From cf2c6712bd7342406e799110e7cd465aa250cdca Mon Sep 17 00:00:00 2001
From: Cole Helbling <cole.e.helbling@outlook.com>
Date: Mon, 13 Feb 2023 14:19:05 -0800
Subject: [PATCH] config: convert PEM to DER format on the fly

hubcaps requires a DER formatted key, but their instructions for
converting PEM to DER didn't work for me. So, we rely on rustls-pemfile
to parse the PEM key into DER bytes and hand that to hubcaps.
---
 Cargo.lock           | 13 ++++++++++---
 ofborg/Cargo.toml    |  1 +
 ofborg/src/config.rs | 13 ++++++++++---
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 91d40b5..09b31ad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -258,6 +258,12 @@ version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
 
+[[package]]
+name = "base64"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a4ddaa51a5bc52a6948f74c06d20aaaddb71924eab79b8c97a8c556e942d6a"
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -1297,6 +1303,7 @@ dependencies = [
  "md5",
  "nom 4.2.3",
  "regex",
+ "rustls-pemfile",
  "separator",
  "serde",
  "serde_derive",
@@ -1678,11 +1685,11 @@ dependencies = [
 
 [[package]]
 name = "rustls-pemfile"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0864aeff53f8c05aa08d86e5ef839d3dfcf07aeba2db32f12db0ef716e87bd55"
+checksum = "d194b56d58803a43635bdc398cd17e383d6f71f9182b9a192c127ca42494a59b"
 dependencies = [
- "base64 0.13.1",
+ "base64 0.21.0",
 ]
 
 [[package]]
diff --git a/ofborg/Cargo.toml b/ofborg/Cargo.toml
index 49fb829..9029188 100644
--- a/ofborg/Cargo.toml
+++ b/ofborg/Cargo.toml
@@ -32,3 +32,4 @@ tempfile = "3.3.0"
 tracing = "0.1.37"
 tracing-subscriber = { version = "0.3.16", features = ["json", "env-filter"] }
 uuid = { version = "1.2", features = ["v4"] }
+rustls-pemfile = "1.0.2"
diff --git a/ofborg/src/config.rs b/ofborg/src/config.rs
index 9e97dce..c095cfe 100644
--- a/ofborg/src/config.rs
+++ b/ofborg/src/config.rs
@@ -4,7 +4,7 @@ use crate::nix::Nix;
 use std::collections::HashMap;
 use std::fmt;
 use std::fs::File;
-use std::io::Read;
+use std::io::{BufReader, Read};
 use std::marker::PhantomData;
 use std::path::{Path, PathBuf};
 
@@ -183,8 +183,15 @@ impl GithubAppVendingMachine {
     }
 
     fn jwt(&self) -> JWTCredentials {
-        let key = std::fs::read(self.conf.private_key.clone()).expect("Unable to read private_key");
-        JWTCredentials::new(self.conf.app_id, key).expect("Unable to create JWTCredentials")
+        let private_key_file =
+            File::open(self.conf.private_key.clone()).expect("Unable to read private_key");
+        let mut private_key_reader = BufReader::new(private_key_file);
+        let private_keys = rustls_pemfile::rsa_private_keys(&mut private_key_reader)
+            .expect("Unable to convert private_key to DER format");
+        // We can be reasonably certain that there will only be one private key in this file
+        let private_key = &private_keys[0];
+        JWTCredentials::new(self.conf.app_id, private_key.to_vec())
+            .expect("Unable to create JWTCredentials")
     }
 
     fn install_id_for_repo(&mut self, owner: &str, repo: &str) -> Option<u64> {