* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
-#include <crypto/algapi.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
+#define XTS_BUFFER_SIZE 128u
+
struct priv {
- struct crypto_cipher *child;
+ struct crypto_skcipher *child;
struct crypto_cipher *tweak;
};
-static int setkey(struct crypto_tfm *parent, const u8 *key,
+struct xts_instance_ctx {
+ struct crypto_skcipher_spawn spawn;
+ char name[CRYPTO_MAX_ALG_NAME];
+};
+
+struct rctx {
+ be128 buf[XTS_BUFFER_SIZE / sizeof(be128)];
+
+ be128 t;
+
+ be128 *ext;
+
+ struct scatterlist srcbuf[2];
+ struct scatterlist dstbuf[2];
+ struct scatterlist *src;
+ struct scatterlist *dst;
+
+ unsigned int left;
+
+ struct skcipher_request subreq;
+};
+
+static int setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
{
- struct priv *ctx = crypto_tfm_ctx(parent);
- struct crypto_cipher *child = ctx->tweak;
+ struct priv *ctx = crypto_skcipher_ctx(parent);
+ struct crypto_skcipher *child;
+ struct crypto_cipher *tweak;
int err;
- err = xts_check_key(parent, key, keylen);
+ 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 */
- crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
- crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
+ 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(child, key + keylen/2, keylen/2);
+ err = crypto_cipher_setkey(tweak, key + keylen, keylen);
+ crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(tweak) &
+ CRYPTO_TFM_RES_MASK);
if (err)
return err;
- crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
- CRYPTO_TFM_RES_MASK);
-
+ /* 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);
+ err = crypto_skcipher_setkey(child, key, keylen);
+ crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
+ CRYPTO_TFM_RES_MASK);
- /* data cipher, uses Key1 i.e. the first half of *key */
- crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
- crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
- CRYPTO_TFM_REQ_MASK);
- err = crypto_cipher_setkey(child, key, keylen/2);
- if (err)
- return err;
+ return err;
+}
- crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
- CRYPTO_TFM_RES_MASK);
+static int post_crypt(struct skcipher_request *req)
+{
+ struct rctx *rctx = skcipher_request_ctx(req);
+ be128 *buf = rctx->ext ?: rctx->buf;
+ struct skcipher_request *subreq;
+ const int bs = XTS_BLOCK_SIZE;
+ struct skcipher_walk w;
+ struct scatterlist *sg;
+ unsigned offset;
+ int err;
- return 0;
-}
+ subreq = &rctx->subreq;
+ err = skcipher_walk_virt(&w, subreq, false);
-struct sinfo {
- be128 *t;
- struct crypto_tfm *tfm;
- void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
-};
+ while (w.nbytes) {
+ unsigned int avail = w.nbytes;
+ be128 *wdst;
-static inline void xts_round(struct sinfo *s, void *dst, const void *src)
-{
- be128_xor(dst, s->t, src); /* PP <- T xor P */
- s->fn(s->tfm, dst, dst); /* CC <- E(Key1,PP) */
- be128_xor(dst, dst, s->t); /* C <- T xor CC */
+ wdst = w.dst.virt.addr;
+
+ do {
+ be128_xor(wdst, buf++, wdst);
+ wdst++;
+ } while ((avail -= bs) >= bs);
+
+ err = skcipher_walk_done(&w, avail);
+ }
+
+ rctx->left -= subreq->cryptlen;
+
+ if (err || !rctx->left)
+ goto out;
+
+ rctx->dst = rctx->dstbuf;
+
+ scatterwalk_done(&w.out, 0, 1);
+ sg = w.out.sg;
+ offset = w.out.offset;
+
+ if (rctx->dst != sg) {
+ rctx->dst[0] = *sg;
+ sg_unmark_end(rctx->dst);
+ scatterwalk_crypto_chain(rctx->dst, sg_next(sg), 0, 2);
+ }
+ rctx->dst[0].length -= offset - sg->offset;
+ rctx->dst[0].offset = offset;
+
+out:
+ return err;
}
-static int crypt(struct blkcipher_desc *d,
- struct blkcipher_walk *w, struct priv *ctx,
- void (*tw)(struct crypto_tfm *, u8 *, const u8 *),
- void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
+static int pre_crypt(struct skcipher_request *req)
{
- int err;
- unsigned int avail;
+ struct rctx *rctx = skcipher_request_ctx(req);
+ be128 *buf = rctx->ext ?: rctx->buf;
