Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 427 insertions, 0 deletions

diff --git a/crypto/cts.c b/crypto/cts.c
new file mode 100644
index 000000000..4e28d83ae
--- /dev/null
+++ b/crypto/cts.c
@@ -0,0 +1,427 @@
+/*
+ * CTS: Cipher Text Stealing mode
+ *
+ * COPYRIGHT (c) 2008
+ * The Regents of the University of Michigan
+ * ALL RIGHTS RESERVED
+ *
+ * Permission is granted to use, copy, create derivative works
+ * and redistribute this software and such derivative works
+ * for any purpose, so long as the name of The University of
+ * Michigan is not used in any advertising or publicity
+ * pertaining to the use of distribution of this software
+ * without specific, written prior authorization.  If the
+ * above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any
+ * portion of this software, then the disclaimer below must
+ * also be included.
+ *
+ * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
+ * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
+ * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
+ * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
+ * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
+ * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
+ * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGES.
+ */
+
+/* Derived from various:
+ *	Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+/*
+ * This is the Cipher Text Stealing mode as described by
+ * Section 8 of rfc2040 and referenced by rfc3962.
+ * rfc3962 includes errata information in its Appendix A.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <crypto/scatterwalk.h>
+#include <linux/slab.h>
+#include <linux/compiler.h>
+
+struct crypto_cts_ctx {
+	struct crypto_skcipher *child;
+};
+
+struct crypto_cts_reqctx {
+	struct scatterlist sg[2];
+	unsigned offset;
+	struct skcipher_request subreq;
+};
+
+static inline u8 *crypto_cts_reqctx_space(struct skcipher_request *req)
+{
+	struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req);
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_skcipher *child = ctx->child;
+
+	return PTR_ALIGN((u8 *)(rctx + 1) + crypto_skcipher_reqsize(child),
+			 crypto_skcipher_alignmask(tfm) + 1);
+}
+
+static int crypto_cts_setkey(struct crypto_skcipher *parent, const u8 *key,
+			     unsigned int keylen)
+{
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(parent);
+	struct crypto_skcipher *child = ctx->child;
+	int err;
+
+	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
+					 CRYPTO_TFM_REQ_MASK);
+	err = crypto_skcipher_setkey(child, key, keylen);
+	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
+					  CRYPTO_TFM_RES_MASK);
+	return err;
+}
+
+static void cts_cbc_crypt_done(struct crypto_async_request *areq, int err)
+{
+	struct skcipher_request *req = areq->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	skcipher_request_complete(req, err);
+}
+
+static int cts_cbc_encrypt(struct skcipher_request *req)
+{
+	struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req);
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int bsize = crypto_skcipher_blocksize(tfm);
+	u8 d[MAX_CIPHER_BLOCKSIZE * 2] __aligned(__alignof__(u32));
+	struct scatterlist *sg;
+	unsigned int offset;
+	int lastn;
+
+	offset = rctx->offset;
+	lastn = req->cryptlen - offset;
+
+	sg = scatterwalk_ffwd(rctx->sg, req->dst, offset - bsize);
+	scatterwalk_map_and_copy(d + bsize, sg, 0, bsize, 0);
+
+	memset(d, 0, bsize);
+	scatterwalk_map_and_copy(d, req->src, offset, lastn, 0);
+
+	scatterwalk_map_and_copy(d, sg, 0, bsize + lastn, 1);
+	memzero_explicit(d, sizeof(d));
+
+	skcipher_request_set_callback(subreq, req->base.flags &
+					      CRYPTO_TFM_REQ_MAY_BACKLOG,
+				      cts_cbc_crypt_done, req);
+	skcipher_request_set_crypt(subreq, sg, sg, bsize, req->iv);
+	return crypto_skcipher_encrypt(subreq);
+}
+
+static void crypto_cts_encrypt_done(struct crypto_async_request *areq, int err)
