issue #1052 port MsgBlockParser from TypeScript to Kotlin

.gitignore

@@ -19,7 +19,13 @@ local.properties
 /.idea/misc.xml
 /release
 /docker-mailserver/maildata_volume/
+
 # Keystore files
 *.jks
+
 # keystore info
-/FlowCrypt/keystore.properties
+/FlowCrypt/keystore.properties
+
+# some runtime files
+.attach*
+

FlowCrypt/src/androidTest/java/com/flowcrypt/email/util/gson/MsgBlockAdapter.kt

@@ -5,7 +5,7 @@
 
 package com.flowcrypt.email.util.gson
 
-import com.flowcrypt.email.api.retrofit.response.model.node.BaseMsgBlock
+import com.flowcrypt.email.api.retrofit.response.model.node.GenericMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.DecryptErrorMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.PublicKeyMsgBlock
@@ -31,7 +31,7 @@ class MsgBlockAdapter : JsonDeserializer<MsgBlock> {
 
       MsgBlock.Type.DECRYPT_ERROR -> return context.deserialize<MsgBlock>(json, DecryptErrorMsgBlock::class.java)
 
-      else -> return context.deserialize<MsgBlock>(json, BaseMsgBlock::class.java)
+      else -> return context.deserialize<MsgBlock>(json, GenericMsgBlock::class.java)
     }
   }
 }

FlowCrypt/src/main/java/com/flowcrypt/email/api/email/model/IncomingMessageInfo.kt

@@ -7,7 +7,7 @@ package com.flowcrypt.email.api.email.model
 
 import android.os.Parcel
 import android.os.Parcelable
-import com.flowcrypt.email.api.retrofit.response.model.node.BaseMsgBlock
+import com.flowcrypt.email.api.retrofit.response.model.node.GenericMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlock
 import com.flowcrypt.email.database.entity.MessageEntity
 import com.flowcrypt.email.model.MessageEncryptionType
@@ -90,7 +90,7 @@ data class IncomingMessageInfo constructor(val msgEntity: MessageEntity,
       source.readParcelable<LocalFolder>(LocalFolder::class.java.classLoader),
       source.readString(),
       source.readString(),
-      mutableListOf<MsgBlock>().apply { source.readTypedList(this, BaseMsgBlock.CREATOR) },
+      mutableListOf<MsgBlock>().apply { source.readTypedList(this, GenericMsgBlock.CREATOR) },
       source.readString(),
       source.readParcelable(MessageEncryptionType::class.java.classLoader)!!
   )

FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/node/gson/MsgBlockDeserializer.kt

@@ -5,7 +5,7 @@
 
 package com.flowcrypt.email.api.retrofit.node.gson
 
-import com.flowcrypt.email.api.retrofit.response.model.node.BaseMsgBlock
+import com.flowcrypt.email.api.retrofit.response.model.node.GenericMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.DecryptErrorMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.DecryptedAttMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlock
@@ -28,14 +28,13 @@ class MsgBlockDeserializer : JsonDeserializer<MsgBlock> {
   override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): MsgBlock? {
     val jsonObject = json.asJsonObject
 
-    val msgBlock: MsgBlock? = when (context.deserialize<MsgBlock.Type>(jsonObject.get(BaseMsgBlock.TAG_TYPE), MsgBlock.Type::class.java)) {
+    val msgBlock: MsgBlock? = when (
+        context.deserialize<MsgBlock.Type>(jsonObject.get(MsgBlock.TAG_TYPE), MsgBlock.Type::class.java)
+    ) {
       MsgBlock.Type.PUBLIC_KEY -> context.deserialize(json, PublicKeyMsgBlock::class.java)
-
       MsgBlock.Type.DECRYPT_ERROR -> context.deserialize(json, DecryptErrorMsgBlock::class.java)
-
       MsgBlock.Type.DECRYPTED_ATT -> context.deserialize(json, DecryptedAttMsgBlock::class.java)
-
-      else -> context.deserialize(json, BaseMsgBlock::class.java)
+      else -> context.deserialize(json, GenericMsgBlock::class.java)
     }
 
     if (msgBlock?.type == MsgBlock.Type.PUBLIC_KEY) {

FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/response/model/node/BaseMsgBlock.kt → FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/response/model/node/GenericMsgBlock.kt

