this patch adds IPsec extended sequence numbers support to esp6.
We use the authencesn crypto algorithm to handle esp with separate
encryption/authentication algorithms.
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
---
net/ipv6/esp6.c | 103 ++++++++++++++++++++++++++++++++++++++++++++----------
1 files changed, 84 insertions(+), 19 deletions(-)
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 672cb69..e018dfa 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -52,16 +52,20 @@ struct esp_skb_cb {
/*
* Allocate an AEAD request structure with extra space for SG and IV.
*
- * For alignment considerations the IV is placed at the front, followed
- * by the request and finally the SG list.
+ * For alignment considerations the upper 32 bits of the sequence number are
+ * placed at the front, if present. Followed by the IV, the request and finally
+ * the SG list.
*
* TODO: Use spare space in skb for this where possible.
*/
-static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags)
+static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
{
unsigned int len;
- len = crypto_aead_ivsize(aead);
+ len = seqihlen;
+
+ len += crypto_aead_ivsize(aead);
+
if (len) {
len += crypto_aead_alignmask(aead) &
~(crypto_tfm_ctx_alignment() - 1);
@@ -76,10 +80,16 @@ static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags)
return kmalloc(len, GFP_ATOMIC);
}
-static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp)
+static inline __be32 *esp_tmp_seqhi(void *tmp)
+{
+ return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
+}
+
+static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
{
return crypto_aead_ivsize(aead) ?
- PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp;
+ PTR_ALIGN((u8 *)tmp + seqhilen,
+ crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
}
static inline struct aead_givcrypt_request *esp_tmp_givreq(
@@ -141,8 +151,12 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
int clen;
int alen;
int nfrags;
+ int assoclen;
+ int sglists;
+ int seqhilen;
u8 *iv;
u8 *tail;
+ __be32 *seqhi;
struct esp_data *esp = x->data;
/* skb is pure payload to encrypt */
@@ -163,14 +177,25 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
goto error;
nfrags = err;
- tmp = esp_alloc_tmp(aead, nfrags + 1);
+ assoclen = sizeof(*esph);
+ sglists = 1;
+ seqhilen = 0;
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists++;
+ seqhilen += sizeof(__be32);
+ assoclen += seqhilen;
+ }
+
+ tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
if (!tmp)
goto error;
- iv = esp_tmp_iv(aead, tmp);
+ seqhi = esp_tmp_seqhi(tmp);
+ iv = esp_tmp_iv(aead, tmp, seqhilen);
req = esp_tmp_givreq(aead, iv);
asg = esp_givreq_sg(aead, req);
- sg = asg + 1;
+ sg = asg + sglists;
/* Fill padding... */
tail = skb_tail_pointer(trailer);
@@ -194,11 +219,18 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
skb_to_sgvec(skb, sg,
esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
clen + alen);
- sg_init_one(asg, esph, sizeof(*esph));
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ sg_init_table(asg, 2);
+ sg_set_buf(asg, esph, sizeof(*esph));
+ *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
+ sg_set_buf(asg + 1, seqhi, seqhilen);
+ } else
+ sg_init_one(asg, esph, sizeof(*esph));
aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
- aead_givcrypt_set_assoc(req, asg, sizeof(*esph));
+ aead_givcrypt_set_assoc(req, asg, assoclen);
aead_givcrypt_set_giv(req, esph->enc_data,
XFRM_SKB_CB(skb)->seq.output.low);
@@ -276,8 +308,12 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
struct sk_buff *trailer;
int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
int nfrags;
+ int assoclen;
+ int sglists;
+ int seqhilen;
int ret = 0;
void *tmp;
+ __be32 *seqhi;
u8 *iv;
struct scatterlist *sg;
struct scatterlist *asg;
@@ -298,12 +334,24 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
}
ret = -ENOMEM;
- tmp = esp_alloc_tmp(aead, nfrags + 1);
+
+ assoclen = sizeof(*esph);
+ sglists = 1;
+ seqhilen = 0;
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists++;
+ seqhilen += sizeof(__be32);
+ assoclen += seqhilen;
+ }
+
+ tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
if (!tmp)
goto out;
ESP_SKB_CB(skb)->tmp = tmp;
- iv = esp_tmp_iv(aead, tmp);
+ seqhi = esp_tmp_seqhi(tmp);
+ iv = esp_tmp_iv(aead, tmp, seqhilen);
req = esp_tmp_req(aead, iv);
asg = esp_req_sg(aead, req);
sg = asg + 1;
@@ -317,11 +365,18 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
sg_init_table(sg, nfrags);
skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
- sg_init_one(asg, esph, sizeof(*esph));
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ sg_init_table(asg, 2);
+ sg_set_buf(asg, esph, sizeof(*esph));
+ *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
+ sg_set_buf(asg + 1, seqhi, seqhilen);
+ } else
+ sg_init_one(asg, esph, sizeof(*esph));
aead_request_set_callback(req, 0, esp_input_done, skb);
aead_request_set_crypt(req, sg, sg, elen, iv);
- aead_request_set_assoc(req, asg, sizeof(*esph));
+ aead_request_set_assoc(req, asg, assoclen);
ret = crypto_aead_decrypt(req);
if (ret == -EINPROGRESS)
@@ -427,10 +482,20 @@ static int esp_init_authenc(struct xfrm_state *x)
goto error;
err = -ENAMETOOLONG;
- if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)",
- x->aalg ? x->aalg->alg_name : "digest_null",
- x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
- goto error;
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
+ "authencesn(%s,%s)",
+ x->aalg ? x->aalg->alg_name : "digest_null",
+ x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
+ goto error;
+ } else {
+ if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
+ "authenc(%s,%s)",
+ x->aalg ? x->aalg->alg_name : "digest_null",
+ x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
+ goto error;
+ }
aead = crypto_alloc_aead(authenc_name, 0, 0);
err = PTR_ERR(aead);
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
