Skip to content

Commit

Permalink
[IPSEC] ESP: Use block ciphers where applicable
Browse files Browse the repository at this point in the history
This patch converts IPSec/ESP to use the new block cipher type where
applicable.  Similar to the HMAC conversion, existing algorithm names
have been kept for compatibility.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  • Loading branch information
Herbert Xu committed Sep 21, 2006
1 parent 04ff126 commit 6b7326c
Show file tree
Hide file tree
Showing 6 changed files with 76 additions and 49 deletions.
2 changes: 1 addition & 1 deletion include/net/esp.h
Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@ struct esp_data
* >= crypto_tfm_alg_ivsize(tfm). */
int ivlen;
int padlen; /* 0..255 */
struct crypto_tfm *tfm; /* crypto handle */
struct crypto_blkcipher *tfm; /* crypto handle */
} conf;

/* Integrity. It is active when icv_full_len != 0 */
Expand Down
1 change: 1 addition & 0 deletions net/ipv4/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -386,6 +386,7 @@ config INET_ESP
select CRYPTO
select CRYPTO_HMAC
select CRYPTO_MD5
select CRYPTO_CBC
select CRYPTO_SHA1
select CRYPTO_DES
---help---
Expand Down
49 changes: 29 additions & 20 deletions net/ipv4/esp4.c
Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
Expand All @@ -16,7 +17,8 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
int err;
struct iphdr *top_iph;
struct ip_esp_hdr *esph;
struct crypto_tfm *tfm;
struct crypto_blkcipher *tfm;
struct blkcipher_desc desc;
struct esp_data *esp;
struct sk_buff *trailer;
int blksize;
Expand All @@ -36,7 +38,9 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
esp = x->data;
alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
desc.tfm = tfm;
desc.flags = 0;
blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4);
clen = ALIGN(clen + 2, blksize);
if (esp->conf.padlen)
clen = ALIGN(clen, esp->conf.padlen);
Expand Down Expand Up @@ -92,7 +96,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
xfrm_aevent_doreplay(x);

if (esp->conf.ivlen)
crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen);

do {
struct scatterlist *sg = &esp->sgbuf[0];
Expand All @@ -103,14 +107,17 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
goto error;
}
skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
crypto_cipher_encrypt(tfm, sg, sg, clen);
err = crypto_blkcipher_encrypt(&desc, sg, sg, clen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
} while (0);

if (unlikely(err))
goto error;

if (esp->conf.ivlen) {
memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen);
crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen);
}

if (esp->auth.icv_full_len) {
Expand All @@ -121,8 +128,6 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)

ip_send_check(top_iph);

err = 0;

error:
return err;
}
Expand All @@ -137,15 +142,18 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
struct iphdr *iph;
struct ip_esp_hdr *esph;
struct esp_data *esp = x->data;
struct crypto_blkcipher *tfm = esp->conf.tfm;
struct blkcipher_desc desc = { .tfm = tfm };
struct sk_buff *trailer;
int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
int blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4);
int alen = esp->auth.icv_trunc_len;
int elen = skb->len - sizeof(struct ip_esp_hdr) - esp->conf.ivlen - alen;
int nfrags;
int ihl;
u8 nexthdr[2];
struct scatterlist *sg;
int padlen;
int err;

if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr)))
goto out;
Expand Down Expand Up @@ -178,7 +186,7 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)

/* Get ivec. This can be wrong, check against another impls. */
if (esp->conf.ivlen)
crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen);

sg = &esp->sgbuf[0];

Expand All @@ -188,9 +196,11 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
goto out;
}
skb_to_sgvec(skb, sg, sizeof(struct ip_esp_hdr) + esp->conf.ivlen, elen);
crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
err = crypto_blkcipher_decrypt(&desc, sg, sg, elen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
if (unlikely(err))
return err;

if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
BUG();
Expand Down Expand Up @@ -254,7 +264,7 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
static u32 esp4_get_max_size(struct xfrm_state *x, int mtu)
{
struct esp_data *esp = x->data;
u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);

if (x->props.mode) {
mtu = ALIGN(mtu + 2, blksize);
Expand Down Expand Up @@ -293,7 +303,7 @@ static void esp_destroy(struct xfrm_state *x)
if (!esp)
return;

crypto_free_tfm(esp->conf.tfm);
crypto_free_blkcipher(esp->conf.tfm);
esp->conf.tfm = NULL;
kfree(esp->conf.ivec);
esp->conf.ivec = NULL;
Expand All @@ -307,6 +317,7 @@ static void esp_destroy(struct xfrm_state *x)
static int esp_init_state(struct xfrm_state *x)
{
struct esp_data *esp = NULL;
struct crypto_blkcipher *tfm;

