1 files changed, 154 insertions, 0 deletions
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..8a6c411
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,154 @@
+use libc::{c_void, free};
+use nitrokey_sys;
+use rand::{OsRng, Rng};
+use std;
+use std::ffi::CStr;
+use std::os::raw::{c_char, c_int};
+
+/// Error types returned by Nitrokey device or by the library.
+#[derive(Debug, PartialEq)]
+pub enum CommandError {
+    /// A packet with a wrong checksum has been sent or received.
+    WrongCrc,
+    /// A command tried to access an OTP slot that does not exist.
+    WrongSlot,
+    /// A command tried to generate an OTP on a slot that is not configured.
+    SlotNotProgrammed,
+    /// The provided password is wrong.
+    WrongPassword,
+    /// You are not authorized for this command or provided a wrong temporary
+    /// password.
+    NotAuthorized,
+    /// An error occured when getting or setting the time.
+    Timestamp,
+    /// You did not provide a name for the OTP slot.
+    NoName,
+    /// This command is not supported by this device.
+    NotSupported,
+    /// This command is unknown.
+    UnknownCommand,
+    /// AES decryptionfailed.
+    AesDecryptionFailed,
+    /// An unknown error occured.
+    Unknown,
+    /// You passed a string containing a null byte.
+    InvalidString,
+    /// You passed an invalid slot.
+    InvalidSlot,
+    /// An error occured during random number generation.
+    RngError,
+}
+
+/// Command execution status.
+#[derive(Debug, PartialEq)]
+pub enum CommandStatus {
+    /// The command was successful.
+    Success,
+    /// An error occured during command execution.
+    Error(CommandError),
+}
+
+/// Log level for libnitrokey.
+#[derive(Debug, PartialEq)]
+pub enum LogLevel {
+    /// Only log error messages.
+    Error,
+    /// Log error messages and warnings.
+    Warning,
+    /// Log error messages, warnings and info messages.
+    Info,
+    /// Log error messages, warnings, info messages and debug messages.
+    DebugL1,
+    /// Log error messages, warnings, info messages and detailed debug
+    /// messages.
+    Debug,
+    /// Log error messages, warnings, info messages and very detailed debug
+    /// messages.
+    DebugL2,
+}
+
+pub fn owned_str_from_ptr(ptr: *const c_char) -> String {
+    unsafe {
+        return CStr::from_ptr(ptr).to_string_lossy().into_owned();
+    }
+}
+
+pub fn result_from_string(ptr: *const c_char) -> Result<String, CommandError> {
+    if ptr.is_null() {
+        return Err(CommandError::Unknown);
+    }
+    unsafe {
+        let s = owned_str_from_ptr(ptr);
+        if s.is_empty() {
+            return Err(get_last_error());
+        }
+        // TODO: move up for newer libnitrokey versions
+        free(ptr as *mut c_void);
+        return Ok(s);
+    }
+}
+
+pub fn get_last_status() -> CommandStatus {
+    unsafe {
+        let status = nitrokey_sys::NK_get_last_command_status();
+        return CommandStatus::from(status as c_int);
+    }
+}
+
+pub fn get_last_error() -> CommandError {
+    return match get_last_status() {
+        CommandStatus::Success => CommandError::Unknown,
+        CommandStatus::Error(err) => err,
+    };
+}
+
+pub fn generate_password(length: usize) -> std::io::Result<Vec<u8>> {
+    let mut rng = match OsRng::new() {
+        Ok(rng) => rng,
+        Err(err) => return Err(err),
+    };
+    let mut data = vec![0u8; length];
+    rng.fill_bytes(&mut data[..]);
+    return Ok(data);
+}
+
+impl From<c_int> for CommandError {
+    fn from(value: c_int) -> Self {
+        match value {
+            1 => CommandError::WrongCrc,
+            2 => CommandError::WrongSlot,
+            3 => CommandError::SlotNotProgrammed,
+            4 => CommandError::WrongPassword,
+            5 => CommandError::NotAuthorized,
+            6 => CommandError::Timestamp,
+            7 => CommandError::NoName,
+            8 => CommandError::NotSupported,
+            9 => CommandError::UnknownCommand,
+            10 => CommandError::AesDecryptionFailed,
+            201 => CommandError::InvalidSlot,
+            _ => CommandError::Unknown,
+        }
+    }
+}
+
+impl From<c_int> for CommandStatus {
+    fn from(value: c_int) -> Self {
+        match value {
+            0 => CommandStatus::Success,
+            other => CommandStatus::Error(CommandError::from(other)),
+        }
+    }
+}
+
+impl Into<i32> for LogLevel {
+    fn into(self) -> i32 {
+        match self {
+            LogLevel::Error => 0,
+            LogLevel::Warning => 1,
+            LogLevel::Info => 2,
+            LogLevel::DebugL1 => 3,
+            LogLevel::Debug => 4,
+            LogLevel::DebugL2 => 5,
+        }
+    }
+}