Print the SHA1 of the cert

Author: sandeepmistry

examples/Tools/ECCX08SelfSignedCert/ECCX08SelfSignedCert.ino

@@ -100,6 +100,10 @@ void setup() {
   Serial.println("Here's your self signed cert, enjoy!");
   Serial.println();
   Serial.println(cert);
+  Serial.println();
+
+  Serial.print("SHA1: ");
+  Serial.println(ECCX08SelfSignedCert.sha1());
 }
 
 void loop() {

src/utility/ECCX08SelfSignedCert.cpp

@@ -19,6 +19,9 @@
 
 #include "ArduinoECCX08.h"
 
+extern "C" {
+  #include "sha1.h"
+}
 #include "ASN1Utils.h"
 #include "PEMUtils.h"
 
@@ -122,6 +125,28 @@ int ECCX08SelfSignedCertClass::length()
   return _length;
 }
 
+String ECCX08SelfSignedCertClass::sha1()
+{
+  char result[20 + 1];
+
+  SHA1(result, (const char*)_bytes, _length);
+
+  String sha1Str;
+
+  sha1Str.reserve(40);
+
+  for (int i = 0; i < 20; i++) {
+    uint8_t b = result[i];
+
+    if (b < 16) {
+      sha1Str += '0';
+    }
+    sha1Str += String(b, HEX);
+  }
+
+  return sha1Str;
+}
+
 void ECCX08SelfSignedCertClass::setIssueYear(int issueYear)
 {
   struct CompressedCert* compressedCert = (struct CompressedCert*)_temp;

src/utility/ECCX08SelfSignedCert.h

@@ -36,6 +36,8 @@ class ECCX08SelfSignedCertClass {
   uint8_t* bytes();
   int length();
 
+  String sha1();
+
   void setIssueYear(int issueYear);
   void setIssueMonth(int issueMonth);
   void setIssueDay(int issueDay);