[CRYPTO] ccm: Added CCM mode
This patch adds Counter with CBC-MAC (CCM) support.
RFC 3610 and NIST Special Publication 800-38C were referenced.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/ccm.c b/crypto/ccm.c
new file mode 100644
index 0000000..7cf7e5a
--- /dev/null
+++ b/crypto/ccm.c
@@ -0,0 +1,889 @@
+/*
+ * CCM: Counter with CBC-MAC
+ *
+ * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <crypto/internal/aead.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+struct ccm_instance_ctx {
+ struct crypto_skcipher_spawn ctr;
+ struct crypto_spawn cipher;
+};
+
+struct crypto_ccm_ctx {
+ struct crypto_cipher *cipher;
+ struct crypto_ablkcipher *ctr;
+};
+
+struct crypto_rfc4309_ctx {
+ struct crypto_aead *child;
+ u8 nonce[3];
+};
+
+struct crypto_ccm_req_priv_ctx {
+ u8 odata[16];
+ u8 idata[16];
+ u8 auth_tag[16];
+ u32 ilen;
+ u32 flags;
+ struct scatterlist src[2];
+ struct scatterlist dst[2];
+ struct ablkcipher_request abreq;
+};
+
+static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
+ struct aead_request *req)
+{
+ unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
+
+ return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
+}
+
+static int set_msg_len(u8 *block, unsigned int msglen, int csize)
+{
+ __be32 data;
+
+ memset(block, 0, csize);
+ block += csize;
+
+ if (csize >= 4)
+ csize = 4;
+ else if (msglen > (1 << (8 * csize)))
+ return -EOVERFLOW;
+
+ data = cpu_to_be32(msglen);
+ memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
+
+ return 0;
+}
+
+static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
+ unsigned int keylen)
+{
+ struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
+ struct crypto_ablkcipher *ctr = ctx->ctr;
+ struct crypto_cipher *tfm = ctx->cipher;
+ int err = 0;
+
+ crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
+ crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_ablkcipher_setkey(ctr, key, keylen);
+ crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
+ CRYPTO_TFM_RES_MASK);
+ if (err)
+ goto out;
+
+ crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
+ crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_cipher_setkey(tfm, key, keylen);
+ crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
+ CRYPTO_TFM_RES_MASK);
+
+out:
+ return err;
+}
+
+static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
+ unsigned int authsize)
+{
+ switch (authsize) {
+ case 4:
+ case 6:
+ case 8:
+ case 10:
+ case 12:
+ case 14:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int format_input(u8 *info, struct aead_request *req,
+ unsigned int cryptlen)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ unsigned int lp = req->iv[0];
+ unsigned int l = lp + 1;
+ unsigned int m;
+
+ m = crypto_aead_authsize(aead);
+
+ memcpy(info, req->iv, 16);
+
+ /* format control info per RFC 3610 and
+ * NIST Special Publication 800-38C
+ */
+ *info |= (8 * ((m - 2) / 2));
+ if (req->assoclen)
+ *info |= 64;
+
+ return set_msg_len(info + 16 - l, cryptlen, l);
+}
+
+static int format_adata(u8 *adata, unsigned int a)
+{
+ int len = 0;
+
+ /* add control info for associated data
+ * RFC 3610 and NIST Special Publication 800-38C
+ */
+ if (a < 65280) {
+ *(__be16 *)adata = cpu_to_be16(a);
+ len = 2;
+ } else {
+ *(__be16 *)adata = cpu_to_be16(0xfffe);
+ *(__be32 *)&adata[2] = cpu_to_be32(a);
+ len = 6;
+ }
+
+ return len;
+}
+
+static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
+ struct crypto_ccm_req_priv_ctx *pctx)
+{
+ unsigned int bs = 16;
+ u8 *odata = pctx->odata;
+ u8 *idata = pctx->idata;
+ int datalen, getlen;
+
+ datalen = n;
+
+ /* first time in here, block may be partially filled. */
+ getlen = bs - pctx->ilen;
+ if (datalen >= getlen) {
+ memcpy(idata + pctx->ilen, data, getlen);
+ crypto_xor(odata, idata, bs);
+ crypto_cipher_encrypt_one(tfm, odata, odata);
+ datalen -= getlen;
+ data += getlen;
+ pctx->ilen = 0;
+ }
+
+ /* now encrypt rest of data */
+ while (datalen >= bs) {
+ crypto_xor(odata, data, bs);
+ crypto_cipher_encrypt_one(tfm, odata, odata);
+
+ datalen -= bs;
+ data += bs;
+ }
+
+ /* check and see if there's leftover data that wasn't
+ * enough to fill a block.
