Quelle adiantum.c Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
* Adiantum length-preserving encryption mode
*
* Copyright 2018 Google LLC
*/

/*
* Adiantum is a tweakable, length-preserving encryption mode designed for fast
* and secure disk encryption, especially on CPUs without dedicated crypto
* instructions.  Adiantum encrypts each sector using the XChaCha12 stream
* cipher, two passes of an ε-almost-∆-universal (ε-∆U) hash function based on
* NH and Poly1305, and an invocation of the AES-256 block cipher on a single
* 16-byte block.  See the paper for details:
*
* Adiantum: length-preserving encryption for entry-level processors
*      (https://eprint.iacr.org/2018/720.pdf)
*
* For flexibility, this implementation also allows other ciphers:
*
* - Stream cipher: XChaCha12 or XChaCha20
* - Block cipher: any with a 128-bit block size and 256-bit key
*
* This implementation doesn't currently allow other ε-∆U hash functions, i.e.
* HPolyC is not supported.  This is because Adiantum is ~20% faster than HPolyC
* but still provably as secure, and also the ε-∆U hash function of HBSH is
* formally defined to take two inputs (tweak, message) which makes it difficult
* to wrap with the crypto_shash API.  Rather, some details need to be handled
* here.  Nevertheless, if needed in the future, support for other ε-∆U hash
* functions could be added here.
*/

#include <crypto/b128ops.h>
#include <crypto/chacha.h>
#include <crypto/internal/cipher.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/poly1305.h>
#include <crypto/internal/skcipher.h>
#include <crypto/nhpoly1305.h>
#include <crypto/scatterwalk.h>
#include <linux/module.h>

/*
* Size of right-hand part of input data, in bytes; also the size of the block
* cipher's block size and the hash function's output.
*/
#define BLOCKCIPHER_BLOCK_SIZE  16

/* Size of the block cipher key (K_E) in bytes */
#define BLOCKCIPHER_KEY_SIZE  32

/* Size of the hash key (K_H) in bytes */
#define HASH_KEY_SIZE  (POLY1305_BLOCK_SIZE + NHPOLY1305_KEY_SIZE)

/*
* The specification allows variable-length tweaks, but Linux's crypto API
* currently only allows algorithms to support a single length.  The "natural"
* tweak length for Adiantum is 16, since that fits into one Poly1305 block for
* the best performance.  But longer tweaks are useful for fscrypt, to avoid
* needing to derive per-file keys.  So instead we use two blocks, or 32 bytes.
*/
#define TWEAK_SIZE  32

struct adiantum_instance_ctx {
struct crypto_skcipher_spawn streamcipher_spawn;
struct crypto_cipher_spawn blockcipher_spawn;
struct crypto_shash_spawn hash_spawn;
};

struct adiantum_tfm_ctx {
struct crypto_skcipher *streamcipher;
struct crypto_cipher *blockcipher;
struct crypto_shash *hash;
struct poly1305_core_key header_hash_key;
};

struct adiantum_request_ctx {

/*
* Buffer for right-hand part of data, i.e.
*
*    P_L => P_M => C_M => C_R when encrypting, or
*    C_R => C_M => P_M => P_L when decrypting.
*
* Also used to build the IV for the stream cipher.
*/
union {
  u8 bytes[XCHACHA_IV_SIZE];
  __le32 words[XCHACHA_IV_SIZE / sizeof(__le32)];
  le128 bignum; /* interpret as element of Z/(2^{128}Z) */
} rbuf;

bool enc; /* true if encrypting, false if decrypting */

/*
* The result of the Poly1305 ε-∆U hash function applied to
* (bulk length, tweak)
*/
le128 header_hash;

/* Sub-requests, must be last */
union {
  struct shash_desc hash_desc;
  struct skcipher_request streamcipher_req;
} u;
};

/*
* Given the XChaCha stream key K_S, derive the block cipher key K_E and the
* hash key K_H as follows:
*
*     K_E || K_H || ... = XChaCha(key=K_S, nonce=1||0^191)
*
* Note that this denotes using bits from the XChaCha keystream, which here we
* get indirectly by encrypting a buffer containing all 0's.
*/
static int adiantum_setkey(struct crypto_skcipher *tfm, const u8 *key,
      unsigned int keylen)
{
struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
struct {
  u8 iv[XCHACHA_IV_SIZE];
  u8 derived_keys[BLOCKCIPHER_KEY_SIZE + HASH_KEY_SIZE];
  struct scatterlist sg;
  struct crypto_wait wait;
  struct skcipher_request req; /* must be last */
} *data;
u8 *keyp;
int err;

