From 10f42b3e648377b2f2f323a5530354710616c6cc Mon Sep 17 00:00:00 2001
From: Ilya Dryomov <idryomov@gmail.com>
Date: Tue, 22 Dec 2020 19:00:48 +0100
Subject: 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>
---
net/ceph/messenger_v2.c | 45 ++++++++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 19 deletions(-)
(limited to 'net/ceph/messenger_v2.c')
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);
--
cgit