[IPSEC]: Use HMAC template and hash interface

This patch converts IPsec to use the new HMAC template.  The names of
existing simple digest algorithms may still be used to refer to their
HMAC composites.

The same structure can be used by other MACs such as AES-XCBC-MAC.

This patch also switches from the digest interface to hash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 1366bc6..2b98943 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -1,3 +1,4 @@
+#include <linux/err.h>
 #include <linux/module.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
@@ -97,7 +98,10 @@
 	ah->spi = x->id.spi;
 	ah->seq_no = htonl(++x->replay.oseq);
 	xfrm_aevent_doreplay(x);
-	ahp->icv(ahp, skb, ah->auth_data);
+	err = ah_mac_digest(ahp, skb, ah->auth_data);
+	if (err)
+		goto error;
+	memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
 
 	top_iph->tos = iph->tos;
 	top_iph->ttl = iph->ttl;
@@ -119,6 +123,7 @@
 {
 	int ah_hlen;
 	int ihl;
+	int err = -EINVAL;
 	struct iphdr *iph;
 	struct ip_auth_hdr *ah;
 	struct ah_data *ahp;
@@ -166,8 +171,11 @@
 		
 		memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
 		skb_push(skb, ihl);
-		ahp->icv(ahp, skb, ah->auth_data);
-		if (memcmp(ah->auth_data, auth_data, ahp->icv_trunc_len)) {
+		err = ah_mac_digest(ahp, skb, ah->auth_data);
+		if (err)
+			goto out;
+		err = -EINVAL;
+		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len)) {
 			x->stats.integrity_failed++;
 			goto out;
 		}
@@ -179,7 +187,7 @@
 	return 0;
 
 out:
-	return -EINVAL;
+	return err;
 }
 
 static void ah4_err(struct sk_buff *skb, u32 info)
@@ -204,6 +212,7 @@
 {
 	struct ah_data *ahp = NULL;
 	struct xfrm_algo_desc *aalg_desc;
+	struct crypto_hash *tfm;
 
 	if (!x->aalg)
 		goto error;
@@ -221,24 +230,27 @@
 
 	ahp->key = x->aalg->alg_key;
 	ahp->key_len = (x->aalg->alg_key_len+7)/8;
-	ahp->tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
-	if (!ahp->tfm)
+	tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm))
 		goto error;
-	ahp->icv = ah_hmac_digest;
+
+	ahp->tfm = tfm;
+	if (crypto_hash_setkey(tfm, ahp->key, ahp->key_len))
+		goto error;
 	
 	/*
 	 * 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_tfm().
+	 * after a successful crypto_alloc_hash().
 	 */
 	aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
 	BUG_ON(!aalg_desc);
 
 	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
-	    crypto_tfm_alg_digestsize(ahp->tfm)) {
+	    crypto_hash_digestsize(tfm)) {
 		printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
-		       x->aalg->alg_name, crypto_tfm_alg_digestsize(ahp->tfm),
+		       x->aalg->alg_name, crypto_hash_digestsize(tfm),
 		       aalg_desc->uinfo.auth.icv_fullbits/8);
 		goto error;
 	}
@@ -262,7 +274,7 @@
 error:
 	if (ahp) {
 		kfree(ahp->work_icv);
-		crypto_free_tfm(ahp->tfm);
+		crypto_free_hash(ahp->tfm);
 		kfree(ahp);
 	}
 	return -EINVAL;
@@ -277,7 +289,7 @@
 
 	kfree(ahp->work_icv);
 	ahp->work_icv = NULL;
-	crypto_free_tfm(ahp->tfm);
+	crypto_free_hash(ahp->tfm);
 	ahp->tfm = NULL;
 	kfree(ahp);
 }