+ */
+ if (datalen) {
+ memcpy(idata + pctx->ilen, data, datalen);
+ pctx->ilen += datalen;
+ }
+}
+
+static void get_data_to_compute(struct crypto_cipher *tfm,
+ struct crypto_ccm_req_priv_ctx *pctx,
+ struct scatterlist *sg, unsigned int len)
+{
+ struct scatter_walk walk;
+ u8 *data_src;
+ int n;
+
+ scatterwalk_start(&walk, sg);
+
+ while (len) {
+ n = scatterwalk_clamp(&walk, len);
+ if (!n) {
+ scatterwalk_start(&walk, sg_next(walk.sg));
+ n = scatterwalk_clamp(&walk, len);
+ }
+ data_src = scatterwalk_map(&walk, 0);
+
+ compute_mac(tfm, data_src, n, pctx);
+ len -= n;
+
+ scatterwalk_unmap(data_src, 0);
+ scatterwalk_advance(&walk, n);
+ scatterwalk_done(&walk, 0, len);
+ if (len)
+ crypto_yield(pctx->flags);
+ }
+
+ /* any leftover needs padding and then encrypted */
+ if (pctx->ilen) {
+ int padlen;
+ u8 *odata = pctx->odata;
+ u8 *idata = pctx->idata;
+
+ padlen = 16 - pctx->ilen;
+ memset(idata + pctx->ilen, 0, padlen);
+ crypto_xor(odata, idata, 16);
+ crypto_cipher_encrypt_one(tfm, odata, odata);
+ pctx->ilen = 0;
+ }
+}
+
+static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
+ unsigned int cryptlen)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
+ struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
+ struct crypto_cipher *cipher = ctx->cipher;
+ unsigned int assoclen = req->assoclen;
+ u8 *odata = pctx->odata;
+ u8 *idata = pctx->idata;
+ int err;
+
+ /* format control data for input */
+ err = format_input(odata, req, cryptlen);
+ if (err)
+ goto out;
+
+ /* encrypt first block to use as start in computing mac */
+ crypto_cipher_encrypt_one(cipher, odata, odata);
+
+ /* format associated data and compute into mac */
+ if (assoclen) {
+ pctx->ilen = format_adata(idata, assoclen);
+ get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
+ }
+
+ /* compute plaintext into mac */
+ get_data_to_compute(cipher, pctx, plain, cryptlen);
+
+out:
+ return err;
+}
+
+static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
+{
+ struct aead_request *req = areq->data;
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
+ u8 *odata = pctx->odata;
+
+ if (!err)
+ scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
+ crypto_aead_authsize(aead), 1);
+ aead_request_complete(req, err);
+}
+
+static inline int crypto_ccm_check_iv(const u8 *iv)
+{
+ /* 2 <= L <= 8, so 1 <= L' <= 7. */
+ if (1 > iv[0] || iv[0] > 7)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int crypto_ccm_encrypt(struct aead_request *req)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
+ struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
+ struct ablkcipher_request *abreq = &pctx->abreq;
+ struct scatterlist *dst;
+ unsigned int cryptlen = req->cryptlen;
+ u8 *odata = pctx->odata;
+ u8 *iv = req->iv;
+ int err;
+
+ err = crypto_ccm_check_iv(iv);
+ if (err)
+ return err;
+
+ pctx->flags = aead_request_flags(req);
+
+ err = crypto_ccm_auth(req, req->src, cryptlen);
+ if (err)
+ return err;
+
+ /* Note: rfc 3610 and NIST 800-38C require counter of
+ * zero to encrypt auth tag.
