Improve code style for the new DER package

okhttp-tls/src/main/kotlin/okhttp3/tls/HeldCertificate.kt

@@ -44,6 +44,11 @@ import okhttp3.tls.internal.der.CertificateAdapters.generalNameDnsName
 import okhttp3.tls.internal.der.CertificateAdapters.generalNameIpAddress
 import okhttp3.tls.internal.der.Extension
 import okhttp3.tls.internal.der.ObjectIdentifiers
+import okhttp3.tls.internal.der.ObjectIdentifiers.basicConstraints
+import okhttp3.tls.internal.der.ObjectIdentifiers.organizationalUnitName
+import okhttp3.tls.internal.der.ObjectIdentifiers.sha256WithRSAEncryption
+import okhttp3.tls.internal.der.ObjectIdentifiers.sha256withEcdsa
+import okhttp3.tls.internal.der.ObjectIdentifiers.subjectAlternativeName
 import okhttp3.tls.internal.der.TbsCertificate
 import okhttp3.tls.internal.der.Validity
 import okio.ByteString
@@ -187,8 +192,8 @@ class HeldCertificate(
   class Builder {
     private var notBefore = -1L
     private var notAfter = -1L
-    private var cn: String? = null
-    private var ou: String? = null
+    private var commonName: String? = null
+    private var organizationalUnit: String? = null
     private val altNames = mutableListOf<String>()
     private var serialNumber: BigInteger? = null
     private var keyPair: KeyPair? = null
@@ -240,12 +245,12 @@ class HeldCertificate(
      * [rfc_2818]: https://tools.ietf.org/html/rfc2818
      */
     fun commonName(cn: String) = apply {
-      this.cn = cn
+      this.commonName = cn
     }
 
     /** Sets the certificate's organizational unit (OU). If unset this field will be omitted. */
     fun organizationalUnit(ou: String) = apply {
-      this.ou = ou
+      this.organizationalUnit = ou
     }
 
     /** Sets this certificate's serial number. If unset the serial number will be 1. */
@@ -378,16 +383,16 @@ class HeldCertificate(
     private fun subject(): List<List<AttributeTypeAndValue>> {
       val result = mutableListOf<List<AttributeTypeAndValue>>()
 
-      if (ou != null) {
+      if (organizationalUnit != null) {
         result += listOf(AttributeTypeAndValue(
-            type = ObjectIdentifiers.organizationalUnitName,
-            value = ou
+            type = organizationalUnitName,
+            value = organizationalUnit
         ))
       }
 
       result += listOf(AttributeTypeAndValue(
           type = ObjectIdentifiers.commonName,
-          value = cn ?: UUID.randomUUID().toString()
+          value = commonName ?: UUID.randomUUID().toString()
       ))
 
       return result
@@ -407,11 +412,11 @@ class HeldCertificate(
 
       if (maxIntermediateCas != -1) {
         result += Extension(
-            extnID = ObjectIdentifiers.basicConstraints,
+            id = basicConstraints,
             critical = true,
-            extnValue = BasicConstraints(
+            value = BasicConstraints(
                 ca = true,
-                pathLenConstraint = 3
+                maxIntermediateCas = maxIntermediateCas.toLong()
             )
         )
       }
@@ -428,9 +433,9 @@ class HeldCertificate(
           }
         }
         result += Extension(
-            extnID = ObjectIdentifiers.subjectAlternativeName,
+            id = subjectAlternativeName,
             critical = true,
-            extnValue = extensionValue
+            value = extensionValue
         )
       }
 
@@ -440,20 +445,21 @@ class HeldCertificate(
     private fun signatureAlgorithm(signedByKeyPair: KeyPair): AlgorithmIdentifier {
       return when (signedByKeyPair.private) {
         is RSAPrivateKey -> AlgorithmIdentifier(
-            algorithm = ObjectIdentifiers.sha256WithRSAEncryption,
+            algorithm = sha256WithRSAEncryption,
             parameters = null
         )
         else -> AlgorithmIdentifier(
-            algorithm = ObjectIdentifiers.sha256withEcdsa,
+            algorithm = sha256withEcdsa,
             parameters = ByteString.EMPTY
         )
       }
     }
 
     private fun generateKeyPair(): KeyPair {
-      val keyPairGenerator = KeyPairGenerator.getInstance(keyAlgorithm)
-      keyPairGenerator.initialize(keySize, SecureRandom())
-      return keyPairGenerator.generateKeyPair()
+      return KeyPairGenerator.getInstance(keyAlgorithm).run {
+        initialize(keySize, SecureRandom())
+        generateKeyPair()
+      }
     }
 
     companion object {

okhttp-tls/src/main/kotlin/okhttp3/tls/internal/der/Adapters.kt

@@ -239,35 +239,29 @@ internal object Adapters {
   ): BasicDerAdapter<T> {
     val codec = object : BasicDerAdapter.Codec<T> {
       override fun decode(reader: DerReader): T {
-        reader.pushTypeHint()
-        try {
+        return reader.withTypeHint {
           val list = mutableListOf<Any?>()
 
           while (list.size < members.size) {
             val member = members[list.size]
-            list += member.readValue(reader)
+            list += member.fromDer(reader)
           }
 
           if (reader.hasNext()) {
-            throw IOException("unexpected ${reader.peekHeader()}")
+            throw IOException("unexpected ${reader.peekHeader()} at $reader")
           }
 
