net/tls: Fix authentication failure in CCM mode

BugLink: https://bugs.launchpad.net/bugs/1953731
commit 5961060692f8b17cd2080620a3d27b95d2ae05ca upstream.

When the TLS cipher suite uses CCM mode, including AES CCM and
SM4 CCM, the first byte of the B0 block is flags, and the real
IV starts from the second byte. The XOR operation of the IV and
rec_seq should be skip this byte, that is, add the iv_offset.

Fixes: f295b3ae9f59 ("net/tls: Add support of AES128-CCM based ciphers")
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Cc: Vakul Garg <vakul.garg@nxp.com>
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index b0cdcea1018066c9479f7f0ac7b0da8162697cfd..bd96ec26f4f997070de93ba79152a8b96c7adc02 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -515,7 +515,7 @@ static int tls_do_encryption(struct sock *sk,
        memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
               prot->iv_size + prot->salt_size);
 
-       xor_iv_with_seq(prot, rec->iv_data, tls_ctx->tx.rec_seq);
+       xor_iv_with_seq(prot, rec->iv_data + iv_offset, tls_ctx->tx.rec_seq);
 
        sge->offset += prot->prepend_size;
        sge->length -= prot->prepend_size;
@@ -1487,7 +1487,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
        else
                memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size);
 
-       xor_iv_with_seq(prot, iv, tls_ctx->rx.rec_seq);
+       xor_iv_with_seq(prot, iv + iv_offset, tls_ctx->rx.rec_seq);
 
        /* Prepare AAD */
        tls_make_aad(aad, rxm->full_len - prot->overhead_size +