1 files changed, 18 insertions, 1 deletions
diff --git a/pkgs/build-support/node/fetch-npm-deps/src/util.rs b/pkgs/build-support/node/fetch-npm-deps/src/util.rs
index 7dd928fdc43fa..023ba56793b90 100644
--- a/pkgs/build-support/node/fetch-npm-deps/src/util.rs
+++ b/pkgs/build-support/node/fetch-npm-deps/src/util.rs
@@ -1,10 +1,18 @@
 use backoff::{retry, ExponentialBackoff};
+use data_encoding::BASE64;
+use digest::Digest;
 use isahc::{
     config::{CaCertificate, Configurable, RedirectPolicy, SslOption},
     Body, Request, RequestExt,
 };
+use nix_nar::{Encoder, NarError};
 use serde_json::{Map, Value};
-use std::{env, io::Read, path::Path};
+use sha2::Sha256;
+use std::{
+    env,
+    io::{self, Read},
+    path::Path,
+};
 use url::Url;
 
 pub fn get_url(url: &Url) -> Result<Body, isahc::Error> {
@@ -64,3 +72,12 @@ pub fn get_url_body_with_retry(url: &Url) -> Result<Vec<u8>, isahc::Error> {
         } => err,
     })
 }
+
+pub fn make_sri_hash(path: &Path) -> Result<String, NarError> {
+    let mut encoder = Encoder::new(path)?;
+    let mut hasher = Sha256::new();
+
+    io::copy(&mut encoder, &mut hasher)?;
+
+    Ok(format!("sha256-{}", BASE64.encode(&hasher.finalize())))
+}