linux/net/ceph/auth_x.c
Sage Weil 27859f9773 libceph: wrap auth ops in wrapper functions
Use wrapper functions that check whether the auth op exists so that callers
do not need a bunch of conditional checks.  Simplifies the external
interface.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:14 -07:00

712 lines
17 KiB
C

#include <linux/ceph/ceph_debug.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/auth.h>
#include "crypto.h"
#include "auth_x.h"
#include "auth_x_protocol.h"
#define TEMP_TICKET_BUF_LEN 256
static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi = ac->private;
int need;
ceph_x_validate_tickets(ac, &need);
dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
ac->want_keys, need, xi->have_keys);
return (ac->want_keys & xi->have_keys) == ac->want_keys;
}
static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi = ac->private;
int need;
ceph_x_validate_tickets(ac, &need);
dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
ac->want_keys, need, xi->have_keys);
return need != 0;
}
static int ceph_x_encrypt_buflen(int ilen)
{
return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
sizeof(u32);
}
static int ceph_x_encrypt(struct ceph_crypto_key *secret,
void *ibuf, int ilen, void *obuf, size_t olen)
{
struct ceph_x_encrypt_header head = {
.struct_v = 1,
.magic = cpu_to_le64(CEPHX_ENC_MAGIC)
};
size_t len = olen - sizeof(u32);
int ret;
ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
&head, sizeof(head), ibuf, ilen);
if (ret)
return ret;
ceph_encode_32(&obuf, len);
return len + sizeof(u32);
}
static int ceph_x_decrypt(struct ceph_crypto_key *secret,
void **p, void *end, void *obuf, size_t olen)
{
struct ceph_x_encrypt_header head;
size_t head_len = sizeof(head);
int len, ret;
len = ceph_decode_32(p);
if (*p + len > end)
return -EINVAL;
dout("ceph_x_decrypt len %d\n", len);
ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
*p, len);
if (ret)
return ret;
if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
return -EPERM;
*p += len;
return olen;
}
/*
* get existing (or insert new) ticket handler
*/
static struct ceph_x_ticket_handler *
get_ticket_handler(struct ceph_auth_client *ac, int service)
{
struct ceph_x_ticket_handler *th;
struct ceph_x_info *xi = ac->private;
struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
while (*p) {
parent = *p;
th = rb_entry(parent, struct ceph_x_ticket_handler, node);
if (service < th->service)
p = &(*p)->rb_left;
else if (service > th->service)
p = &(*p)->rb_right;
else
return th;
}
/* add it */
th = kzalloc(sizeof(*th), GFP_NOFS);
if (!th)
return ERR_PTR(-ENOMEM);
th->service = service;
rb_link_node(&th->node, parent, p);
rb_insert_color(&th->node, &xi->ticket_handlers);
return th;
}
static void remove_ticket_handler(struct ceph_auth_client *ac,
struct ceph_x_ticket_handler *th)
{
struct ceph_x_info *xi = ac->private;
dout("remove_ticket_handler %p %d\n", th, th->service);
rb_erase(&th->node, &xi->ticket_handlers);
ceph_crypto_key_destroy(&th->session_key);
if (th->ticket_blob)
ceph_buffer_put(th->ticket_blob);
kfree(th);
}
static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
struct ceph_crypto_key *secret,
void *buf, void *end)
{
struct ceph_x_info *xi = ac->private;
int num;
void *p = buf;
int ret;
char *dbuf;
char *ticket_buf;
u8 reply_struct_v;
dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
if (!dbuf)
return -ENOMEM;
ret = -ENOMEM;
ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
if (!ticket_buf)
goto out_dbuf;
ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
reply_struct_v = ceph_decode_8(&p);
if (reply_struct_v != 1)
goto bad;
num = ceph_decode_32(&p);
dout("%d tickets\n", num);
while (num--) {
int type;
u8 tkt_struct_v, blob_struct_v;
struct ceph_x_ticket_handler *th;
void *dp, *dend;
int dlen;
char is_enc;
struct timespec validity;
struct ceph_crypto_key old_key;
void *tp, *tpend;
struct ceph_timespec new_validity;
struct ceph_crypto_key new_session_key;
struct ceph_buffer *new_ticket_blob;
