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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /crypto/xts.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'crypto/xts.c')
-rw-r--r--crypto/xts.c477
1 files changed, 477 insertions, 0 deletions
diff --git a/crypto/xts.c b/crypto/xts.c
new file mode 100644
index 000000000..1dc948745
--- /dev/null
+++ b/crypto/xts.c
@@ -0,0 +1,477 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* XTS: as defined in IEEE1619/D16
+ * http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
+ *
+ * Copyright (c) 2007 Rik Snel <rsnel@cube.dyndns.org>
+ *
+ * Based on ecb.c
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#include <crypto/internal/cipher.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/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <crypto/xts.h>
+#include <crypto/b128ops.h>
+#include <crypto/gf128mul.h>
+
+struct xts_tfm_ctx {
+ struct crypto_skcipher *child;
+ struct crypto_cipher *tweak;
+};
+
+struct xts_instance_ctx {
+ struct crypto_skcipher_spawn spawn;
+ struct crypto_cipher_spawn tweak_spawn;
+};
+
+struct xts_request_ctx {
+ le128 t;
+ struct scatterlist *tail;
+ struct scatterlist sg[2];
+ struct skcipher_request subreq;
+};
+
+static int xts_setkey(struct crypto_skcipher *parent, const u8 *key,
+ unsigned int keylen)
+{
+ struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(parent);
+ struct crypto_skcipher *child;
+ struct crypto_cipher *tweak;
+ int err;
+
+ err = xts_verify_key(parent, key, keylen);
+ if (err)
+ return err;
+
+ keylen /= 2;
+
+ /* we need two cipher instances: one to compute the initial 'tweak'
+ * by encrypting the IV (usually the 'plain' iv) and the other
+ * one to encrypt and decrypt the data */
+
+ /* tweak cipher, uses Key2 i.e. the second half of *key */
+ tweak = ctx->tweak;
+ crypto_cipher_clear_flags(tweak, CRYPTO_TFM_REQ_MASK);
+ crypto_cipher_set_flags(tweak, crypto_skcipher_get_flags(parent) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_cipher_setkey(tweak, key + keylen, keylen);
+ if (err)
+ return err;
+
+ /* data cipher, uses Key1 i.e. the first half of *key */
+ child = ctx->child;
+ crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
+ CRYPTO_TFM_REQ_MASK);
+ return crypto_skcipher_setkey(child, key, keylen);
+}
+
+/*
+ * We compute the tweak masks twice (both before and after the ECB encryption or
+ * decryption) to avoid having to allocate a temporary buffer and/or make
+ * multiple calls to the 'ecb(..)' instance, which usually would be slower than
+ * just doing the gf128mul_x_ble() calls again.
+ */
+static int xts_xor_tweak(struct skcipher_request *req, bool second_pass,
+ bool enc)
+{
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ const bool cts = (req->cryptlen % XTS_BLOCK_SIZE);
+ const int bs = XTS_BLOCK_SIZE;
+ struct skcipher_walk w;
+ le128 t = rctx->t;
+ int err;
+
+ if (second_pass) {
+ req = &rctx->subreq;
+ /* set to our TFM to enforce correct alignment: */
+ skcipher_request_set_tfm(req, tfm);
+ }
+ err = skcipher_walk_virt(&w, req, false);
+
+ while (w.nbytes) {
+ unsigned int avail = w.nbytes;
+ const le128 *wsrc;
+ le128 *wdst;
+
+ wsrc = w.src.virt.addr;
+ wdst = w.dst.virt.addr;
+
+ do {
+ if (unlikely(cts) &&
+ w.total - w.nbytes + avail < 2 * XTS_BLOCK_SIZE) {
+ if (!enc) {
+ if (second_pass)
+ rctx->t = t;
+ gf128mul_x_ble(&t, &t);
+ }
+ le128_xor(wdst, &t, wsrc);
+ if (enc && second_pass)
+ gf128mul_x_ble(&rctx->t, &t);
+ skcipher_walk_done(&w, avail - bs);
+ return 0;
+ }
+
+ le128_xor(wdst++, &t, wsrc++);
+ gf128mul_x_ble(&t, &t);
+ } while ((avail -= bs) >= bs);
+
+ err = skcipher_walk_done(&w, avail);
+ }
+
+ return err;
+}
+
+static int xts_xor_tweak_pre(struct skcipher_request *req, bool enc)
+{
+ return xts_xor_tweak(req, false, enc);
+}
+
+static int xts_xor_tweak_post(struct skcipher_request *req, bool enc)
+{
+ return xts_xor_tweak(req, true, enc);
+}
+
+static void xts_cts_done(void *data, int err)
+{
+ struct skcipher_request *req = data;
+ le128 b;
+
+ if (!err) {
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+
+ scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+ le128_xor(&b, &rctx->t, &b);
+ scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
+ }
+
+ skcipher_request_complete(req, err);
+}
+
+static int xts_cts_final(struct skcipher_request *req,
+ int (*crypt)(struct skcipher_request *req))
+{
+ const struct xts_tfm_ctx *ctx =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+ int offset = req->cryptlen & ~(XTS_BLOCK_SIZE - 1);
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq = &rctx->subreq;
+ int tail = req->cryptlen % XTS_BLOCK_SIZE;
+ le128 b[2];
+ int err;
+
+ rctx->tail = scatterwalk_ffwd(rctx->sg, req->dst,
+ offset - XTS_BLOCK_SIZE);
+
+ scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+ b[1] = b[0];
+ scatterwalk_map_and_copy(b, req->src, offset, tail, 0);
+
+ le128_xor(b, &rctx->t, b);
+
+ scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE + tail, 1);
+
+ skcipher_request_set_tfm(subreq, ctx->child);
+ skcipher_request_set_callback(subreq, req->base.flags, xts_cts_done,
+ req);
+ skcipher_request_set_crypt(subreq, rctx->tail, rctx->tail,
+ XTS_BLOCK_SIZE, NULL);
+
+ err = crypt(subreq);
+ if (err)
+ return err;
+
+ scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+ le128_xor(b, &rctx->t, b);
+ scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
+
+ return 0;
+}
+
+static void xts_encrypt_done(void *data, int err)
+{
+ struct skcipher_request *req = data;
+
+ if (!err) {
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+
+ rctx->subreq.base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+ err = xts_xor_tweak_post(req, true);
+
+ if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
+ err = xts_cts_final(req, crypto_skcipher_encrypt);
+ if (err == -EINPROGRESS || err == -EBUSY)
+ return;
+ }
+ }
+
+ skcipher_request_complete(req, err);
+}
+
+static void xts_decrypt_done(void *data, int err)
+{
+ struct skcipher_request *req = data;
+
+ if (!err) {
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+
+ rctx->subreq.base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+ err = xts_xor_tweak_post(req, false);
+
+ if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
+ err = xts_cts_final(req, crypto_skcipher_decrypt);
+ if (err == -EINPROGRESS || err == -EBUSY)
+ return;
+ }
+ }
+
+ skcipher_request_complete(req, err);
+}
+
+static int xts_init_crypt(struct skcipher_request *req,
+ crypto_completion_t compl)
+{
+ const struct xts_tfm_ctx *ctx =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq = &rctx->subreq;
+
+ if (req->cryptlen < XTS_BLOCK_SIZE)
+ return -EINVAL;
+
+ skcipher_request_set_tfm(subreq, ctx->child);
+ skcipher_request_set_callback(subreq, req->base.flags, compl, req);
+ skcipher_request_set_crypt(subreq, req->dst, req->dst,
+ req->cryptlen & ~(XTS_BLOCK_SIZE - 1), NULL);
+
+ /* calculate first value of T */
+ crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv);
+
+ return 0;
+}
+
+static int xts_encrypt(struct skcipher_request *req)
+{
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq = &rctx->subreq;
+ int err;
+
+ err = xts_init_crypt(req, xts_encrypt_done) ?:
+ xts_xor_tweak_pre(req, true) ?:
+ crypto_skcipher_encrypt(subreq) ?:
+ xts_xor_tweak_post(req, true);
+
+ if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
+ return err;
+
+ return xts_cts_final(req, crypto_skcipher_encrypt);
+}
+
+static int xts_decrypt(struct skcipher_request *req)
+{
+ struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq = &rctx->subreq;
+ int err;
+
+ err = xts_init_crypt(req, xts_decrypt_done) ?:
+ xts_xor_tweak_pre(req, false) ?:
+ crypto_skcipher_decrypt(subreq) ?:
+ xts_xor_tweak_post(req, false);
+
+ if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
+ return err;
+
+ return xts_cts_final(req, crypto_skcipher_decrypt);
+}
+
+static int xts_init_tfm(struct crypto_skcipher *tfm)
+{
+ struct skcipher_instance *inst = skcipher_alg_instance(tfm);
+ struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
+ struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_skcipher *child;
+ struct crypto_cipher *tweak;
