Added support for external git credentials helper [BETA]

Fixes https://github.com/JetpackDuba/Gitnuro/issues/16

src/main/kotlin/com/jetpackduba/gitnuro/credentials/HttpCredentialsProvider.kt

@@ -1,19 +1,27 @@
 package com.jetpackduba.gitnuro.credentials
 
+import com.jetpackduba.gitnuro.exceptions.NotSupportedHelper
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedInject
+import org.eclipse.jgit.api.Git
+import org.eclipse.jgit.lib.Config
 import org.eclipse.jgit.transport.CredentialItem
 import org.eclipse.jgit.transport.CredentialsProvider
 import org.eclipse.jgit.transport.URIish
-import javax.inject.Inject
+import java.io.*
+import java.util.concurrent.TimeUnit
 
-class HttpCredentialsProvider @Inject constructor(
+private const val TIMEOUT_MIN = 1L
-    private val credentialsStateManager: CredentialsStateManager
+
+class HttpCredentialsProvider @AssistedInject constructor(
+    private val credentialsStateManager: CredentialsStateManager,
+    @Assisted val git: Git?,
 ) : CredentialsProvider() {
     override fun isInteractive(): Boolean {
         return true
     }
 
     override fun supports(vararg items: CredentialItem?): Boolean {
-        println(items)
         val fields = items.map { credentialItem -> credentialItem?.promptText }
         return if (fields.isEmpty()) {
             true
@@ -23,30 +31,199 @@ class HttpCredentialsProvider @Inject constructor(
                     fields.contains("Password")
     }
 
-    override fun get(uri: URIish?, vararg items: CredentialItem?): Boolean {
+    override fun get(uri: URIish, vararg items: CredentialItem): Boolean {
-        credentialsStateManager.updateState(CredentialsState.HttpCredentialsRequested)
+        val userItem = items.firstOrNull { it.promptText == "Username" }
+        val passwordItem = items.firstOrNull { it.promptText == "Password" }
 
-        var credentials = credentialsStateManager.currentCredentialsState
+        if (userItem !is CredentialItem.Username || passwordItem !is CredentialItem.Password) {
-        while (credentials is CredentialsState.CredentialsRequested) {
+            return false
-            credentials = credentialsStateManager.currentCredentialsState
         }
 
-        if (credentials is CredentialsState.HttpCredentialsAccepted) {
+        val externalCredentialsHelper = getExternalCredentialsHelper(uri, git)
-            val userItem = items.firstOrNull { it?.promptText == "Username" }
-            val passwordItem = items.firstOrNull { it?.promptText == "Password" }
 
-            if (userItem is CredentialItem.Username &&
+        if (externalCredentialsHelper == null) {
-                passwordItem is CredentialItem.Password
+            val credentials = askForCredentials()
-            ) {
 
+            if (credentials is CredentialsState.HttpCredentialsAccepted) {
                 userItem.value = credentials.user
                 passwordItem.value = credentials.password.toCharArray()
 
                 return true
             }
-        }
 
-        return false
+            return false
+
+        } else {
+            when (handleExternalCredentialHelper(externalCredentialsHelper, uri, items)) {
+                ExternalCredentialsRequestResult.SUCCESS -> return true
+                ExternalCredentialsRequestResult.FAIL -> return false
+                ExternalCredentialsRequestResult.CREDENTIALS_NOT_STORED -> {
+                    val credentials = askForCredentials()
+                    if (credentials is CredentialsState.HttpCredentialsAccepted) {
+                        userItem.value = credentials.user
+                        passwordItem.value = credentials.password.toCharArray()
+
+                        saveCredentialsInExternalHelper(uri, externalCredentialsHelper, credentials)
+
+                        return true
+                    }
+
+                    return false
+                }
+            }
+        }
     }
 
