Add 'Have I Been Pwnd' method that returns a breach count (#281)

app/src/main/java/com/x8bit/bitwarden/data/auth/datasource/network/service/HaveIBeenPwnedService.kt

@@ -5,6 +5,13 @@ package com.x8bit.bitwarden.data.auth.datasource.network.service
  */
 interface HaveIBeenPwnedService {
 
+    /**
+     * Check to see if the given password has been breached. Returns the number of breaches.
+     */
+    suspend fun getPasswordBreachCount(
+        password: String,
+    ): Result<Int>
+
     /**
      * Check to see if the given password has been breached. Returns true if breached.
      */

app/src/main/java/com/x8bit/bitwarden/data/auth/datasource/network/service/HaveIBeenPwnedServiceImpl.kt

@@ -6,7 +6,7 @@ import java.security.MessageDigest
 class HaveIBeenPwnedServiceImpl(private val api: HaveIBeenPwnedApi) : HaveIBeenPwnedService {
 
     @Suppress("MagicNumber")
-    override suspend fun hasPasswordBeenBreached(password: String): Result<Boolean> {
+    override suspend fun getPasswordBreachCount(password: String): Result<Int> {
         // Hash the password:
         val hashedPassword = MessageDigest
             .getInstance("SHA-1")
@@ -18,19 +18,31 @@ class HaveIBeenPwnedServiceImpl(private val api: HaveIBeenPwnedApi) : HaveIBeenP
         return api
             .fetchBreachedPasswords(hashPrefix = hashPrefix)
             .mapCatching { responseBody ->
-                val allPwnedPasswords = responseBody.string()
+                responseBody.string()
                     // First split the response by newline: each hashed password is on a new line.
-                    .split("\r\n")
-                    .map { pwnedSuffix ->
-                        // Then remove everything after the ":", since we only want the pwned hash:
-                        // Before: 20d61603aba324bf08799896110561f05e1ad3be:12
-                        // After: 20d61603aba324bf08799896110561f05e1ad3be
-                        pwnedSuffix.substring(0, endIndex = pwnedSuffix.indexOf(":"))
+                    .split("\r\n", "\r", "\n")
+                    .associate { pwnedSuffix ->
+                        // Then split everything on the ":", since we want to compare the pwned
+                        // hash but we also want to return the count:
+                        // Pattern: <pwnd_hash_suffix>:<breach_count>
+                        // Example: 20d61603aba324bf08799896110561f05e1ad3be:12
+                        val split = pwnedSuffix.split(":")
+                        split[0] to split[1]
                     }
-                // Then see if any of those passwords match our full password hash:
-                allPwnedPasswords.any { pwnedSuffix ->
-                    (hashPrefix + pwnedSuffix).equals(hashedPassword, ignoreCase = true)
-                }
+                    .entries
+                    .find { (pwnedSuffix, _) ->
+                        // Then see if any of those passwords match our full password hash:
+                        (hashPrefix + pwnedSuffix).equals(hashedPassword, ignoreCase = true)
+                    }
+                    // If we found a match, return the value as this is the number of breaches.
+                    ?.value
+                    ?.toIntOrNull()
+                    ?: 0
             }
     }
+
+    override suspend fun hasPasswordBeenBreached(
+        password: String,
+    ): Result<Boolean> = getPasswordBreachCount(password)
+        .map { numberOfBreaches -> numberOfBreaches > 0 }
 }