+ */
+ memset(iv + 15 - iv[0], 0, iv[0] + 1);
+
+ sg_init_table(pctx->src, 2);
+ sg_set_buf(pctx->src, odata, 16);
+ scatterwalk_sg_chain(pctx->src, 2, req->src);
+
+ dst = pctx->src;
+ if (req->src != req->dst) {
+ sg_init_table(pctx->dst, 2);
+ sg_set_buf(pctx->dst, odata, 16);
+ scatterwalk_sg_chain(pctx->dst, 2, req->dst);
+ dst = pctx->dst;
+ }
+
+ ablkcipher_request_set_tfm(abreq, ctx->ctr);
+ ablkcipher_request_set_callback(abreq, pctx->flags,
+ crypto_ccm_encrypt_done, req);
+ ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
+ err = crypto_ablkcipher_encrypt(abreq);
+ if (err)
+ return err;
+
+ /* copy authtag to end of dst */
+ scatterwalk_map_and_copy(odata, req->dst, cryptlen,
+ crypto_aead_authsize(aead), 1);
+ return err;
+}
+
+static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
+ int err)
+{
+ struct aead_request *req = areq->data;
+ struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ unsigned int authsize = crypto_aead_authsize(aead);
+ unsigned int cryptlen = req->cryptlen - authsize;
+
+ if (!err) {
+ err = crypto_ccm_auth(req, req->dst, cryptlen);
+ if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
+ err = -EBADMSG;
+ }
+ aead_request_complete(req, err);
+}
+
+static int crypto_ccm_decrypt(struct aead_request *req)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
+ struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
+ struct ablkcipher_request *abreq = &pctx->abreq;
+ struct scatterlist *dst;
+ unsigned int authsize = crypto_aead_authsize(aead);
+ unsigned int cryptlen = req->cryptlen;
+ u8 *authtag = pctx->auth_tag;
+ u8 *odata = pctx->odata;
+ u8 *iv = req->iv;
+ int err;
+
+ if (cryptlen < authsize)
+ return -EINVAL;
+ cryptlen -= authsize;
+
+ err = crypto_ccm_check_iv(iv);
+ if (err)
+ return err;
+
+ pctx->flags = aead_request_flags(req);
+
+ scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
+
+ memset(iv + 15 - iv[0], 0, iv[0] + 1);
+
+ sg_init_table(pctx->src, 2);
+ sg_set_buf(pctx->src, authtag, 16);
+ scatterwalk_sg_chain(pctx->src, 2, req->src);
+
+ dst = pctx->src;
+ if (req->src != req->dst) {
+ sg_init_table(pctx->dst, 2);
+ sg_set_buf(pctx->dst, authtag, 16);
+ scatterwalk_sg_chain(pctx->dst, 2, req->dst);
+ dst = pctx->dst;
+ }
+
+ ablkcipher_request_set_tfm(abreq, ctx->ctr);
+ ablkcipher_request_set_callback(abreq, pctx->flags,
+ crypto_ccm_decrypt_done, req);
+ ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
+ err = crypto_ablkcipher_decrypt(abreq);
+ if (err)
+ return err;
+
+ err = crypto_ccm_auth(req, req->dst, cryptlen);
+ if (err)
+ return err;
+
+ /* verify */
+ if (memcmp(authtag, odata, authsize))
+ return -EBADMSG;
+
+ return err;
+}
+
+static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_instance *inst = (void *)tfm->__crt_alg;
+ struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
+ struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct crypto_cipher *cipher;
+ struct crypto_ablkcipher *ctr;
+ unsigned long align;
+ int err;
+
+ cipher = crypto_spawn_cipher(&ictx->cipher);
+ if (IS_ERR(cipher))
+ return PTR_ERR(cipher);
+
+ ctr = crypto_spawn_skcipher(&ictx->ctr);
+ err = PTR_ERR(ctr);
+ if (IS_ERR(ctr))
+ goto err_free_cipher;
+
+ ctx->cipher = cipher;
+ ctx->ctr = ctr;
+
+ align = crypto_tfm_alg_alignmask(tfm);
+ align &= ~(crypto_tfm_ctx_alignment() - 1);
+ tfm->crt_aead.reqsize = align +
+ sizeof(struct crypto_ccm_req_priv_ctx) +
+ crypto_ablkcipher_reqsize(ctr);
+
+ return 0;
+
