pkstrings: Split Invalid errors

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

pkstrings/src/pkstring.rs

@@ -88,13 +88,15 @@ const fn hextostr(hex: u8) -> Option<char> {
 
 #[derive(Debug, Eq, PartialEq)]
 pub enum Error {
-    InvalidCharacter,
+    InvalidByte(u8),
+    InvalidCharacter(char),
 }
 
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         match self {
-            Error::InvalidCharacter => write!(f, "Invalid character"),
+            Error::InvalidByte(ord) => write!(f, "Invalid byte: {:?}", ord),
+            Error::InvalidCharacter(chr) => write!(f, "Invalid character: {:?}", chr),
         }
     }
 }
@@ -124,7 +126,7 @@ impl TryFrom<u8> for PKString {
 
         match hextostr(ord) {
             Some(chr) => buf.push(chr.clone()),
-            None => return Err(Error::InvalidCharacter),
+            None => return Err(Error::InvalidByte(ord)),
         }
 
         Ok(PKString(buf))
@@ -140,7 +142,7 @@ impl TryFrom<&[u8]> for PKString {
         for ord in data {
             match hextostr(*ord) {
                 Some(chr) => buf.push(chr.clone()),
-                None => return Err(Error::InvalidCharacter),
+                None => return Err(Error::InvalidByte(*ord)),
             }
         }
 
@@ -170,7 +172,7 @@ impl TryFrom<String> for PKString {
     fn try_from(data: String) -> Result<PKString, Error> {
         for chr in data.chars() {
             if strtohex(&chr).is_none() {
-                return Err(Error::InvalidCharacter);
+                return Err(Error::InvalidCharacter(chr));
             }
         }