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Commit dff3bb06 authored by Steffen Klassert's avatar Steffen Klassert Committed by David S. Miller
Browse files

ah4: convert to ahash



This patch converts ah4 to the new ahash interface.

Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 49cbf952
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+236 −59
Original line number Diff line number Diff line
#include <crypto/hash.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
@@ -5,10 +6,67 @@
#include <net/ah.h>
#include <linux/crypto.h>
#include <linux/pfkeyv2.h>
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <net/icmp.h>
#include <net/protocol.h>

struct ah_skb_cb {
	struct xfrm_skb_cb xfrm;
	void *tmp;
};

#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))

static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
			  unsigned int size)
{
	unsigned int len;

	len = size + crypto_ahash_digestsize(ahash) +
	      (crypto_ahash_alignmask(ahash) &
	       ~(crypto_tfm_ctx_alignment() - 1));

	len = ALIGN(len, crypto_tfm_ctx_alignment());

	len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
	len = ALIGN(len, __alignof__(struct scatterlist));

	len += sizeof(struct scatterlist) * nfrags;

	return kmalloc(len, GFP_ATOMIC);
}

static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
{
	return tmp + offset;
}

static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
			     unsigned int offset)
{
	return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
}

static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
					       u8 *icv)
{
	struct ahash_request *req;

	req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
				crypto_tfm_ctx_alignment());

	ahash_request_set_tfm(req, ahash);

	return req;
}

static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
					     struct ahash_request *req)
{
	return (void *)ALIGN((unsigned long)(req + 1) +
			     crypto_ahash_reqsize(ahash),
			     __alignof__(struct scatterlist));
}

/* Clear mutable options and find final destination to substitute
 * into IP header for icv calculation. Options are already checked
@@ -54,20 +112,72 @@ static int ip_clear_mutable_options(struct iphdr *iph, __be32 *daddr)
	return 0;
}

static void ah_output_done(struct crypto_async_request *base, int err)
{
	u8 *icv;
	struct iphdr *iph;
	struct sk_buff *skb = base->data;
	struct xfrm_state *x = skb_dst(skb)->xfrm;
	struct ah_data *ahp = x->data;
	struct iphdr *top_iph = ip_hdr(skb);
	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
	int ihl = ip_hdrlen(skb);

	iph = AH_SKB_CB(skb)->tmp;
	icv = ah_tmp_icv(ahp->ahash, iph, ihl);
	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);

	top_iph->tos = iph->tos;
	top_iph->ttl = iph->ttl;
	top_iph->frag_off = iph->frag_off;
	if (top_iph->ihl != 5) {
		top_iph->daddr = iph->daddr;
		memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
	}

	err = ah->nexthdr;

	kfree(AH_SKB_CB(skb)->tmp);
	xfrm_output_resume(skb, err);
}

static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;
	int nfrags;
	int ihl;
	u8 *icv;
	struct sk_buff *trailer;
	struct crypto_ahash *ahash;
	struct ahash_request *req;
	struct scatterlist *sg;
	struct iphdr *iph, *top_iph;
	struct ip_auth_hdr *ah;
	struct ah_data *ahp;
	union {
		struct iphdr	iph;
		char 		buf[60];
	} tmp_iph;

	ahp = x->data;
	ahash = ahp->ahash;

	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
		goto out;
	nfrags = err;

	skb_push(skb, -skb_network_offset(skb));
	ah = ip_auth_hdr(skb);
	ihl = ip_hdrlen(skb);

	err = -ENOMEM;
	iph = ah_alloc_tmp(ahash, nfrags, ihl);
	if (!iph)
		goto out;

	icv = ah_tmp_icv(ahash, iph, ihl);
	req = ah_tmp_req(ahash, icv);
	sg = ah_req_sg(ahash, req);

	memset(ah->auth_data, 0, ahp->icv_trunc_len);

	top_iph = ip_hdr(skb);
	iph = &tmp_iph.iph;

	iph->tos = top_iph->tos;
	iph->ttl = top_iph->ttl;
@@ -78,10 +188,9 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
		memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
		err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
		if (err)
			goto error;
			goto out_free;
	}

	ah = ip_auth_hdr(skb);
	ah->nexthdr = *skb_mac_header(skb);
	*skb_mac_header(skb) = IPPROTO_AH;