+
+ child = crypto_spawn_skcipher(&ictx->spawn);
+ if (IS_ERR(child))
+ return PTR_ERR(child);
+
+ ctx->child = child;
+
+ tweak = crypto_spawn_cipher(&ictx->tweak_spawn);
+ if (IS_ERR(tweak)) {
+ crypto_free_skcipher(ctx->child);
+ return PTR_ERR(tweak);
+ }
+
+ ctx->tweak = tweak;
+
+ crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) +
+ sizeof(struct xts_request_ctx));
+
+ return 0;
+}
+
+static void xts_exit_tfm(struct crypto_skcipher *tfm)
+{
+ struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ crypto_free_skcipher(ctx->child);
+ crypto_free_cipher(ctx->tweak);
+}
+
+static void xts_free_instance(struct skcipher_instance *inst)
+{
+ struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
+
+ crypto_drop_skcipher(&ictx->spawn);
+ crypto_drop_cipher(&ictx->tweak_spawn);
+ kfree(inst);
+}
+
+static int xts_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+ struct skcipher_alg_common *alg;
+ char name[CRYPTO_MAX_ALG_NAME];
+ struct skcipher_instance *inst;
+ struct xts_instance_ctx *ctx;
+ const char *cipher_name;
+ u32 mask;
+ int err;
+
+ err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
+ if (err)
+ return err;
+
+ cipher_name = crypto_attr_alg_name(tb[1]);
+ if (IS_ERR(cipher_name))
+ return PTR_ERR(cipher_name);
+
+ inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+ if (!inst)
+ return -ENOMEM;
+
+ ctx = skcipher_instance_ctx(inst);
+
+ err = crypto_grab_skcipher(&ctx->spawn, skcipher_crypto_instance(inst),
+ cipher_name, 0, mask);
+ if (err == -ENOENT && memcmp(cipher_name, "ecb(", 4)) {
+ err = -ENAMETOOLONG;
+ if (snprintf(name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
+ cipher_name) >= CRYPTO_MAX_ALG_NAME)
+ goto err_free_inst;
+
+ err = crypto_grab_skcipher(&ctx->spawn,
+ skcipher_crypto_instance(inst),
+ name, 0, mask);
+ }
+
+ if (err)
+ goto err_free_inst;
+
+ alg = crypto_spawn_skcipher_alg_common(&ctx->spawn);
+
+ err = -EINVAL;
+ if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
+ goto err_free_inst;
+
+ if (alg->ivsize)
+ goto err_free_inst;
+
+ err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
+ &alg->base);
+ if (err)
+ goto err_free_inst;
+
+ err = -EINVAL;
+ cipher_name = alg->base.cra_name;
+
+ /* Alas we screwed up the naming so we have to mangle the
+ * cipher name.
+ */
+ if (!memcmp(cipher_name, "ecb(", 4)) {
+ int len;
+
+ len = strscpy(name, cipher_name + 4);
+ if (len < 2)
+ goto err_free_inst;
+
+ if (name[len - 1] != ')')
+ goto err_free_inst;
+
+ name[len - 1] = 0;
+
+ if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
+ "xts(%s)", name) >= CRYPTO_MAX_ALG_NAME) {
+ err = -ENAMETOOLONG;
+ goto err_free_inst;
+ }
+ } else
+ goto err_free_inst;
+
+ err = crypto_grab_cipher(&ctx->tweak_spawn,
+ skcipher_crypto_instance(inst), name, 0, mask);
+ if (err)
+ goto err_free_inst;
+
+ inst->alg.base.cra_priority = alg->base.cra_priority;
+ inst->alg.base.cra_blocksize = XTS_BLOCK_SIZE;
+ inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
+ (__alignof__(u64) - 1);
+
+ inst->alg.ivsize = XTS_BLOCK_SIZE;
+ inst->alg.min_keysize = alg->min_keysize * 2;
+ inst->alg.max_keysize = alg->max_keysize * 2;
+
+ inst->alg.base.cra_ctxsize = sizeof(struct xts_tfm_ctx);
+
+ inst->alg.init = xts_init_tfm;
+ inst->alg.exit = xts_exit_tfm;
+
+ inst->alg.setkey = xts_setkey;
+ inst->alg.encrypt = xts_encrypt;
+ inst->alg.decrypt = xts_decrypt;
+
+ inst->free = xts_free_instance;
+
+ err = skcipher_register_instance(tmpl, inst);
+ if (err) {
+err_free_inst:
+ xts_free_instance(inst);
+ }
+ return err;
+}
+
+static struct crypto_template xts_tmpl = {
+ .name = "xts",
+ .create = xts_create,
+ .module = THIS_MODULE,
+};
+
+static int __init xts_module_init(void)
+{
+ return crypto_register_template(&xts_tmpl);
+}
+
+static void __exit xts_module_exit(void)
+{
+ crypto_unregister_template(&xts_tmpl);
+}
+
+module_init(xts_module_init);
+module_exit(xts_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("XTS block cipher mode");
+MODULE_ALIAS_CRYPTO("xts");
+MODULE_IMPORT_NS("CRYPTO_INTERNAL");
+MODULE_SOFTDEP("pre: ecb");