unsigned long new_expires, new_renew_after;
u64 new_secret_id;
ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
type = ceph_decode_32(&p);
dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
tkt_struct_v = ceph_decode_8(&p);
if (tkt_struct_v != 1)
goto bad;
th = get_ticket_handler(ac, type);
if (IS_ERR(th)) {
ret = PTR_ERR(th);
goto out;
}
/* blob for me */
dlen = ceph_x_decrypt(secret, &p, end, dbuf,
TEMP_TICKET_BUF_LEN);
if (dlen <= 0) {
ret = dlen;
goto out;
}
dout(" decrypted %d bytes\n", dlen);
dend = dbuf + dlen;
dp = dbuf;
tkt_struct_v = ceph_decode_8(&dp);
if (tkt_struct_v != 1)
goto bad;
memcpy(&old_key, &th->session_key, sizeof(old_key));
ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
if (ret)
goto out;
ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
ceph_decode_timespec(&validity, &new_validity);
new_expires = get_seconds() + validity.tv_sec;
new_renew_after = new_expires - (validity.tv_sec / 4);
dout(" expires=%lu renew_after=%lu\n", new_expires,
new_renew_after);
/* ticket blob for service */
ceph_decode_8_safe(&p, end, is_enc, bad);
tp = ticket_buf;
if (is_enc) {
/* encrypted */
dout(" encrypted ticket\n");
dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
TEMP_TICKET_BUF_LEN);
if (dlen < 0) {
ret = dlen;
goto out;
}
dlen = ceph_decode_32(&tp);
} else {
/* unencrypted */
ceph_decode_32_safe(&p, end, dlen, bad);
ceph_decode_need(&p, end, dlen, bad);
ceph_decode_copy(&p, ticket_buf, dlen);
}
tpend = tp + dlen;
dout(" ticket blob is %d bytes\n", dlen);
ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
blob_struct_v = ceph_decode_8(&tp);
new_secret_id = ceph_decode_64(&tp);
ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
if (ret)
goto out;
/* all is well, update our ticket */
ceph_crypto_key_destroy(&th->session_key);
if (th->ticket_blob)
ceph_buffer_put(th->ticket_blob);
th->session_key = new_session_key;
th->ticket_blob = new_ticket_blob;
th->validity = new_validity;
th->secret_id = new_secret_id;
th->expires = new_expires;
th->renew_after = new_renew_after;
dout(" got ticket service %d (%s) secret_id %lld len %d\n",
type, ceph_entity_type_name(type), th->secret_id,
(int)th->ticket_blob->vec.iov_len);
xi->have_keys |= th->service;
}
ret = 0;
out:
kfree(ticket_buf);
out_dbuf:
kfree(dbuf);
return ret;
bad:
ret = -EINVAL;
goto out;
}
static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
struct ceph_x_ticket_handler *th,
struct ceph_x_authorizer *au)
{
int maxlen;
struct ceph_x_authorize_a *msg_a;
struct ceph_x_authorize_b msg_b;
void *p, *end;
int ret;
int ticket_blob_len =
(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
dout("build_authorizer for %s %p\n",
ceph_entity_type_name(th->service), au);
maxlen = sizeof(*msg_a) + sizeof(msg_b) +
ceph_x_encrypt_buflen(ticket_blob_len);
dout(" need len %d\n", maxlen);
if (au->buf && au->buf->alloc_len < maxlen) {
ceph_buffer_put(au->buf);
au->buf = NULL;
}
if (!au->buf) {
au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
if (!au->buf)
return -ENOMEM;
}
au->service = th->service;
au->secret_id = th->secret_id;
msg_a = au->buf->vec.iov_base;
msg_a->struct_v = 1;
msg_a->global_id = cpu_to_le64(ac->global_id);
msg_a->service_id = cpu_to_le32(th->service);
msg_a->ticket_blob.struct_v = 1;
msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
if (ticket_blob_len) {
memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
th->ticket_blob->vec.iov_len);
}
dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
le64_to_cpu(msg_a->ticket_blob.secret_id));
p = msg_a + 1;
p += ticket_blob_len;
end = au->buf->vec.iov_base + au->buf->vec.iov_len;
get_random_bytes(&au->nonce, sizeof(au->nonce));
msg_b.struct_v = 1;
msg_b.nonce = cpu_to_le64(au->nonce);
ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
p, end - p);
if (ret < 0)
goto out_buf;
p += ret;
au->buf->vec.iov_len = p - au->buf->vec.iov_base;
dout(" built authorizer nonce %llx len %d\n", au->nonce,
(int)au->buf->vec.iov_len);
BUG_ON(au->buf->vec.iov_len > maxlen);
return 0;
out_buf:
ceph_buffer_put(au->buf);