+err_free_cipher:
+ crypto_free_cipher(cipher);
+ return err;
+}
+
+static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_cipher(ctx->cipher);
+ crypto_free_ablkcipher(ctx->ctr);
+}
+
+static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
+ const char *full_name,
+ const char *ctr_name,
+ const char *cipher_name)
+{
+ struct crypto_attr_type *algt;
+ struct crypto_instance *inst;
+ struct crypto_alg *ctr;
+ struct crypto_alg *cipher;
+ struct ccm_instance_ctx *ictx;
+ int err;
+
+ algt = crypto_get_attr_type(tb);
+ err = PTR_ERR(algt);
+ if (IS_ERR(algt))
+ return ERR_PTR(err);
+
+ if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+ return ERR_PTR(-EINVAL);
+
+ cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
+ CRYPTO_ALG_TYPE_MASK);
+ err = PTR_ERR(cipher);
+ if (IS_ERR(cipher))
+ return ERR_PTR(err);
+
+ err = -EINVAL;
+ if (cipher->cra_blocksize != 16)
+ goto out_put_cipher;
+
+ inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
+ err = -ENOMEM;
+ if (!inst)
+ goto out_put_cipher;
+
+ ictx = crypto_instance_ctx(inst);
+
+ err = crypto_init_spawn(&ictx->cipher, cipher, inst,
+ CRYPTO_ALG_TYPE_MASK);
+ if (err)
+ goto err_free_inst;
+
+ crypto_set_skcipher_spawn(&ictx->ctr, inst);
+ err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
+ crypto_requires_sync(algt->type,
+ algt->mask));
+ if (err)
+ goto err_drop_cipher;
+
+ ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
+
+ /* Not a stream cipher? */
+ err = -EINVAL;
+ if (ctr->cra_blocksize != 1)
+ goto err_drop_ctr;
+
+ /* We want the real thing! */
+ if (ctr->cra_ablkcipher.ivsize != 16)
+ goto err_drop_ctr;
+
+ err = -ENAMETOOLONG;
+ if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "ccm_base(%s,%s)", ctr->cra_driver_name,
+ cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
+ goto err_drop_ctr;
+
+ memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
+
+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+ inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
+ inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
+ inst->alg.cra_blocksize = 1;
+ inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
+ (__alignof__(u32) - 1);
+ inst->alg.cra_type = &crypto_aead_type;
+ inst->alg.cra_aead.ivsize = 16;
+ inst->alg.cra_aead.maxauthsize = 16;
+ inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
+ inst->alg.cra_init = crypto_ccm_init_tfm;
+ inst->alg.cra_exit = crypto_ccm_exit_tfm;
+ inst->alg.cra_aead.setkey = crypto_ccm_setkey;
+ inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
+ inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
+ inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
+
+out:
+ crypto_mod_put(cipher);
+ return inst;
+
+err_drop_ctr:
+ crypto_drop_skcipher(&ictx->ctr);
+err_drop_cipher:
+ crypto_drop_spawn(&ictx->cipher);
+err_free_inst:
+ kfree(inst);
+out_put_cipher:
+ inst = ERR_PTR(err);
+ goto out;
+}
+
+static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
+{
+ int err;
+ const char *cipher_name;
+ char ctr_name[CRYPTO_MAX_ALG_NAME];
+ char full_name[CRYPTO_MAX_ALG_NAME];
+
+ cipher_name = crypto_attr_alg_name(tb[1]);
+ err = PTR_ERR(cipher_name);
+ if (IS_ERR(cipher_name))
+ return ERR_PTR(err);
+
+ if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
+ cipher_name) >= CRYPTO_MAX_ALG_NAME)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
+}
+
+static void crypto_ccm_free(struct crypto_instance *inst)
+{
+ struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
