[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 <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/ah.h

···
 	int			icv_full_len;
 	int			icv_trunc_len;
 
-	void			(*icv)(struct ah_data*,
-	                               struct sk_buff *skb, u8 *icv);
-
-	struct crypto_tfm	*tfm;
+	struct crypto_hash	*tfm;
 };
 
-static inline void
-ah_hmac_digest(struct ah_data *ahp, struct sk_buff *skb, u8 *auth_data)
+static inline int ah_mac_digest(struct ah_data *ahp, struct sk_buff *skb,
+				u8 *auth_data)
 {
-	struct crypto_tfm *tfm = ahp->tfm;
+	struct hash_desc desc;
+	int err;
+
+	desc.tfm = ahp->tfm;
+	desc.flags = 0;
 
 	memset(auth_data, 0, ahp->icv_trunc_len);
-	crypto_hmac_init(tfm, ahp->key, &ahp->key_len);
-	skb_icv_walk(skb, tfm, 0, skb->len, crypto_hmac_update);
-	crypto_hmac_final(tfm, ahp->key, &ahp->key_len, ahp->work_icv);
-	memcpy(auth_data, ahp->work_icv, ahp->icv_trunc_len);
+	err = crypto_hash_init(&desc);
+	if (unlikely(err))
+		goto out;
+	err = skb_icv_walk(skb, &desc, 0, skb->len, crypto_hash_update);
+	if (unlikely(err))
+		goto out;
+	err = crypto_hash_final(&desc, ahp->work_icv);
+
+out:
+	return err;
 }
 
 #endif

include/net/esp.h

···
 		void			(*icv)(struct esp_data*,
 		                               struct sk_buff *skb,
 		                               int offset, int len, u8 *icv);
-		struct crypto_tfm	*tfm;
+		struct crypto_hash	*tfm;
 	} auth;
 };
 
···
 extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
 extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
 
-static inline void
-esp_hmac_digest(struct esp_data *esp, struct sk_buff *skb, int offset,
-                int len, u8 *auth_data)
+static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,
+				 int offset, int len)
 {
-	struct crypto_tfm *tfm = esp->auth.tfm;
-	char *icv = esp->auth.work_icv;
+	struct hash_desc desc;
+	int err;
 
-	memset(auth_data, 0, esp->auth.icv_trunc_len);
-	crypto_hmac_init(tfm, esp->auth.key, &esp->auth.key_len);
-	skb_icv_walk(skb, tfm, offset, len, crypto_hmac_update);
-	crypto_hmac_final(tfm, esp->auth.key, &esp->auth.key_len, icv);
-	memcpy(auth_data, icv, esp->auth.icv_trunc_len);
+	desc.tfm = esp->auth.tfm;
+	desc.flags = 0;
+
+	err = crypto_hash_init(&desc);
+	if (unlikely(err))
+		return err;
+	err = skb_icv_walk(skb, &desc, offset, len, crypto_hash_update);
+	if (unlikely(err))
+		return err;
+	return crypto_hash_final(&desc, esp->auth.work_icv);
 }
 
 #endif

include/net/xfrm.h

···
 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe);
 extern struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe);
 
-struct crypto_tfm;
+struct hash_desc;
 struct scatterlist;
-typedef void (icv_update_fn_t)(struct crypto_tfm *, struct scatterlist *, unsigned int);
+typedef int (icv_update_fn_t)(struct hash_desc *, struct scatterlist *,
+			      unsigned int);
 
-extern void skb_icv_walk(const struct sk_buff *skb, struct crypto_tfm *tfm,
-			 int offset, int len, icv_update_fn_t icv_update);
+extern int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *tfm,
+			int offset, int len, icv_update_fn_t icv_update);
 
 static inline int xfrm_addr_cmp(xfrm_address_t *a, xfrm_address_t *b,
 				int family)

net/ipv4/ah4.c

···
+#include <linux/err.h>
 #include <linux/module.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
···
 	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;
···
 {
 	int ah_hlen;
 	int ihl;
+	int err = -EINVAL;
 	struct iphdr *iph;
 	struct ip_auth_hdr *ah;
 	struct ah_data *ahp;
···
 		