@@ -1,6 +1,8 @@
 /*
  * © 2016-present FlowCrypt a.s. Limitations apply. Contact human@flowcrypt.com
- * Contributors: DenBond7
+ * Contributors:
+ *   DenBond7
+ *   Ivan Pizhenko
  */
 
 package com.flowcrypt.email.api.retrofit.response.model.node
@@ -10,16 +12,18 @@ import android.os.Parcelable
 import com.google.gson.annotations.Expose
 
 /**
- * It's a base [MsgBlock]
+ * Generic message block represents any message block without a dedicated support.
  *
  * @author Denis Bondarenko
  * Date: 3/26/19
  * Time: 9:46 AM
  * E-mail: DenBond7@gmail.com
+ *
+ * @author Ivan Pizhenko
  */
-data class BaseMsgBlock(@Expose override val type: MsgBlock.Type = MsgBlock.Type.UNKNOWN,
-                        @Expose override val content: String?,
-                        @Expose override val complete: Boolean) : MsgBlock {
+data class GenericMsgBlock(@Expose override val type: MsgBlock.Type = MsgBlock.Type.UNKNOWN,
+                           @Expose override val content: String?,
+                           @Expose override val complete: Boolean) : MsgBlock {
 
   constructor(source: Parcel, type: MsgBlock.Type) : this(
       type,
@@ -35,34 +39,14 @@ data class BaseMsgBlock(@Expose override val type: MsgBlock.Type = MsgBlock.Type
   }
 
   companion object {
-    const val TAG_TYPE = "type"
-
-    val handledMsgBlockTypes = listOf(
-        MsgBlock.Type.PUBLIC_KEY,
-        MsgBlock.Type.DECRYPT_ERROR,
-        MsgBlock.Type.DECRYPTED_ATT
-    )
-
     @JvmField
     val CREATOR: Parcelable.Creator<MsgBlock> = object : Parcelable.Creator<MsgBlock> {
       override fun createFromParcel(source: Parcel): MsgBlock {
         val partType = source.readParcelable<MsgBlock.Type>(MsgBlock.Type::class.java.classLoader)!!
-        return genMsgBlockFromType(source, partType)
+        return MsgBlockFactory.fromParcel(partType, source)
       }
 
       override fun newArray(size: Int): Array<MsgBlock?> = arrayOfNulls(size)
     }
-
-    fun genMsgBlockFromType(source: Parcel, type: MsgBlock.Type): MsgBlock {
-      return when (type) {
-        MsgBlock.Type.PUBLIC_KEY -> PublicKeyMsgBlock(source)
-
-        MsgBlock.Type.DECRYPT_ERROR -> DecryptErrorMsgBlock(source)
-
-        MsgBlock.Type.DECRYPTED_ATT -> DecryptedAttMsgBlock(source)
-
-        else -> BaseMsgBlock(source, type)
-      }
-    }
   }
 }

FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/response/model/node/MsgBlock.kt

@@ -63,7 +63,13 @@ interface MsgBlock : Parcelable {
     DECRYPTED_HTML,
 
     @SerializedName("decryptErr")
-    DECRYPT_ERROR;
+    DECRYPT_ERROR,
+
+    @SerializedName("certificate")
+    CERTIFICATE,
+
+    @SerializedName("signature")
+    SIGNATURE;
 
     override fun describeContents(): Int {
       return 0
@@ -81,4 +87,8 @@ interface MsgBlock : Parcelable {
       }
     }
   }
+
+  companion object {
+    const val TAG_TYPE = "type"
+  }
 }

FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/response/model/node/MsgBlockFactory.kt