au->buf = NULL;
return ret;
}
static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
void **p, void *end)
{
ceph_decode_need(p, end, 1 + sizeof(u64), bad);
ceph_encode_8(p, 1);
ceph_encode_64(p, th->secret_id);
if (th->ticket_blob) {
const char *buf = th->ticket_blob->vec.iov_base;
u32 len = th->ticket_blob->vec.iov_len;
ceph_encode_32_safe(p, end, len, bad);
ceph_encode_copy_safe(p, end, buf, len, bad);
} else {
ceph_encode_32_safe(p, end, 0, bad);
}
return 0;
bad:
return -ERANGE;
}
static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
{
int want = ac->want_keys;
struct ceph_x_info *xi = ac->private;
int service;
*pneed = ac->want_keys & ~(xi->have_keys);
for (service = 1; service <= want; service <<= 1) {
struct ceph_x_ticket_handler *th;
if (!(ac->want_keys & service))
continue;
if (*pneed & service)
continue;
th = get_ticket_handler(ac, service);
if (IS_ERR(th)) {
*pneed |= service;
continue;
}
if (get_seconds() >= th->renew_after)
*pneed |= service;
if (get_seconds() >= th->expires)
xi->have_keys &= ~service;
}
}
static int ceph_x_build_request(struct ceph_auth_client *ac,
void *buf, void *end)
{
struct ceph_x_info *xi = ac->private;
int need;
struct ceph_x_request_header *head = buf;
int ret;
struct ceph_x_ticket_handler *th =
get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
if (IS_ERR(th))
return PTR_ERR(th);
ceph_x_validate_tickets(ac, &need);
dout("build_request want %x have %x need %x\n",
ac->want_keys, xi->have_keys, need);
if (need & CEPH_ENTITY_TYPE_AUTH) {
struct ceph_x_authenticate *auth = (void *)(head + 1);
void *p = auth + 1;
struct ceph_x_challenge_blob tmp;
char tmp_enc[40];
u64 *u;
if (p > end)
return -ERANGE;
dout(" get_auth_session_key\n");
head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
/* encrypt and hash */
get_random_bytes(&auth->client_challenge, sizeof(u64));
tmp.client_challenge = auth->client_challenge;
tmp.server_challenge = cpu_to_le64(xi->server_challenge);
ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
tmp_enc, sizeof(tmp_enc));
if (ret < 0)
return ret;
auth->struct_v = 1;
auth->key = 0;
for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
auth->key ^= *(__le64 *)u;
dout(" server_challenge %llx client_challenge %llx key %llx\n",
xi->server_challenge, le64_to_cpu(auth->client_challenge),
le64_to_cpu(auth->key));
/* now encode the old ticket if exists */
ret = ceph_x_encode_ticket(th, &p, end);
if (ret < 0)
return ret;
return p - buf;
}
if (need) {
void *p = head + 1;
struct ceph_x_service_ticket_request *req;
if (p > end)
return -ERANGE;
head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
if (ret)
return ret;
ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
xi->auth_authorizer.buf->vec.iov_len);
req = p;
req->keys = cpu_to_le32(need);
p += sizeof(*req);
return p - buf;
}
return 0;
}
static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
void *buf, void *end)
{
struct ceph_x_info *xi = ac->private;
struct ceph_x_reply_header *head = buf;
struct ceph_x_ticket_handler *th;
int len = end - buf;
int op;
int ret;
if (result)
return result; /* XXX hmm? */
if (xi->starting) {
/* it's a hello */
struct ceph_x_server_challenge *sc = buf;
if (len != sizeof(*sc))
return -EINVAL;
xi->server_challenge = le64_to_cpu(sc->server_challenge);
dout("handle_reply got server challenge %llx\n",
xi->server_challenge);
xi->starting = false;
xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
return -EAGAIN;
}
op = le16_to_cpu(head->op);
result = le32_to_cpu(head->result);
dout("handle_reply op %d result %d\n", op, result);
switch (op) {
case CEPHX_GET_AUTH_SESSION_KEY:
/* verify auth key */
ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
buf + sizeof(*head), end);
break;
case CEPHX_GET_PRINCIPAL_SESSION_KEY:
th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
if (IS_ERR(th))
return PTR_ERR(th);
ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
buf + sizeof(*head), end);
break;
default:
return -EINVAL;
}
if (ret)
return ret;