/* Set the stream cipher key (K_S) */
crypto_skcipher_clear_flags(tctx->streamcipher, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(tctx->streamcipher,
      crypto_skcipher_get_flags(tfm) &
      CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(tctx->streamcipher, key, keylen);
if (err)
  return err;

/* Derive the subkeys */
data = kzalloc(sizeof(*data) +
         crypto_skcipher_reqsize(tctx->streamcipher), GFP_KERNEL);
if (!data)
  return -ENOMEM;
data->iv[0] = 1;
sg_init_one(&data->sg, data->derived_keys, sizeof(data->derived_keys));
crypto_init_wait(&data->wait);
skcipher_request_set_tfm(&data->req, tctx->streamcipher);
skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
        CRYPTO_TFM_REQ_MAY_BACKLOG,
          crypto_req_done, &data->wait);
skcipher_request_set_crypt(&data->req, &data->sg, &data->sg,
       sizeof(data->derived_keys), data->iv);
err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), &data->wait);
if (err)
  goto out;
keyp = data->derived_keys;

/* Set the block cipher key (K_E) */
crypto_cipher_clear_flags(tctx->blockcipher, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(tctx->blockcipher,
    crypto_skcipher_get_flags(tfm) &
    CRYPTO_TFM_REQ_MASK);
err = crypto_cipher_setkey(tctx->blockcipher, keyp,
       BLOCKCIPHER_KEY_SIZE);
if (err)
  goto out;
keyp += BLOCKCIPHER_KEY_SIZE;

/* Set the hash key (K_H) */
poly1305_core_setkey(&tctx->header_hash_key, keyp);
keyp += POLY1305_BLOCK_SIZE;

crypto_shash_clear_flags(tctx->hash, CRYPTO_TFM_REQ_MASK);
crypto_shash_set_flags(tctx->hash, crypto_skcipher_get_flags(tfm) &
        CRYPTO_TFM_REQ_MASK);
err = crypto_shash_setkey(tctx->hash, keyp, NHPOLY1305_KEY_SIZE);
keyp += NHPOLY1305_KEY_SIZE;
WARN_ON(keyp != &data->derived_keys[ARRAY_SIZE(data->derived_keys)]);
out:
kfree_sensitive(data);
return err;
}

/* Addition in Z/(2^{128}Z) */
static inline void le128_add(le128 *r, const le128 *v1, const le128 *v2)
{
u64 x = le64_to_cpu(v1->b);
u64 y = le64_to_cpu(v2->b);

r->b = cpu_to_le64(x + y);
r->a = cpu_to_le64(le64_to_cpu(v1->a) + le64_to_cpu(v2->a) +
      (x + y < x));
}

/* Subtraction in Z/(2^{128}Z) */
static inline void le128_sub(le128 *r, const le128 *v1, const le128 *v2)
{
u64 x = le64_to_cpu(v1->b);
u64 y = le64_to_cpu(v2->b);

r->b = cpu_to_le64(x - y);
r->a = cpu_to_le64(le64_to_cpu(v1->a) - le64_to_cpu(v2->a) -
      (x - y > x));
}

/*
* Apply the Poly1305 ε-∆U hash function to (bulk length, tweak) and save the
* result to rctx->header_hash.  This is the calculation
*
* H_T ← Poly1305_{K_T}(bin_{128}(|L|) || T)
*
* from the procedure in section 6.4 of the Adiantum paper.  The resulting value
* is reused in both the first and second hash steps.  Specifically, it's added
* to the result of an independently keyed ε-∆U hash function (for equal length
* inputs only) taken over the left-hand part (the "bulk") of the message, to
* give the overall Adiantum hash of the (tweak, left-hand part) pair.
*/
static void adiantum_hash_header(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
struct {
  __le64 message_bits;
  __le64 padding;
} header = {
  .message_bits = cpu_to_le64((u64)bulk_len * 8)
};
struct poly1305_state state;

poly1305_core_init(&state);

BUILD_BUG_ON(sizeof(header) % POLY1305_BLOCK_SIZE != 0);
poly1305_core_blocks(&state, &tctx->header_hash_key,
        &header, sizeof(header) / POLY1305_BLOCK_SIZE, 1);