 		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;
 		}
···
 	return 0;
 
 out:
-	return -EINVAL;
+	return err;
 }
 
 static void ah4_err(struct sk_buff *skb, u32 info)
···
 {
 	struct ah_data *ahp = NULL;
 	struct xfrm_algo_desc *aalg_desc;
+	struct crypto_hash *tfm;
 
 	if (!x->aalg)
 		goto error;
···
 
 	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;
 	}
···
 error:
 	if (ahp) {
 		kfree(ahp->work_icv);
-		crypto_free_tfm(ahp->tfm);
+		crypto_free_hash(ahp->tfm);
 		kfree(ahp);
 	}
 	return -EINVAL;
···
 
 	kfree(ahp->work_icv);
 	ahp->work_icv = NULL;
-	crypto_free_tfm(ahp->tfm);
+	crypto_free_hash(ahp->tfm);
 	ahp->tfm = NULL;
 	kfree(ahp);
 }

net/ipv4/esp4.c

···
 	}
 
 	if (esp->auth.icv_full_len) {
-		esp->auth.icv(esp, skb, (u8*)esph-skb->data,
-		              sizeof(struct ip_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
-		pskb_put(skb, trailer, alen);
+		err = esp_mac_digest(esp, skb, (u8 *)esph - skb->data,
+				     sizeof(*esph) + esp->conf.ivlen + clen);
+		memcpy(pskb_put(skb, trailer, alen), esp->auth.work_icv, alen);
 	}
 
 	ip_send_check(top_iph);
···
 
 	/* If integrity check is required, do this. */
 	if (esp->auth.icv_full_len) {
-		u8 sum[esp->auth.icv_full_len];
-		u8 sum1[alen];
-		
-		esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
+		u8 sum[alen];
 
-		if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
+		err = esp_mac_digest(esp, skb, 0, skb->len - alen);
+		if (err)
+			goto out;
+
+		if (skb_copy_bits(skb, skb->len - alen, sum, alen))
 			BUG();
 
-		if (unlikely(memcmp(sum, sum1, alen))) {
+		if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) {
 			x->stats.integrity_failed++;
 			goto out;
 		}
···
 	esp->conf.tfm = NULL;
 	kfree(esp->conf.ivec);
 	esp->conf.ivec = NULL;
-	crypto_free_tfm(esp->auth.tfm);
+	crypto_free_hash(esp->auth.tfm);
 	esp->auth.tfm = NULL;
 	kfree(esp->auth.work_icv);
 	esp->auth.work_icv = NULL;
···
 
 	if (x->aalg) {
 		struct xfrm_algo_desc *aalg_desc;
+		struct crypto_hash *hash;
 
 		esp->auth.key = x->aalg->alg_key;
 		esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
-		esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
-		if (esp->auth.tfm == NULL)
+		hash = crypto_alloc_hash(x->aalg->alg_name, 0,
+					 CRYPTO_ALG_ASYNC);
+		if (IS_ERR(hash))
 			goto error;
-		esp->auth.icv = esp_hmac_digest;
+
+		esp->auth.tfm = hash;
+		if (crypto_hash_setkey(hash, esp->auth.key, esp->auth.key_len))
+			goto error;
 
 		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(esp->auth.tfm)) {
+		    crypto_hash_digestsize(hash)) {
 			NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
 				 x->aalg->alg_name,
-				 crypto_tfm_alg_digestsize(esp->auth.tfm),
+				 crypto_hash_digestsize(hash),
 				 aalg_desc->uinfo.auth.icv_fullbits/8);
 			goto error;
 		}

net/ipv6/ah6.c

···
 	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_free_iph;
+	memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
 
 	err = 0;
 
···
 	u16 hdr_len;
 	u16 ah_hlen;
 	int nexthdr;
+	int err = -EINVAL;
 
 	if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
 		goto out;
···
 		memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
 		memset(ah->auth_data, 0, ahp->icv_trunc_len);
 		skb_push(skb, hdr_len);
-		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 free_out;
+		err = -EINVAL;
+		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len)) {
 			LIMIT_NETDEBUG(KERN_WARNING "ipsec ah authentication error\n");
 			x->stats.integrity_failed++;
 			goto free_out;
···
 free_out:
 	kfree(tmp_hdr);
 out:
-	return -EINVAL;
+	return err;
 }
 
 static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 
···
 {
 	struct ah_data *ahp = NULL;
 	struct xfrm_algo_desc *aalg_desc;
+	struct crypto_hash *tfm;
 
 	if (!x->aalg)
 		goto error;
···
 
 	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;
 	}
···
 error:
 	if (ahp) {
 		kfree(ahp->work_icv);
-		crypto_free_tfm(ahp->tfm);
+		crypto_free_hash(ahp->tfm);
 		kfree(ahp);
 	}
 	return -EINVAL;
···
 
 	kfree(ahp->work_icv);
 	ahp->work_icv = NULL;
-	crypto_free_tfm(ahp->tfm);
+	crypto_free_hash(ahp->tfm);
 	ahp->tfm = NULL;
 	kfree(ahp);
 }

net/ipv6/esp6.c

···
 	}
 
 	if (esp->auth.icv_full_len) {
-		esp->auth.icv(esp, skb, (u8*)esph-skb->data,
-			sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
-		pskb_put(skb, trailer, alen);
+		err = esp_mac_digest(esp, skb, (u8 *)esph - skb->data,
+				     sizeof(*esph) + esp->conf.ivlen + clen);
+		memcpy(pskb_put(skb, trailer, alen), esp->auth.work_icv, alen);
 	}
 
 error:
···
 
 	/* If integrity check is required, do this. */
         if (esp->auth.icv_full_len) {
-		u8 sum[esp->auth.icv_full_len];
-		u8 sum1[alen];
+		u8 sum[alen];
 
