Address some of Cory's feedback

Author: yim-lee

Sources/PackageCollectionsSigning/Certificate/Certificate.swift

@@ -155,8 +155,7 @@ final class BoringSSLCertificate {
             throw CertificateError.keyExtractionFailure
         }
 
-        let bytes = UnsafeBufferPointer(start: buffer, count: Int(length)).map { $0 }
-        let data = Data(bytes)
+        let data = Data(UnsafeBufferPointer(start: buffer, count: Int(length)))
 
         switch try self.keyType(of: key) {
         case .RSA:
@@ -217,7 +216,7 @@ private extension UnsafeMutablePointer where Pointee == X509_NAME {
             return nil
         }
 
-        return value.map { String(validatingUTF8: $0) } ?? nil
+        return String.decodeCString(value, as: UTF8.self, repairingInvalidCodeUnits: true)?.result
     }
 }
 

Sources/PackageCollectionsSigning/Key/BoringSSLKey.swift

@@ -30,21 +30,23 @@ protocol BoringSSLKey {}
 
 extension BoringSSLKey {
     // Source: https://github.com/vapor/jwt-kit/blob/master/Sources/JWTKit/Utilities/OpenSSLSigner.swift
-    static func load<Data, T>(pem data: Data,
-                              _ closure: (UnsafeMutablePointer<BIO>) -> (T?)) throws -> T where Data: DataProtocol {
+    static func load<Data, KeyType>(pem data: Data,
+                                    _ createKey: (UnsafeMutablePointer<BIO>) -> (KeyType?)) throws -> KeyType where Data: DataProtocol {
         let bytes = data.copyBytes()
 
+        // Not doing `CCryptoBoringSSL_BIO_new_mem_buf(bytes, numericCast(bytes.count))` because
+        // it causes `bioConversionFailure` error on *some* Linux builds (e.g., SPM Linux smoke test)
         let bio = CCryptoBoringSSL_BIO_new(CCryptoBoringSSL_BIO_s_mem())
         defer { CCryptoBoringSSL_BIO_free(bio) }
 
         guard let bioPointer = bio, CCryptoBoringSSL_BIO_write(bioPointer, bytes, numericCast(bytes.count)) > 0 else {
             throw BoringSSLKeyError.bioInitializationFailure
         }
-        guard let result = closure(bioPointer) else {
+        guard let key = createKey(bioPointer) else {
             throw BoringSSLKeyError.bioConversionFailure
         }
 
-        return result
+        return key
     }
 }