+    private fun saveCredentialsInExternalHelper(
+        uri: URIish,
+        externalCredentialsHelper: ExternalCredentialsHelper,
+        credentials: CredentialsState.HttpCredentialsAccepted
+    ) {
+        val process = Runtime.getRuntime()
+            .exec(String.format("${externalCredentialsHelper.path} %s", "store"));
+
+        val output = process.outputStream // write to the input stream of the helper
+        val bufferedWriter = BufferedWriter(OutputStreamWriter(output))
+
+        bufferedWriter.use {
+            bufferedWriter.write("protocol=${uri.scheme}\n")
+            bufferedWriter.write("host=${uri.host}\n")
+
+            if (externalCredentialsHelper.useHttpPath) {
+                bufferedWriter.write("path=${uri.path}\n")
+            }
+
+            bufferedWriter.write("username=${credentials.user}\n")
+            bufferedWriter.write("password=${credentials.password}\n")
+            bufferedWriter.write("")
+
+            bufferedWriter.flush()
+        }
+    }
+
+    private fun askForCredentials(): CredentialsState {
+        credentialsStateManager.updateState(CredentialsState.HttpCredentialsRequested)
+        var credentials = credentialsStateManager.currentCredentialsState
+        while (credentials is CredentialsState.CredentialsRequested) {
+            credentials = credentialsStateManager.currentCredentialsState
+        }
+
+        return credentials
+    }
+
+    private fun handleExternalCredentialHelper(
+        externalCredentialsHelper: ExternalCredentialsHelper,
+        uri: URIish,
+        items: Array<out CredentialItem>
+    ): ExternalCredentialsRequestResult {
+        val process = Runtime.getRuntime()
+            .exec(String.format("${externalCredentialsHelper.path} %s", "get"))
+
+        val output = process.outputStream // write to the input stream of the helper
+        val input = process.inputStream // reads from the output stream of the helper
+
+        val bufferedWriter = BufferedWriter(OutputStreamWriter(output))
+        val bufferedReader = BufferedReader(InputStreamReader(input))
+
+        bufferedWriter.use {
+            bufferedWriter.write("protocol=${uri.scheme}\n")
+            bufferedWriter.write("host=${uri.host}\n")
+
+            if (externalCredentialsHelper.useHttpPath) {
+                bufferedWriter.write("path=${uri.path}\n")
+            }
+
+            bufferedWriter.write("")
+
+            bufferedWriter.flush()
+        }
+
+        var usernameSet = false
+        var passwordSet = false
+
+        process.waitFor(TIMEOUT_MIN, TimeUnit.MINUTES)
+
+        // If the process is alive after $TIMEOUT_MIN, it means that it hasn't given an answer and then finished
+        if(process.isAlive) {
+            process.destroy()
+            return ExternalCredentialsRequestResult.FAIL
+        }
+
+        bufferedReader.use {
+            var line: String;
+            while (bufferedReader.readLine().also { line = it } != null && !(usernameSet && passwordSet)) {
+                if (line.startsWith("username=")) {
+                    val split = line.split("=")
+                    val userName = split.getOrNull(1) ?: return ExternalCredentialsRequestResult.CREDENTIALS_NOT_STORED
+
+                    val userNameItem = items.firstOrNull { it.promptText == "Username" }
+
+                    if (userNameItem is CredentialItem.Username) {
+                        userNameItem.value = userName
+                        usernameSet = true
+                    }
+
+                } else if (line.startsWith("password=")) {
+                    val split = line.split("=")
+                    val password = split.getOrNull(1) ?: return ExternalCredentialsRequestResult.CREDENTIALS_NOT_STORED
+
+                    val passwordItem = items.firstOrNull { it.promptText == "Password" }
+
+                    if (passwordItem is CredentialItem.Password) {
+                        passwordItem.value = password.toCharArray()
+                        passwordSet = true
+                    }
+                }
+            }
+        }
+
+        return if (usernameSet && passwordSet)
+            ExternalCredentialsRequestResult.SUCCESS
+        else
+            ExternalCredentialsRequestResult.CREDENTIALS_NOT_STORED
+    }
+
+    private fun getExternalCredentialsHelper(uri: URIish, git: Git?): ExternalCredentialsHelper? {
+        val config = if (git == null) {
+            val homePath = System.getProperty("user.home")
+            val configFile = File("$homePath/.gitconfig")
+
+            Config().apply {
+                if (configFile.exists()) {
+                    fromText(configFile.readText())
+                }
+            }
+        } else {
+            git.repository.config
+        }
+
+        val hostWithProtocol = "${uri.scheme}://${uri.host}"
+
+        val genericCredentialHelper = config.getString("credential", null, "helper")
+        val uriSpecificCredentialHelper = config.getString("credential", hostWithProtocol, "helper")
+        val credentialHelperPath = uriSpecificCredentialHelper ?: genericCredentialHelper ?: return null
+
+        if(credentialHelperPath == "cache" || credentialHelperPath == "store") {
+            throw NotSupportedHelper("Invalid credentials: \"$credentialHelperPath\" is not yet supported")
+        }
+
+        // Use getString instead of getBoolean as boolean has a default value by we want null if the config field is not set
+        val uriSpecificUseHttpHelper = config.getString("credential", hostWithProtocol, "useHttpPath")
+        val genericUseHttpHelper = config.getBoolean("credential", "useHttpPath", false)
+
+        val useHttpPath = uriSpecificUseHttpHelper?.toBoolean() ?: genericUseHttpHelper
+
+        return ExternalCredentialsHelper(credentialHelperPath, useHttpPath)
+    }
+}
+
+data class ExternalCredentialsHelper(
+    val path: String,
+    val useHttpPath: Boolean,
+)
+
+enum class ExternalCredentialsRequestResult {
+    SUCCESS,
+    FAIL,
+    CREDENTIALS_NOT_STORED;
 }

src/main/kotlin/com/jetpackduba/gitnuro/di/factories/HttpCredentialsFactory.kt

@@ -0,0 +1,10 @@
+package com.jetpackduba.gitnuro.di.factories
+
+import com.jetpackduba.gitnuro.credentials.HttpCredentialsProvider
+import dagger.assisted.AssistedFactory
+import org.eclipse.jgit.api.Git
+
+@AssistedFactory
+interface HttpCredentialsFactory {
+    fun create(git: Git?) : HttpCredentialsProvider
+}

src/main/kotlin/com/jetpackduba/gitnuro/exceptions/NotSupportedHelper.kt

@@ -0,0 +1,3 @@
+package com.jetpackduba.gitnuro.exceptions
+
+class NotSupportedHelper(message: String) : GitnuroException(message)

