feat: added exported sha256 function

Author: mrejdak

android/src/main/java/com/sbaiahmed1/reactnativebiometrics/ReactNativeBiometricsSharedImpl.kt

@@ -25,6 +25,7 @@ import java.security.NoSuchProviderException
 import java.security.Signature
 import java.security.UnrecoverableKeyException
 import java.security.cert.CertificateException
+import java.security.MessageDigest
 import java.security.interfaces.RSAPublicKey
 import androidx.core.content.edit
 
@@ -1378,6 +1379,33 @@ class ReactNativeBiometricsSharedImpl(private val context: ReactApplicationConte
     }
   }
 
+  fun sha256(data: String, inputEncoding: String?, promise: Promise) {
+    try {
+      val encoding = inputEncoding ?: "utf8"
+      val dataBytes = decodeInputData(data, encoding)
+      if (dataBytes == null) {
+        promise.resolve(Arguments.createMap().apply {
+          putString("hash", "")
+          putString("error", "Invalid base64 data")
+        })
+        return
+      }
+
+      val digest = MessageDigest.getInstance("SHA-256")
+      val hashBytes = digest.digest(dataBytes)
+      val hashBase64 = BiometricUtils.encodeBase64(hashBytes)
+
+      promise.resolve(Arguments.createMap().apply {
+        putString("hash", hashBase64)
+      })
+    } catch (e: Exception) {
+      promise.resolve(Arguments.createMap().apply {
+        putString("hash", "")
+        putString("error", e.message ?: "SHA256 failed")
+      })
+    }
+  }
+
   fun getKeyAttributes(keyAlias: String?, promise: Promise) {
     val actualKeyAlias = getKeyAlias(keyAlias)
     debugLog("getKeyAttributes called with keyAlias: ${keyAlias ?: "default"}, using: $actualKeyAlias")

android/src/newarch/java/com/sbaiahmed1/reactnativebiometrics/ReactNativeBiometricsModule.kt

@@ -107,6 +107,11 @@ class ReactNativeBiometricsModule(reactContext: ReactApplicationContext) :
     sharedImpl.validateSignature(keyAlias, data, signature, promise)
   }
 
+  @ReactMethod
+  override fun sha256(data: String, inputEncoding: String?, promise: Promise) {
+    sharedImpl.sha256(data, inputEncoding, promise)
+  }
+
   @ReactMethod
   override fun getKeyAttributes(keyAlias: String?, promise: Promise) {
     sharedImpl.getKeyAttributes(keyAlias, promise)

android/src/oldarch/java/com/sbaiahmed1/reactnativebiometrics/ReactNativeBiometricsModule.kt

@@ -81,6 +81,11 @@ class ReactNativeBiometricsModule(reactContext: ReactApplicationContext) :
     sharedImpl.validateSignature(keyAlias, data, signature, promise)
   }
 
+  @ReactMethod
+  fun sha256(data: String, inputEncoding: String?, promise: Promise) {
+    sharedImpl.sha256(data, inputEncoding, promise)
+  }
+
   @ReactMethod
   fun getKeyAttributes(keyAlias: String?, promise: Promise) {
     sharedImpl.getKeyAttributes(keyAlias, promise)

ios/ReactNativeBiometrics.swift

@@ -1080,6 +1080,33 @@ class ReactNativeBiometrics: RCTEventEmitter {
     }
   }
 
+  @objc
+  func sha256(_ data: NSString,
+              inputEncoding: NSString?,
+              resolver resolve: @escaping RCTPromiseResolveBlock,
+              rejecter reject: @escaping RCTPromiseRejectBlock) {
+    let encoding = (inputEncoding as String?) ?? "utf8"
+
+    let dataBytes: Data
+    if encoding.lowercased() == "base64" {
+      guard let decoded = Data(base64Encoded: data as String) else {
+        resolve(["hash": "", "error": "Invalid base64 data"])
+        return
+      }
+      dataBytes = decoded
+    } else {
+      guard let utf8Data = (data as String).data(using: .utf8) else {
+        resolve(["hash": "", "error": "UTF-8 encoding failed"])
+        return
+      }
+      dataBytes = utf8Data
+    }
+
+    let hash = SHA256.hash(data: dataBytes)
+    let hashData = Data(hash)
+    resolve(["hash": hashData.base64EncodedString()])
+  }
+
   @objc
   func getKeyAttributes(_ keyAlias: NSString?,
                         resolver resolve: @escaping RCTPromiseResolveBlock,

ios/ReactNativeBiometricsBridge.mm

@@ -101,6 +101,12 @@ @interface RCT_EXTERN_MODULE(ReactNativeBiometrics, RCTEventEmitter)
     resolver:(RCTPromiseResolveBlock)resolve
     rejecter:(RCTPromiseRejectBlock)reject)
 
+RCT_EXTERN_METHOD(sha256:
+    (NSString *)data
+    inputEncoding:(NSString *)inputEncoding
+    resolver:(RCTPromiseResolveBlock)resolve
+    rejecter:(RCTPromiseRejectBlock)reject)
+
 RCT_EXTERN_METHOD(getKeyAttributes:
     (NSString *)keyAlias
     resolver:(RCTPromiseResolveBlock)resolve

src/NativeReactNativeBiometrics.ts

@@ -134,6 +134,13 @@ export interface Spec extends TurboModule {
     valid: boolean;
     error?: string;
   }>;
+  sha256(
+    data: string,
+    inputEncoding?: 'utf8' | 'base64' | null
+  ): Promise<{
+    hash: string;
+    error?: string;
+  }>;
   getKeyAttributes(keyAlias?: string | null): Promise<{
     exists: boolean;
     attributes?: {

src/index.tsx

@@ -437,6 +437,25 @@ export function validateSignature(
     });
 }
 
+export function sha256(
+  data: string,
+  inputEncoding: 'utf8' | 'base64' = 'utf8'
+): Promise<Sha256Result> {
+  logger.debug('Computing SHA256', 'sha256', {
+    dataLength: data.length,
+    inputEncoding,
+  });
+  return ReactNativeBiometrics.sha256(data, inputEncoding)
+    .then((result) => {
+      logger.info('SHA256 completed', 'sha256');
+      return result;
+    })
+    .catch((error) => {
+      logger.error('SHA256 failed', 'sha256', error);
+      throw error;
+    });
+}
+
 export function getKeyAttributes(
   keyAlias?: string
 ): Promise<KeyAttributesResult> {
@@ -774,6 +793,11 @@ export type SignatureValidationResult = {
   error?: string;
 };
 
+export type Sha256Result = {
+  hash: string;
+  error?: string;
+};
+
 export type KeyAttributesResult = {
   exists: boolean;
   attributes?: {