-          return construct(list)
-        } finally {
-          reader.popTypeHint()
+          return@withTypeHint construct(list)
         }
       }
 
       override fun encode(writer: DerWriter, value: T) {
         val list = decompose(value)
-        writer.pushTypeHint()
-        try {
+        writer.withTypeHint {
           for (i in list.indices) {
             val adapter = members[i] as DerAdapter<Any?>
-            adapter.writeValue(writer, list[i])
+            adapter.toDer(writer, list[i])
           }
-        } finally {
-          writer.popTypeHint()
         }
       }
     }
@@ -285,19 +279,19 @@ internal object Adapters {
     return object : DerAdapter<Pair<DerAdapter<*>, Any?>> {
       override fun matches(header: DerHeader): Boolean = true
 
-      override fun readValue(reader: DerReader): Pair<DerAdapter<*>, Any?> {
+      override fun fromDer(reader: DerReader): Pair<DerAdapter<*>, Any?> {
         val peekedHeader = reader.peekHeader()
-            ?: throw IOException("expected a value")
+            ?: throw IOException("expected a value at $reader")
 
         val choice = choices.firstOrNull { it.matches(peekedHeader) }
-            ?: throw IOException("expected a matching choice but was $peekedHeader")
+            ?: throw IOException("expected a matching choice but was $peekedHeader at $reader")
 
-        return choice to choice.readValue(reader)
+        return choice to choice.fromDer(reader)
       }
 
-      override fun writeValue(writer: DerWriter, value: Pair<DerAdapter<*>, Any?>) {
+      override fun toDer(writer: DerWriter, value: Pair<DerAdapter<*>, Any?>) {
         val (adapter, v) = value
-        (adapter as DerAdapter<Any?>).writeValue(writer, v)
+        (adapter as DerAdapter<Any?>).toDer(writer, v)
       }
 
       override fun toString() = choices.joinToString(separator = " OR ")
@@ -317,27 +311,23 @@ internal object Adapters {
     chooser: (Any?) -> DerAdapter<*>?
   ): DerAdapter<Any?> {
     return object : DerAdapter<Any?> {
-      override fun matches(header: DerHeader): Boolean = true
+      override fun matches(header: DerHeader) = true
 
-      override fun writeValue(writer: DerWriter, value: Any?) {
+      override fun toDer(writer: DerWriter, value: Any?) {
         // If we don't understand this hint, encode the body as a byte string. The byte string
         // will include a tag and length header as a prefix.
-        val adapter = chooser(writer.typeHint)
-
-        if (adapter != null) {
-          (adapter as DerAdapter<Any?>).writeValue(writer, value)
-        } else {
-          writer.writeOctetString(value as ByteString)
+        val adapter = chooser(writer.typeHint) as DerAdapter<Any?>?
+        when {
+          adapter != null -> adapter.toDer(writer, value)
+          else -> writer.writeOctetString(value as ByteString)
         }
       }
 
-      override fun readValue(reader: DerReader): Any? {
-        val adapter = chooser(reader.typeHint)
-
-        if (adapter != null) {
-          return (adapter as DerAdapter<Any?>).readValue(reader)
-        } else {
-          return reader.readOctetString()
+      override fun fromDer(reader: DerReader): Any? {
+        val adapter = chooser(reader.typeHint) as DerAdapter<Any?>?
+        return when {
+          adapter != null -> adapter.fromDer(reader)
+          else -> reader.readOctetString()
         }
       }
     }
@@ -370,7 +360,7 @@ internal object Adapters {
     return object : DerAdapter<Any?> {
       override fun matches(header: DerHeader): Boolean = true
 
-      override fun writeValue(writer: DerWriter, value: Any?) {
+      override fun toDer(writer: DerWriter, value: Any?) {
         when {
           isOptional && value == optionalValue -> {
             // Write nothing.
@@ -385,20 +375,20 @@ internal object Adapters {
           else -> {
             for ((type, adapter) in choices) {
               if (type.isInstance(value) || (value == null && type == Unit::class)) {
-                (adapter as DerAdapter<Any?>).writeValue(writer, value)
+                (adapter as DerAdapter<Any?>).toDer(writer, value)
                 return
               }
             }
           }
         }
       }
 
-      override fun readValue(reader: DerReader): Any? {
+      override fun fromDer(reader: DerReader): Any? {
         if (isOptional && !reader.hasNext()) return optionalValue
 
         for ((_, adapter) in choices) {
           if (adapter.matches(reader.peekHeader()!!)) {
-            return adapter.readValue(reader)
+            return adapter.fromDer(reader)
           }
         }
 

okhttp-tls/src/main/kotlin/okhttp3/tls/internal/der/BasicDerAdapter.kt

@@ -52,7 +52,7 @@ internal data class BasicDerAdapter<T>(
 
   override fun matches(header: DerHeader) = header.tagClass == tagClass && header.tag == tag
 
-  override fun readValue(reader: DerReader): T {
+  override fun fromDer(reader: DerReader): T {
     val peekedHeader = reader.peekHeader()
     if (peekedHeader == null || peekedHeader.tagClass != tagClass || peekedHeader.tag != tag) {
       if (isOptional) return defaultValue as T
@@ -70,7 +70,7 @@ internal data class BasicDerAdapter<T>(
     return result
   }
 
-  override fun writeValue(writer: DerWriter, value: T) {
+  override fun toDer(writer: DerWriter, value: T) {
     if (typeHint) {
       writer.typeHint = value
     }