From f295b3ae9f5927e084bd5decdff82390e3471801 Mon Sep 17 00:00:00 2001 From: Vakul Garg Date: Wed, 20 Mar 2019 02:03:36 +0000 Subject: net/tls: Add support of AES128-CCM based ciphers Added support for AES128-CCM based record encryption. AES128-CCM is similar to AES128-GCM. Both of them have same salt/iv/mac size. The notable difference between the two is that while invoking AES128-CCM operation, the salt||nonce (which is passed as IV) has to be prefixed with a hardcoded value '2'. Further, CCM implementation in kernel requires IV passed in crypto_aead_request() to be full '16' bytes. Therefore, the record structure 'struct tls_rec' has been modified to reserve '16' bytes for IV. This works for both GCM and CCM based cipher. Signed-off-by: Vakul Garg Signed-off-by: David S. Miller --- include/net/tls.h | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'include/net/tls.h') diff --git a/include/net/tls.h b/include/net/tls.h index a5a938583295..3ce71d78414c 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -60,6 +60,17 @@ #define TLS_AAD_SPACE_SIZE 13 #define TLS_DEVICE_NAME_MAX 32 +#define MAX_IV_SIZE 16 + +/* For AES-CCM, the full 16-bytes of IV is made of '4' fields of given sizes. + * + * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3] + * + * The field 'length' is encoded in field 'b0' as '(length width - 1)'. + * Hence b0 contains (3 - 1) = 2. + */ +#define TLS_AES_CCM_IV_B0_BYTE 2 + /* * This structure defines the routines for Inline TLS driver. * The following routines are optional and filled with a @@ -123,8 +134,7 @@ struct tls_rec { struct scatterlist sg_content_type; char aad_space[TLS_AAD_SPACE_SIZE]; - u8 iv_data[TLS_CIPHER_AES_GCM_128_IV_SIZE + - TLS_CIPHER_AES_GCM_128_SALT_SIZE]; + u8 iv_data[MAX_IV_SIZE]; struct aead_request aead_req; u8 aead_req_ctx[]; }; @@ -219,6 +229,7 @@ struct tls_prot_info { u16 tag_size; u16 overhead_size; u16 iv_size; + u16 salt_size; u16 rec_seq_size; u16 aad_size; u16 tail_size; -- cgit v1.2.3-59-g8ed1b