Add simple ReadSlotName command implementation

This patch adds a simple implementation for the command ReadSlotName
that provides access to the names of TOTP and HOTP slots.  It returns
the name test for the first TOTP slot and the SlotNotProgrammed error
for all other slots.

2 files changed, 16 insertions, 1 deletions

diff --git a/README.md b/README.md
index 3a9512f..a31e315 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ development and supports:
 - connecting as a HID class device
 - using these Nitrokey commands:
   - `GET_STATUS`
+  - `READ_SLOT_NAME`
 
 ## Resources
 
diff --git a/src/device.rs b/src/device.rs
index 960f698..9ffc39a 100644
--- a/src/device.rs
+++ b/src/device.rs
@@ -50,6 +50,7 @@ enum_u8! {
     #[derive(Clone, Copy, Debug, PartialEq)]
     pub enum CommandId {
         GetStatus = 0,
+        ReadSlotName = 2,
     }
 }
 
@@ -69,7 +70,6 @@ impl Nitrokey {
         command_id: CommandId,
         data: &[u8],
     ) -> Result<[u8; 53], CommandStatus> {
-        let _ = data;
         match command_id {
             CommandId::GetStatus => {
                 let mut data = [0u8; 53];
@@ -85,6 +85,20 @@ impl Nitrokey {
                 data[9] = 0; // delete_user_password
                 Ok(data)
             }
+            CommandId::ReadSlotName => {
+                assert!(data.len() > 1);
+                let slot_number = data[0];
+                if slot_number != 0x20 {
+                    Err(CommandStatus::SlotNotProgrammed)
+                } else {
+                    let mut data = [0u8; 53];
+                    data[0] = 0x74; // t
+                    data[1] = 0x65; // e
+                    data[2] = 0x73; // s
+                    data[3] = 0x74; // t
+                    Ok(data)
+                }
+            }
         }
     }
 }