@@ -0,0 +1,47 @@
+/*
+ * © 2016-present FlowCrypt a.s. Limitations apply. Contact human@flowcrypt.com
+ * Contributors: Ivan Pizhenko
+ */
+
+package com.flowcrypt.email.api.retrofit.response.model.node
+
+import android.os.Parcel
+import java.lang.IllegalArgumentException
+
+object MsgBlockFactory {
+  @JvmStatic
+  val supportedMsgBlockTypes = listOf(
+      MsgBlock.Type.PUBLIC_KEY,
+      MsgBlock.Type.DECRYPT_ERROR,
+      MsgBlock.Type.DECRYPTED_ATT
+  )
+
+  @JvmStatic
+  fun fromParcel(type: MsgBlock.Type, source: Parcel): MsgBlock {
+    return when (type) {
+      MsgBlock.Type.PUBLIC_KEY -> PublicKeyMsgBlock(source)
+      MsgBlock.Type.DECRYPT_ERROR -> DecryptErrorMsgBlock(source)
+      MsgBlock.Type.DECRYPTED_ATT -> DecryptedAttMsgBlock(source)
+      else -> GenericMsgBlock(source, type)
+    }
+  }
+
+  @JvmStatic
+  fun fromContent(type: MsgBlock.Type, content: String, missingEnd: Boolean = false): MsgBlock {
+    val complete = !missingEnd
+    return when (type) {
+      MsgBlock.Type.PUBLIC_KEY -> PublicKeyMsgBlock(content, complete, null)
+      MsgBlock.Type.DECRYPT_ERROR -> DecryptErrorMsgBlock(content, complete, null)
+      else -> GenericMsgBlock(type, content, complete)
+    }
+  }
+
+  @JvmStatic
+  fun fromAttachment(type: MsgBlock.Type, content: String, attMeta: AttMeta): MsgBlock {
+    return when (type) {
+      MsgBlock.Type.DECRYPTED_ATT -> DecryptedAttMsgBlock(content, true, attMeta, null)
+      else ->
+        throw IllegalArgumentException("Can't create block of type ${type.name} from attachment")
+    }
+  }
+}

FlowCrypt/src/main/java/com/flowcrypt/email/api/retrofit/response/node/ParseDecryptedMsgResult.kt

@@ -11,7 +11,7 @@ import android.os.Parcelable
 import android.util.Base64
 import com.flowcrypt.email.api.retrofit.node.gson.NodeGson
 import com.flowcrypt.email.api.retrofit.response.base.ApiError
-import com.flowcrypt.email.api.retrofit.response.model.node.BaseMsgBlock
+import com.flowcrypt.email.api.retrofit.response.model.node.GenericMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.DecryptedAttMsgBlock
 import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlock
 import com.flowcrypt.email.model.MessageEncryptionType
@@ -123,7 +123,7 @@ data class ParseDecryptedMsgResult constructor(
       source.readString()!!,
       source.readString(),
       source.readParcelable<ApiError>(ApiError::class.java.classLoader),
-      mutableListOf<MsgBlock>().apply { source.readTypedList(this, BaseMsgBlock.CREATOR) }
+      mutableListOf<MsgBlock>().apply { source.readTypedList(this, GenericMsgBlock.CREATOR) }
   )
 