@@ -91,20 +200,31 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
	top_iph->ttl = 0;
	top_iph->check = 0;

	ahp = x->data;
	ah->hdrlen  = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;

	ah->reserved = 0;
	ah->spi = x->id.spi;
	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);

	spin_lock_bh(&x->lock);
	err = ah_mac_digest(ahp, skb, ah->auth_data);
	memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
	spin_unlock_bh(&x->lock);
	sg_init_table(sg, nfrags);
	skb_to_sgvec(skb, sg, 0, skb->len);

	if (err)
		goto error;
	ahash_request_set_crypt(req, sg, icv, skb->len);
	ahash_request_set_callback(req, 0, ah_output_done, skb);

	AH_SKB_CB(skb)->tmp = iph;

	err = crypto_ahash_digest(req);
	if (err) {
		if (err == -EINPROGRESS)
			goto out;

		if (err == -EBUSY)
			err = NET_XMIT_DROP;
		goto out_free;
	}

	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);

	top_iph->tos = iph->tos;
	top_iph->ttl = iph->ttl;
@@ -114,28 +234,67 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
		memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
	}

	err = 0;

error:
out_free:
	kfree(iph);
out:
	return err;
}

static void ah_input_done(struct crypto_async_request *base, int err)
{
	u8 *auth_data;
	u8 *icv;
	struct iphdr *work_iph;
	struct sk_buff *skb = base->data;
	struct xfrm_state *x = xfrm_input_state(skb);
	struct ah_data *ahp = x->data;
	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
	int ihl = ip_hdrlen(skb);
	int ah_hlen = (ah->hdrlen + 2) << 2;

	work_iph = AH_SKB_CB(skb)->tmp;
	auth_data = ah_tmp_auth(work_iph, ihl);
	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);

	err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
	if (err)
		goto out;

	skb->network_header += ah_hlen;
	memcpy(skb_network_header(skb), work_iph, ihl);
	__skb_pull(skb, ah_hlen + ihl);
	skb_set_transport_header(skb, -ihl);

	err = ah->nexthdr;
out:
	kfree(AH_SKB_CB(skb)->tmp);
	xfrm_input_resume(skb, err);
}

static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int ah_hlen;
	int ihl;
	int nexthdr;
	int err = -EINVAL;
	struct iphdr *iph;
	int nfrags;
	u8 *auth_data;
	u8 *icv;
	struct sk_buff *trailer;
	struct crypto_ahash *ahash;
	struct ahash_request *req;
	struct scatterlist *sg;
	struct iphdr *iph, *work_iph;
	struct ip_auth_hdr *ah;
	struct ah_data *ahp;
	char work_buf[60];
	int err = -ENOMEM;

	if (!pskb_may_pull(skb, sizeof(*ah)))
		goto out;

	ah = (struct ip_auth_hdr *)skb->data;
	ahp = x->data;
	ahash = ahp->ahash;

	nexthdr = ah->nexthdr;
	ah_hlen = (ah->hdrlen + 2) << 2;

@@ -156,9 +315,24 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)

	ah = (struct ip_auth_hdr *)skb->data;
	iph = ip_hdr(skb);
	ihl = ip_hdrlen(skb);

	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
		goto out;
	nfrags = err;

	work_iph = ah_alloc_tmp(ahash, nfrags, ihl + ahp->icv_trunc_len);
	if (!work_iph)
		goto out;

	ihl = skb->data - skb_network_header(skb);
	memcpy(work_buf, iph, ihl);
	auth_data = ah_tmp_auth(work_iph, ihl);
	icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
	req = ah_tmp_req(ahash, icv);
	sg = ah_req_sg(ahash, req);

	memcpy(work_iph, iph, ihl);
	memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
	memset(ah->auth_data, 0, ahp->icv_trunc_len);

	iph->ttl = 0;
	iph->tos = 0;
@@ -166,35 +340,44 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
	iph->check = 0;
	if (ihl > sizeof(*iph)) {
		__be32 dummy;
		if (ip_clear_mutable_options(iph, &dummy))
			goto out;
		err = ip_clear_mutable_options(iph, &dummy);
		if (err)
			goto out_free;
	}

