keyfork-shard: traitify functionality

crates/keyfork-shard/src/lib.rs

@@ -180,9 +180,7 @@ pub trait Format {
         // receive remote data via scanning QR code from camera
         #[cfg(feature = "qrcode")]
         {
-            pm.prompt_message(PromptMessage::Text(
-                "Press enter, then present QR code to camera".to_string(),
-            ))?;
+            pm.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
             if let Ok(Some(hex)) =
                 keyfork_qrcode::scan_camera(std::time::Duration::from_secs(30), 0)
             {
@@ -190,9 +188,7 @@ pub trait Format {
                 nonce_data = Some(decoded_data[..12].try_into().map_err(|_| InvalidData)?);
                 pubkey_data = Some(decoded_data[12..].try_into().map_err(|_| InvalidData)?)
             } else {
-                pm.prompt_message(PromptMessage::Text(
-                    "Unable to detect QR code, falling back to text".to_string(),
-                ))?;
+                pm.prompt_message(PromptMessage::Text(QRCODE_ERROR.to_string()))?;
             };
         }
 
@@ -203,8 +199,12 @@ pub trait Format {
                 let validator = MnemonicSetValidator {
                     word_lengths: [9, 24],
                 };
-                let [nonce_mnemonic, pubkey_mnemonic] =
-                    pm.prompt_validated_wordlist("Their words: ", &wordlist, 3, validator.to_fn())?;
+                let [nonce_mnemonic, pubkey_mnemonic] = pm.prompt_validated_wordlist(
+                    QRCODE_COULDNT_READ,
+                    &wordlist,
+                    3,
+                    validator.to_fn(),
+                )?;
 
                 let nonce = nonce_mnemonic
                     .as_bytes()
@@ -279,13 +279,21 @@ pub trait Format {
             use keyfork_qrcode::{qrencode, ErrorCorrection};
             let mut qrcode_data = our_pubkey_mnemonic.to_bytes();
             qrcode_data.extend(payload_mnemonic.as_bytes());
-            if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Lowest) {
+            if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) {
+                pm.prompt_message(PromptMessage::Text(
+                    concat!(
+                        "A QR code will be displayed after this prompt. ",
+                        "Send the QR code back to the operator combining the shards. ",
+                        "Nobody else should scan this QR code."
+                    )
+                    .to_string(),
+                ))?;
                 pm.prompt_message(PromptMessage::Data(qrcode))?;
             }
         }
 
         pm.prompt_message(PromptMessage::Text(format!(
-            "Our words: {our_pubkey_mnemonic} {payload_mnemonic}"
+            "Upon request, these words should be sent: {our_pubkey_mnemonic} {payload_mnemonic}"
         )))?;
 
         Ok(())