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-rw-r--r--crypto/gcm.c287
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");
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