Commit 59610606 authored by Tianjia Zhang's avatar Tianjia Zhang Committed by David S. Miller
Browse files

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: f295b3ae ("net/tls: Add support of AES128-CCM based ciphers")
Signed-off-by: default avatarTianjia Zhang <tianjia.zhang@linux.alibaba.com>
Cc: Vakul Garg <vakul.garg@nxp.com>
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ef56b640

net/tls/tls_sw.c

+2 −2
Original line number Diff line number Diff line
@@ -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 +