+{
+	struct skcipher_request *req = areq->data;
+
+	if (err)
+		goto out;
+
+	err = cts_cbc_encrypt(req);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return;
+
+out:
+	skcipher_request_complete(req, err);
+}
+
+static int crypto_cts_encrypt(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req);
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int bsize = crypto_skcipher_blocksize(tfm);
+	unsigned int nbytes = req->cryptlen;
+	int cbc_blocks = (nbytes + bsize - 1) / bsize - 1;
+	unsigned int offset;
+
+	skcipher_request_set_tfm(subreq, ctx->child);
+
+	if (cbc_blocks <= 0) {
+		skcipher_request_set_callback(subreq, req->base.flags,
+					      req->base.complete,
+					      req->base.data);
+		skcipher_request_set_crypt(subreq, req->src, req->dst, nbytes,
+					   req->iv);
+		return crypto_skcipher_encrypt(subreq);
+	}
+
+	offset = cbc_blocks * bsize;
+	rctx->offset = offset;
+
+	skcipher_request_set_callback(subreq, req->base.flags,
+				      crypto_cts_encrypt_done, req);
+	skcipher_request_set_crypt(subreq, req->src, req->dst,
+				   offset, req->iv);
+
+	return crypto_skcipher_encrypt(subreq) ?:
+	       cts_cbc_encrypt(req);
+}
+
+static int cts_cbc_decrypt(struct skcipher_request *req)
+{
+	struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req);
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int bsize = crypto_skcipher_blocksize(tfm);
+	u8 d[MAX_CIPHER_BLOCKSIZE * 2] __aligned(__alignof__(u32));
+	struct scatterlist *sg;
+	unsigned int offset;
+	u8 *space;
+	int lastn;
+
+	offset = rctx->offset;
+	lastn = req->cryptlen - offset;
+
+	sg = scatterwalk_ffwd(rctx->sg, req->dst, offset - bsize);
+
+	/* 1. Decrypt Cn-1 (s) to create Dn */
+	scatterwalk_map_and_copy(d + bsize, sg, 0, bsize, 0);
+	space = crypto_cts_reqctx_space(req);
+	crypto_xor(d + bsize, space, bsize);
+	/* 2. Pad Cn with zeros at the end to create C of length BB */
+	memset(d, 0, bsize);
+	scatterwalk_map_and_copy(d, req->src, offset, lastn, 0);
+	/* 3. Exclusive-or Dn with C to create Xn */
+	/* 4. Select the first Ln bytes of Xn to create Pn */
+	crypto_xor(d + bsize, d, lastn);
+
+	/* 5. Append the tail (BB - Ln) bytes of Xn to Cn to create En */
+	memcpy(d + lastn, d + bsize + lastn, bsize - lastn);
+	/* 6. Decrypt En to create Pn-1 */
+
+	scatterwalk_map_and_copy(d, sg, 0, bsize + lastn, 1);
+	memzero_explicit(d, sizeof(d));
+
+	skcipher_request_set_callback(subreq, req->base.flags &
+					      CRYPTO_TFM_REQ_MAY_BACKLOG,
+				      cts_cbc_crypt_done, req);
+
+	skcipher_request_set_crypt(subreq, sg, sg, bsize, space);
+	return crypto_skcipher_decrypt(subreq);
+}
+
+static void crypto_cts_decrypt_done(struct crypto_async_request *areq, int err)
+{
+	struct skcipher_request *req = areq->data;
+
+	if (err)
+		goto out;
+
+	err = cts_cbc_decrypt(req);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return;
+
+out:
+	skcipher_request_complete(req, err);
+}
+
+static int crypto_cts_decrypt(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req);
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int bsize = crypto_skcipher_blocksize(tfm);
+	unsigned int nbytes = req->cryptlen;
+	int cbc_blocks = (nbytes + bsize - 1) / bsize - 1;
+	unsigned int offset;
+	u8 *space;
+
+	skcipher_request_set_tfm(subreq, ctx->child);
+
+	if (cbc_blocks <= 0) {
+		skcipher_request_set_callback(subreq, req->base.flags,
+					      req->base.complete,
+					      req->base.data);
+		skcipher_request_set_crypt(subreq, req->src, req->dst, nbytes,
+					   req->iv);
+		return crypto_skcipher_decrypt(subreq);
+	}
+
+	skcipher_request_set_callback(subreq, req->base.flags,
+				      crypto_cts_decrypt_done, req);
+
+	space = crypto_cts_reqctx_space(req);
+
+	offset = cbc_blocks * bsize;
+	rctx->offset = offset;
+
+	if (cbc_blocks <= 1)
+		memcpy(space, req->iv, bsize);
+	else