/* null auth and encryption can have zero length keys */
if (x->aalg) {
Expand Down Expand Up @@ -351,21 +362,19 @@ static int esp_init_state(struct xfrm_state *x)
}
esp->conf.key = x->ealg->alg_key;
esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
if (x->props.ealgo == SADB_EALG_NULL)
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
else
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
if (esp->conf.tfm == NULL)
tfm = crypto_alloc_blkcipher(x->ealg->alg_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm))
goto error;
esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
esp->conf.tfm = tfm;
esp->conf.ivlen = crypto_blkcipher_ivsize(tfm);
esp->conf.padlen = 0;
if (esp->conf.ivlen) {
esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
if (unlikely(esp->conf.ivec == NULL))
goto error;
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
}
if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
if (crypto_blkcipher_setkey(tfm, esp->conf.key, esp->conf.key_len))
goto error;
x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
if (x->props.mode)
Expand Down
1 change: 1 addition & 0 deletions net/ipv6/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,7 @@ config INET6_ESP
select CRYPTO
select CRYPTO_HMAC
select CRYPTO_MD5
select CRYPTO_CBC
select CRYPTO_SHA1
select CRYPTO_DES
---help---
Expand Down
48 changes: 28 additions & 20 deletions net/ipv6/esp6.c
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@
* This file is derived from net/ipv4/esp.c
*/

#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
Expand All @@ -44,7 +45,8 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
int hdr_len;
struct ipv6hdr *top_iph;
struct ipv6_esp_hdr *esph;
struct crypto_tfm *tfm;
struct crypto_blkcipher *tfm;
struct blkcipher_desc desc;
struct esp_data *esp;
struct sk_buff *trailer;
int blksize;
Expand All @@ -67,7 +69,9 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)

alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
desc.tfm = tfm;
desc.flags = 0;
blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4);
clen = ALIGN(clen + 2, blksize);
if (esp->conf.padlen)
clen = ALIGN(clen, esp->conf.padlen);
Expand Down Expand Up @@ -96,7 +100,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
xfrm_aevent_doreplay(x);

if (esp->conf.ivlen)
crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen);

do {
struct scatterlist *sg = &esp->sgbuf[0];
Expand All @@ -107,14 +111,17 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
goto error;
}
skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
crypto_cipher_encrypt(tfm, sg, sg, clen);
err = crypto_blkcipher_encrypt(&desc, sg, sg, clen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
} while (0);

if (unlikely(err))
goto error;

if (esp->conf.ivlen) {
memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen);
crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen);
}

if (esp->auth.icv_full_len) {
Expand All @@ -123,8 +130,6 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
pskb_put(skb, trailer, alen);
}

err = 0;

error:
return err;
}
Expand All @@ -134,8 +139,10 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
struct ipv6hdr *iph;
struct ipv6_esp_hdr *esph;
struct esp_data *esp = x->data;
struct crypto_blkcipher *tfm = esp->conf.tfm;
struct blkcipher_desc desc = { .tfm = tfm };
struct sk_buff *trailer;
int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
int blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4);
int alen = esp->auth.icv_trunc_len;
int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;

Expand Down Expand Up @@ -182,7 +189,7 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)

/* Get ivec. This can be wrong, check against another impls. */
if (esp->conf.ivlen)
crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen);

{
u8 nexthdr[2];
Expand All @@ -197,9 +204,11 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
}
}
skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
ret = crypto_blkcipher_decrypt(&desc, sg, sg, elen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
if (unlikely(ret))
goto out;

if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
BUG();
Expand All @@ -225,7 +234,7 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
{
struct esp_data *esp = x->data;
u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);

if (x->props.mode) {
mtu = ALIGN(mtu + 2, blksize);
Expand Down Expand Up @@ -266,7 +275,7 @@ static void esp6_destroy(struct xfrm_state *x)
if (!esp)
return;

crypto_free_tfm(esp->conf.tfm);
crypto_free_blkcipher(esp->conf.tfm);
esp->conf.tfm = NULL;
kfree(esp->conf.ivec);
esp->conf.ivec = NULL;
Expand All @@ -280,6 +289,7 @@ static void esp6_destroy(struct xfrm_state *x)
static int esp6_init_state(struct xfrm_state *x)
{
struct esp_data *esp = NULL;
struct crypto_blkcipher *tfm;

/* null auth and encryption can have zero length keys */
if (x->aalg) {
Expand Down Expand Up @@ -327,21 +337,19 @@ static int esp6_init_state(struct xfrm_state *x)
}
esp->conf.key = x->ealg->alg_key;
esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
if (x->props.ealgo == SADB_EALG_NULL)
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
else
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
if (esp->conf.tfm == NULL)
tfm = crypto_alloc_blkcipher(x->ealg->alg_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm))
goto error;
esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
esp->conf.tfm = tfm;
esp->conf.ivlen = crypto_blkcipher_ivsize(tfm);
esp->conf.padlen = 0;
if (esp->conf.ivlen) {
esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
if (unlikely(esp->conf.ivec == NULL))
goto error;
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
}
if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
if (crypto_blkcipher_setkey(tfm, esp->conf.key, esp->conf.key_len))
goto error;
x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
if (x->props.mode)
Expand Down
Loading

0 comments on commit 6b7326c

Please sign in to comment.