   override fun describeContents() = 0

FlowCrypt/src/main/java/com/flowcrypt/email/core/msg/MsgBlockParser.kt

@@ -0,0 +1,128 @@
+/*
+ * © 2016-present FlowCrypt a.s. Limitations apply. Contact human@flowcrypt.com
+ * Contributors: ivan
+ */
+
+package com.flowcrypt.email.core.msg
+
+import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlock
+import com.flowcrypt.email.api.retrofit.response.model.node.MsgBlockFactory
+import com.flowcrypt.email.security.pgp.PgpArmor
+
+@Suppress("unused")
+object MsgBlockParser {
+
+  private const val ARMOR_HEADER_MAX_LENGTH = 50
+
+  @JvmStatic
+  fun detectBlocks(text: String): List<MsgBlock> {
+    val normalized = normalize(text)
+    val blocks = mutableListOf<MsgBlock>()
+    var startAt = 0
+    while (true) {
+      val continueAt = detectBlockNext(normalized, startAt, blocks)
+      if (startAt >= continueAt) return blocks
+      startAt = continueAt
+    }
+  }
+
+  @JvmStatic
+  private fun detectBlockNext(text: String, startAt: Int, blocks: MutableList<MsgBlock>): Int {
+    val initialBlockCount = blocks.size
+    var continueAt = -1
+    val beginIndex = text.indexOf(
+        PgpArmor.ARMOR_HEADER_DICT[MsgBlock.Type.UNKNOWN]!!.begin, startAt)
+    if (beginIndex != -1) { // found
+      val potentialBeginHeader = text.substring(beginIndex, beginIndex + ARMOR_HEADER_MAX_LENGTH)
+      for (blockHeaderKvp in PgpArmor.ARMOR_HEADER_DICT) {
+        val blockHeaderDef = blockHeaderKvp.value
+        if (!blockHeaderDef.replace || potentialBeginHeader.indexOf(blockHeaderDef.begin) != 0) {
+          continue
+        }
+
+        if (beginIndex > startAt) {
+          // only replace blocks if they begin on their own line
+          // contains deliberate block: `-----BEGIN PGP PUBLIC KEY BLOCK-----\n...`
+          // contains deliberate block: `Hello\n-----BEGIN PGP PUBLIC KEY BLOCK-----\n...`
+          // just plaintext (accidental block): `Hello -----BEGIN PGP PUBLIC KEY BLOCK-----\n...`
+          // block treated as plaintext, not on dedicated line - considered accidental
+          // this will actually cause potential deliberate blocks
+          // that follow accidental block to be ignored
+          // but if the message already contains accidental
+          // (not on dedicated line) blocks, it's probably a good thing to ignore the rest
+          var textBeforeBlock = text.substring(startAt, beginIndex)
+          if (!textBeforeBlock.endsWith('\n')) continue
+          textBeforeBlock = textBeforeBlock.trim()
+          if (textBeforeBlock.isNotEmpty()) {
+            blocks.add(MsgBlockFactory.fromContent(MsgBlock.Type.PLAIN_TEXT, textBeforeBlock))
+          }
+        }
+
+        val endHeaderIndex: Int
+        val endHeaderLength: Int
+        if (blockHeaderDef.endRegexp != null) {
+          val found = blockHeaderDef.endRegexp.find(text.substring(beginIndex))
+          if (found != null) {
+            endHeaderIndex = beginIndex + found.range.first
+            endHeaderLength = found.range.last - found.range.first
+          } else {
+            endHeaderIndex = -1
+            endHeaderLength = 0
+          }
+        } else { // string
+          val end = blockHeaderDef.end!!
+          endHeaderIndex = text.indexOf(end, beginIndex + blockHeaderDef.begin.length)
+          endHeaderLength = if (endHeaderIndex == -1) 0 else end.length
+        }
+
+        if (endHeaderIndex != -1) {
+          // identified end of the same block
+          continueAt = endHeaderIndex + endHeaderLength
+          blocks.add(
+              MsgBlockFactory.fromContent(
+                  blockHeaderKvp.key,
+                  text.substring(beginIndex, continueAt).trim()
+              )
+          )
+        } else {
+          // corresponding end not found
+          blocks.add(
+              MsgBlockFactory.fromContent(blockHeaderKvp.key, text.substring(beginIndex), true)
+          )
+        }
+        break
+      }
+    }
+
+    if (text.isNotEmpty() && blocks.size == initialBlockCount) {
+      // didn't find any blocks, but input is non-empty
+      val remainingText = text.substring(startAt).trim()
+      if (remainingText.isNotEmpty()) {
+        blocks.add(MsgBlockFactory.fromContent(MsgBlock.Type.PLAIN_TEXT, remainingText))
+      }
+    }
+
+    return continueAt
+  }
+
+  @JvmStatic
+  fun normalize(str: String): String {
+    return normalizeSpaces(normalizeDashes(str))
+  }
+
+  @JvmStatic
+  private fun normalizeSpaces(str: String): String {
+    return str.replace(char160, ' ')
+  }
+
+  @JvmStatic
+  private fun normalizeDashes(str: String): String {
+    return str.replace(dashesRegex, "-----")
+  }
+
+  @JvmStatic
+  private val char160 = 160.toChar()
+
+  @JvmStatic
+  private val dashesRegex = Regex("^—–|—–$")
+}

FlowCrypt/src/main/java/com/flowcrypt/email/security/pgp/CryptoArmorHeaderDefinition.kt

@@ -0,0 +1,14 @@
+/*
+ * © 2016-present FlowCrypt a.s. Limitations apply. Contact human@flowcrypt.com
+ * Contributors: Ivan Pizhenko
+ */
+
+package com.flowcrypt.email.security.pgp
+
+data class CryptoArmorHeaderDefinition (
+        val begin: String,
+        val middle: String? = null,
+        val end: String?,
+        val endRegexp: Regex? = null,
+        val replace: Boolean
+)