if (ac->want_keys == xi->have_keys)
return 0;
return -EAGAIN;
}
static int ceph_x_create_authorizer(
struct ceph_auth_client *ac, int peer_type,
struct ceph_auth_handshake *auth)
{
struct ceph_x_authorizer *au;
struct ceph_x_ticket_handler *th;
int ret;
th = get_ticket_handler(ac, peer_type);
if (IS_ERR(th))
return PTR_ERR(th);
au = kzalloc(sizeof(*au), GFP_NOFS);
if (!au)
return -ENOMEM;
ret = ceph_x_build_authorizer(ac, th, au);
if (ret) {
kfree(au);
return ret;
}
auth->authorizer = (struct ceph_authorizer *) au;
auth->authorizer_buf = au->buf->vec.iov_base;
auth->authorizer_buf_len = au->buf->vec.iov_len;
auth->authorizer_reply_buf = au->reply_buf;
auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
return 0;
}
static int ceph_x_update_authorizer(
struct ceph_auth_client *ac, int peer_type,
struct ceph_auth_handshake *auth)
{
struct ceph_x_authorizer *au;
struct ceph_x_ticket_handler *th;
th = get_ticket_handler(ac, peer_type);
if (IS_ERR(th))
return PTR_ERR(th);
au = (struct ceph_x_authorizer *)auth->authorizer;
if (au->secret_id < th->secret_id) {
dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
au->service, au->secret_id, th->secret_id);
return ceph_x_build_authorizer(ac, th, au);
}
return 0;
}
static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
struct ceph_authorizer *a, size_t len)
{
struct ceph_x_authorizer *au = (void *)a;
struct ceph_x_ticket_handler *th;
int ret = 0;
struct ceph_x_authorize_reply reply;
void *p = au->reply_buf;
void *end = p + sizeof(au->reply_buf);
th = get_ticket_handler(ac, au->service);
if (IS_ERR(th))
return PTR_ERR(th);
ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
if (ret < 0)
return ret;
if (ret != sizeof(reply))
return -EPERM;
if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
ret = -EPERM;
else
ret = 0;
dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
return ret;
}
static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
struct ceph_authorizer *a)
{
struct ceph_x_authorizer *au = (void *)a;
ceph_buffer_put(au->buf);
kfree(au);
}
static void ceph_x_reset(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi = ac->private;
dout("reset\n");
xi->starting = true;
xi->server_challenge = 0;
}
static void ceph_x_destroy(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi = ac->private;
struct rb_node *p;
dout("ceph_x_destroy %p\n", ac);
ceph_crypto_key_destroy(&xi->secret);
while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
struct ceph_x_ticket_handler *th =
rb_entry(p, struct ceph_x_ticket_handler, node);
remove_ticket_handler(ac, th);
}
if (xi->auth_authorizer.buf)
ceph_buffer_put(xi->auth_authorizer.buf);
kfree(ac->private);
ac->private = NULL;
}
static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
int peer_type)
{
struct ceph_x_ticket_handler *th;
th = get_ticket_handler(ac, peer_type);
if (!IS_ERR(th))
memset(&th->validity, 0, sizeof(th->validity));
}
static const struct ceph_auth_client_ops ceph_x_ops = {
.name = "x",
.is_authenticated = ceph_x_is_authenticated,
.should_authenticate = ceph_x_should_authenticate,
.build_request = ceph_x_build_request,
.handle_reply = ceph_x_handle_reply,
.create_authorizer = ceph_x_create_authorizer,
.update_authorizer = ceph_x_update_authorizer,
.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
.destroy_authorizer = ceph_x_destroy_authorizer,
.invalidate_authorizer = ceph_x_invalidate_authorizer,
.reset = ceph_x_reset,
.destroy = ceph_x_destroy,
};
int ceph_x_init(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi;
int ret;
dout("ceph_x_init %p\n", ac);
ret = -ENOMEM;
xi = kzalloc(sizeof(*xi), GFP_NOFS);
if (!xi)
goto out;
ret = -EINVAL;
if (!ac->key) {
pr_err("no secret set (for auth_x protocol)\n");
goto out_nomem;
}
ret = ceph_crypto_key_clone(&xi->secret, ac->key);
if (ret < 0) {
pr_err("cannot clone key: %d\n", ret);
goto out_nomem;
}
xi->starting = true;
xi->ticket_handlers = RB_ROOT;
ac->protocol = CEPH_AUTH_CEPHX;
ac->private = xi;
ac->ops = &ceph_x_ops;
return 0;
out_nomem:
kfree(xi);
out:
return ret;
}