Remove CommandError::RngError

We switched to rand::thread_rng() which cannot fail.  Therefore the
CommandError::RngError is no longer needed and removed in this patch.

3 files changed, 4 insertions, 9 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 34f9ac9..7878d74 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # Unreleased
 - Add a `force` argument to `ConfigureOtp::set_time`.
+- Remove the obsolete `CommandError::RngError`.
 
 # v0.2.3 (2018-12-31)
 
diff --git a/src/auth.rs b/src/auth.rs
index 017cdbb..a129bd8 100644
--- a/src/auth.rs
+++ b/src/auth.rs
@@ -149,10 +149,7 @@ where
     A: AuthenticatedDevice<D>,
     T: Fn(*const i8, *const i8) -> c_int,
 {
-    let temp_password = match generate_password(TEMPORARY_PASSWORD_LENGTH) {
-        Ok(pw) => pw,
-        Err(_) => return Err((device, CommandError::RngError)),
-    };
+    let temp_password = generate_password(TEMPORARY_PASSWORD_LENGTH);
     let password = match get_cstring(password) {
         Ok(password) => password,
         Err(err) => return Err((device, err)),
diff --git a/src/util.rs b/src/util.rs
index a2e957e..ccec5e6 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -35,8 +35,6 @@ pub enum CommandError {
     InvalidString,
     /// You passed an invalid slot.
     InvalidSlot,
-    /// An error occured during random number generation.
-    RngError,
 }
 
 /// Log level for libnitrokey.
@@ -99,10 +97,10 @@ pub fn get_last_error() -> CommandError {
     };
 }
 
-pub fn generate_password(length: usize) -> std::io::Result<Vec<u8>> {
+pub fn generate_password(length: usize) -> Vec<u8> {
     let mut data = vec![0u8; length];
     rand::thread_rng().fill(&mut data[..]);
-    return Ok(data);
+    return data;
 }
 
 pub fn get_cstring<T: Into<Vec<u8>>>(s: T) -> Result<CString, CommandError> {
@@ -127,7 +125,6 @@ impl fmt::Display for CommandError {
             CommandError::Unknown => "An unknown error occured",
             CommandError::InvalidString => "You passed a string containing a null byte",
             CommandError::InvalidSlot => "The given slot is invalid",
-            CommandError::RngError => "An error occured during random number generation",
         };
         write!(f, "{}", msg)
     }