take into account zero input

Author: fgimenez

crates/precompile/src/bls12_381.rs

@@ -42,6 +42,23 @@ fn add_padding(input: [u8; 96]) -> [u8; OUTPUT_LENGTH] {
     output
 }
 
+// Wrapper around G1Affine::from_uncompressed to handle the case in which all
+// the input bytes are zero, which should represent the infinity point in the
+// curve.
+fn g1_affine_from_uncompressed(input: [u8; 96]) -> Result<G1Affine, PrecompileError> {
+    if input == [0; 96] {
+        Ok(G1Affine::identity())
+    } else {
+        let output = G1Affine::from_uncompressed(&input);
+        if (!output.is_some()).into() {
+            return Err(PrecompileError::Other(
+                "The given input did not represent a valid elliptic curve point".to_string(),
+            ));
+        }
+        Ok(output.unwrap())
+    }
+}
+
 fn extract_input(input: &[u8]) -> Result<[u8; 96], PrecompileError> {
     if input.len() != INPUT_LENGTH / 2 {
         return Err(PrecompileError::Other(format!(
@@ -78,19 +95,13 @@ fn g1_add(input: &Bytes, gas_limit: u64) -> PrecompileResult {
     }
 
     let input_p0 = extract_input(&input[..128])?;
-    let p0 = G1Affine::from_uncompressed(&input_p0);
-    if (!p0.is_some()).into() {
-        return Err(PrecompileError::Other("p0 was not a valid elliptic curve point".to_string()));
-    }
+    let p0 = g1_affine_from_uncompressed(input_p0)?;
 
     let input_p1 = extract_input(&input[128..])?;
-    let p1 = G1Affine::from_uncompressed(&input_p1);
-    if (!p1.is_some()).into() {
-        return Err(PrecompileError::Other("p1 was not a valid elliptic curve point".to_string()));
-    }
+    let p1 = g1_affine_from_uncompressed(input_p1)?;
 
-    let p1_projective: G1Projective = p1.unwrap().into();
-    let out = p0.unwrap().add(p1_projective);
+    let p1_projective: G1Projective = p1.into();
+    let out = p0.add(p1_projective);
     let out: G1Affine = out.into();
     let out_bytes = add_padding(out.to_uncompressed());
 
@@ -226,6 +237,8 @@ mod test {
     // test vectors from https://github.com/ethereum/go-ethereum/blob/master/core/vm/testdata/precompiles/blsG1Add.json and https://github.com/ethereum/go-ethereum/blob/master/core/vm/testdata/precompiles/fail-blsG1Add.json
     #[case::g1_plus_g1_equals_two_times_g1("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", "000000000000000000000000000000000572cbea904d67468808c8eb50a9450c9721db309128012543902d0ac358a62ae28f75bb8f1c7c42c39a8c5529bf0f4e00000000000000000000000000000000166a9d8cabc673a322fda673779d8e3822ba3ecb8670e461f73bb9021d5fd76a4c56d9d4cd16bd1bba86881979749d28", false, 500)]
     #[case::two_times_g1_plus_three_times_g1_equals_five_times_g1("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", "0000000000000000000000000000000010e7791fb972fe014159aa33a98622da3cdc98ff707965e536d8636b5fcc5ac7a91a8c46e59a00dca575af0f18fb13dc0000000000000000000000000000000016ba437edcc6551e30c10512367494bfb6b01cc6681e8a4c3cd2501832ab5c4abc40b4578b85cbaffbf0bcd70d67c6e2", false, 500)]
+    #[case::inf_plus_g1_equals_g1("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", "0000000000000000000000000000000017f1d3a73197d7942695638c4fa9ac0fc3688c4f9774b905a14e3a3f171bac586c55e83ff97a1aeffb3af00adb22c6bb0000000000000000000000000000000008b3f481e3aaa0f1a09e30ed741d8ae4fcf5e095d5d00af600db18cb2c04b3edd03cc744a2888ae40caa232946c5e7e1", false, 500)]
+    #[case::matter_g1_add_47("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", "0000000000000000000000000000000015b164c854a2277658f5d08e04887d896a082c6c20895c8809ed4b349da8492d6fa0333ace6059a1f0d37e92ae9bad30000000000000000000000000000000001510d176ddba09ab60bb452188c2705ef154f449bed26abf0255897673a625637b5761355b17676748f67844a61d4e9f", false, 500)]
     fn test_g1_add(
         #[case] input: &str,
         #[case] expected_output: &str,