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Commit f295b3ae authored by Vakul Garg's avatar Vakul Garg Committed by David S. Miller
Browse files

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: default avatarVakul Garg <vakul.garg@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6a23c0a6

include/net/tls.h

+13 −2
Original line number Diff line number Diff line
@@ -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;

include/uapi/linux/tls.h

+15 −0
Original line number Diff line number Diff line
@@ -70,6 +70,13 @@ 
#define TLS_CIPHER_AES_GCM_256_TAG_SIZE		16

#define TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE		8



#define TLS_CIPHER_AES_CCM_128				53

#define TLS_CIPHER_AES_CCM_128_IV_SIZE			8

#define TLS_CIPHER_AES_CCM_128_KEY_SIZE		16

#define TLS_CIPHER_AES_CCM_128_SALT_SIZE		4

#define TLS_CIPHER_AES_CCM_128_TAG_SIZE		16

#define TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE		8



#define TLS_SET_RECORD_TYPE	1

#define TLS_GET_RECORD_TYPE	2
@@ -94,4 +101,12 @@ struct tls12_crypto_info_aes_gcm_256 { 
	unsigned char rec_seq[TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE];

};



struct tls12_crypto_info_aes_ccm_128 {

	struct tls_crypto_info info;

	unsigned char iv[TLS_CIPHER_AES_CCM_128_IV_SIZE];

	unsigned char key[TLS_CIPHER_AES_CCM_128_KEY_SIZE];

	unsigned char salt[TLS_CIPHER_AES_CCM_128_SALT_SIZE];

	unsigned char rec_seq[TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE];

};



#endif /* _UAPI_LINUX_TLS_H */

net/tls/tls_main.c

+18 −13
Original line number Diff line number Diff line
@@ -469,26 +469,31 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval, 


	switch (crypto_info->cipher_type) {

	case TLS_CIPHER_AES_GCM_128:

		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);

		break;

	case TLS_CIPHER_AES_GCM_256: {

		optsize = crypto_info->cipher_type == TLS_CIPHER_AES_GCM_128 ?

			sizeof(struct tls12_crypto_info_aes_gcm_128) :

			sizeof(struct tls12_crypto_info_aes_gcm_256);

		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);

		break;

	}

	case TLS_CIPHER_AES_CCM_128:

		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);

		break;

	default:

		rc = -EINVAL;

		goto err_crypto_info;

	}



	if (optlen != optsize) {

		rc = -EINVAL;

		goto err_crypto_info;

	}



	rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),

			    optlen - sizeof(*crypto_info));

	if (rc) {

		rc = -EFAULT;

		goto err_crypto_info;

	}

		break;

	}

	default:

		rc = -EINVAL;

		goto err_crypto_info;

	}



	if (tx) {

#ifdef CONFIG_TLS_DEVICE

net/tls/tls_sw.c

+51 −16
Original line number Diff line number Diff line
@@ -42,8 +42,6 @@ 
#include <net/strparser.h>

#include <net/tls.h>



#define MAX_IV_SIZE	TLS_CIPHER_AES_GCM_128_IV_SIZE



static int __skb_nsg(struct sk_buff *skb, int offset, int len,

                     unsigned int recursion_level)

{
@@ -479,11 +477,18 @@ static int tls_do_encryption(struct sock *sk, 
	struct tls_rec *rec = ctx->open_rec;

	struct sk_msg *msg_en = &rec->msg_encrypted;

	struct scatterlist *sge = sk_msg_elem(msg_en, start);

	int rc;

	int rc, iv_offset = 0;



	/* For CCM based ciphers, first byte of IV is a constant */

	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {

		rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;

		iv_offset = 1;

	}



	memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,

	       prot->iv_size + prot->salt_size);



	memcpy(rec->iv_data, tls_ctx->tx.iv, sizeof(rec->iv_data));

	xor_iv_with_seq(prot->version, rec->iv_data,

			tls_ctx->tx.rec_seq);

	xor_iv_with_seq(prot->version, rec->iv_data, tls_ctx->tx.rec_seq);



	sge->offset += prot->prepend_size;

	sge->length -= prot->prepend_size;
@@ -1344,6 +1349,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, 
	struct scatterlist *sgout = NULL;

	const int data_len = rxm->full_len - prot->overhead_size +

			     prot->tail_size;

	int iv_offset = 0;



	if (*zc && (out_iov || out_sg)) {

		if (out_iov)
@@ -1386,18 +1392,25 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, 
	aad = (u8 *)(sgout + n_sgout);

	iv = aad + prot->aad_size;



