diff options
| -rw-r--r-- | fs/crypto/keyinfo.c | 102 |
1 files changed, 68 insertions, 34 deletions
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index 41f6025d5d7a..e997ca51192f 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -148,44 +148,64 @@ static int find_and_derive_key(const struct inode *inode, return err; } -static const struct { +static struct fscrypt_mode { + const char *friendly_name; const char *cipher_str; int keysize; + bool logged_impl_name; } available_modes[] = { - [FS_ENCRYPTION_MODE_AES_256_XTS] = { "xts(aes)", 64 }, - [FS_ENCRYPTION_MODE_AES_256_CTS] = { "cts(cbc(aes))", 32 }, - [FS_ENCRYPTION_MODE_AES_128_CBC] = { "cbc(aes)", 16 }, - [FS_ENCRYPTION_MODE_AES_128_CTS] = { "cts(cbc(aes))", 16 }, - [FS_ENCRYPTION_MODE_SPECK128_256_XTS] = { "xts(speck128)", 64 }, - [FS_ENCRYPTION_MODE_SPECK128_256_CTS] = { "cts(cbc(speck128))", 32 }, + [FS_ENCRYPTION_MODE_AES_256_XTS] = { + .friendly_name = "AES-256-XTS", + .cipher_str = "xts(aes)", + .keysize = 64, + }, + [FS_ENCRYPTION_MODE_AES_256_CTS] = { + .friendly_name = "AES-256-CTS-CBC", + .cipher_str = "cts(cbc(aes))", + .keysize = 32, + }, + [FS_ENCRYPTION_MODE_AES_128_CBC] = { + .friendly_name = "AES-128-CBC", + .cipher_str = "cbc(aes)", + .keysize = 16, + }, + [FS_ENCRYPTION_MODE_AES_128_CTS] = { + .friendly_name = "AES-128-CTS-CBC", + .cipher_str = "cts(cbc(aes))", + .keysize = 16, + }, + [FS_ENCRYPTION_MODE_SPECK128_256_XTS] = { + .friendly_name = "Speck128/256-XTS", + .cipher_str = "xts(speck128)", + .keysize = 64, + }, + [FS_ENCRYPTION_MODE_SPECK128_256_CTS] = { + .friendly_name = "Speck128/256-CTS-CBC", + .cipher_str = "cts(cbc(speck128))", + .keysize = 32, + }, }; -static int determine_cipher_type(struct fscrypt_info *ci, struct inode *inode, - const char **cipher_str_ret, int *keysize_ret) +static struct fscrypt_mode * +select_encryption_mode(const struct fscrypt_info *ci, const struct inode *inode) { - u32 mode; - if (!fscrypt_valid_enc_modes(ci->ci_data_mode, ci->ci_filename_mode)) { fscrypt_warn(inode->i_sb, "inode %lu uses unsupported encryption modes (contents mode %d, filenames mode %d)", inode->i_ino, ci->ci_data_mode, ci->ci_filename_mode); - return -EINVAL; + return ERR_PTR(-EINVAL); } - if (S_ISREG(inode->i_mode)) { - mode = ci->ci_data_mode; - } else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) { - mode = ci->ci_filename_mode; - } else { - WARN_ONCE(1, "fscrypt: filesystem tried to load encryption info for inode %lu, which is not encryptable (file type %d)\n", - inode->i_ino, (inode->i_mode & S_IFMT)); - return -EINVAL; - } + if (S_ISREG(inode->i_mode)) + return &available_modes[ci->ci_data_mode]; + + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) + return &available_modes[ci->ci_filename_mode]; - *cipher_str_ret = available_modes[mode].cipher_str; - *keysize_ret = available_modes[mode].keysize; - return 0; + WARN_ONCE(1, "fscrypt: filesystem tried to load encryption info for inode %lu, which is not encryptable (file type %d)\n", + inode->i_ino, (inode->i_mode & S_IFMT)); + return ERR_PTR(-EINVAL); } static void put_crypt_info(struct fscrypt_info *ci) @@ -270,8 +290,7 @@ int fscrypt_get_encryption_info(struct inode *inode) struct fscrypt_info *crypt_info; struct fscrypt_context ctx; struct crypto_skcipher *ctfm; - const char *cipher_str; - int keysize; + struct fscrypt_mode *mode; u8 *raw_key = NULL; int res; @@ -315,40 +334,55 @@ int fscrypt_get_encryption_info(struct inode *inode) memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, sizeof(crypt_info->ci_master_key)); - res = determine_cipher_type(crypt_info, inode, &cipher_str, &keysize); - if (res) + mode = select_encryption_mode(crypt_info, inode); + if (IS_ERR(mode)) { + res = PTR_ERR(mode); goto out; + } /* * This cannot be a stack buffer because it is passed to the scatterlist * crypto API as part of key derivation. */ res = -ENOMEM; - raw_key = kmalloc(keysize, GFP_NOFS); + raw_key = kmalloc(mode->keysize, GFP_NOFS); if (!raw_key) goto out; - res = find_and_derive_key(inode, &ctx, raw_key, keysize); + res = find_and_derive_key(inode, &ctx, raw_key, mode->keysize); if (res) goto out; - ctfm = crypto_alloc_skcipher(cipher_str, 0, 0); + ctfm = crypto_alloc_skcipher(mode->cipher_str, 0, 0); if (IS_ERR(ctfm)) { res = PTR_ERR(ctfm); fscrypt_warn(inode->i_sb, "error allocating '%s' transform for inode %lu: %d", - cipher_str, inode->i_ino, res); + mode->cipher_str, inode->i_ino, res); goto out; } + if (unlikely(!mode->logged_impl_name)) { + /* + * fscrypt performance can vary greatly depending on which + * crypto algorithm implementation is used. Help people debug + * performance problems by logging the ->cra_driver_name the + * first time a mode is used. Note that multiple threads can + * race here, but it doesn't really matter. + */ + mode->logged_impl_name = true; + pr_info("fscrypt: %s using implementation \"%s\"\n", + mode->friendly_name, + crypto_skcipher_alg(ctfm)->base.cra_driver_name); + } crypt_info->ci_ctfm = ctfm; crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY); - res = crypto_skcipher_setkey(ctfm, raw_key, keysize); + res = crypto_skcipher_setkey(ctfm, raw_key, mode->keysize); if (res) goto out; if (S_ISREG(inode->i_mode) && crypt_info->ci_data_mode == FS_ENCRYPTION_MODE_AES_128_CBC) { - res = init_essiv_generator(crypt_info, raw_key, keysize); + res = init_essiv_generator(crypt_info, raw_key, mode->keysize); if (res) { fscrypt_warn(inode->i_sb, "error initializing ESSIV generator for inode %lu: %d", |