@@ -23,6 +23,9 @@
#include <linux/scatterlist.h>
#include <asm/page.h>
#include <asm/unaligned.h>
+#include <crypto/hash.h>
+#include <crypto/md5.h>
+#include <crypto/algapi.h>
#include <linux/device-mapper.h>
@@ -90,6 +93,12 @@ struct iv_benbi_private {
int shift;
};
+#define LMK_SEED_SIZE 64 /* hash + 0 */
+struct iv_lmk_private {
+ struct crypto_shash *hash_tfm;
+ u8 *seed;
+};
+
/*
* Crypt: maps a linear range of a block device
* and encrypts / decrypts at the same time.
@@ -131,6 +140,7 @@ struct crypt_config {
union {
struct iv_essiv_private essiv;
struct iv_benbi_private benbi;
+ struct iv_lmk_private lmk;
} iv_gen_private;
sector_t iv_offset;
unsigned int iv_size;
@@ -446,6 +456,164 @@ static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
return 0;
}
+static void crypt_iv_lmk_dtr(struct crypt_config *cc)
+{
+ struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+ if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
+ crypto_free_shash(lmk->hash_tfm);
+ lmk->hash_tfm = NULL;
+
+ kzfree(lmk->seed);
+ lmk->seed = NULL;
+}
+
+static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
+ const char *opts)
+{
+ struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+ lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
+ if (IS_ERR(lmk->hash_tfm)) {
+ ti->error = "Error initializing LMK hash";
+ return PTR_ERR(lmk->hash_tfm);
+ }
+
+ /* No seed in LMK version 2 */
+ if (cc->key_parts == cc->tfms_count) {
+ lmk->seed = NULL;
+ return 0;
+ }
+
+ lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
+ if (!lmk->seed) {
+ crypt_iv_lmk_dtr(cc);
+ ti->error = "Error kmallocing seed storage in LMK";
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int crypt_iv_lmk_init(struct crypt_config *cc)
+{
+ struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+ int subkey_size = cc->key_size / cc->key_parts;
+
+ /* LMK seed is on the position of LMK_KEYS + 1 key */
+ if (lmk->seed)
+ memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
+ crypto_shash_digestsize(lmk->hash_tfm));
+
+ return 0;
+}
+
+static int crypt_iv_lmk_wipe(struct crypt_config *cc)
+{
+ struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+ if (lmk->seed)
+ memset(lmk->seed, 0, LMK_SEED_SIZE);
+
+ return 0;
+}
+
+static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
+{
+ while (words--) {
+ __cpu_to_le32s(buf);
+ buf++;
+ }
+}
+
+static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
+ struct dm_crypt_request *dmreq,
+ u8 *data)
+{
+ struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+ struct {
+ struct shash_desc desc;
+ char ctx[crypto_shash_descsize(lmk->hash_tfm)];
+ } sdesc;
+ struct md5_state md5state;
+ u32 buf[4];
+ int r;
+
+ sdesc.desc.tfm = lmk->hash_tfm;
+ sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ r = crypto_shash_init(&sdesc.desc);
+ if (r)
+ return r;
+
+ if (lmk->seed) {
+ r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
+ if (r)
+ return r;
+ }
+
+ /* Sector is always 512B, block size 16, add data of blocks 1-31 */
+ r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
+ if (r)
+ return r;
+
+ /* Sector is cropped to 56 bits here */
+ buf[0] = dmreq->iv_sector & 0xFFFFFFFF;
+ buf[1] = ((dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000;
+ buf[2] = 4024;
+ buf[3] = 0;
+ cpu_to_le32_array(buf, 4);
+
+ r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
+ if (r)
+ return r;
+
+ /* No MD5 padding here */
+ r = crypto_shash_export(&sdesc.desc, &md5state);
+ if (r)
+ return r;
+
+ cpu_to_le32_array(md5state.hash, 4);
+ memcpy(iv, &md5state.hash, cc->iv_size);
+ return 0;
+}
+
+static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
+ struct dm_crypt_request *dmreq)
+{
+ u8 *src;
+ int r = 0;
+
+ if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
+ src = kmap_atomic(sg_page(&dmreq->sg_in), KM_USER0);
+ r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
+ kunmap_atomic(src, KM_USER0);
+ } else
+ memset(iv, 0, cc->iv_size);
+
+ return r;
+}
+
+static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
+ struct dm_crypt_request *dmreq)
+{
+ u8 *dst;
+ int r;
+
+ if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
+ return 0;
+
+ dst = kmap_atomic(sg_page(&dmreq->sg_out), KM_USER0);
+ r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
+
+ /* Code must fix the first block of plaintext sector */
+ if (!r)
+ crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
+
+ kunmap_atomic(dst, KM_USER0);
+ return r;
+}
+
static struct crypt_iv_operations crypt_iv_plain_ops = {
.generator = crypt_iv_plain_gen
};
@@ -472,6 +640,15 @@ static struct crypt_iv_operations crypt_iv_null_ops = {
.generator = crypt_iv_null_gen
};
+static struct crypt_iv_operations crypt_iv_lmk_ops = {
+ .ctr = crypt_iv_lmk_ctr,
+ .dtr = crypt_iv_lmk_dtr,
+ .init = crypt_iv_lmk_init,
+ .wipe = crypt_iv_lmk_wipe,
+ .generator = crypt_iv_lmk_gen,
+ .post = crypt_iv_lmk_post
+};
+
static void crypt_convert_init(struct crypt_config *cc,
struct convert_context *ctx,
struct bio *bio_out, struct bio *bio_in,
@@ -1349,7 +1526,12 @@ static int crypt_ctr_cipher(struct dm_target *ti,
cc->iv_gen_ops = &crypt_iv_benbi_ops;
else if (strcmp(ivmode, "null") == 0)
cc->iv_gen_ops = &crypt_iv_null_ops;
- else {
+ else if (strcmp(ivmode, "lmk") == 0) {
+ cc->iv_gen_ops = &crypt_iv_lmk_ops;
+ /* loop-aes multikey version 3 - last key used for IV seed */
+ if (cc->key_size % cc->key_parts)
+ cc->key_parts++;
+ } else {
ret = -EINVAL;
ti->error = "Invalid IV mode";
goto bad;