1 files changed, 23 insertions, 9 deletions
diff --git a/third_party/rust/prio/src/vdaf/prio2/test_vector.rs b/third_party/rust/prio/src/vdaf/prio2/test_vector.rs
index ae2b8b0f9d..114b437b55 100644
--- a/third_party/rust/prio/src/vdaf/prio2/test_vector.rs
+++ b/third_party/rust/prio/src/vdaf/prio2/test_vector.rs
@@ -48,9 +48,16 @@ mod base64 {
     //! instead of an array of an array of integers when serializing to JSON.
     //
     // Thank you, Alice! https://users.rust-lang.org/t/serialize-a-vec-u8-to-json-as-base64/57781/2
-    use crate::field::{FieldElement, FieldPrio2};
+    use crate::{
+        codec::ParameterizedDecode,
+        field::{encode_fieldvec, FieldElement, FieldPrio2},
+        vdaf::{Share, ShareDecodingParameter},
+    };
+    use assert_matches::assert_matches;
     use base64::{engine::Engine, prelude::BASE64_STANDARD};
-    use serde::{de::Error, Deserialize, Deserializer, Serialize, Serializer};
+    use serde::{
+        de::Error as _, ser::Error as _, Deserialize, Deserializer, Serialize, Serializer,
+    };
 
     pub fn serialize_bytes<S: Serializer>(v: &[Vec<u8>], s: S) -> Result<S::Ok, S::Error> {
         let base64_vec = v
@@ -63,21 +70,28 @@ mod base64 {
     pub fn deserialize_bytes<'de, D: Deserializer<'de>>(d: D) -> Result<Vec<Vec<u8>>, D::Error> {
         <Vec<String>>::deserialize(d)?
             .iter()
-            .map(|s| BASE64_STANDARD.decode(s.as_bytes()).map_err(Error::custom))
+            .map(|s| {
+                BASE64_STANDARD
+                    .decode(s.as_bytes())
+                    .map_err(D::Error::custom)
+            })
             .collect()
     }
 
     pub fn serialize_field<S: Serializer>(v: &[FieldPrio2], s: S) -> Result<S::Ok, S::Error> {
-        String::serialize(
-            &BASE64_STANDARD.encode(FieldPrio2::slice_into_byte_vec(v)),
-            s,
-        )
+        let mut bytes = Vec::new();
+        encode_fieldvec(v, &mut bytes).map_err(S::Error::custom)?;
+        String::serialize(&BASE64_STANDARD.encode(&bytes), s)
     }
 
     pub fn deserialize_field<'de, D: Deserializer<'de>>(d: D) -> Result<Vec<FieldPrio2>, D::Error> {
         let bytes = BASE64_STANDARD
             .decode(String::deserialize(d)?.as_bytes())
-            .map_err(Error::custom)?;
-        FieldPrio2::byte_slice_into_vec(&bytes).map_err(Error::custom)
+            .map_err(D::Error::custom)?;
+        let decoding_parameter =
+            ShareDecodingParameter::<32>::Leader(bytes.len() / FieldPrio2::ENCODED_SIZE);
+        let share = Share::<FieldPrio2, 32>::get_decoded_with_param(&decoding_parameter, &bytes)
+            .map_err(D::Error::custom)?;
+        assert_matches!(share, Share::Leader(vec) => Ok(vec))
     }
 }