BUILD_BUG_ON(TWEAK_SIZE % POLY1305_BLOCK_SIZE != 0);
poly1305_core_blocks(&state, &tctx->header_hash_key, req->iv,
        TWEAK_SIZE / POLY1305_BLOCK_SIZE, 1);

poly1305_core_emit(&state, NULL, &rctx->header_hash);
}

/* Hash the left-hand part (the "bulk") of the message using NHPoly1305 */
static int adiantum_hash_message(struct skcipher_request *req,
     struct scatterlist *sgl, unsigned int nents,
     le128 *digest)
{
struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
struct shash_desc *hash_desc = &rctx->u.hash_desc;
struct sg_mapping_iter miter;
unsigned int i, n;
int err;

err = crypto_shash_init(hash_desc);
if (err)
  return err;

sg_miter_start(&miter, sgl, nents, SG_MITER_FROM_SG | SG_MITER_ATOMIC);
for (i = 0; i < bulk_len; i += n) {
  sg_miter_next(&miter);
  n = min_t(unsigned int, miter.length, bulk_len - i);
  err = crypto_shash_update(hash_desc, miter.addr, n);
  if (err)
   break;
}
sg_miter_stop(&miter);
if (err)
  return err;

return crypto_shash_final(hash_desc, (u8 *)digest);
}

/* Continue Adiantum encryption/decryption after the stream cipher step */
static int adiantum_finish(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
struct scatterlist *dst = req->dst;
const unsigned int dst_nents = sg_nents(dst);
le128 digest;
int err;

/* If decrypting, decrypt C_M with the block cipher to get P_M */
if (!rctx->enc)
  crypto_cipher_decrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
       rctx->rbuf.bytes);

/*
* Second hash step
* enc: C_R = C_M - H_{K_H}(T, C_L)
* dec: P_R = P_M - H_{K_H}(T, P_L)
*/
rctx->u.hash_desc.tfm = tctx->hash;
le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &rctx->header_hash);
if (dst_nents == 1 && dst->offset + req->cryptlen <= PAGE_SIZE) {
  /* Fast path for single-page destination */
  struct page *page = sg_page(dst);
  void *virt = kmap_local_page(page) + dst->offset;

  err = crypto_shash_digest(&rctx->u.hash_desc, virt, bulk_len,
       (u8 *)&digest);
  if (err) {
   kunmap_local(virt);
   return err;
  }
  le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
  memcpy(virt + bulk_len, &rctx->rbuf.bignum, sizeof(le128));
  flush_dcache_page(page);
  kunmap_local(virt);
} else {
  /* Slow path that works for any destination scatterlist */
  err = adiantum_hash_message(req, dst, dst_nents, &digest);
  if (err)
   return err;
  le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
  scatterwalk_map_and_copy(&rctx->rbuf.bignum, dst,
      bulk_len, sizeof(le128), 1);
}
return 0;
}

static void adiantum_streamcipher_done(void *data, int err)
{
struct skcipher_request *req = data;

if (!err)
  err = adiantum_finish(req);

skcipher_request_complete(req, err);
}

static int adiantum_crypt(struct skcipher_request *req, bool enc)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
struct scatterlist *src = req->src;
const unsigned int src_nents = sg_nents(src);
unsigned int stream_len;
le128 digest;
int err;

if (req->cryptlen < BLOCKCIPHER_BLOCK_SIZE)
  return -EINVAL;

rctx->enc = enc;

/*
* First hash step
* enc: P_M = P_R + H_{K_H}(T, P_L)
* dec: C_M = C_R + H_{K_H}(T, C_L)
*/
adiantum_hash_header(req);
rctx->u.hash_desc.tfm = tctx->hash;
if (src_nents == 1 && src->offset + req->cryptlen <= PAGE_SIZE) {
  /* Fast path for single-page source */
  void *virt = kmap_local_page(sg_page(src)) + src->offset;

  err = crypto_shash_digest(&rctx->u.hash_desc, virt, bulk_len,
       (u8 *)&digest);
  memcpy(&rctx->rbuf.bignum, virt + bulk_len, sizeof(le128));
  kunmap_local(virt);
} else {
  /* Slow path that works for any source scatterlist */
  err = adiantum_hash_message(req, src, src_nents, &digest);
  scatterwalk_map_and_copy(&rctx->rbuf.bignum, src,
      bulk_len, sizeof(le128), 0);
}
if (err)
  return err;
le128_add(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &rctx->header_hash);
le128_add(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);

/* If encrypting, encrypt P_M with the block cipher to get C_M */
if (enc)
  crypto_cipher_encrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
       rctx->rbuf.bytes);

/* Initialize the rest of the XChaCha IV (first part is C_M) */
BUILD_BUG_ON(BLOCKCIPHER_BLOCK_SIZE != 16);
BUILD_BUG_ON(XCHACHA_IV_SIZE != 32); /* nonce || stream position */
rctx->rbuf.words[4] = cpu_to_le32(1);
rctx->rbuf.words[5] = 0;
rctx->rbuf.words[6] = 0;
rctx->rbuf.words[7] = 0;