	spin_lock(&x->lock);
	{
		u8 auth_data[MAX_AH_AUTH_LEN];

		memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
	skb_push(skb, ihl);
		err = ah_mac_digest(ahp, skb, ah->auth_data);
		if (err)
			goto unlock;
		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len))
			err = -EBADMSG;

	sg_init_table(sg, nfrags);
	skb_to_sgvec(skb, sg, 0, skb->len);

	ahash_request_set_crypt(req, sg, icv, skb->len);
	ahash_request_set_callback(req, 0, ah_input_done, skb);

	AH_SKB_CB(skb)->tmp = work_iph;

	err = crypto_ahash_digest(req);
	if (err) {
		if (err == -EINPROGRESS)
			goto out;

		if (err == -EBUSY)
			err = NET_XMIT_DROP;
		goto out_free;
	}
unlock:
	spin_unlock(&x->lock);

	err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
	if (err)
		goto out;
		goto out_free;

	skb->network_header += ah_hlen;
	memcpy(skb_network_header(skb), work_buf, ihl);
	skb->transport_header = skb->network_header;
	memcpy(skb_network_header(skb), work_iph, ihl);
	__skb_pull(skb, ah_hlen + ihl);
	skb_set_transport_header(skb, -ihl);

	return nexthdr;
	err = nexthdr;

out_free:
	kfree (work_iph);
out:
	return err;
}
@@ -222,7 +405,7 @@ static int ah_init_state(struct xfrm_state *x)
{
	struct ah_data *ahp = NULL;
	struct xfrm_algo_desc *aalg_desc;
	struct crypto_hash *tfm;
	struct crypto_ahash *ahash;

	if (!x->aalg)
		goto error;
@@ -231,15 +414,15 @@ static int ah_init_state(struct xfrm_state *x)
		goto error;

	ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
	if (ahp == NULL)
	if (!ahp)
		return -ENOMEM;

	tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm))
	ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
	if (IS_ERR(ahash))
		goto error;

	ahp->tfm = tfm;
	if (crypto_hash_setkey(tfm, x->aalg->alg_key,
	ahp->ahash = ahash;
	if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
				(x->aalg->alg_key_len + 7) / 8))
		goto error;

@@ -247,15 +430,15 @@ static int ah_init_state(struct xfrm_state *x)
	 * Lookup the algorithm description maintained by xfrm_algo,
	 * verify crypto transform properties, and store information
	 * we need for AH processing.  This lookup cannot fail here
	 * after a successful crypto_alloc_hash().
	 * after a successful crypto_alloc_ahash().
	 */
	aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
	BUG_ON(!aalg_desc);

	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
	    crypto_hash_digestsize(tfm)) {
	    crypto_ahash_digestsize(ahash)) {
		printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
		       x->aalg->alg_name, crypto_hash_digestsize(tfm),
		       x->aalg->alg_name, crypto_ahash_digestsize(ahash),
		       aalg_desc->uinfo.auth.icv_fullbits/8);
		goto error;
	}
@@ -265,10 +448,6 @@ static int ah_init_state(struct xfrm_state *x)

	BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);

	ahp->work_icv = kmalloc(ahp->icv_full_len, GFP_KERNEL);
	if (!ahp->work_icv)
		goto error;

	x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
					  ahp->icv_trunc_len);
	if (x->props.mode == XFRM_MODE_TUNNEL)
@@ -279,8 +458,7 @@ static int ah_init_state(struct xfrm_state *x)

error:
	if (ahp) {
		kfree(ahp->work_icv);
		crypto_free_hash(ahp->tfm);
		crypto_free_ahash(ahp->ahash);
		kfree(ahp);
	}
	return -EINVAL;
@@ -293,8 +471,7 @@ static void ah_destroy(struct xfrm_state *x)
	if (!ahp)
		return;

	kfree(ahp->work_icv);
	crypto_free_hash(ahp->tfm);
	crypto_free_ahash(ahp->ahash);
	kfree(ahp);
}