_key[4], tsec->session_key[5], + tsec->session_key[6], tsec->session_key[7]); + if (tsec->ticket_len >= 8) + _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x", + tsec->ticket[0], tsec->ticket[1], + tsec->ticket[2], tsec->ticket[3], + tsec->ticket[4], tsec->ticket[5], + tsec->ticket[6], tsec->ticket[7]); + + ret = -EPROTONOSUPPORT; + if (tsec->security_index != 2) + goto error; + + key->type_data.x[0] = tsec->security_index; + + plen = sizeof(*upayload) + tsec->ticket_len; + ret = key_payload_reserve(key, plen); + if (ret < 0) + goto error; + + ret = -ENOMEM; + upayload = kmalloc(plen, GFP_KERNEL); + if (!upayload) + goto error; + + /* attach the data */ + memcpy(&upayload->k, tsec, sizeof(*tsec)); + memcpy(&upayload->k.ticket, (void *)tsec + sizeof(*tsec), + tsec->ticket_len); + key->payload.data = upayload; + key->expiry = tsec->expiry; + ret = 0; + +error: + return ret; +} + +/* + * instantiate a server secret key + * data should be a pointer to the 8-byte secret key + */ +static int rxrpc_instantiate_s(struct key *key, const void *data, + size_t datalen) +{ + struct crypto_blkcipher *ci; + + _enter("{%x},,%zu", key_serial(key), datalen); + + if (datalen != 8) + return -EINVAL; + + memcpy(&key->type_data, data, 8); + + ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(ci)) { + _leave(" = %ld", PTR_ERR(ci)); + return PTR_ERR(ci); + } + + if (crypto_blkcipher_setkey(ci, data, 8) < 0) + BUG(); + + key->payload.data = ci; + _leave(" = 0"); + return 0; +} + +/* + * dispose of the data dangling from the corpse of a rxrpc key + */ +static void rxrpc_destroy(struct key *key) +{ + kfree(key->payload.data); +} + +/* + * dispose of the data dangling from the corpse of a rxrpc key + */ +static void rxrpc_destroy_s(struct key *key) +{ + if (key->payload.data) { + crypto_free_blkcipher(key->payload.data); + key->payload.data = NULL; + } +} + +/* + * describe the rxrpc key + */ +static void rxrpc_describe(const struct key *key, struct seq_file *m) +{ + seq_puts(m, key->description); +} + +/* + * grab the security key for a socket + */ +int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen) +{ + struct key *key; + char *description; + + _enter(""); + + if (optlen <= 0 || optlen > PAGE_SIZE - 1) + return -EINVAL; + + description = kmalloc(optlen + 1, GFP_KERNEL); + if (!description) + return -ENOMEM; + + if (copy_from_user(description, optval, optlen)) { + kfree(description); + return -EFAULT; + } + description[optlen] = 0; + + key = request_key(&key_type_rxrpc, description, NULL); + if (IS_ERR(key)) { + kfree(description); + _leave(" = %ld", PTR_ERR(key)); + return PTR_ERR(key); + } + + rx->key = key; + kfree(description); + _leave(" = 0 [key %x]", key->serial); + return 0; +} + +/* + * grab the security keyring for a server socket + */ +int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval, + int optlen) +{ + struct key *key; + char *description; + + _enter(""); + + if (optlen <= 0 || optlen > PAGE_SIZE - 1) + return -EINVAL; + + description = kmalloc(optlen + 1, GFP_KERNEL); + if (!description) + return -ENOMEM; + + if (copy_from_user(description, optval, optlen)) { + kfree(description); + return -EFAULT; + } + description[optlen] = 0; + + key = request_key(&key_type_keyring, description, NULL); + if (IS_ERR(key)) { + kfree(description); + _leave(" = %ld", PTR_ERR(key)); + return PTR_ERR(key); + } + + rx->securities = key; + kfree(description); + _leave(" = 0 [key %x]", key->serial); + return 0; +} + +/* + * generate a server data key + */ +int rxrpc_get_server_data_key(struct rxrpc_connection *conn, + const void *session_key, + time_t expiry, + u32 kvno) +{ + struct key *key; + int ret; + + struct { + u32 kver; + struct rxkad_key tsec; + } data; + + _enter(""); + + key = key_alloc(&key_type_rxrpc, "x", 0, 0, current, 0, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(key)) { + _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key)); + return -ENOMEM; + } + + _debug("key %d", key_serial(key)); + + data.kver = 1; + data.tsec.security_index = 2; + data.tsec.ticket_len = 0; + data.tsec.expiry = expiry; + data.tsec.kvno = 0; + + memcpy(&data.tsec.session_key, session_key, + sizeof(data.tsec.session_key)); + + ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL); + if (ret < 0) + goto error; + + conn->key = key; + _leave(" = 0 [%d]", key_serial(key)); + return 0; + +error: + key_revoke(key); + key_put(key); + _leave(" = -ENOMEM [ins %d]", ret); + return -ENOMEM; +} + +EXPORT_SYMBOL(rxrpc_get_server_data_key); |