/*
* XChaCha needs to be done on all the data except the last 16 bytes;
* for disk encryption that usually means 4080 or 496 bytes.  But ChaCha
* implementations tend to be most efficient when passed a whole number
* of 64-byte ChaCha blocks, or sometimes even a multiple of 256 bytes.
* And here it doesn't matter whether the last 16 bytes are written to,
* as the second hash step will overwrite them.  Thus, round the XChaCha
* length up to the next 64-byte boundary if possible.
*/
stream_len = bulk_len;
if (round_up(stream_len, CHACHA_BLOCK_SIZE) <= req->cryptlen)
  stream_len = round_up(stream_len, CHACHA_BLOCK_SIZE);

skcipher_request_set_tfm(&rctx->u.streamcipher_req, tctx->streamcipher);
skcipher_request_set_crypt(&rctx->u.streamcipher_req, req->src,
       req->dst, stream_len, &rctx->rbuf);
skcipher_request_set_callback(&rctx->u.streamcipher_req,
          req->base.flags,
          adiantum_streamcipher_done, req);
return crypto_skcipher_encrypt(&rctx->u.streamcipher_req) ?:
  adiantum_finish(req);
}

static int adiantum_encrypt(struct skcipher_request *req)
{
return adiantum_crypt(req, true);
}

static int adiantum_decrypt(struct skcipher_request *req)
{
return adiantum_crypt(req, false);
}

static int adiantum_init_tfm(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct adiantum_instance_ctx *ictx = skcipher_instance_ctx(inst);
struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *streamcipher;
struct crypto_cipher *blockcipher;
struct crypto_shash *hash;
unsigned int subreq_size;
int err;

streamcipher = crypto_spawn_skcipher(&ictx->streamcipher_spawn);
if (IS_ERR(streamcipher))
  return PTR_ERR(streamcipher);

blockcipher = crypto_spawn_cipher(&ictx->blockcipher_spawn);
if (IS_ERR(blockcipher)) {
  err = PTR_ERR(blockcipher);
  goto err_free_streamcipher;
}

hash = crypto_spawn_shash(&ictx->hash_spawn);
if (IS_ERR(hash)) {
  err = PTR_ERR(hash);
  goto err_free_blockcipher;
}

tctx->streamcipher = streamcipher;
tctx->blockcipher = blockcipher;
tctx->hash = hash;

BUILD_BUG_ON(offsetofend(struct adiantum_request_ctx, u) !=
       sizeof(struct adiantum_request_ctx));
subreq_size = max(sizeof_field(struct adiantum_request_ctx,
           u.hash_desc) +
     crypto_shash_descsize(hash),
     sizeof_field(struct adiantum_request_ctx,
           u.streamcipher_req) +
     crypto_skcipher_reqsize(streamcipher));

crypto_skcipher_set_reqsize(tfm,
        offsetof(struct adiantum_request_ctx, u) +
        subreq_size);
return 0;

err_free_blockcipher:
crypto_free_cipher(blockcipher);
err_free_streamcipher:
crypto_free_skcipher(streamcipher);
return err;
}

static void adiantum_exit_tfm(struct crypto_skcipher *tfm)
{
struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);

crypto_free_skcipher(tctx->streamcipher);
crypto_free_cipher(tctx->blockcipher);
crypto_free_shash(tctx->hash);
}

static void adiantum_free_instance(struct skcipher_instance *inst)
{
struct adiantum_instance_ctx *ictx = skcipher_instance_ctx(inst);

crypto_drop_skcipher(&ictx->streamcipher_spawn);
crypto_drop_cipher(&ictx->blockcipher_spawn);
crypto_drop_shash(&ictx->hash_spawn);
kfree(inst);
}

/*
* Check for a supported set of inner algorithms.
* See the comment at the beginning of this file.
*/
static bool adiantum_supported_algorithms(struct skcipher_alg_common *streamcipher_alg,
       struct crypto_alg *blockcipher_alg,
       struct shash_alg *hash_alg)
{
if (strcmp(streamcipher_alg->base.cra_name, "xchacha12") != 0 &&
     strcmp(streamcipher_alg->base.cra_name, "xchacha20") != 0)
  return false;

if (blockcipher_alg->cra_cipher.cia_min_keysize > BLOCKCIPHER_KEY_SIZE ||
     blockcipher_alg->cra_cipher.cia_max_keysize < BLOCKCIPHER_KEY_SIZE)
  return false;
if (blockcipher_alg->cra_blocksize != BLOCKCIPHER_BLOCK_SIZE)
  return false;

if (strcmp(hash_alg->base.cra_name, "nhpoly1305") != 0)
  return false;

return true;
}

static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
{
u32 mask;
const char *nhpoly1305_name;
struct skcipher_instance *inst;
struct adiantum_instance_ctx *ictx;
struct skcipher_alg_common *streamcipher_alg;
struct crypto_alg *blockcipher_alg;
struct shash_alg *hash_alg;
int err;

err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
if (err)
  return err;

inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
if (!inst)
  return -ENOMEM;
ictx = skcipher_instance_ctx(inst);

