linux/net/ceph/auth_x.c
Tommi Virtanen 8323c3aa74 ceph: Move secret key parsing earlier.
This makes the base64 logic be contained in mount option parsing,
and prepares us for replacing the homebew key management with the
kernel key retention service.

Signed-off-by: Tommi Virtanen <tommi.virtanen@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-03-29 12:11:16 -07:00

691 lines
16 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;
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_authorizer **a,
void **buf, size_t *len,
void **reply_buf, size_t *reply_len)
{
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;
}
*a = (struct ceph_authorizer *)au;
*buf = au->buf->vec.iov_base;
*len = au->buf->vec.iov_len;
*reply_buf = au->reply_buf;
*reply_len = sizeof(au->reply_buf);
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))
remove_ticket_handler(ac, th);
}
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,
.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;
}