+
+ crypto_drop_spawn(&ctx->cipher);
+ crypto_drop_skcipher(&ctx->ctr);
+ kfree(inst);
+}
+
+static struct crypto_template crypto_ccm_tmpl = {
+ .name = "ccm",
+ .alloc = crypto_ccm_alloc,
+ .free = crypto_ccm_free,
+ .module = THIS_MODULE,
+};
+
+static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
+{
+ int err;
+ const char *ctr_name;
+ const char *cipher_name;
+ char full_name[CRYPTO_MAX_ALG_NAME];
+
+ ctr_name = crypto_attr_alg_name(tb[1]);
+ err = PTR_ERR(ctr_name);
+ if (IS_ERR(ctr_name))
+ return ERR_PTR(err);
+
+ cipher_name = crypto_attr_alg_name(tb[2]);
+ err = PTR_ERR(cipher_name);
+ if (IS_ERR(cipher_name))
+ return ERR_PTR(err);
+
+ if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
+ ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
+}
+
+static struct crypto_template crypto_ccm_base_tmpl = {
+ .name = "ccm_base",
+ .alloc = crypto_ccm_base_alloc,
+ .free = crypto_ccm_free,
+ .module = THIS_MODULE,
+};
+
+static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
+ unsigned int keylen)
+{
+ struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
+ struct crypto_aead *child = ctx->child;
+ int err;
+
+ if (keylen < 3)
+ return -EINVAL;
+
+ keylen -= 3;
+ memcpy(ctx->nonce, key + keylen, 3);
+
+ crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_aead_setkey(child, key, keylen);
+ crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
+ CRYPTO_TFM_RES_MASK);
+
+ return err;
+}
+
+static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
+ unsigned int authsize)
+{
+ struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
+
+ switch (authsize) {
+ case 8:
+ case 12:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return crypto_aead_setauthsize(ctx->child, authsize);
+}
+
+static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
+{
+ struct aead_request *subreq = aead_request_ctx(req);
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
+ struct crypto_aead *child = ctx->child;
+ u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
+ crypto_aead_alignmask(child) + 1);
+
+ /* L' */
+ iv[0] = 3;
+
+ memcpy(iv + 1, ctx->nonce, 3);
+ memcpy(iv + 4, req->iv, 8);
+
+ aead_request_set_tfm(subreq, child);
+ aead_request_set_callback(subreq, req->base.flags, req->base.complete,
+ req->base.data);
+ aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
+ aead_request_set_assoc(subreq, req->assoc, req->assoclen);
+
+ return subreq;
+}
+
+static int crypto_rfc4309_encrypt(struct aead_request *req)
+{
+ req = crypto_rfc4309_crypt(req);
+
+ return crypto_aead_encrypt(req);
+}
+
+static int crypto_rfc4309_decrypt(struct aead_request *req)
+{
+ req = crypto_rfc4309_crypt(req);
+
+ return crypto_aead_decrypt(req);
+}
+
+static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_instance *inst = (void *)tfm->__crt_alg;
+ struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
+ struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct crypto_aead *aead;
+ unsigned long align;
+
+ aead = crypto_spawn_aead(spawn);
+ if (IS_ERR(aead))
+ return PTR_ERR(aead);
+
+ ctx->child = aead;
+
+ align = crypto_aead_alignmask(aead);
+ align &= ~(crypto_tfm_ctx_alignment() - 1);
+ tfm->crt_aead.reqsize = sizeof(struct aead_request) +
+ ALIGN(crypto_aead_reqsize(aead),
+ crypto_tfm_ctx_alignment()) +
+ align + 16;
+
+ return 0;
+}
+
+static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_aead(ctx->child);
+}
+
+static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