+ struct skcipher_request *subreq;
const int bs = XTS_BLOCK_SIZE;
- struct sinfo s = {
- .tfm = crypto_cipher_tfm(ctx->child),
- .fn = fn
- };
- u8 *wsrc;
- u8 *wdst;
-
- err = blkcipher_walk_virt(d, w);
- if (!w->nbytes)
- return err;
+ struct skcipher_walk w;
+ struct scatterlist *sg;
+ unsigned cryptlen;
+ unsigned offset;
+ bool more;
+ int err;
- s.t = (be128 *)w->iv;
- avail = w->nbytes;
+ subreq = &rctx->subreq;
+ cryptlen = subreq->cryptlen;
- wsrc = w->src.virt.addr;
- wdst = w->dst.virt.addr;
+ more = rctx->left > cryptlen;
+ if (!more)
+ cryptlen = rctx->left;
- /* calculate first value of T */
- tw(crypto_cipher_tfm(ctx->tweak), w->iv, w->iv);
+ skcipher_request_set_crypt(subreq, rctx->src, rctx->dst,
+ cryptlen, NULL);
- goto first;
+ err = skcipher_walk_virt(&w, subreq, false);
- for (;;) {
- do {
- gf128mul_x_ble(s.t, s.t);
+ while (w.nbytes) {
+ unsigned int avail = w.nbytes;
+ be128 *wsrc;
+ be128 *wdst;
-first:
- xts_round(&s, wdst, wsrc);
+ wsrc = w.src.virt.addr;
+ wdst = w.dst.virt.addr;
- wsrc += bs;
- wdst += bs;
+ do {
+ *buf++ = rctx->t;
+ be128_xor(wdst++, &rctx->t, wsrc++);
+ gf128mul_x_ble(&rctx->t, &rctx->t);
} while ((avail -= bs) >= bs);
- err = blkcipher_walk_done(d, w, avail);
- if (!w->nbytes)
- break;
+ err = skcipher_walk_done(&w, avail);
+ }
+
+ skcipher_request_set_crypt(subreq, rctx->dst, rctx->dst,
+ cryptlen, NULL);
- avail = w->nbytes;
+ if (err || !more)
+ goto out;
- wsrc = w->src.virt.addr;
- wdst = w->dst.virt.addr;
+ rctx->src = rctx->srcbuf;
+
+ scatterwalk_done(&w.in, 0, 1);
+ sg = w.in.sg;
+ offset = w.in.offset;
+
+ if (rctx->src != sg) {
+ rctx->src[0] = *sg;
+ sg_unmark_end(rctx->src);
+ scatterwalk_crypto_chain(rctx->src, sg_next(sg), 0, 2);
}
+ rctx->src[0].length -= offset - sg->offset;
+ rctx->src[0].offset = offset;
+out:
return err;
}
-static int encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
- struct scatterlist *src, unsigned int nbytes)
+static int init_crypt(struct skcipher_request *req, crypto_completion_t done)
{
- struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
- struct blkcipher_walk w;
+ struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+ struct rctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq;
+ gfp_t gfp;
+
+ subreq = &rctx->subreq;
+ skcipher_request_set_tfm(subreq, ctx->child);
+ skcipher_request_set_callback(subreq, req->base.flags, done, req);
+
+ gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
+ GFP_ATOMIC;
+ rctx->ext = NULL;
+
+ subreq->cryptlen = XTS_BUFFER_SIZE;
+ if (req->cryptlen > XTS_BUFFER_SIZE) {
+ subreq->cryptlen = min(req->cryptlen, (unsigned)PAGE_SIZE);
+ rctx->ext = kmalloc(subreq->cryptlen, gfp);
+ }
+
+ rctx->src = req->src;
+ rctx->dst = req->dst;
+ rctx->left = req->cryptlen;
- blkcipher_walk_init(&w, dst, src, nbytes);
- return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
- crypto_cipher_alg(ctx->child)->cia_encrypt);
+ /* calculate first value of T */
+ crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv);
+
+ return 0;
}
-static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
- struct scatterlist *src, unsigned int nbytes)
+static void exit_crypt(struct skcipher_request *req)
{
- struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
- struct blkcipher_walk w;
+ struct rctx *rctx = skcipher_request_ctx(req);
+
+ rctx->left = 0;
- blkcipher_walk_init(&w, dst, src, nbytes);
- return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
- crypto_cipher_alg(ctx->child)->cia_decrypt);
+ if (rctx->ext)
+ kzfree(rctx->ext);
+}
+
+static int do_encrypt(struct skcipher_request *req, int err)
+{
+ struct rctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq;
+
+ subreq = &rctx->subreq;
+
+ while (!err && rctx->left) {
+ err = pre_crypt(req) ?:
+ crypto_skcipher_encrypt(subreq) ?:
+ post_crypt(req);
+
+ if (err == -EINPROGRESS ||
+ (err == -EBUSY &&
