LibCrypto: Add PEM encoder

This commit adds a new method to create a PEM encoded ASN1 from its DER variant.
cubiclove · Apr 4, 2023 · 8b881ea · 8b881ea
1 parent 7ce75ee
commit 8b881ea
Show file tree

Hide file tree

Showing 2 changed files with 42 additions and 0 deletions.
diff --git a/Userland/Libraries/LibCrypto/ASN1/PEM.cpp b/Userland/Libraries/LibCrypto/ASN1/PEM.cpp
@@ -93,4 +93,40 @@ ErrorOr<Vector<ByteBuffer>> decode_pems(ReadonlyBytes data)
  return pems;
 }
 
+ErrorOr<ByteBuffer> encode_pem(ReadonlyBytes data, PEMType type)
+{
+ ByteBuffer encoded;
+ StringView block_start;
+ StringView block_end;
+
+ switch (type) {
+ case Certificate:
+ block_start = "-----BEGIN CERTIFICATE-----\n"sv;
+ block_end = "-----END CERTIFICATE-----\n"sv;
+ break;
+ case PrivateKey:
+ block_start = "-----BEGIN PRIVATE KEY-----\n"sv;
+ block_end = "-----END PRIVATE KEY-----\n"sv;
+ break;
+ default:
+ VERIFY_NOT_REACHED();
+ }
+
+ auto b64encoded = TRY(encode_base64(data));
+
+ TRY(encoded.try_append(block_start.bytes()));
+
+ size_t to_read = 64;
+ for (size_t i = 0; i < b64encoded.bytes().size(); i += to_read) {
+ if (i + to_read > b64encoded.bytes().size())
+ to_read = b64encoded.bytes().size() - i;
+ TRY(encoded.try_append(b64encoded.bytes().slice(i, to_read)));
+ TRY(encoded.try_append("\n"sv.bytes()));
+ }
+
+ TRY(encoded.try_append(block_end.bytes()));
+
+ return encoded;
+}
+
 }
diff --git a/Userland/Libraries/LibCrypto/ASN1/PEM.h b/Userland/Libraries/LibCrypto/ASN1/PEM.h
@@ -12,7 +12,13 @@
 
 namespace Crypto {
 
+enum PEMType {
+ Certificate,
+ PrivateKey,
+};
+
 ByteBuffer decode_pem(ReadonlyBytes);
 ErrorOr<Vector<ByteBuffer>> decode_pems(ReadonlyBytes);
+ErrorOr<ByteBuffer> encode_pem(ReadonlyBytes, PEMType = PEMType::Certificate);
 
 }