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/CloneRepositoryUseCase.kt

@@ -59,7 +59,7 @@ class CloneRepositoryUseCase @Inject constructor(
                         }
                     }
                 )
-                .setTransportConfigCallback { handleTransportUseCase(it) }
+                .setTransportConfigCallback { handleTransportUseCase(it, null) }
                 .call()
 
             ensureActive()

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/DeleteRemoteBranchUseCase.kt

@@ -27,7 +27,7 @@ class DeleteRemoteBranchUseCase @Inject constructor(
 
         val pushResults = git.push()
             .setTransportConfigCallback {
-                handleTransportUseCase(it)
+                handleTransportUseCase(it, git)
             }
             .setRefSpecs(refSpec)
             .setRemote(remoteName)

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/FetchAllBranchesUseCase.kt

@@ -16,7 +16,7 @@ class FetchAllBranchesUseCase @Inject constructor(
             git.fetch()
                 .setRemote(remote.name)
                 .setRefSpecs(remote.fetchRefSpecs)
-                .setTransportConfigCallback { handleTransportUseCase(it) }
+                .setTransportConfigCallback { handleTransportUseCase(it, git) }
                 .setCredentialsProvider(CredentialsProvider.getDefault())
                 .call()
         }

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/HandleTransportUseCase.kt

@@ -2,6 +2,8 @@ package com.jetpackduba.gitnuro.git.remote_operations
 
 import com.jetpackduba.gitnuro.credentials.GSessionManager
 import com.jetpackduba.gitnuro.credentials.HttpCredentialsProvider
+import com.jetpackduba.gitnuro.di.factories.HttpCredentialsFactory
+import org.eclipse.jgit.api.Git
 import org.eclipse.jgit.transport.HttpTransport
 import org.eclipse.jgit.transport.SshTransport
 import org.eclipse.jgit.transport.Transport
@@ -10,13 +12,13 @@ import javax.inject.Provider
 
 class HandleTransportUseCase @Inject constructor(
     private val sessionManager: GSessionManager,
-    private val httpCredentialsProvider: Provider<HttpCredentialsProvider>,
+    private val httpCredentialsProvider: HttpCredentialsFactory,
 ) {
-    operator fun invoke(transport: Transport?) {
+    operator fun invoke(transport: Transport?, git: Git?) {
         if (transport is SshTransport) {
             transport.sshSessionFactory = sessionManager.generateSshSessionFactory()
         } else if (transport is HttpTransport) {
-            transport.credentialsProvider = httpCredentialsProvider.get()
+            transport.credentialsProvider = httpCredentialsProvider.create(git)
         }
     }
 }

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/PullBranchUseCase.kt

@@ -13,7 +13,7 @@ class PullBranchUseCase @Inject constructor(
     suspend operator fun invoke(git: Git, rebase: Boolean) = withContext(Dispatchers.IO) {
         val pullResult = git
             .pull()
-            .setTransportConfigCallback { handleTransportUseCase(it) }
+            .setTransportConfigCallback { handleTransportUseCase(it, git) }
             .setRebase(rebase)
             .setCredentialsProvider(CredentialsProvider.getDefault())
             .call()

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/PullFromSpecificBranchUseCase.kt

@@ -16,7 +16,7 @@ class PullFromSpecificBranchUseCase @Inject constructor(
     suspend operator fun invoke(git: Git, rebase: Boolean, remoteBranch: Ref) = withContext(Dispatchers.IO) {
         val pullResult = git
             .pull()
-            .setTransportConfigCallback { handleTransportUseCase(it) }
+            .setTransportConfigCallback { handleTransportUseCase(it, git) }
             .setRemote(remoteBranch.remoteName)
             .setRemoteBranchName(remoteBranch.simpleName)
             .setRebase(rebase)

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/PushBranchUseCase.kt

@@ -22,7 +22,7 @@ class PushBranchUseCase @Inject constructor(
                 if (pushTags)
                     setPushTags()
             }
-            .setTransportConfigCallback { handleTransportUseCase(it) }
+            .setTransportConfigCallback { handleTransportUseCase(it, git) }
             .call()
 
         val results =

src/main/kotlin/com/jetpackduba/gitnuro/git/remote_operations/PushToSpecificBranchUseCase.kt

@@ -27,7 +27,7 @@ class PushToSpecificBranchUseCase @Inject constructor(
                     if (pushTags)
                         setPushTags()
                 }
-                .setTransportConfigCallback { handleTransportUseCase(it) }
+                .setTransportConfigCallback { handleTransportUseCase(it, git) }
                 .call()
 
             val results =