firmware: return mnemonic as bytes in debug link

firmware/config.c

@@ -172,6 +172,18 @@ static secbool config_get_bool(uint16_t key, bool *value)
     }
 }
 
+static secbool config_get_bytes(uint16_t key, uint8_t *dest, uint16_t dest_size, uint16_t *real_size)
+{
+    if (dest_size == 0) {
+        return secfalse;
+    }
+
+    if (sectrue != storage_get(key, dest, dest_size, real_size)) {
+        return secfalse;
+    }
+    return sectrue;
+}
+
 static secbool config_get_string(uint16_t key, char *dest, uint16_t dest_size)
 {
     if (dest_size == 0) {
@@ -688,6 +700,11 @@ bool config_setMnemonic(const char *mnemonic)
     return true;
 }
 
+bool config_getMnemonicBytes(uint8_t *dest, uint16_t dest_size, uint16_t *real_size)
+{
+    return sectrue == config_get_bytes(KEY_MNEMONIC, dest, dest_size, real_size);
+}
+
 bool config_getMnemonic(char *dest, uint16_t dest_size)
 {
     return sectrue == config_get_string(KEY_MNEMONIC, dest, dest_size);

firmware/config.h

@@ -114,6 +114,7 @@ bool session_getState(const uint8_t *salt, uint8_t *state, const char *passphras
 bool config_setMnemonic(const char *mnemonic);
 bool config_containsMnemonic(const char *mnemonic);
 bool config_getMnemonic(char *dest, uint16_t dest_size);
+bool config_getMnemonicBytes(uint8_t *dest, uint16_t dest_size, uint16_t *real_size);
 
 #if DEBUG_LINK
 bool config_dumpNode(HDNodeType *node);

firmware/fsm_msg_debug.h

@@ -49,7 +49,8 @@ void fsm_msgDebugLinkGetState(const DebugLinkGetState *msg)
 	resp.has_recovery_word_pos = true;
 	resp.recovery_word_pos = recovery_get_word_pos();
 
-	resp.has_mnemonic = config_getMnemonic(resp.mnemonic, sizeof(resp.mnemonic));
+	resp.has_mnemonic_secret = config_getMnemonicBytes(resp.mnemonic_secret.bytes, sizeof(resp.mnemonic_secret.bytes), &resp.mnemonic_secret.size);
+	resp.mnemonic_type = 0;  // BIP-39
 
 	resp.has_node = config_dumpNode(&(resp.node));
 

firmware/protob/messages-debug.options

@@ -3,7 +3,7 @@ DebugLinkDecision.input                 max_size:33
 DebugLinkState.layout                   max_size:1024
 DebugLinkState.pin                      max_size:10
 DebugLinkState.matrix                   max_size:10
-DebugLinkState.mnemonic                 max_size:241
+DebugLinkState.mnemonic_secret          max_size:240
 DebugLinkState.reset_word               max_size:12
 DebugLinkState.reset_entropy            max_size:128
 DebugLinkState.recovery_fake_word       max_size:12