From: Vratislav Podzimek Date: Sun, 3 Feb 2019 16:53:40 +0100 Subject: Use 512bit keys in LUKS by default This is what Debian FDE does and what was suggested in the following research/analysis: https://www.whonix.org/wiki/Full_Disk_Encryption_and_Encrypted_Images#Protection_Against_Powerful_Adversaries We need to adapt the tests because AES only supports 256bit keys and only the XTS mode splits the 512bit key into two parts. Fixes: GH-416 (cherry picked from commit 9dc4e2463860810cac5a1dbfb7064c47200260f6) --- src/plugins/crypto.h | 2 +- tests/crypto_test.py | 26 +++++++++++++------------- 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/src/plugins/crypto.h b/src/plugins/crypto.h index 81a051c..8848c46 100644 --- a/src/plugins/crypto.h +++ b/src/plugins/crypto.h @@ -36,7 +36,7 @@ typedef enum { /* 20 chars * 6 bits per char (64-item charset) = 120 "bits of security" */ #define BD_CRYPTO_BACKUP_PASSPHRASE_LENGTH 20 -#define DEFAULT_LUKS_KEYSIZE_BITS 256 +#define DEFAULT_LUKS_KEYSIZE_BITS 512 #define DEFAULT_LUKS_CIPHER "aes-xts-plain64" #define DEFAULT_LUKS2_SECTOR_SIZE 512 diff --git a/tests/crypto_test.py b/tests/crypto_test.py index 7fe2677..c048570 100644 --- a/tests/crypto_test.py +++ b/tests/crypto_test.py @@ -110,15 +110,15 @@ class CryptoTestFormat(CryptoTestCase): BlockDev.crypto_luks_format(self.loop_dev, None, 0, None, None, 0) # the simple case with password - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, PASSWD, None, 0) + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, PASSWD, None, 0) self.assertTrue(succ) # create with a keyfile - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0) + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0) self.assertTrue(succ) # the simple case with password blob - succ = BlockDev.crypto_luks_format_blob(self.loop_dev, "aes-cbc-essiv:sha256", 0, [ord(c) for c in PASSWD], 0) + succ = BlockDev.crypto_luks_format_blob(self.loop_dev, "aes-xts-plain64", 0, [ord(c) for c in PASSWD], 0) self.assertTrue(succ) @unittest.skipIf("SKIP_SLOW" in os.environ, "skipping slow tests") @@ -131,20 +131,20 @@ class CryptoTestFormat(CryptoTestCase): BlockDev.crypto_luks_format(self.loop_dev, None, 0, None, None, 0) # the simple case with password - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, PASSWD, None, 0) + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, PASSWD, None, 0) self.assertTrue(succ) # create with a keyfile - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0) + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0) self.assertTrue(succ) # the simple case with password blob - succ = BlockDev.crypto_luks_format_blob(self.loop_dev, "aes-cbc-essiv:sha256", 0, [ord(c) for c in PASSWD], 0) + succ = BlockDev.crypto_luks_format_blob(self.loop_dev, "aes-xts-plain64", 0, [ord(c) for c in PASSWD], 0) self.assertTrue(succ) # simple case with extra options extra = BlockDev.CryptoLUKSExtra(label="blockdevLUKS") - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ) @@ -154,7 +154,7 @@ class CryptoTestFormat(CryptoTestCase): # different key derivation function pbkdf = BlockDev.CryptoLUKSPBKDF(type="pbkdf2") extra = BlockDev.CryptoLUKSExtra(pbkdf=pbkdf) - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ) @@ -167,7 +167,7 @@ class CryptoTestFormat(CryptoTestCase): # different options for argon2 -- all parameters set pbkdf = BlockDev.CryptoLUKSPBKDF(type="argon2id", max_memory_kb=100*1024, iterations=10, parallel_threads=1) extra = BlockDev.CryptoLUKSExtra(pbkdf=pbkdf) - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ) @@ -196,7 +196,7 @@ class CryptoTestFormat(CryptoTestCase): # different options for argon2 -- only memory set pbkdf = BlockDev.CryptoLUKSPBKDF(max_memory_kb=100*1024) extra = BlockDev.CryptoLUKSExtra(pbkdf=pbkdf) - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ) @@ -211,7 +211,7 @@ class CryptoTestFormat(CryptoTestCase): # different options for argon2 -- only miterations set pbkdf = BlockDev.CryptoLUKSPBKDF(iterations=5) extra = BlockDev.CryptoLUKSExtra(pbkdf=pbkdf) - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, None, self.keyfile, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-xts-plain64", 0, None, self.keyfile, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ) @@ -852,7 +852,7 @@ class CryptoTestInfo(CryptoTestCase): def test_luks_format(self): """Verify that we can get information about a LUKS device""" - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, PASSWD, None, 0) + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 256, PASSWD, None, 0) self.assertTrue(succ) succ = BlockDev.crypto_luks_open(self.loop_dev, "libblockdevTestLUKS", PASSWD, None, False) @@ -880,7 +880,7 @@ class CryptoTestInfo(CryptoTestCase): extra = BlockDev.CryptoLUKSExtra() extra.sector_size = 4096 - succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 0, PASSWD, None, 0, + succ = BlockDev.crypto_luks_format(self.loop_dev, "aes-cbc-essiv:sha256", 256, PASSWD, None, 0, BlockDev.CryptoLUKSVersion.LUKS2, extra) self.assertTrue(succ)