+		scatterwalk_map_and_copy(space, req->src, offset - 2 * bsize,
+					 bsize, 0);
+
+	skcipher_request_set_crypt(subreq, req->src, req->dst,
+				   offset, req->iv);
+
+	return crypto_skcipher_decrypt(subreq) ?:
+	       cts_cbc_decrypt(req);
+}
+
+static int crypto_cts_init_tfm(struct crypto_skcipher *tfm)
+{
+	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
+	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_skcipher *cipher;
+	unsigned reqsize;
+	unsigned bsize;
+	unsigned align;
+
+	cipher = crypto_spawn_skcipher(spawn);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	ctx->child = cipher;
+
+	align = crypto_skcipher_alignmask(tfm);
+	bsize = crypto_skcipher_blocksize(cipher);
+	reqsize = ALIGN(sizeof(struct crypto_cts_reqctx) +
+			crypto_skcipher_reqsize(cipher),
+			crypto_tfm_ctx_alignment()) +
+		  (align & ~(crypto_tfm_ctx_alignment() - 1)) + bsize;
+
+	crypto_skcipher_set_reqsize(tfm, reqsize);
+
+	return 0;
+}
+
+static void crypto_cts_exit_tfm(struct crypto_skcipher *tfm)
+{
+	struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+	crypto_free_skcipher(ctx->child);
+}
+
+static void crypto_cts_free(struct skcipher_instance *inst)
+{
+	crypto_drop_skcipher(skcipher_instance_ctx(inst));
+	kfree(inst);
+}
+
+static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct crypto_skcipher_spawn *spawn;
+	struct skcipher_instance *inst;
+	struct crypto_attr_type *algt;
+	struct skcipher_alg *alg;
+	const char *cipher_name;
+	int err;
+
+	algt = crypto_get_attr_type(tb);
+	if (IS_ERR(algt))
+		return PTR_ERR(algt);
+
+	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
+		return -EINVAL;
+
+	cipher_name = crypto_attr_alg_name(tb[1]);
+	if (IS_ERR(cipher_name))
+		return PTR_ERR(cipher_name);
+
+	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+	if (!inst)
+		return -ENOMEM;
+
+	spawn = skcipher_instance_ctx(inst);
+
+	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
+	err = crypto_grab_skcipher(spawn, cipher_name, 0,
+				   crypto_requires_sync(algt->type,
+							algt->mask));
+	if (err)
+		goto err_free_inst;
+
+	alg = crypto_spawn_skcipher_alg(spawn);
+
+	err = -EINVAL;
+	if (crypto_skcipher_alg_ivsize(alg) != alg->base.cra_blocksize)
+		goto err_drop_spawn;
+
+	if (strncmp(alg->base.cra_name, "cbc(", 4))
+		goto err_drop_spawn;
+
+	err = crypto_inst_setname(skcipher_crypto_instance(inst), "cts",
+				  &alg->base);
+	if (err)
+		goto err_drop_spawn;
+
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_priority = alg->base.cra_priority;
+	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
+	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
+
+	inst->alg.ivsize = alg->base.cra_blocksize;
+	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
+	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg);
+	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg);
+
+	inst->alg.base.cra_ctxsize = sizeof(struct crypto_cts_ctx);
+
+	inst->alg.init = crypto_cts_init_tfm;
+	inst->alg.exit = crypto_cts_exit_tfm;
+
+	inst->alg.setkey = crypto_cts_setkey;
+	inst->alg.encrypt = crypto_cts_encrypt;
+	inst->alg.decrypt = crypto_cts_decrypt;
+
+	inst->free = crypto_cts_free;
+
+	err = skcipher_register_instance(tmpl, inst);
+	if (err)
+		goto err_drop_spawn;
+
+out:
+	return err;
+
+err_drop_spawn:
+	crypto_drop_skcipher(spawn);
+err_free_inst:
+	kfree(inst);
+	goto out;
+}
+
+static struct crypto_template crypto_cts_tmpl = {
+	.name = "cts",
+	.create = crypto_cts_create,
+	.module = THIS_MODULE,
+};
+
+static int __init crypto_cts_module_init(void)
+{
+	return crypto_register_template(&crypto_cts_tmpl);
+}
+
+static void __exit crypto_cts_module_exit(void)
+{
+	crypto_unregister_template(&crypto_cts_tmpl);
+}
+
+module_init(crypto_cts_module_init);
+module_exit(crypto_cts_module_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("CTS-CBC CipherText Stealing for CBC");
+MODULE_ALIAS_CRYPTO("cts");