Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ilya Dryomov <idryomov@gmail.com>,
        Sage Weil <sage@redhat.com>,
        Ben Hutchings <ben.hutchings@codethink.co.uk>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 015/146] libceph: factor out __ceph_x_decrypt()
Date:   Tue,  4 Dec 2018 11:48:21 +0100
Message-Id: <20181204103727.414274640@linuxfoundation.org>
In-Reply-To: <20181204103726.750894136@linuxfoundation.org>
References: <20181204103726.750894136@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

commit c571fe24d243bfe7017f0e67fe800b3cc2a1d1f7 upstream.

Will be used for decrypting the server challenge which is only preceded
by ceph_x_encrypt_header.

Drop struct_v check to allow for extending ceph_x_encrypt_header in the
future.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ceph/auth_x.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c
index 2f4a1baf5f52..9cac05239346 100644
--- a/net/ceph/auth_x.c
+++ b/net/ceph/auth_x.c
@@ -70,25 +70,40 @@ static int ceph_x_encrypt(struct ceph_crypto_key *secret, void *buf,
 	return sizeof(u32) + ciphertext_len;
 }
 
+static int __ceph_x_decrypt(struct ceph_crypto_key *secret, void *p,
+			    int ciphertext_len)
+{
+	struct ceph_x_encrypt_header *hdr = p;
+	int plaintext_len;
+	int ret;
+
+	ret = ceph_crypt(secret, false, p, ciphertext_len, ciphertext_len,
+			 &plaintext_len);
+	if (ret)
+		return ret;
+
+	if (le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC) {
+		pr_err("%s bad magic\n", __func__);
+		return -EINVAL;
+	}
+
+	return plaintext_len - sizeof(*hdr);
+}
+
 static int ceph_x_decrypt(struct ceph_crypto_key *secret, void **p, void *end)
 {
-	struct ceph_x_encrypt_header *hdr = *p + sizeof(u32);
-	int ciphertext_len, plaintext_len;
+	int ciphertext_len;
 	int ret;
 
 	ceph_decode_32_safe(p, end, ciphertext_len, e_inval);
 	ceph_decode_need(p, end, ciphertext_len, e_inval);
 
-	ret = ceph_crypt(secret, false, *p, end - *p, ciphertext_len,
-			 &plaintext_len);
-	if (ret)
+	ret = __ceph_x_decrypt(secret, *p, ciphertext_len);
+	if (ret < 0)
 		return ret;
 
-	if (hdr->struct_v != 1 || le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC)
-		return -EPERM;
-
 	*p += ciphertext_len;
-	return plaintext_len - sizeof(struct ceph_x_encrypt_header);
+	return ret;
 
 e_inval:
 	return -EINVAL;
-- 
2.17.1