1 files changed, 287 insertions, 0 deletions

diff --git a/crypto/gcm.c b/crypto/gcm.c
index c654713..2f5fbba 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -37,6 +37,19 @@ struct crypto_rfc4106_ctx {
 	u8 nonce[4];
 };
 
+struct crypto_rfc4543_ctx {
+	struct crypto_aead *child;
+	u8 nonce[4];
+};
+
+struct crypto_rfc4543_req_ctx {
+	u8 auth_tag[16];
+	struct scatterlist cipher[1];
+	struct scatterlist payload[2];
+	struct scatterlist assoc[2];
+	struct aead_request subreq;
+};
+
 struct crypto_gcm_ghash_ctx {
 	unsigned int cryptlen;
 	struct scatterlist *src;
@@ -1047,6 +1060,272 @@ static struct crypto_template crypto_rfc4106_tmpl = {
 	.module = THIS_MODULE,
 };
 
+static inline struct crypto_rfc4543_req_ctx *crypto_rfc4543_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 crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
+				 unsigned int keylen)
+{
+	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
+	struct crypto_aead *child = ctx->child;
+	int err;
+
+	if (keylen < 4)
+		return -EINVAL;
+
+	keylen -= 4;
+	memcpy(ctx->nonce, key + keylen, 4);
+
+	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_rfc4543_setauthsize(struct crypto_aead *parent,
+				      unsigned int authsize)
+{
+	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
+
+	if (authsize != 16)
+		return -EINVAL;
+
+	return crypto_aead_setauthsize(ctx->child, authsize);
+}
+
+/* this is the same as crypto_authenc_chain */
+static void crypto_rfc4543_chain(struct scatterlist *head,
+				 struct scatterlist *sg, int chain)
+{
+	if (chain) {
+		head->length += sg->length;
+		sg = scatterwalk_sg_next(sg);
+	}
+
+	if (sg)
+		scatterwalk_sg_chain(head, 2, sg);
+	else
+		sg_mark_end(head);
+}
+
+static struct aead_request *crypto_rfc4543_crypt(struct aead_request *req,
+						 int enc)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
+	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
+	struct aead_request *subreq = &rctx->subreq;
+	struct scatterlist *dst = req->dst;
+	struct scatterlist *cipher = rctx->cipher;
+	struct scatterlist *payload = rctx->payload;
+	struct scatterlist *assoc = rctx->assoc;
+	unsigned int authsize = crypto_aead_authsize(aead);
+	unsigned int assoclen = req->assoclen;
+	struct page *dstp;
+	u8 *vdst;
+	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
+			   crypto_aead_alignmask(ctx->child) + 1);
+
+	memcpy(iv, ctx->nonce, 4);
+	memcpy(iv + 4, req->iv, 8);
+
+	/* construct cipher/plaintext */
+	if (enc)
+		memset(rctx->auth_tag, 0, authsize);
+	else
+		scatterwalk_map_and_copy(rctx->auth_tag, dst,
+					 req->cryptlen - authsize,
+					 authsize, 0);
+
+	sg_init_one(cipher, rctx->auth_tag, authsize);
+
+	/* construct the aad */
+	dstp = sg_page(dst);
+	vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
+
+	sg_init_table(payload, 2);
+	sg_set_buf(payload, req->iv, 8);
+	crypto_rfc4543_chain(payload, dst, vdst == req->iv + 8);
+	assoclen += 8 + req->cryptlen - (enc ? 0 : authsize);
+
+	sg_init_table(assoc, 2);
+	sg_set_page(assoc, sg_page(req->assoc), req->assoc->length,
+		    req->assoc->offset);
+	crypto_rfc4543_chain(assoc, payload, 0);
+
+	aead_request_set_tfm(subreq, ctx->child);
+	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
+				  req->base.data);
+	aead_request_set_crypt(subreq, cipher, cipher, enc ? 0 : authsize, iv);
+	aead_request_set_assoc(subreq, assoc, assoclen);
+
+	return subreq;
+}
+
+static int crypto_rfc4543_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
+	struct aead_request *subreq;
+	int err;
+
+	subreq = crypto_rfc4543_crypt(req, 1);
+	err = crypto_aead_encrypt(subreq);
+	if (err)
+		return err;
+
+	scatterwalk_map_and_copy(rctx->auth_tag, req->dst, req->cryptlen,
+				 crypto_aead_authsize(aead), 1);
+
+	return 0;
+}
+
+static int crypto_rfc4543_decrypt(struct aead_request *req)
+{
+	req = crypto_rfc4543_crypt(req, 0);
+
+	return crypto_aead_decrypt(req);
+}
+
+static int crypto_rfc4543_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_rfc4543_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 crypto_rfc4543_req_ctx) +
+				ALIGN(crypto_aead_reqsize(aead),
+				      crypto_tfm_ctx_alignment()) +
+				align + 16;
+
+	return 0;
+}
+
+static void crypto_rfc4543_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_rfc4543_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_aead(ctx->child);
+}
+
+static struct crypto_instance *crypto_rfc4543_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,
+		     "rfc4543(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
+	    snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+		     "rfc4543(%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_rfc4543_ctx);
+
+	inst->alg.cra_init = crypto_rfc4543_init_tfm;
+	inst->alg.cra_exit = crypto_rfc4543_exit_tfm;
+
+	inst->alg.cra_aead.setkey = crypto_rfc4543_setkey;
+	inst->alg.cra_aead.setauthsize = crypto_rfc4543_setauthsize;
+	inst->alg.cra_aead.encrypt = crypto_rfc4543_encrypt;
+	inst->alg.cra_aead.decrypt = crypto_rfc4543_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_rfc4543_free(struct crypto_instance *inst)
+{
+	crypto_drop_spawn(crypto_instance_ctx(inst));
+	kfree(inst);
+}
+
+static struct crypto_template crypto_rfc4543_tmpl = {
+	.name = "rfc4543",
+	.alloc = crypto_rfc4543_alloc,
+	.free = crypto_rfc4543_free,
+	.module = THIS_MODULE,
+};
+
 static int __init crypto_gcm_module_init(void)
 {
 	int err;
@@ -1067,8 +1346,14 @@ static int __init crypto_gcm_module_init(void)
 	if (err)
 		goto out_undo_gcm;
 
+	err = crypto_register_template(&crypto_rfc4543_tmpl);
+	if (err)
+		goto out_undo_rfc4106;
+
 	return 0;
 
+out_undo_rfc4106:
+	crypto_unregister_template(&crypto_rfc4106_tmpl);
 out_undo_gcm:
 	crypto_unregister_template(&crypto_gcm_tmpl);
 out_undo_base:
@@ -1081,6 +1366,7 @@ out:
 static void __exit crypto_gcm_module_exit(void)
 {
 	kfree(gcm_zeroes);
+	crypto_unregister_template(&crypto_rfc4543_tmpl);
 	crypto_unregister_template(&crypto_rfc4106_tmpl);
 	crypto_unregister_template(&crypto_gcm_tmpl);
 	crypto_unregister_template(&crypto_gcm_base_tmpl);
@@ -1094,3 +1380,4 @@ MODULE_DESCRIPTION("Galois/Counter Mode");
 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
 MODULE_ALIAS("gcm_base");
 MODULE_ALIAS("rfc4106");
+MODULE_ALIAS("rfc4543");