From 38320c70d282be1997a5204c7c7fe14c3aa6bfaa Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 28 Jan 2008 19:35:05 -0800 Subject: [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 Signed-off-by: David S. Miller --- net/ipv6/Kconfig | 1 + net/ipv6/esp6.c | 460 +++++++++++++++++++++++++++++++++---------------------- 2 files changed, 280 insertions(+), 181 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index eb0b8085949b..3ffb0323668c 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -85,6 +85,7 @@ config INET6_ESP depends on IPV6 select XFRM select CRYPTO + select CRYPTO_AEAD select CRYPTO_HMAC select CRYPTO_MD5 select CRYPTO_CBC diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 5bd5292ad9fa..dc821acf3d33 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -24,33 +24,124 @@ * This file is derived from net/ipv4/esp.c */ +#include +#include #include #include #include #include #include #include -#include #include #include #include +#include #include #include #include #include #include +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 esp6_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 sk_buff *trailer; + void *tmp; int blksize; int clen; int alen; int nfrags; + u8 *iv; u8 *tail; struct esp_data *esp = x->data; @@ -60,18 +151,26 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) /* Round to block size */ clen = skb->len; - 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 ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) { + if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0) goto error; - } + nfrags = err; + + 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); @@ -81,86 +180,113 @@ static int esp6_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; esph->spi = x->id.spi; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq); - spin_lock_bh(&x->lock); + 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)); - 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); - } + 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); - do { - struct scatterlist *sg = &esp->sgbuf[0]; + ESP_SKB_CB(skb)->tmp = tmp; + err = crypto_aead_givencrypt(req); + if (err == -EINPROGRESS) + goto error; - 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 (err == -EBUSY) + err = NET_XMIT_DROP; + + kfree(tmp); + +error: + return err; +} + +static int esp_input_done2(struct sk_buff *skb, int err) +{ + struct xfrm_state *x = xfrm_input_state(skb); + struct esp_data *esp = x->data; + 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 hdr_len = skb_network_header_len(skb); + int padlen; + u8 nexthdr[2]; + + kfree(ESP_SKB_CB(skb)->tmp); if (unlikely(err)) - goto unlock; + goto out; - 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); - } + if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) + BUG(); - 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); + err = -EINVAL; + padlen = nexthdr[0]; + if (padlen + 2 + alen >= elen) { + LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage " + "padlen=%d, elen=%d\n", padlen + 2, elen - alen); + goto out; } -unlock: - spin_unlock_bh(&x->lock); + /* ... check padding bits here. Silly. :-) */ -error: + pskb_trim(skb, skb->len - alen - padlen - 2); + __skb_pull(skb, hlen); + skb_set_transport_header(skb, -hdr_len); + + 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)); +} + static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) { - struct ipv6hdr *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 crypto_aead *aead = esp->aead; + struct aead_request *req; 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 hdr_len = skb_network_header_len(skb); + int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead); int nfrags; int ret = 0; + void *tmp; + u8 *iv; + struct scatterlist *sg; + struct scatterlist *asg; if (!pskb_may_pull(skb, sizeof(*esph))) { ret = -EINVAL; goto out; } - if (elen <= 0 || (elen & (blksize-1))) { + if (elen <= 0) { ret = -EINVAL; goto out; } @@ -170,86 +296,38 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) goto out; } - 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]; - - ret = esp_mac_digest(esp, skb, 0, skb->len - alen); - if (ret) - goto unlock; + ret = -ENOMEM; + tmp = esp_alloc_tmp(aead, nfrags + 1); + if (!tmp) + goto out; - if (skb_copy_bits(skb, skb->len - alen, sum, alen)) - BUG(); + 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; - if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) { - ret = -EBADMSG; - goto unlock; - } - } + skb->ip_summed = CHECKSUM_NONE; esph = (struct ip_esp_hdr *)skb->data; - iph = ipv6_hdr(skb); /* 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); - - { - struct scatterlist *sg = &esp->sgbuf[0]; - - if (unlikely(nfrags > ESP_NUM_FAST_SG)) { - sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); - if (!sg) { - ret = -ENOMEM; - goto unlock; - } - } - sg_init_table(sg, nfrags); - skb_to_sgvec(skb, sg, - sizeof(*esph) + esp->conf.ivlen, - elen); - ret = crypto_blkcipher_decrypt(&desc, sg, sg, elen); - if (unlikely(sg != &esp->sgbuf[0])) - kfree(sg); - } + iv = esph->enc_data; -unlock: - spin_unlock(&x->lock); + sg_init_table(sg, nfrags); + skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen); + sg_init_one(asg, esph, sizeof(*esph)); - if (unlikely(ret)) - goto out; + 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)); - { - u8 nexthdr[2]; - u8 padlen; - - if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) - BUG(); - - padlen = nexthdr[0]; - if (padlen+2 >= elen) { - LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen); - ret = -EINVAL; - goto out; - } - /* ... check padding bits here. Silly. :-) */ - - /* RFC4303: Drop dummy packets without any error */ - if (nexthdr[1] == IPPROTO_NONE) { - ret = -EINVAL; - goto out; - } + ret = crypto_aead_decrypt(req); + if (ret == -EINPROGRESS) + goto out; - pskb_trim(skb, skb->len - alen - padlen - 2); - ret = nexthdr[1]; - } + ret = esp_input_done2(skb, ret); - __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen); - skb_set_transport_header(skb, -hdr_len); out: return ret; } @@ -257,11 +335,11 @@ out: static u32 esp6_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); @@ -300,81 +378,101 @@ static void esp6_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 esp6_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 (x->encap) - 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; - } - 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; + err = crypto_aead_setauthsize( + aead, aalg_desc->uinfo.auth.icv_truncbits / 8); + if (err) + goto free_key; } - 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); switch (x->props.mode) { case XFRM_MODE_BEET: case XFRM_MODE_TRANSPORT: @@ -385,14 +483,14 @@ static int esp6_init_state(struct xfrm_state *x) default: goto error; } - x->data = esp; - 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; - esp6_destroy(x); - x->data = NULL; - return -EINVAL; + return err; } static struct xfrm_type esp6_type = -- cgit v1.2.3