add padding with point to bytes (#54)

WeBankBlockchain · Apr 13, 2024 · ffeaaab · ffeaaab
1 parent ab00740
commit ffeaaab
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Showing 2 changed files with 112 additions and 14 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crypto/zkp/utils/src/lib.rs b/crypto/zkp/utils/src/lib.rs
@@ -394,22 +394,60 @@ pub fn point_to_slice(point: &RistrettoPoint) -> [u8; 32] {
 }
 
 /// Converts a vector to RistrettoPoint.
+// pub fn bytes_to_point(point: &[u8]) -> Result<RistrettoPoint, WedprError> {
+//     if point.len() != RISTRETTO_POINT_SIZE_IN_BYTES {
+//         wedpr_println!("bytes_to_point decode failed");
+//         return Err(WedprError::FormatError);
+//     }
+//     let point_value = match CompressedRistretto::from_slice(&point).decompress()
+//     {
+//         Some(v) => v,
+//         None => {
+//             wedpr_println!(
+//                 "bytes_to_point decompress CompressedRistretto failed"
+//             );
+//             return Err(WedprError::FormatError);
+//         },
+//     };
+//     Ok(point_value)
+// }
+
+/// Bytes to point with padding
 pub fn bytes_to_point(point: &[u8]) -> Result<RistrettoPoint, WedprError> {
-    if point.len() != RISTRETTO_POINT_SIZE_IN_BYTES {
-        wedpr_println!("bytes_to_point decode failed");
+    if point.len() > RISTRETTO_POINT_SIZE_IN_BYTES {
+        wedpr_println!("bytes_to_point decode failed, point: {:?}", point);
         return Err(WedprError::FormatError);
     }
-    let point_value = match CompressedRistretto::from_slice(&point).decompress()
-    {
-        Some(v) => v,
-        None => {
-            wedpr_println!(
-                "bytes_to_point decompress CompressedRistretto failed"
+    if point.len() < RISTRETTO_POINT_SIZE_IN_BYTES {
+        let padding = vec![0; RISTRETTO_POINT_SIZE_IN_BYTES - point.len()];
+        let mut padded_point = padding;
+        padded_point.extend_from_slice(point);
+        let point_value = match CompressedRistretto::from_slice(&padded_point).decompress()
+        {
+            Some(v) => v,
+            None => {
+                wedpr_println!(
+                "bytes_to_point decompress CompressedRistretto failed, padded_point:{:?}, point: {:?}", padded_point, point
             );
-            return Err(WedprError::FormatError);
-        },
-    };
-    Ok(point_value)
+                return Err(WedprError::FormatError);
+            },
+        };
+        Ok(point_value)
+    }
+    else {
+        let point_value = match CompressedRistretto::from_slice(&point).decompress()
+        {
+            Some(v) => v,
+            None => {
+                wedpr_println!(
+                "bytes_to_point decompress CompressedRistretto failed, point:{:?}", point
+            );
+                return Err(WedprError::FormatError);
+            },
+        };
+        Ok(point_value)
+    }
+
 }
 
 /// Gets a random u32 integer.
@@ -418,3 +456,65 @@ pub fn get_random_u32() -> u32 {
     let blinding: u32 = rng.gen();
     blinding
 }
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_point_length()
+    {
+        let count = 10000;
+        println!("run {} times", count);
+        for i in 0..count {
+            let random_scalar = get_random_scalar();
+            let random_point1 = *BASEPOINT_G1 * random_scalar;
+            let new_point_vec1 = point_to_bytes(&random_point1);
+            assert_eq!(new_point_vec1.len(), 32);
+        }
+    }
+
+    #[test]
+    fn test_point_padding()
+    {
+        let re_slice  = [0, 219, 114, 57, 172, 179, 141, 252, 215, 70, 84, 226, 211, 59, 127, 202, 166, 66, 113, 48, 223, 179, 56, 123, 205, 134, 62, 12, 175, 172, 250, 108];
+        let re_vector = re_slice.to_vec();
+        let re_point = bytes_to_point( &re_vector).unwrap();
+        let re_re_vector = point_to_bytes(&re_point);
+        assert_eq!(re_re_vector, re_vector);
+
+        let re_slice_31 = [219, 114, 57, 172, 179, 141, 252, 215, 70, 84, 226, 211, 59, 127, 202, 166, 66, 113, 48, 223, 179, 56, 123, 205, 134, 62, 12, 175, 172, 250, 108];
+        let re_vector_31 = re_slice_31.to_vec();
+        let re_point_with_padding = bytes_to_point( &re_vector_31).unwrap();
+        let re_point_vector = point_to_bytes(&re_point_with_padding);
+        assert_eq!(re_vector, re_point_vector);
+
+    }
+
+    #[test]
+    fn test_point_random_padding()
+    {
+        let count = 10000;
+        let mut times = 0;
+        println!("run {} times", count);
+
+        for i in 0..count {
+            let random_scalar = get_random_scalar();
+            let random_point1 = *BASEPOINT_G1 * random_scalar;
+            let new_point_vec1 = point_to_bytes(&random_point1);
+            let mut mut_new_point_vec1 = new_point_vec1.clone();
+            if mut_new_point_vec1[0] == 0u8 {
+                mut_new_point_vec1.remove(0);
+                times = times + 1;
+            }
+            let re_point_with_padding = bytes_to_point( &mut_new_point_vec1).unwrap();
+            let re_point_vector = point_to_bytes(&re_point_with_padding);
+            assert_eq!(new_point_vec1, re_point_vector);
+        }
+        println!("padding {} times", times);
+    }
+
+
+}
+