1 files changed, 31 insertions, 0 deletions
diff --git a/ext/crypto/shared.rs b/ext/crypto/shared.rs
index 696b1c087..1af0169ef 100644
--- a/ext/crypto/shared.rs
+++ b/ext/crypto/shared.rs
@@ -1,8 +1,12 @@
 use std::borrow::Cow;
 
 use deno_core::error::custom_error;
+use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::ZeroCopyBuf;
+use rsa::pkcs1::FromRsaPrivateKey;
+use rsa::pkcs1::ToRsaPublicKey;
+use rsa::RsaPrivateKey;
 use serde::Deserialize;
 use serde::Serialize;
 
@@ -61,6 +65,33 @@ pub enum RawKeyData {
   Public(ZeroCopyBuf),
 }
 
+impl RawKeyData {
+  pub fn as_rsa_public_key(&self) -> Result<Cow<'_, [u8]>, AnyError> {
+    match self {
+      RawKeyData::Public(data) => Ok(Cow::Borrowed(data)),
+      RawKeyData::Private(data) => {
+        let private_key = RsaPrivateKey::from_pkcs1_der(data)
+          .map_err(|_| type_error("expected valid private key"))?;
+
+        let public_key_doc = private_key
+          .to_public_key()
+          .to_pkcs1_der()
+          .map_err(|_| type_error("expected valid public key"))?;
+
+        Ok(Cow::Owned(public_key_doc.as_der().into()))
+      }
+      _ => Err(type_error("expected public key")),
+    }
+  }
+
+  pub fn as_rsa_private_key(&self) -> Result<&[u8], AnyError> {
+    match self {
+      RawKeyData::Private(data) => Ok(data),
+      _ => Err(type_error("expected private key")),
+    }
+  }
+}
+
 pub fn data_error(msg: impl Into<Cow<'static, str>>) -> AnyError {
   custom_error("DOMExceptionDataError", msg)
 }