/* Stream cipher, e.g. "xchacha12" */
err = crypto_grab_skcipher(&ictx->streamcipher_spawn,
       skcipher_crypto_instance(inst),
       crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
  goto err_free_inst;
streamcipher_alg = crypto_spawn_skcipher_alg_common(&ictx->streamcipher_spawn);

/* Block cipher, e.g. "aes" */
err = crypto_grab_cipher(&ictx->blockcipher_spawn,
     skcipher_crypto_instance(inst),
     crypto_attr_alg_name(tb[2]), 0, mask);
if (err)
  goto err_free_inst;
blockcipher_alg = crypto_spawn_cipher_alg(&ictx->blockcipher_spawn);

/* NHPoly1305 ε-∆U hash function */
nhpoly1305_name = crypto_attr_alg_name(tb[3]);
if (nhpoly1305_name == ERR_PTR(-ENOENT))
  nhpoly1305_name = "nhpoly1305";
err = crypto_grab_shash(&ictx->hash_spawn,
    skcipher_crypto_instance(inst),
    nhpoly1305_name, 0, mask);
if (err)
  goto err_free_inst;
hash_alg = crypto_spawn_shash_alg(&ictx->hash_spawn);

/* Check the set of algorithms */
if (!adiantum_supported_algorithms(streamcipher_alg, blockcipher_alg,
        hash_alg)) {
  pr_warn("Unsupported Adiantum instantiation: (%s,%s,%s)\n",
   streamcipher_alg->base.cra_name,
   blockcipher_alg->cra_name, hash_alg->base.cra_name);
  err = -EINVAL;
  goto err_free_inst;
}

/* Instance fields */

err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
       "adiantum(%s,%s)", streamcipher_alg->base.cra_name,
       blockcipher_alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
  goto err_free_inst;
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
       "adiantum(%s,%s,%s)",
       streamcipher_alg->base.cra_driver_name,
       blockcipher_alg->cra_driver_name,
       hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
  goto err_free_inst;

inst->alg.base.cra_blocksize = BLOCKCIPHER_BLOCK_SIZE;
inst->alg.base.cra_ctxsize = sizeof(struct adiantum_tfm_ctx);
inst->alg.base.cra_alignmask = streamcipher_alg->base.cra_alignmask;
/*
* The block cipher is only invoked once per message, so for long
* messages (e.g. sectors for disk encryption) its performance doesn't
* matter as much as that of the stream cipher and hash function.  Thus,
* weigh the block cipher's ->cra_priority less.
*/
inst->alg.base.cra_priority = (4 * streamcipher_alg->base.cra_priority +
           2 * hash_alg->base.cra_priority +
           blockcipher_alg->cra_priority) / 7;

inst->alg.setkey = adiantum_setkey;
inst->alg.encrypt = adiantum_encrypt;
inst->alg.decrypt = adiantum_decrypt;
inst->alg.init = adiantum_init_tfm;
inst->alg.exit = adiantum_exit_tfm;
inst->alg.min_keysize = streamcipher_alg->min_keysize;
inst->alg.max_keysize = streamcipher_alg->max_keysize;
inst->alg.ivsize = TWEAK_SIZE;

inst->free = adiantum_free_instance;

err = skcipher_register_instance(tmpl, inst);
if (err) {
err_free_inst:
  adiantum_free_instance(inst);
}
return err;
}

/* adiantum(streamcipher_name, blockcipher_name [, nhpoly1305_name]) */
static struct crypto_template adiantum_tmpl = {
.name = "adiantum",
.create = adiantum_create,
.module = THIS_MODULE,
};

static int __init adiantum_module_init(void)
{
return crypto_register_template(&adiantum_tmpl);
}

static void __exit adiantum_module_exit(void)
{
crypto_unregister_template(&adiantum_tmpl);
}

module_init(adiantum_module_init);
module_exit(adiantum_module_exit);

MODULE_DESCRIPTION("Adiantum length-preserving encryption mode");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Eric Biggers ");
MODULE_ALIAS_CRYPTO("adiantum");
MODULE_IMPORT_NS("CRYPTO_INTERNAL");

quality95%

¤ Dauer der Verarbeitung: 0.8 Sekunden ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.