summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorIlya Dryomov <idryomov@gmail.com>2020-12-22 19:00:48 +0100
committerIlya Dryomov <idryomov@gmail.com>2021-01-04 17:31:32 +0100
commit10f42b3e648377b2f2f323a5530354710616c6cc (patch)
treedf088d623ba005d946e6c8e3a30d68fd24ebe998
parente71ba9452f0b5b2e8dc8aa5445198cd9214a6a62 (diff)
libceph: zero out session key and connection secret
Try and avoid leaving bits and pieces of session key and connection secret (gets split into GCM key and a pair of GCM IVs) around. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
-rw-r--r--net/ceph/auth_x.c57
-rw-r--r--net/ceph/crypto.c3
-rw-r--r--net/ceph/messenger_v2.c45
3 files changed, 62 insertions, 43 deletions
diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c
index 9815cfe42af0..ca44c327bace 100644
--- a/net/ceph/auth_x.c
+++ b/net/ceph/auth_x.c
@@ -569,6 +569,34 @@ e_range:
return -ERANGE;
}
+static int decode_con_secret(void **p, void *end, u8 *con_secret,
+ int *con_secret_len)
+{
+ int len;
+
+ ceph_decode_32_safe(p, end, len, bad);
+ ceph_decode_need(p, end, len, bad);
+
+ dout("%s len %d\n", __func__, len);
+ if (con_secret) {
+ if (len > CEPH_MAX_CON_SECRET_LEN) {
+ pr_err("connection secret too big %d\n", len);
+ goto bad_memzero;
+ }
+ memcpy(con_secret, *p, len);
+ *con_secret_len = len;
+ }
+ memzero_explicit(*p, len);
+ *p += len;
+ return 0;
+
+bad_memzero:
+ memzero_explicit(*p, len);
+bad:
+ pr_err("failed to decode connection secret\n");
+ return -EINVAL;
+}
+
static int handle_auth_session_key(struct ceph_auth_client *ac,
void **p, void *end,
u8 *session_key, int *session_key_len,
@@ -612,17 +640,9 @@ static int handle_auth_session_key(struct ceph_auth_client *ac,
dout("%s decrypted %d bytes\n", __func__, ret);
dend = dp + ret;
- ceph_decode_32_safe(&dp, dend, len, e_inval);
- if (len > CEPH_MAX_CON_SECRET_LEN) {
- pr_err("connection secret too big %d\n", len);
- return -EINVAL;
- }
-
- dout("%s connection secret len %d\n", __func__, len);
- if (con_secret) {
- memcpy(con_secret, dp, len);
- *con_secret_len = len;
- }
+ ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
+ if (ret)
+ return ret;
}
/* service tickets */
@@ -828,7 +848,6 @@ static int decrypt_authorizer_reply(struct ceph_crypto_key *secret,
{
void *dp, *dend;
u8 struct_v;
- int len;
int ret;
dp = *p + ceph_x_encrypt_offset();
@@ -843,17 +862,9 @@ static int decrypt_authorizer_reply(struct ceph_crypto_key *secret,
ceph_decode_64_safe(&dp, dend, *nonce_plus_one, e_inval);
dout("%s nonce_plus_one %llu\n", __func__, *nonce_plus_one);
if (struct_v >= 2) {
- ceph_decode_32_safe(&dp, dend, len, e_inval);
- if (len > CEPH_MAX_CON_SECRET_LEN) {
- pr_err("connection secret too big %d\n", len);
- return -EINVAL;
- }
-
- dout("%s connection secret len %d\n", __func__, len);
- if (con_secret) {
- memcpy(con_secret, dp, len);
- *con_secret_len = len;
- }
+ ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
+ if (ret)
+ return ret;
}
return 0;
diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c
index 4f75df40fb12..92d89b331645 100644
--- a/net/ceph/crypto.c
+++ b/net/ceph/crypto.c
@@ -96,6 +96,7 @@ int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
key->len = ceph_decode_16(p);
ceph_decode_need(p, end, key->len, bad);
ret = set_secret(key, *p);
+ memzero_explicit(*p, key->len);
*p += key->len;
return ret;
@@ -134,7 +135,7 @@ int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
{
if (key) {
- kfree(key->key);
+ kfree_sensitive(key->key);
key->key = NULL;
if (key->tfm) {
crypto_free_sync_skcipher(key->tfm);
diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index c38d8de93836..cc40ce4e02fb 100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -689,11 +689,10 @@ static int verify_epilogue_crcs(struct ceph_connection *con, u32 front_crc,
}
static int setup_crypto(struct ceph_connection *con,
- u8 *session_key, int session_key_len,
- u8 *con_secret, int con_secret_len)
+ const u8 *session_key, int session_key_len,
+ const u8 *con_secret, int con_secret_len)
{
unsigned int noio_flag;
- void *p;
int ret;
dout("%s con %p con_mode %d session_key_len %d con_secret_len %d\n",
@@ -751,15 +750,14 @@ static int setup_crypto(struct ceph_connection *con,
return ret;
}
- p = con_secret;
- WARN_ON((unsigned long)p & crypto_aead_alignmask(con->v2.gcm_tfm));
- ret = crypto_aead_setkey(con->v2.gcm_tfm, p, CEPH_GCM_KEY_LEN);
+ WARN_ON((unsigned long)con_secret &
+ crypto_aead_alignmask(con->v2.gcm_tfm));
+ ret = crypto_aead_setkey(con->v2.gcm_tfm, con_secret, CEPH_GCM_KEY_LEN);
if (ret) {
pr_err("failed to set gcm key: %d\n", ret);
return ret;
}
- p += CEPH_GCM_KEY_LEN;
WARN_ON(crypto_aead_ivsize(con->v2.gcm_tfm) != CEPH_GCM_IV_LEN);
ret = crypto_aead_setauthsize(con->v2.gcm_tfm, CEPH_GCM_TAG_LEN);
if (ret) {
@@ -777,8 +775,11 @@ static int setup_crypto(struct ceph_connection *con,
aead_request_set_callback(con->v2.gcm_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &con->v2.gcm_wait);
- memcpy(&con->v2.in_gcm_nonce, p, CEPH_GCM_IV_LEN);
- memcpy(&con->v2.out_gcm_nonce, p + CEPH_GCM_IV_LEN, CEPH_GCM_IV_LEN);
+ memcpy(&con->v2.in_gcm_nonce, con_secret + CEPH_GCM_KEY_LEN,
+ CEPH_GCM_IV_LEN);
+ memcpy(&con->v2.out_gcm_nonce,
+ con_secret + CEPH_GCM_KEY_LEN + CEPH_GCM_IV_LEN,
+ CEPH_GCM_IV_LEN);
return 0; /* auth_x, secure mode */
}
@@ -800,7 +801,7 @@ static int hmac_sha256(struct ceph_connection *con, const struct kvec *kvecs,
desc->tfm = con->v2.hmac_tfm;
ret = crypto_shash_init(desc);
if (ret)
- return ret;
+ goto out;
for (i = 0; i < kvec_cnt; i++) {
WARN_ON((unsigned long)kvecs[i].iov_base &
@@ -808,15 +809,14 @@ static int hmac_sha256(struct ceph_connection *con, const struct kvec *kvecs,
ret = crypto_shash_update(desc, kvecs[i].iov_base,
kvecs[i].iov_len);
if (ret)
- return ret;
+ goto out;
}
ret = crypto_shash_final(desc, hmac);
- if (ret)
- return ret;
+out:
shash_desc_zero(desc);
- return 0; /* auth_x, both plain and secure modes */
+ return ret; /* auth_x, both plain and secure modes */
}
static void gcm_inc_nonce(struct ceph_gcm_nonce *nonce)
@@ -2072,27 +2072,32 @@ static int process_auth_done(struct ceph_connection *con, void *p, void *end)
if (con->state != CEPH_CON_S_V2_AUTH) {
dout("%s con %p state changed to %d\n", __func__, con,
con->state);
- return -EAGAIN;
+ ret = -EAGAIN;
+ goto out;
}
dout("%s con %p handle_auth_done ret %d\n", __func__, con, ret);
if (ret)
- return ret;
+ goto out;
ret = setup_crypto(con, session_key, session_key_len, con_secret,
con_secret_len);
if (ret)
- return ret;
+ goto out;
reset_out_kvecs(con);
ret = prepare_auth_signature(con);
if (ret) {
pr_err("prepare_auth_signature failed: %d\n", ret);
- return ret;
+ goto out;
}
con->state = CEPH_CON_S_V2_AUTH_SIGNATURE;
- return 0;
+
+out:
+ memzero_explicit(session_key_buf, sizeof(session_key_buf));
+ memzero_explicit(con_secret_buf, sizeof(con_secret_buf));
+ return ret;
bad:
pr_err("failed to decode auth_done\n");
@@ -3436,6 +3441,8 @@ void ceph_con_v2_reset_protocol(struct ceph_connection *con)
}
con->v2.con_mode = CEPH_CON_MODE_UNKNOWN;
+ memzero_explicit(&con->v2.in_gcm_nonce, CEPH_GCM_IV_LEN);
+ memzero_explicit(&con->v2.out_gcm_nonce, CEPH_GCM_IV_LEN);
if (con->v2.hmac_tfm) {
crypto_free_shash(con->v2.hmac_tfm);