From a3af73261cdeea0f97681d0128482e4ae1fe2f8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Damir=20Jeli=C4=87?= <poljar@termina.org.uk>
Date: Mon, 15 Nov 2021 10:31:55 +0100
Subject: [PATCH] crypto: Throw decode errors when creating a recovery key

---
 rust-sdk/src/backup_recovery_key.rs | 32 ++++++++++++++---------------
 rust-sdk/src/lib.rs                 |  6 ++++--
 rust-sdk/src/olm.udl                | 11 +++++++---
 3 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/rust-sdk/src/backup_recovery_key.rs b/rust-sdk/src/backup_recovery_key.rs
index 3eb82a30c5..67b9c16290 100644
--- a/rust-sdk/src/backup_recovery_key.rs
+++ b/rust-sdk/src/backup_recovery_key.rs
@@ -21,6 +21,13 @@ pub enum PkDecryptionError {
     Olm(#[from] OlmPkDecryptionError),
 }
 
+#[derive(Debug, Error)]
+pub enum DecodeError {
+    /// An error happened while decoding the recovery key.
+    #[error(transparent)]
+    Decode(#[from] matrix_sdk_crypto::backups::DecodeError),
+}
+
 /// Struct containing info about the way the backup key got derived from a
 /// passphrase.
 #[derive(Debug, Clone)]
@@ -56,21 +63,19 @@ impl BackupRecoveryKey {
     }
 
     /// Try to create a [`BackupRecoveryKey`] from a base 64 encoded string.
-    pub fn from_base64(key: String) -> Self {
-        Self {
-            // TODO remove the unwrap
-            inner: RecoveryKey::from_base64(&key).unwrap(),
+    pub fn from_base64(key: String) -> Result<Self, DecodeError> {
+        Ok(Self {
+            inner: RecoveryKey::from_base64(&key)?,
             passphrase_info: None,
-        }
+        })
     }
 
     /// Try to create a [`BackupRecoveryKey`] from a base 58 encoded string.
-    pub fn from_base58(key: String) -> Self {
-        Self {
-            // TODO remove the unwrap
-            inner: RecoveryKey::from_base58(&key).unwrap(),
+    pub fn from_base58(key: String) -> Result<Self, DecodeError> {
+        Ok(Self {
+            inner: RecoveryKey::from_base58(&key)?,
             passphrase_info: None,
-        }
+        })
     }
 
     /// Create a new [`BackupRecoveryKey`] from the given passphrase.
@@ -90,12 +95,7 @@ impl BackupRecoveryKey {
         let mut key = [0u8; Self::KEY_SIZE];
         let rounds = rounds as u32;
 
-        pbkdf2::<Hmac<Sha512>>(
-            passphrase.as_bytes(),
-            salt.as_bytes(),
-            rounds,
-            &mut key,
-        );
+        pbkdf2::<Hmac<Sha512>>(passphrase.as_bytes(), salt.as_bytes(), rounds, &mut key);
 
         Self {
             inner: RecoveryKey::from_bytes(key),
diff --git a/rust-sdk/src/lib.rs b/rust-sdk/src/lib.rs
index 301eebf776..0add76b18c 100644
--- a/rust-sdk/src/lib.rs
+++ b/rust-sdk/src/lib.rs
@@ -3,7 +3,7 @@
     trivial_casts,
     trivial_numeric_casts,
     unused_extern_crates,
-    unused_import_braces,
+    unused_import_braces
 )]
 
 //! TODO
@@ -17,7 +17,9 @@ mod responses;
 mod users;
 mod verification;
 
-pub use backup_recovery_key::{BackupKey, BackupRecoveryKey, PassphraseInfo, PkDecryptionError};
+pub use backup_recovery_key::{
+    BackupKey, BackupRecoveryKey, DecodeError, PassphraseInfo, PkDecryptionError,
+};
 pub use device::Device;
 pub use error::{
     CryptoStoreError, DecryptionError, KeyImportError, SecretImportError, SignatureError,
diff --git a/rust-sdk/src/olm.udl b/rust-sdk/src/olm.udl
index 977b171e9c..10ca65fc0c 100644
--- a/rust-sdk/src/olm.udl
+++ b/rust-sdk/src/olm.udl
@@ -395,15 +395,20 @@ dictionary RoomKeyCounts {
     i64 backed_up;
 };
 
+[Error]
+enum DecodeError {
+    "Decode",
+};
+
 interface BackupRecoveryKey {
     constructor();
-    [Name=from_base64]
-    constructor(string key);
     [Name=from_passphrase]
     constructor(string passphrase, string salt, i32 rounds);
     [Name=new_from_passphrase]
     constructor(string passphrase);
-    [Name=from_base58]
+    [Name=from_base64, Throws=DecodeError]
+    constructor(string key);
+    [Name=from_base58, Throws=DecodeError]
     constructor(string key);
     string to_base58();
     string to_base64();