From c8bc35f2f6bb63d6146e10de2a5c76c1c7305c82 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 8 Jul 2020 14:57:22 -0700 Subject: [PATCH] BACKPORT: fscrypt: rename FS_KEY_DERIVATION_NONCE_SIZE The name "FS_KEY_DERIVATION_NONCE_SIZE" is a bit outdated since due to the addition of FSCRYPT_POLICY_FLAG_DIRECT_KEY, the file nonce may now be used as a tweak instead of for key derivation. Also, we're now prefixing the fscrypt constants with "FSCRYPT_" instead of "FS_". Therefore, rename this constant to FSCRYPT_FILE_NONCE_SIZE. Bug: 254441685 Link: https://lore.kernel.org/r/20200708215722.147154-1-ebiggers@kernel.org Signed-off-by: Eric Biggers [Lee: Back-ported to solve a dependency issue] (cherry picked from commit 1d6217a4f9905917ee63315c8ea3d63833792f51) Signed-off-by: Lee Jones Change-Id: I5eae506505d9432b95dabf620b79a6b8ca1e0d6a --- Documentation/filesystems/fscrypt.rst | 6 +++--- fs/crypto/crypto.c | 2 +- fs/crypto/fscrypt_private.h | 12 ++++++------ fs/crypto/keysetup.c | 7 +++---- fs/crypto/keysetup_v1.c | 4 ++-- fs/crypto/policy.c | 2 +- 6 files changed, 16 insertions(+), 17 deletions(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 7f9a372031fd..48e1dad581fb 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -1158,7 +1158,7 @@ setxattr() because of the special semantics of the encryption xattr. were to be added to or removed from anything other than an empty directory.) These structs are defined as follows:: - #define FS_KEY_DERIVATION_NONCE_SIZE 16 + #define FSCRYPT_FILE_NONCE_SIZE 16 #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8 struct fscrypt_context_v1 { @@ -1167,7 +1167,7 @@ directory.) These structs are defined as follows:: u8 filenames_encryption_mode; u8 flags; u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; - u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; #define FSCRYPT_KEY_IDENTIFIER_SIZE 16 @@ -1178,7 +1178,7 @@ directory.) These structs are defined as follows:: u8 flags; u8 __reserved[4]; u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; - u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; The context structs contain the same information as the corresponding diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index d2ceda7448d3..edc398c19198 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -92,7 +92,7 @@ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, WARN_ON_ONCE(lblk_num > U32_MAX); lblk_num = (u32)(ci->ci_hashed_ino + lblk_num); } else if (flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) { - memcpy(iv->nonce, ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE); + memcpy(iv->nonce, ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE); } iv->lblk_num = cpu_to_le64(lblk_num); } diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index d3b9e0d14b20..4adbaafbd161 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -19,9 +19,9 @@ #define CONST_STRLEN(str) (sizeof(str) - 1) -#define FS_KEY_DERIVATION_NONCE_SIZE 16 +#define FSCRYPT_FILE_NONCE_SIZE 16 -#define FSCRYPT_MIN_KEY_SIZE 16 +#define FSCRYPT_MIN_KEY_SIZE 16 #define FSCRYPT_MAX_HW_WRAPPED_KEY_SIZE 128 #define FSCRYPT_CONTEXT_V1 1 @@ -36,7 +36,7 @@ struct fscrypt_context_v1 { u8 filenames_encryption_mode; u8 flags; u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; - u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; struct fscrypt_context_v2 { @@ -46,7 +46,7 @@ struct fscrypt_context_v2 { u8 flags; u8 __reserved[4]; u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; - u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; /* @@ -249,7 +249,7 @@ struct fscrypt_info { union fscrypt_policy ci_policy; /* This inode's nonce, copied from the fscrypt_context */ - u8 ci_nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 ci_nonce[FSCRYPT_FILE_NONCE_SIZE]; /* Hashed inode number. Only set for IV_INO_LBLK_32 */ u32 ci_hashed_ino; @@ -285,7 +285,7 @@ union fscrypt_iv { __le64 lblk_num; /* per-file nonce; only set in DIRECT_KEY mode */ - u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; + u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; u8 raw[FSCRYPT_MAX_IV_SIZE]; __le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)]; diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 94293ea9f809..54082550599c 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -246,7 +246,7 @@ int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, int err; err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf, HKDF_CONTEXT_DIRHASH_KEY, - ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE, + ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE, (u8 *)&ci->ci_dirhash_key, sizeof(ci->ci_dirhash_key)); if (err) @@ -335,8 +335,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf, HKDF_CONTEXT_PER_FILE_ENC_KEY, - ci->ci_nonce, - FS_KEY_DERIVATION_NONCE_SIZE, + ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE, derived_key, ci->ci_mode->keysize); if (err) return err; @@ -545,7 +544,7 @@ int fscrypt_get_encryption_info(struct inode *inode) } memcpy(crypt_info->ci_nonce, fscrypt_context_nonce(&ctx), - FS_KEY_DERIVATION_NONCE_SIZE); + FSCRYPT_FILE_NONCE_SIZE); if (!fscrypt_supported_policy(&crypt_info->ci_policy, inode)) { res = -EINVAL; diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c index a39a5fb24e8c..4bbba0104df9 100644 --- a/fs/crypto/keysetup_v1.c +++ b/fs/crypto/keysetup_v1.c @@ -45,7 +45,7 @@ static DEFINE_SPINLOCK(fscrypt_direct_keys_lock); * key is longer, then only the first 'derived_keysize' bytes are used. */ static int derive_key_aes(const u8 *master_key, - const u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE], + const u8 nonce[FSCRYPT_FILE_NONCE_SIZE], u8 *derived_key, unsigned int derived_keysize) { int res = 0; @@ -68,7 +68,7 @@ static int derive_key_aes(const u8 *master_key, skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &wait); - res = crypto_skcipher_setkey(tfm, nonce, FS_KEY_DERIVATION_NONCE_SIZE); + res = crypto_skcipher_setkey(tfm, nonce, FSCRYPT_FILE_NONCE_SIZE); if (res < 0) goto out; diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index cc1fb8b58307..6290dec842f1 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -551,7 +551,7 @@ int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg) if (!fscrypt_context_is_valid(&ctx, ret)) return -EINVAL; if (copy_to_user(arg, fscrypt_context_nonce(&ctx), - FS_KEY_DERIVATION_NONCE_SIZE)) + FSCRYPT_FILE_NONCE_SIZE)) return -EFAULT; return 0; }