+ req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
+ return err;
+ }
+
+ exit_crypt(req);
+ return err;
+}
+
+static void encrypt_done(struct crypto_async_request *areq, int err)
+{
+ struct skcipher_request *req = areq->data;
+ struct skcipher_request *subreq;
+ struct rctx *rctx;
+
+ rctx = skcipher_request_ctx(req);
+ subreq = &rctx->subreq;
+ subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+
+ err = do_encrypt(req, err ?: post_crypt(req));
+ if (rctx->left)
+ return;
+
+ skcipher_request_complete(req, err);
+}
+
+static int encrypt(struct skcipher_request *req)
+{
+ return do_encrypt(req, init_crypt(req, encrypt_done));
+}
+
+static int do_decrypt(struct skcipher_request *req, int err)
+{
+ struct rctx *rctx = skcipher_request_ctx(req);
+ struct skcipher_request *subreq;
+
+ subreq = &rctx->subreq;
+
+ while (!err && rctx->left) {
+ err = pre_crypt(req) ?:
+ crypto_skcipher_decrypt(subreq) ?:
+ post_crypt(req);
+
+ if (err == -EINPROGRESS ||
+ (err == -EBUSY &&
+ req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
+ return err;
+ }
+
+ exit_crypt(req);
+ return err;
+}
+
+static void decrypt_done(struct crypto_async_request *areq, int err)
+{
+ struct skcipher_request *req = areq->data;
+ struct skcipher_request *subreq;
+ struct rctx *rctx;
+
+ rctx = skcipher_request_ctx(req);
+ subreq = &rctx->subreq;
+ subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+
+ err = do_decrypt(req, err ?: post_crypt(req));
+ if (rctx->left)
+ return;
+
+ skcipher_request_complete(req, err);
+}
+
+static int decrypt(struct skcipher_request *req)
+{
+ return do_decrypt(req, init_crypt(req, decrypt_done));
}
int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
}
EXPORT_SYMBOL_GPL(xts_crypt);
-static int init_tfm(struct crypto_tfm *tfm)
+static int init_tfm(struct crypto_skcipher *tfm)
{
- struct crypto_cipher *cipher;
- struct crypto_instance *inst = (void *)tfm->__crt_alg;
- struct crypto_spawn *spawn = crypto_instance_ctx(inst);
- struct priv *ctx = crypto_tfm_ctx(tfm);
- u32 *flags = &tfm->crt_flags;
-
- cipher = crypto_spawn_cipher(spawn);
- if (IS_ERR(cipher))
- return PTR_ERR(cipher);
-
- if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
- *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
- crypto_free_cipher(cipher);
- return -EINVAL;
- }
+ struct skcipher_instance *inst = skcipher_alg_instance(tfm);
+ struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
+ struct priv *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_skcipher *child;
+ struct crypto_cipher *tweak;
- ctx->child = cipher;
+ child = crypto_spawn_skcipher(&ictx->spawn);
+ if (IS_ERR(child))
+ return PTR_ERR(child);
- cipher = crypto_spawn_cipher(spawn);
- if (IS_ERR(cipher)) {
- crypto_free_cipher(ctx->child);
- return PTR_ERR(cipher);
- }
+ ctx->child = child;
- /* this check isn't really needed, leave it here just in case */
- if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
- crypto_free_cipher(cipher);
- crypto_free_cipher(ctx->child);
- *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
- return -EINVAL;
+ tweak = crypto_alloc_cipher(ictx->name, 0, 0);
+ if (IS_ERR(tweak)) {
+ crypto_free_skcipher(ctx->child);
+ return PTR_ERR(tweak);
}
- ctx->tweak = cipher;
+ ctx->tweak = tweak;
+
+ crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) +
+ sizeof(struct rctx));
return 0;
}
-static void exit_tfm(struct crypto_tfm *tfm)
+static void exit_tfm(struct crypto_skcipher *tfm)
{
- struct priv *ctx = crypto_tfm_ctx(tfm);
- crypto_free_cipher(ctx->child);
+ struct priv *ctx = crypto_skcipher_ctx(tfm);
+
+ crypto_free_skcipher(ctx->child);
crypto_free_cipher(ctx->tweak);
}
-static struct crypto_instance *alloc(struct rtattr **tb)
+static void free(struct skcipher_instance *inst)
+{
+ crypto_drop_skcipher(skcipher_instance_ctx(inst));
+ kfree(inst);
+}
+