-		esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
+		ret = esp_mac_digest(esp, skb, 0, skb->len - alen);
+		if (ret)
+			goto out;
 
-		if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
+		if (skb_copy_bits(skb, skb->len - alen, sum, alen))
 			BUG();
 
-		if (unlikely(memcmp(sum, sum1, alen))) {
+		if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) {
 			x->stats.integrity_failed++;
 			ret = -EINVAL;
 			goto out;
···
 	esp->conf.tfm = NULL;
 	kfree(esp->conf.ivec);
 	esp->conf.ivec = NULL;
-	crypto_free_tfm(esp->auth.tfm);
+	crypto_free_hash(esp->auth.tfm);
 	esp->auth.tfm = NULL;
 	kfree(esp->auth.work_icv);
 	esp->auth.work_icv = NULL;
···
 
 	if (x->aalg) {
 		struct xfrm_algo_desc *aalg_desc;
+		struct crypto_hash *hash;
 
 		esp->auth.key = x->aalg->alg_key;
 		esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
-		esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
-		if (esp->auth.tfm == NULL)
+		hash = crypto_alloc_hash(x->aalg->alg_name, 0,
+					 CRYPTO_ALG_ASYNC);
+		if (IS_ERR(hash))
 			goto error;
-		esp->auth.icv = esp_hmac_digest;
+
+		esp->auth.tfm = hash;
+		if (crypto_hash_setkey(hash, esp->auth.key, esp->auth.key_len))
+			goto error;
  
 		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(esp->auth.tfm)) {
-				printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
-					x->aalg->alg_name,
-					crypto_tfm_alg_digestsize(esp->auth.tfm),
-					aalg_desc->uinfo.auth.icv_fullbits/8);
-				goto error;
+		    crypto_hash_digestsize(hash)) {
+			NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
+				 x->aalg->alg_name,
+				 crypto_hash_digestsize(hash),
+				 aalg_desc->uinfo.auth.icv_fullbits/8);
+			goto error;
 		}
  
 		esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;

net/xfrm/xfrm_algo.c

···
  */
 static struct xfrm_algo_desc aalg_list[] = {
 {
-	.name = "digest_null",
+	.name = "hmac(digest_null)",
+	.compat = "digest_null",
 	
 	.uinfo = {
 		.auth = {
···
 	}
 },
 {
-	.name = "md5",
+	.name = "hmac(md5)",
+	.compat = "md5",
 
 	.uinfo = {
 		.auth = {
···
 	}
 },
 {
-	.name = "sha1",
+	.name = "hmac(sha1)",
+	.compat = "sha1",
 
 	.uinfo = {
 		.auth = {
···
 	}
 },
 {
-	.name = "sha256",
+	.name = "hmac(sha256)",
+	.compat = "sha256",
 
 	.uinfo = {
 		.auth = {
···
 	}
 },
 {
-	.name = "ripemd160",
+	.name = "hmac(ripemd160)",
+	.compat = "ripemd160",
 
 	.uinfo = {
 		.auth = {
···
 
 /* Move to common area: it is shared with AH. */
 
-void skb_icv_walk(const struct sk_buff *skb, struct crypto_tfm *tfm,
-		  int offset, int len, icv_update_fn_t icv_update)
+int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
+		 int offset, int len, icv_update_fn_t icv_update)
 {
 	int start = skb_headlen(skb);
 	int i, copy = start - offset;
+	int err;
 	struct scatterlist sg;
 
 	/* Checksum header. */
···
 		sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
 		sg.length = copy;
 		
-		icv_update(tfm, &sg, 1);
+		err = icv_update(desc, &sg, copy);
+		if (unlikely(err))
+			return err;
 		
 		if ((len -= copy) == 0)
-			return;
+			return 0;
 		offset += copy;
 	}
 
···
 			sg.offset = frag->page_offset + offset-start;
 			sg.length = copy;
 			
-			icv_update(tfm, &sg, 1);
+			err = icv_update(desc, &sg, copy);
+			if (unlikely(err))
+				return err;
 
 			if (!(len -= copy))
-				return;
+				return 0;
 			offset += copy;
 		}
 		start = end;
···
 			if ((copy = end - offset) > 0) {
 				if (copy > len)
 					copy = len;
-				skb_icv_walk(list, tfm, offset-start, copy, icv_update);
+				err = skb_icv_walk(list, desc, offset-start,
+						   copy, icv_update);
+				if (unlikely(err))
+					return err;
 				if ((len -= copy) == 0)
-					return;
+					return 0;
 				offset += copy;
 			}
 			start = end;
 		}
 	}
 	BUG_ON(len);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(skb_icv_walk);