2 files changed, 36 insertions, 1 deletions
diff --git a/cli/tests/unit/webcrypto_test.ts b/cli/tests/unit/webcrypto_test.ts
index a6cab93dd..6695b157a 100644
--- a/cli/tests/unit/webcrypto_test.ts
+++ b/cli/tests/unit/webcrypto_test.ts
@@ -1827,3 +1827,30 @@ Deno.test(async function exportKeyNotExtractable() {
     await crypto.subtle.exportKey("raw", key);
   }, DOMException);
 });
+
+// https://github.com/denoland/deno/issues/15126
+Deno.test(async function testImportLeadingZeroesKey() {
+  const alg = { name: "ECDSA", namedCurve: "P-256" };
+
+  const jwk = {
+    kty: "EC",
+    crv: "P-256",
+    alg: "ES256",
+    x: "EvidcdFB1xC6tgfakqZsU9aIURxAJkcX62zHe1Nt6xU",
+    y: "AHsk6BioGM7MZWeXOE_49AGmtuaXFT3Ill3DYtz9uYg",
+    d: "WDeYo4o1heCF9l_2VIaClRyIeO16zsMlN8UG6Le9dU8",
+    "key_ops": ["sign"],
+    ext: true,
+  };
+
+  const key = await crypto.subtle.importKey(
+    "jwk",
+    jwk,
+    alg,
+    true,
+    ["sign"],
+  );
+
+  assert(key instanceof CryptoKey);
+  assertEquals(key.type, "private");
+});
diff --git a/ext/crypto/import_key.rs b/ext/crypto/import_key.rs
index 015ee41d5..225950aa7 100644
--- a/ext/crypto/import_key.rs
+++ b/ext/crypto/import_key.rs
@@ -637,7 +637,15 @@ fn decode_b64url_to_field_bytes<C: elliptic_curve::Curve>(
   jwt_b64_int_or_err!(val, b64, "invalid b64 coordinate");
 
   let mut bytes = elliptic_curve::FieldBytes::<C>::default();
-  let val = val.as_bytes();
+  let original_bytes = val.as_bytes();
+  let mut new_bytes: Vec<u8> = vec![];
+  if original_bytes.len() < bytes.len() {
+    new_bytes = vec![0; bytes.len() - original_bytes.len()];
+  }
+  new_bytes.extend_from_slice(original_bytes);
+
+  let val = new_bytes.as_slice();
+
   if val.len() != bytes.len() {
     return Err(data_error("invalid b64 coordinate"));
   }