+static int create(struct crypto_template *tmpl, struct rtattr **tb)
{
- struct crypto_instance *inst;
- struct crypto_alg *alg;
+ struct skcipher_instance *inst;
+ struct crypto_attr_type *algt;
+ struct xts_instance_ctx *ctx;
+ struct skcipher_alg *alg;
+ const char *cipher_name;
int err;
- err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
+ 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(*ctx), GFP_KERNEL);
+ if (!inst)
+ return -ENOMEM;
+
+ ctx = skcipher_instance_ctx(inst);
+
+ crypto_set_skcipher_spawn(&ctx->spawn, skcipher_crypto_instance(inst));
+ err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0,
+ crypto_requires_sync(algt->type,
+ algt->mask));
+ if (err == -ENOENT) {
+ err = -ENAMETOOLONG;
+ if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
+ cipher_name) >= CRYPTO_MAX_ALG_NAME)
+ goto err_free_inst;
+
+ err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0,
+ crypto_requires_sync(algt->type,
+ algt->mask));
+ }
+
if (err)
- return ERR_PTR(err);
+ goto err_free_inst;
- alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
- CRYPTO_ALG_TYPE_MASK);
- if (IS_ERR(alg))
- return ERR_CAST(alg);
+ alg = crypto_skcipher_spawn_alg(&ctx->spawn);
- inst = crypto_alloc_instance("xts", alg);
- if (IS_ERR(inst))
- goto out_put_alg;
+ err = -EINVAL;
+ if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
+ goto err_drop_spawn;
- inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
- inst->alg.cra_priority = alg->cra_priority;
- inst->alg.cra_blocksize = alg->cra_blocksize;
+ if (crypto_skcipher_alg_ivsize(alg))
+ goto err_drop_spawn;
- if (alg->cra_alignmask < 7)
- inst->alg.cra_alignmask = 7;
- else
- inst->alg.cra_alignmask = alg->cra_alignmask;
+ err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
+ &alg->base);
+ if (err)
+ goto err_drop_spawn;
- inst->alg.cra_type = &crypto_blkcipher_type;
+ err = -EINVAL;
+ cipher_name = alg->base.cra_name;
- inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
- inst->alg.cra_blkcipher.min_keysize =
- 2 * alg->cra_cipher.cia_min_keysize;
- inst->alg.cra_blkcipher.max_keysize =
- 2 * alg->cra_cipher.cia_max_keysize;
+ /* Alas we screwed up the naming so we have to mangle the
+ * cipher name.
+ */
+ if (!strncmp(cipher_name, "ecb(", 4)) {
+ unsigned len;
- inst->alg.cra_ctxsize = sizeof(struct priv);
+ len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
+ if (len < 2 || len >= sizeof(ctx->name))
+ goto err_drop_spawn;
- inst->alg.cra_init = init_tfm;
- inst->alg.cra_exit = exit_tfm;
+ if (ctx->name[len - 1] != ')')
+ goto err_drop_spawn;
- inst->alg.cra_blkcipher.setkey = setkey;
- inst->alg.cra_blkcipher.encrypt = encrypt;
- inst->alg.cra_blkcipher.decrypt = decrypt;
+ ctx->name[len - 1] = 0;
-out_put_alg:
- crypto_mod_put(alg);
- return inst;
-}
+ if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
+ "xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME)
+ return -ENAMETOOLONG;
+ } else
+ goto err_drop_spawn;
-static void free(struct crypto_instance *inst)
-{
- crypto_drop_spawn(crypto_instance_ctx(inst));
+ 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 = 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 = crypto_skcipher_alg_min_keysize(alg) * 2;
+ inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) * 2;
+
+ inst->alg.base.cra_ctxsize = sizeof(struct priv);
+
+ inst->alg.init = init_tfm;
+ inst->alg.exit = exit_tfm;
+
+ inst->alg.setkey = setkey;
+ inst->alg.encrypt = encrypt;
+ inst->alg.decrypt = decrypt;
+
+ inst->free = free;
+
+ err = skcipher_register_instance(tmpl, inst);
+ if (err)
+ goto err_drop_spawn;
+
+out:
+ return err;
+
+err_drop_spawn:
+ crypto_drop_skcipher(&ctx->spawn);
+err_free_inst:
kfree(inst);
+ goto out;
}
static struct crypto_template crypto_tmpl = {
.name = "xts",
- .alloc = alloc,
- .free = free,
+ .create = create,
.module = THIS_MODULE,
};
projects / mirror_ubuntu-artful-kernel.git / blobdiff