net/tls: Fix authentication failure in CCM mode

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>

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index d3e7ff9..dfe623a 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -521,7 +521,7 @@ 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;
@@ -1499,7 +1499,7 @@ 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 +