From 45468a9a6f866a81f51782e3f91e24732576f5c9 Mon Sep 17 00:00:00 2001 From: Mae Kasza Date: Thu, 15 Aug 2024 22:50:16 -0400 Subject: [PATCH] Fix set-passphrase on --no_passphrase FS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This also fixes a bug where the set-passphrase command failed to derive the key for disks initially formatted with --encrypted and --no_passphrase, due to bch_sb_crypt_init not configuring the KDF params if the passphrase wasn't specified during formatting. Signed-off-by: Mae Kasza Tested-by: Jérôme Poulin --- c_src/cmd_key.c | 26 ++++++++++---------------- c_src/crypto.c | 49 +++++++++++++++++++++++++++++++++++-------------- c_src/crypto.h | 3 +++ 3 files changed, 48 insertions(+), 30 deletions(-) diff --git a/c_src/cmd_key.c b/c_src/cmd_key.c index adb0ac8d..ac8a94a8 100644 --- a/c_src/cmd_key.c +++ b/c_src/cmd_key.c @@ -104,24 +104,19 @@ int cmd_set_passphrase(int argc, char *argv[]) if (IS_ERR(c)) die("Error opening %s: %s", argv[1], bch2_err_str(PTR_ERR(c))); - struct bch_sb_field_crypt *crypt = bch2_sb_field_get(c->disk_sb.sb, crypt); + struct bch_sb *sb = c->disk_sb.sb; + struct bch_sb_field_crypt *crypt = bch2_sb_field_get(sb, crypt); if (!crypt) die("Filesystem does not have encryption enabled"); - struct bch_encrypted_key new_key; - new_key.magic = BCH_KEY_MAGIC; - - int ret = bch2_decrypt_sb_key(c, crypt, &new_key.key); + struct bch_key key; + int ret = bch2_decrypt_sb_key(c, crypt, &key); if (ret) die("Error getting current key"); char *new_passphrase = read_passphrase_twice("Enter new passphrase: "); - struct bch_key passphrase_key = derive_passphrase(crypt, new_passphrase); - if (bch2_chacha_encrypt_key(&passphrase_key, __bch2_sb_key_nonce(c->disk_sb.sb), - &new_key, sizeof(new_key))) - die("error encrypting key"); - crypt->key = new_key; + bch_crypt_update_passphrase(sb, crypt, &key, new_passphrase); bch2_revoke_key(c->disk_sb.sb); bch2_write_super(c); @@ -142,18 +137,17 @@ int cmd_remove_passphrase(int argc, char *argv[]) if (IS_ERR(c)) die("Error opening %s: %s", argv[1], bch2_err_str(PTR_ERR(c))); - struct bch_sb_field_crypt *crypt = bch2_sb_field_get(c->disk_sb.sb, crypt); + struct bch_sb *sb = c->disk_sb.sb; + struct bch_sb_field_crypt *crypt = bch2_sb_field_get(sb, crypt); if (!crypt) die("Filesystem does not have encryption enabled"); - struct bch_encrypted_key new_key; - new_key.magic = BCH_KEY_MAGIC; - - int ret = bch2_decrypt_sb_key(c, crypt, &new_key.key); + struct bch_key key; + int ret = bch2_decrypt_sb_key(c, crypt, &key); if (ret) die("Error getting current key"); - crypt->key = new_key; + bch_crypt_update_passphrase(sb, crypt, &key, NULL); bch2_write_super(c); bch2_fs_stop(c); diff --git a/c_src/crypto.c b/c_src/crypto.c index 32671bd8..301dbebe 100644 --- a/c_src/crypto.c +++ b/c_src/crypto.c @@ -176,26 +176,47 @@ void bch_sb_crypt_init(struct bch_sb *sb, struct bch_sb_field_crypt *crypt, const char *passphrase) { + struct bch_key key; + get_random_bytes(&key, sizeof(key)); + crypt->key.magic = BCH_KEY_MAGIC; - get_random_bytes(&crypt->key.key, sizeof(crypt->key.key)); + crypt->key.key = key; - if (passphrase) { + bch_crypt_update_passphrase(sb, crypt, &key, passphrase); +} +void bch_crypt_update_passphrase( + struct bch_sb *sb, + struct bch_sb_field_crypt *crypt, + struct bch_key *key, + const char *new_passphrase) +{ + + struct bch_encrypted_key new_key; + new_key.magic = BCH_KEY_MAGIC; + new_key.key = *key; + + if(!new_passphrase) { + crypt->key = new_key; + return; + } + + // If crypt already has an encrypted key reuse it's encryption params + if (!bch2_key_is_encrypted(&crypt->key)) { SET_BCH_CRYPT_KDF_TYPE(crypt, BCH_KDF_SCRYPT); SET_BCH_KDF_SCRYPT_N(crypt, ilog2(16384)); SET_BCH_KDF_SCRYPT_R(crypt, ilog2(8)); SET_BCH_KDF_SCRYPT_P(crypt, ilog2(16)); - - struct bch_key passphrase_key = derive_passphrase(crypt, passphrase); - - assert(!bch2_key_is_encrypted(&crypt->key)); - - if (bch2_chacha_encrypt_key(&passphrase_key, __bch2_sb_key_nonce(sb), - &crypt->key, sizeof(crypt->key))) - die("error encrypting key"); - - assert(bch2_key_is_encrypted(&crypt->key)); - - memzero_explicit(&passphrase_key, sizeof(passphrase_key)); } + + struct bch_key passphrase_key = derive_passphrase(crypt, new_passphrase); + + if (bch2_chacha_encrypt_key(&passphrase_key, __bch2_sb_key_nonce(sb), + &new_key, sizeof(new_key))) + die("error encrypting key"); + + memzero_explicit(&passphrase_key, sizeof(passphrase_key)); + + crypt->key = new_key; + assert(bch2_key_is_encrypted(&crypt->key)); } diff --git a/c_src/crypto.h b/c_src/crypto.h index baea6d86..cd3baac8 100644 --- a/c_src/crypto.h +++ b/c_src/crypto.h @@ -19,4 +19,7 @@ void bch2_add_key(struct bch_sb *, const char *, const char *, const char *); void bch_sb_crypt_init(struct bch_sb *sb, struct bch_sb_field_crypt *, const char *); +void bch_crypt_update_passphrase(struct bch_sb *sb, struct bch_sb_field_crypt *crypt, + struct bch_key *key, const char *new_passphrase); + #endif /* _CRYPTO_H */