Compare sha256 hash with Crypto lib

TestSHA256/src/main.cpp

+#include <Arduino.h>
+#include <sha256.h>
+#include <DFRobot_ID809.h>
+
+// use serial3 as interface with fingerprint
+// sensor .
+#define FPSerial Serial3
+
+// define buillt_in led
+#define BUILTIN_LED 13
+// Collect the fingerprint 3 times
+#define COLLECT_NUMBER 3
+#define SHA256_SIZE	32 
+
+/*------Funciotion dclarations----------*/
+// function to blink blitin_led
+// to make sure that code is working
+void blink_led();
+
+/*------Global variables--------------*/
+DFRobot_ID809 fingerprint;
+byte hash[SHA256_SIZE];
+
+uint8_t ID, i, ret;
+uint8_t temp[1008];
+
+void compute_hash() {
+
+	SHA256_CTX ctx;
+	sha256_init(&ctx);
+	sha256_update(&ctx, temp, sizeof(temp));
+	sha256_final(&ctx, hash);
+ // SHA256 hasher;
+ // hasher.doUpdate(temp, sizeof(temp));
+ // hasher.doFinal(hash);
+}
+
+void setup() {
+  // config led_pin as output
+  pinMode(BUILTIN_LED, OUTPUT);
+  // use serial port to print the baud rate
+  Serial.begin(9600);
+
+  FPSerial.begin(115200);
+  fingerprint.begin(FPSerial);
+
+  while (fingerprint.isConnected() == false) {
+    Serial.println("Communication with the device failed");
+    delay(1000);
+  }
+
+  // fingerprint.getTemplate(1, temp);
+
+  // for(uint8_t i=0; i<1008; i++) {
+  //         Serial.print(i);
+  //         Serial.print(": ");
+  //         Serial.println(temp[i]);
+  //         delay(100);
+  // }
+
+  // compute_hash();
+  // Serial.println("------------------------");
+  //  for (uint8_t i = 0; i < SHA256_SIZE; i++) {
+  //
+  //    if (hash[i] < 0x10) {
+  //      Serial.print('0');
+  //    }
+  //    Serial.print(hash[i], HEX);
+  //    Serial.print(" ");
+  //  }
+  //  Serial.println("------------------------");
+}
+
+void loop() {
+
+  uint8_t ret = 0;
+  /*Set fingerprint LED ring mode, color, and number of blinks
+    Can be set as follows:
+    Parameter 1:<LEDMode>
+    eBreathing   eFastBlink   eKeepsOn    eNormalClose
+    eFadeIn      eFadeOut     eSlowBlink
+    Parameter 2:<LEDColor>
+    eLEDGreen  eLEDRed      eLEDYellow   eLEDBlue
+    eLEDCyan   eLEDMagenta  eLEDWhite
+    Parameter 3:<number of blinks> 0 represents blinking all the time
+    This parameter will only be valid in mode eBreathing, eFastBlink, eSlowBlink
+   */
+  fingerprint.ctrlLED(/*LEDMode = */ fingerprint.eBreathing,
+                      /*LEDColor = */ fingerprint.eLEDBlue,
+                      /*blinkCount = */ 0);
+  Serial.println("Please press down your finger");
+  /*Capture fingerprint image, Disable the collection timeout function
+    If succeed return 0, otherwise return ERR_ID809
+   */
+  if ((fingerprint.collectionFingerprint(/*timeout=*/0)) != ERR_ID809) {
+    /*Set fingerprint LED ring to quick blink in yellow 3 times*/
+    fingerprint.ctrlLED(/*LEDMode = */ fingerprint.eFastBlink,
+                        /*LEDColor = */ fingerprint.eLEDYellow,
+                        /*blinkCount = */ 3);
+    Serial.println("Capturing succeeds");
+    Serial.println("Please release your finger");
+    /*Wait for finger to release
+      Return 1 when finger is detected, otherwise return 0
+     */
+    while (fingerprint.detectFinger())
+      ;
+
+    /*Compare the captured fingerprint with all the fingerprints in the
+      fingerprint library Return fingerprint ID(1-80) if succeed, return 0 when
+      failed
+     */
+    ret = fingerprint.search();
+    /*Compare the captured fingerprint with a fingerprint of specific ID
+      Return fingerprint ID(1-80) if succeed, return 0 when failed
+     */
+    // ret = fingerprint.verify(/*Fingerprint ID = */1);
+    if (ret != 0) {
+      /*Set fingerprint LED ring to always ON in green */
+      fingerprint.ctrlLED(/*LEDMode = */ fingerprint.eKeepsOn,
+                          /*LEDColor = */ fingerprint.eLEDGreen,
+                          /*blinkCount = */ 0);
+      Serial.print("Matching succeeds,ID=");
+      Serial.println(ret);
+
+      fingerprint.getTemplate(ret, temp);
+
+      // for(uint8_t i=0; i<1008; i++) {
+      //         Serial.print(i);
+      //         Serial.print(": ");
+      //         Serial.println(temp[i]);
+      //         delay(100);
+      // }
+
+       compute_hash();
+      Serial.println("--------------------");
+      for (uint8_t i = 0; i < SHA256_SIZE; i++) {
+
+        if (hash[i] < 0x10) {
+          Serial.print('0');
+        }
+        Serial.print(hash[i], HEX);
+        Serial.print(" ");
+      }
+      Serial.println("---------------------");
+      for (uint16_t i = 0; i < 1008; i++) {
+        Serial.print(temp[i], HEX);
+        Serial.print(" ");
+      }
+
+    } else {
+      /*Set fingerprint LED ring to always ON in red*/
+      fingerprint.ctrlLED(/*LEDMode = */ fingerprint.eKeepsOn,
+                          /*LEDColor = */ fingerprint.eLEDRed,
+                          /*blinkCount = */ 0);
+      Serial.println("Matching fails");
+    }
+  } else {
+    Serial.println("Capturing fails");
+    /*Get error code information*/
+    // desc = fingerprint.getErrorDescription();
+    // Serial.println(desc);
+  }
+  Serial.println("-----------------------------");
+  delay(1000);
+  /*Set the fingerprint LED ring as blue breathing light*/
+  fingerprint.ctrlLED(/*LEDMode = */ fingerprint.eBreathing,
+                      /*LEDColor = */ fingerprint.eLEDBlue,
+                      /*blinkCount = */ 0);
+
+  blink_led();
+}
+
+void blink_led() {
+  digitalWrite(BUILTIN_LED, HIGH);
+  delay(500);
+  digitalWrite(BUILTIN_LED, LOW);
+  delay(500);
+}