eessppeelllloo/cryptsetup
1
0
Fork 0
mirror of https://gitlab.com/cryptsetup/cryptsetup.git synced 2025-12-05 16:00:05 +01:00
Code Issues Packages Projects Releases Wiki Activity

Implement EBOIV in userspace storage wrapper.

Browse Source 
The EBOIV initialization vector is intended to be used
internally with BitLocker devices (for CBC mode).
It can be used in some specific cases for other devices.

This patch adds userspace implementation duplicating
the same EBOIV as the dm-crypt kernel.

Fixes: #562
This commit is contained in:
Milan Broz
2020-05-15 16:08:16 +02:00
parent 86cc67e081
commit 61f4363ed7
1 changed files with 27 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
lib/crypto_backend/crypto_storage.c
View File

@@ -31,11 +31,11 @@
* IV documentation: https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt
*/
struct crypt_sector_iv {
enum { IV_NONE, IV_NULL, IV_PLAIN, IV_PLAIN64, IV_ESSIV, IV_BENBI, IV_PLAIN64BE } type;
enum { IV_NONE, IV_NULL, IV_PLAIN, IV_PLAIN64, IV_ESSIV, IV_BENBI, IV_PLAIN64BE, IV_EBOIV } type;
int iv_size;
char *iv;
struct crypt_cipher *essiv_cipher;
int benbi_shift;
struct crypt_cipher *cipher;
int shift;
};
/* Block encryption storage context */
@@ -56,8 +56,10 @@ static int int_log2(unsigned int x)
static int crypt_sector_iv_init(struct crypt_sector_iv *ctx,
const char *cipher_name, const char *mode_name,
const char *iv_name, const void *key, size_t key_length)
const char *iv_name, const void *key, size_t key_length, size_t sector_size)
{
int r;
memset(ctx, 0, sizeof(*ctx));
ctx->iv_size = crypt_cipher_ivsize(cipher_name, mode_name);
@@ -86,7 +88,6 @@ static int crypt_sector_iv_init(struct crypt_sector_iv *ctx,
char *hash_name = strchr(iv_name, ':');
int hash_size;
char tmp[256];
int r;
if (!hash_name)
return -EINVAL;
@@ -114,7 +115,7 @@ static int crypt_sector_iv_init(struct crypt_sector_iv *ctx,
return r;
}
r = crypt_cipher_init(&ctx->essiv_cipher, cipher_name, "ecb",
r = crypt_cipher_init(&ctx->cipher, cipher_name, "ecb",
tmp, hash_size);
crypt_backend_memzero(tmp, sizeof(tmp));
if (r)
@@ -127,7 +128,15 @@ static int crypt_sector_iv_init(struct crypt_sector_iv *ctx,
return -EINVAL;
ctx->type = IV_BENBI;
ctx->benbi_shift = SECTOR_SHIFT - log;
ctx->shift = SECTOR_SHIFT - log;
} else if (!strncasecmp(iv_name, "eboiv", 5)) {
r = crypt_cipher_init(&ctx->cipher, cipher_name, "ecb",
key, key_length);
if (r)
return r;
ctx->type = IV_EBOIV;
ctx->shift = int_log2(sector_size);
} else
return -ENOENT;
@@ -163,14 +172,20 @@ static int crypt_sector_iv_generate(struct crypt_sector_iv *ctx, uint64_t sector
case IV_ESSIV:
memset(ctx->iv, 0, ctx->iv_size);
*(uint64_t *)ctx->iv = cpu_to_le64(sector);
return crypt_cipher_encrypt(ctx->essiv_cipher,
return crypt_cipher_encrypt(ctx->cipher,
ctx->iv, ctx->iv, ctx->iv_size, NULL, 0);
break;
case IV_BENBI:
memset(ctx->iv, 0, ctx->iv_size);
val = cpu_to_be64((sector << ctx->benbi_shift) + 1);
val = cpu_to_be64((sector << ctx->shift) + 1);
memcpy(ctx->iv + ctx->iv_size - sizeof(val), &val, sizeof(val));
break;
case IV_EBOIV:
memset(ctx->iv, 0, ctx->iv_size);
*(uint64_t *)ctx->iv = cpu_to_le64(sector << ctx->shift);
return crypt_cipher_encrypt(ctx->cipher,
ctx->iv, ctx->iv, ctx->iv_size, NULL, 0);
break;
default:
return -EINVAL;
}
@@ -180,8 +195,8 @@ static int crypt_sector_iv_generate(struct crypt_sector_iv *ctx, uint64_t sector
static void crypt_sector_iv_destroy(struct crypt_sector_iv *ctx)
{
if (ctx->type == IV_ESSIV)
crypt_cipher_destroy(ctx->essiv_cipher);
if (ctx->type == IV_ESSIV || ctx->type == IV_EBOIV)
crypt_cipher_destroy(ctx->cipher);
if (ctx->iv) {
memset(ctx->iv, 0, ctx->iv_size);
@@ -229,7 +244,7 @@ int crypt_storage_init(struct crypt_storage **ctx,
return r;
}
r = crypt_sector_iv_init(&s->cipher_iv, cipher, mode_name, cipher_iv, key, key_length);
r = crypt_sector_iv_init(&s->cipher_iv, cipher, mode_name, cipher_iv, key, key_length, sector_size);
if (r) {
crypt_storage_destroy(s);
return r;