	/* For CCM based ciphers, first byte of nonce+iv is always '2' */

	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {

		iv[0] = 2;

		iv_offset = 1;

	}



	/* Prepare IV */

	err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,

			    iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,

			    iv + iv_offset + prot->salt_size,

			    prot->iv_size);

	if (err < 0) {

		kfree(mem);

		return err;

	}

	if (prot->version == TLS_1_3_VERSION)

		memcpy(iv, tls_ctx->rx.iv, crypto_aead_ivsize(ctx->aead_recv));

		memcpy(iv + iv_offset, tls_ctx->rx.iv,

		       crypto_aead_ivsize(ctx->aead_recv));

	else

		memcpy(iv, tls_ctx->rx.iv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);

		memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size);



	xor_iv_with_seq(prot->version, iv, tls_ctx->rx.rec_seq);
@@ -2152,14 +2165,15 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx) 
	struct tls_crypto_info *crypto_info;

	struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;

	struct tls12_crypto_info_aes_gcm_256 *gcm_256_info;

	struct tls12_crypto_info_aes_ccm_128 *ccm_128_info;

	struct tls_sw_context_tx *sw_ctx_tx = NULL;

	struct tls_sw_context_rx *sw_ctx_rx = NULL;

	struct cipher_context *cctx;

	struct crypto_aead **aead;

	struct strp_callbacks cb;

	u16 nonce_size, tag_size, iv_size, rec_seq_size;

	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;

	struct crypto_tfm *tfm;

	char *iv, *rec_seq, *key, *salt;

	char *iv, *rec_seq, *key, *salt, *cipher_name;

	size_t keysize;

	int rc = 0;
@@ -2224,6 +2238,8 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx) 
		keysize = TLS_CIPHER_AES_GCM_128_KEY_SIZE;

		key = gcm_128_info->key;

		salt = gcm_128_info->salt;

		salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;

		cipher_name = "gcm(aes)";

		break;

	}

	case TLS_CIPHER_AES_GCM_256: {
@@ -2239,6 +2255,25 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx) 
		keysize = TLS_CIPHER_AES_GCM_256_KEY_SIZE;

		key = gcm_256_info->key;

		salt = gcm_256_info->salt;

		salt_size = TLS_CIPHER_AES_GCM_256_SALT_SIZE;

		cipher_name = "gcm(aes)";

		break;

	}

	case TLS_CIPHER_AES_CCM_128: {

		nonce_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;

		tag_size = TLS_CIPHER_AES_CCM_128_TAG_SIZE;

		iv_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;

		iv = ((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->iv;

		rec_seq_size = TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE;

		rec_seq =

		((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->rec_seq;

		ccm_128_info =

		(struct tls12_crypto_info_aes_ccm_128 *)crypto_info;

		keysize = TLS_CIPHER_AES_CCM_128_KEY_SIZE;

		key = ccm_128_info->key;

		salt = ccm_128_info->salt;

		salt_size = TLS_CIPHER_AES_CCM_128_SALT_SIZE;

		cipher_name = "ccm(aes)";

		break;

	}

	default:
@@ -2268,16 +2303,16 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx) 
	prot->overhead_size = prot->prepend_size +

			      prot->tag_size + prot->tail_size;

	prot->iv_size = iv_size;

	cctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,

			   GFP_KERNEL);

	prot->salt_size = salt_size;

	cctx->iv = kmalloc(iv_size + salt_size, GFP_KERNEL);

	if (!cctx->iv) {

		rc = -ENOMEM;

		goto free_priv;

	}

	/* Note: 128 & 256 bit salt are the same size */

	memcpy(cctx->iv, salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);

	memcpy(cctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);

	prot->rec_seq_size = rec_seq_size;

	memcpy(cctx->iv, salt, salt_size);

	memcpy(cctx->iv + salt_size, iv, iv_size);

	cctx->rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);

	if (!cctx->rec_seq) {

		rc = -ENOMEM;
@@ -2285,7 +2320,7 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx) 
	}



	if (!*aead) {

		*aead = crypto_alloc_aead("gcm(aes)", 0, 0);

		*aead = crypto_alloc_aead(cipher_name, 0, 0);

		if (IS_ERR(*aead)) {

			rc = PTR_ERR(*aead);

			*aead = NULL;