+{
+ struct crypto_attr_type *algt;
+ struct crypto_instance *inst;
+ struct crypto_aead_spawn *spawn;
+ struct crypto_alg *alg;
+ const char *ccm_name;
+ int err;
+
+ algt = crypto_get_attr_type(tb);
+ err = PTR_ERR(algt);
+ if (IS_ERR(algt))
+ return ERR_PTR(err);
+
+ if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+ return ERR_PTR(-EINVAL);
+
+ ccm_name = crypto_attr_alg_name(tb[1]);
+ err = PTR_ERR(ccm_name);
+ if (IS_ERR(ccm_name))
+ return ERR_PTR(err);
+
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ if (!inst)
+ return ERR_PTR(-ENOMEM);
+
+ spawn = crypto_instance_ctx(inst);
+ crypto_set_aead_spawn(spawn, inst);
+ err = crypto_grab_aead(spawn, ccm_name, 0,
+ crypto_requires_sync(algt->type, algt->mask));
+ if (err)
+ goto out_free_inst;
+
+ alg = crypto_aead_spawn_alg(spawn);
+
+ err = -EINVAL;
+
+ /* We only support 16-byte blocks. */
+ if (alg->cra_aead.ivsize != 16)
+ goto out_drop_alg;
+
+ /* Not a stream cipher? */
+ if (alg->cra_blocksize != 1)
+ goto out_drop_alg;
+
+ err = -ENAMETOOLONG;
+ if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
+ "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
+ snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "rfc4309(%s)", alg->cra_driver_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+
+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+ inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
+ inst->alg.cra_priority = alg->cra_priority;
+ inst->alg.cra_blocksize = 1;
+ inst->alg.cra_alignmask = alg->cra_alignmask;
+ inst->alg.cra_type = &crypto_nivaead_type;
+
+ inst->alg.cra_aead.ivsize = 8;
+ inst->alg.cra_aead.maxauthsize = 16;
+
+ inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
+
+ inst->alg.cra_init = crypto_rfc4309_init_tfm;
+ inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
+
+ inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
+ inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
+ inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
+ inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
+
+ inst->alg.cra_aead.geniv = "seqiv";
+
+out:
+ return inst;
+
+out_drop_alg:
+ crypto_drop_aead(spawn);
+out_free_inst:
+ kfree(inst);
+ inst = ERR_PTR(err);
+ goto out;
+}
+
+static void crypto_rfc4309_free(struct crypto_instance *inst)
+{
+ crypto_drop_spawn(crypto_instance_ctx(inst));
+ kfree(inst);
+}
+
+static struct crypto_template crypto_rfc4309_tmpl = {
+ .name = "rfc4309",
+ .alloc = crypto_rfc4309_alloc,
+ .free = crypto_rfc4309_free,
+ .module = THIS_MODULE,
+};
+
+static int __init crypto_ccm_module_init(void)
+{
+ int err;
+
+ err = crypto_register_template(&crypto_ccm_base_tmpl);
+ if (err)
+ goto out;
+
+ err = crypto_register_template(&crypto_ccm_tmpl);
+ if (err)
+ goto out_undo_base;
+
+ err = crypto_register_template(&crypto_rfc4309_tmpl);
+ if (err)
+ goto out_undo_ccm;
+
+out:
+ return err;
+
+out_undo_ccm:
+ crypto_unregister_template(&crypto_ccm_tmpl);
+out_undo_base:
+ crypto_unregister_template(&crypto_ccm_base_tmpl);
+ goto out;
+}
+
+static void __exit crypto_ccm_module_exit(void)
+{
+ crypto_unregister_template(&crypto_rfc4309_tmpl);
+ crypto_unregister_template(&crypto_ccm_tmpl);
+ crypto_unregister_template(&crypto_ccm_base_tmpl);
+}
+
+module_init(crypto_ccm_module_init);
+module_exit(crypto_ccm_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Counter with CBC MAC");
+MODULE_ALIAS("ccm_base");
+MODULE_ALIAS("rfc4309");