loose with padding in indy-utils (#1055)

Signed-off-by: George Mulhearn <[email protected]>

libvdrtools/indy-utils/src/crypto/base64/rust_base64.rs

@@ -1,6 +1,17 @@
-use base64::{engine::general_purpose, Engine};
+use base64::{
+    alphabet,
+    engine::{general_purpose, DecodePaddingMode, GeneralPurpose, GeneralPurposeConfig},
+    Engine,
+};
 use indy_api_types::errors::prelude::*;
 
+/// Default general purpose configuration, but padding decode mode of 'indifferent' (will decode
+/// either)
+const ANY_PADDING: GeneralPurposeConfig =
+    GeneralPurposeConfig::new().with_decode_padding_mode(DecodePaddingMode::Indifferent);
+/// Standard Base64 URL Safe decoding and encoding, with indifference for padding mode when decoding
+const URL_SAFE_ANY_PADDING: GeneralPurpose = GeneralPurpose::new(&alphabet::URL_SAFE, ANY_PADDING);
+
 pub fn encode(doc: &[u8]) -> String {
     general_purpose::STANDARD.encode(doc)
 }
@@ -16,7 +27,7 @@ pub fn encode_urlsafe(doc: &[u8]) -> String {
 }
 
 pub fn decode_urlsafe(doc: &str) -> Result<Vec<u8>, IndyError> {
-    general_purpose::URL_SAFE.decode(doc).map_err(|e| {
+    URL_SAFE_ANY_PADDING.decode(doc).map_err(|e| {
         e.to_indy(
             IndyErrorKind::InvalidStructure,
             "Invalid base64URL_SAFE sequence",
@@ -55,4 +66,13 @@ mod tests {
         assert!(result.is_ok(), "Got error");
         assert_eq!(&[1, 2, 3], &result.unwrap()[..]);
     }
+
+    #[test]
+    fn decode_urlsafe_works_with_or_without_padding() {
+        let result = decode_urlsafe("YWJjZA==");
+        assert_eq!(vec![97, 98, 99, 100], result.unwrap());
+
+        let result = decode_urlsafe("YWJjZA");
+        assert_eq!(vec![97, 98, 99, 100], result.unwrap());
+    }
 }