diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2008-01-29 04:35:05 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2008-02-01 04:27:02 +0100 |
commit | 38320c70d282be1997a5204c7c7fe14c3aa6bfaa (patch) | |
tree | aa86d8c3e26a3cc6d283a31b21116a35c7659f8f /net/ipv4/esp4.c | |
parent | Add new driver 'rndis_wlan' for wireless RNDIS devices. (diff) | |
download | linux-38320c70d282be1997a5204c7c7fe14c3aa6bfaa.tar.xz linux-38320c70d282be1997a5204c7c7fe14c3aa6bfaa.zip |
[IPSEC]: Use crypto_aead and authenc in ESP
This patch converts ESP to use the crypto_aead interface and in particular
the authenc algorithm. This lays the foundations for future support of
combined mode algorithms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/esp4.c')
-rw-r--r-- | net/ipv4/esp4.c | 497 |
1 files changed, 302 insertions, 195 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 28ea5c77ca23..c4047223bfbe 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -1,27 +1,118 @@ +#include <crypto/aead.h> +#include <crypto/authenc.h> #include <linux/err.h> #include <linux/module.h> #include <net/ip.h> #include <net/xfrm.h> #include <net/esp.h> #include <linux/scatterlist.h> -#include <linux/crypto.h> #include <linux/kernel.h> #include <linux/pfkeyv2.h> -#include <linux/random.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> #include <linux/spinlock.h> #include <linux/in6.h> #include <net/icmp.h> #include <net/protocol.h> #include <net/udp.h> +struct esp_skb_cb { + struct xfrm_skb_cb xfrm; + void *tmp; +}; + +#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) + +/* + * 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. + * + * TODO: Use spare space in skb for this where possible. + */ +static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags) +{ + unsigned int len; + + len = crypto_aead_ivsize(aead); + if (len) { + len += crypto_aead_alignmask(aead) & + ~(crypto_tfm_ctx_alignment() - 1); + len = ALIGN(len, crypto_tfm_ctx_alignment()); + } + + len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead); + len = ALIGN(len, __alignof__(struct scatterlist)); + + len += sizeof(struct scatterlist) * nfrags; + + return kmalloc(len, GFP_ATOMIC); +} + +static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp) +{ + return crypto_aead_ivsize(aead) ? + PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp; +} + +static inline struct aead_givcrypt_request *esp_tmp_givreq( + struct crypto_aead *aead, u8 *iv) +{ + struct aead_givcrypt_request *req; + + req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), + crypto_tfm_ctx_alignment()); + aead_givcrypt_set_tfm(req, aead); + return req; +} + +static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) +{ + struct aead_request *req; + + req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), + crypto_tfm_ctx_alignment()); + aead_request_set_tfm(req, aead); + return req; +} + +static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, + struct aead_request *req) +{ + return (void *)ALIGN((unsigned long)(req + 1) + + crypto_aead_reqsize(aead), + __alignof__(struct scatterlist)); +} + +static inline struct scatterlist *esp_givreq_sg( + struct crypto_aead *aead, struct aead_givcrypt_request *req) +{ + return (void *)ALIGN((unsigned long)(req + 1) + + crypto_aead_reqsize(aead), + __alignof__(struct scatterlist)); +} + +static void esp_output_done(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + + kfree(ESP_SKB_CB(skb)->tmp); + xfrm_output_resume(skb, err); +} + static int esp_output(struct xfrm_state *x, struct sk_buff *skb) { int err; struct ip_esp_hdr *esph; - struct crypto_blkcipher *tfm; - struct blkcipher_desc desc; + struct crypto_aead *aead; + struct aead_givcrypt_request *req; + struct scatterlist *sg; + struct scatterlist *asg; struct esp_data *esp; struct sk_buff *trailer; + void *tmp; + u8 *iv; u8 *tail; int blksize; int clen; @@ -36,18 +127,27 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) clen = skb->len; esp = x->data; - alen = esp->auth.icv_trunc_len; - tfm = esp->conf.tfm; - desc.tfm = tfm; - desc.flags = 0; - blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4); + aead = esp->aead; + alen = crypto_aead_authsize(aead); + + blksize = ALIGN(crypto_aead_blocksize(aead), 4); clen = ALIGN(clen + 2, blksize); - if (esp->conf.padlen) - clen = ALIGN(clen, esp->conf.padlen); + if (esp->padlen) + clen = ALIGN(clen, esp->padlen); + + if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0) + goto error; + nfrags = err; - if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) + tmp = esp_alloc_tmp(aead, nfrags + 1); + if (!tmp) goto error; + iv = esp_tmp_iv(aead, tmp); + req = esp_tmp_givreq(aead, iv); + asg = esp_givreq_sg(aead, req); + sg = asg + 1; + /* Fill padding... */ tail = skb_tail_pointer(trailer); do { @@ -56,28 +156,34 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) tail[i] = i + 1; } while (0); tail[clen - skb->len - 2] = (clen - skb->len) - 2; - pskb_put(skb, trailer, clen - skb->len); + tail[clen - skb->len - 1] = *skb_mac_header(skb); + pskb_put(skb, trailer, clen - skb->len + alen); skb_push(skb, -skb_network_offset(skb)); esph = ip_esp_hdr(skb); - *(skb_tail_pointer(trailer) - 1) = *skb_mac_header(skb); *skb_mac_header(skb) = IPPROTO_ESP; - spin_lock_bh(&x->lock); - /* this is non-NULL only with UDP Encapsulation */ if (x->encap) { struct xfrm_encap_tmpl *encap = x->encap; struct udphdr *uh; __be32 *udpdata32; + unsigned int sport, dport; + int encap_type; + + spin_lock_bh(&x->lock); + sport = encap->encap_sport; + dport = encap->encap_dport; + encap_type = encap->encap_type; + spin_unlock_bh(&x->lock); uh = (struct udphdr *)esph; - uh->source = encap->encap_sport; - uh->dest = encap->encap_dport; - uh->len = htons(skb->len + alen - skb_transport_offset(skb)); + uh->source = sport; + uh->dest = dport; + uh->len = htons(skb->len - skb_transport_offset(skb)); uh->check = 0; - switch (encap->encap_type) { + switch (encap_type) { default: case UDP_ENCAP_ESPINUDP: esph = (struct ip_esp_hdr *)(uh + 1); @@ -95,131 +201,45 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) esph->spi = x->id.spi; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq); - if (esp->conf.ivlen) { - if (unlikely(!esp->conf.ivinitted)) { - get_random_bytes(esp->conf.ivec, esp->conf.ivlen); - esp->conf.ivinitted = 1; - } - crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen); - } - - do { - struct scatterlist *sg = &esp->sgbuf[0]; - - if (unlikely(nfrags > ESP_NUM_FAST_SG)) { - sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); - if (!sg) - goto unlock; - } - sg_init_table(sg, nfrags); - skb_to_sgvec(skb, sg, - esph->enc_data + - esp->conf.ivlen - - skb->data, clen); - err = crypto_blkcipher_encrypt(&desc, sg, sg, clen); - if (unlikely(sg != &esp->sgbuf[0])) - kfree(sg); - } while (0); - - if (unlikely(err)) - goto unlock; - - if (esp->conf.ivlen) { - memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen); - crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen); - } + sg_init_table(sg, nfrags); + skb_to_sgvec(skb, sg, + esph->enc_data + crypto_aead_ivsize(aead) - skb->data, + clen + alen); + 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_giv(req, esph->enc_data, XFRM_SKB_CB(skb)->seq); + + ESP_SKB_CB(skb)->tmp = tmp; + err = crypto_aead_givencrypt(req); + if (err == -EINPROGRESS) + goto error; - if (esp->auth.icv_full_len) { - 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); - } + if (err == -EBUSY) + err = NET_XMIT_DROP; -unlock: - spin_unlock_bh(&x->lock); + kfree(tmp); error: return err; } -/* - * Note: detecting truncated vs. non-truncated authentication data is very - * expensive, so we only support truncated data, which is the recommended - * and common case. - */ -static int esp_input(struct xfrm_state *x, struct sk_buff *skb) +static int esp_input_done2(struct sk_buff *skb, int err) { struct iphdr *iph; - struct ip_esp_hdr *esph; + struct xfrm_state *x = xfrm_input_state(skb); 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_blkcipher_blocksize(tfm), 4); - int alen = esp->auth.icv_trunc_len; - int elen = skb->len - sizeof(*esph) - esp->conf.ivlen - alen; - int nfrags; + struct crypto_aead *aead = esp->aead; + int alen = crypto_aead_authsize(aead); + int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); + int elen = skb->len - hlen; int ihl; u8 nexthdr[2]; - struct scatterlist *sg; int padlen; - int err = -EINVAL; - if (!pskb_may_pull(skb, sizeof(*esph))) - goto out; - - if (elen <= 0 || (elen & (blksize-1))) - goto out; - - if ((err = skb_cow_data(skb, 0, &trailer)) < 0) - goto out; - nfrags = err; - - skb->ip_summed = CHECKSUM_NONE; - - spin_lock(&x->lock); - - /* If integrity check is required, do this. */ - if (esp->auth.icv_full_len) { - u8 sum[alen]; - - err = esp_mac_digest(esp, skb, 0, skb->len - alen); - if (err) - goto unlock; - - if (skb_copy_bits(skb, skb->len - alen, sum, alen)) - BUG(); - - if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) { - err = -EBADMSG; - goto unlock; - } - } - - esph = (struct ip_esp_hdr *)skb->data; - - /* Get ivec. This can be wrong, check against another impls. */ - if (esp->conf.ivlen) - crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen); - - sg = &esp->sgbuf[0]; - - if (unlikely(nfrags > ESP_NUM_FAST_SG)) { - err = -ENOMEM; - sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); - if (!sg) - goto unlock; - } - sg_init_table(sg, nfrags); - skb_to_sgvec(skb, sg, - sizeof(*esph) + esp->conf.ivlen, - elen); - err = crypto_blkcipher_decrypt(&desc, sg, sg, elen); - if (unlikely(sg != &esp->sgbuf[0])) - kfree(sg); - -unlock: - spin_unlock(&x->lock); + kfree(ESP_SKB_CB(skb)->tmp); if (unlikely(err)) goto out; @@ -229,15 +249,11 @@ unlock: err = -EINVAL; padlen = nexthdr[0]; - if (padlen+2 >= elen) + if (padlen + 2 + alen >= elen) goto out; /* ... check padding bits here. Silly. :-) */ - /* RFC4303: Drop dummy packets without any error */ - if (nexthdr[1] == IPPROTO_NONE) - goto out; - iph = ip_hdr(skb); ihl = iph->ihl * 4; @@ -279,10 +295,87 @@ unlock: } pskb_trim(skb, skb->len - alen - padlen - 2); - __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen); + __skb_pull(skb, hlen); skb_set_transport_header(skb, -ihl); - return nexthdr[1]; + err = nexthdr[1]; + + /* RFC4303: Drop dummy packets without any error */ + if (err == IPPROTO_NONE) + err = -EINVAL; + +out: + return err; +} + +static void esp_input_done(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + + xfrm_input_resume(skb, esp_input_done2(skb, err)); +} + +/* + * Note: detecting truncated vs. non-truncated authentication data is very + * expensive, so we only support truncated data, which is the recommended + * and common case. + */ +static int esp_input(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ip_esp_hdr *esph; + struct esp_data *esp = x->data; + struct crypto_aead *aead = esp->aead; + struct aead_request *req; + struct sk_buff *trailer; + int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead); + int nfrags; + void *tmp; + u8 *iv; + struct scatterlist *sg; + struct scatterlist *asg; + int err = -EINVAL; + + if (!pskb_may_pull(skb, sizeof(*esph))) + goto out; + + if (elen <= 0) + goto out; + + if ((err = skb_cow_data(skb, 0, &trailer)) < 0) + goto out; + nfrags = err; + + err = -ENOMEM; + tmp = esp_alloc_tmp(aead, nfrags + 1); + if (!tmp) + goto out; + + ESP_SKB_CB(skb)->tmp = tmp; + iv = esp_tmp_iv(aead, tmp); + req = esp_tmp_req(aead, iv); + asg = esp_req_sg(aead, req); + sg = asg + 1; + + skb->ip_summed = CHECKSUM_NONE; + + esph = (struct ip_esp_hdr *)skb->data; + + /* Get ivec. This can be wrong, check against another impls. */ + iv = esph->enc_data; + + sg_init_table(sg, nfrags); + skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen); + 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)); + + err = crypto_aead_decrypt(req); + if (err == -EINPROGRESS) + goto out; + + err = esp_input_done2(skb, err); out: return err; @@ -291,11 +384,11 @@ out: static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) { struct esp_data *esp = x->data; - u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4); - u32 align = max_t(u32, blksize, esp->conf.padlen); + u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4); + u32 align = max_t(u32, blksize, esp->padlen); u32 rem; - mtu -= x->props.header_len + esp->auth.icv_trunc_len; + mtu -= x->props.header_len + crypto_aead_authsize(esp->aead); rem = mtu & (align - 1); mtu &= ~(align - 1); @@ -342,80 +435,98 @@ static void esp_destroy(struct xfrm_state *x) if (!esp) return; - crypto_free_blkcipher(esp->conf.tfm); - esp->conf.tfm = NULL; - kfree(esp->conf.ivec); - esp->conf.ivec = NULL; - crypto_free_hash(esp->auth.tfm); - esp->auth.tfm = NULL; - kfree(esp->auth.work_icv); - esp->auth.work_icv = NULL; + crypto_free_aead(esp->aead); kfree(esp); } static int esp_init_state(struct xfrm_state *x) { struct esp_data *esp = NULL; - struct crypto_blkcipher *tfm; + struct crypto_aead *aead; + struct crypto_authenc_key_param *param; + struct rtattr *rta; + char *key; + char *p; + char authenc_name[CRYPTO_MAX_ALG_NAME]; u32 align; + unsigned int keylen; + int err; if (x->ealg == NULL) - goto error; + return -EINVAL; + + 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) + return -ENAMETOOLONG; esp = kzalloc(sizeof(*esp), GFP_KERNEL); if (esp == NULL) return -ENOMEM; + x->data = esp; + + aead = crypto_alloc_aead(authenc_name, 0, 0); + err = PTR_ERR(aead); + if (IS_ERR(aead)) + goto error; + + esp->aead = aead; + + keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + + (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); + err = -ENOMEM; + key = kmalloc(keylen, GFP_KERNEL); + if (!key) + goto error; + + p = key; + rta = (void *)p; + rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; + rta->rta_len = RTA_LENGTH(sizeof(*param)); + param = RTA_DATA(rta); + p += RTA_SPACE(sizeof(*param)); + if (x->aalg) { struct xfrm_algo_desc *aalg_desc; - struct crypto_hash *hash; - - hash = crypto_alloc_hash(x->aalg->alg_name, 0, - CRYPTO_ALG_ASYNC); - if (IS_ERR(hash)) - goto error; - esp->auth.tfm = hash; - if (crypto_hash_setkey(hash, x->aalg->alg_key, - (x->aalg->alg_key_len + 7) / 8)) - goto error; + memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); + p += (x->aalg->alg_key_len + 7) / 8; aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); BUG_ON(!aalg_desc); + err = -EINVAL; if (aalg_desc->uinfo.auth.icv_fullbits/8 != - crypto_hash_digestsize(hash)) { + crypto_aead_authsize(aead)) { NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n", x->aalg->alg_name, - crypto_hash_digestsize(hash), + crypto_aead_authsize(aead), aalg_desc->uinfo.auth.icv_fullbits/8); - goto error; + goto free_key; } - esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; - esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8; - - esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL); - if (!esp->auth.work_icv) - goto error; + err = crypto_aead_setauthsize( + aead, aalg_desc->uinfo.auth.icv_truncbits / 8); + if (err) + goto free_key; } - tfm = crypto_alloc_blkcipher(x->ealg->alg_name, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(tfm)) - goto error; - 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; - esp->conf.ivinitted = 0; - } - if (crypto_blkcipher_setkey(tfm, x->ealg->alg_key, - (x->ealg->alg_key_len + 7) / 8)) + esp->padlen = 0; + + param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); + memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); + + err = crypto_aead_setkey(aead, key, keylen); + +free_key: + kfree(key); + + if (err) goto error; - x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen; + + x->props.header_len = sizeof(struct ip_esp_hdr) + + crypto_aead_ivsize(aead); if (x->props.mode == XFRM_MODE_TUNNEL) x->props.header_len += sizeof(struct iphdr); else if (x->props.mode == XFRM_MODE_BEET) @@ -434,18 +545,14 @@ static int esp_init_state(struct xfrm_state *x) break; } } - x->data = esp; - align = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4); - if (esp->conf.padlen) - align = max_t(u32, align, esp->conf.padlen); - x->props.trailer_len = align + 1 + esp->auth.icv_trunc_len; - return 0; + + align = ALIGN(crypto_aead_blocksize(aead), 4); + if (esp->padlen) + align = max_t(u32, align, esp->padlen); + x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead); error: - x->data = esp; - esp_destroy(x); - x->data = NULL; - return -EINVAL; + return err; } static struct xfrm_type esp_type = |