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sandeepmistrysandeepmistry
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Add JWS support utilty and setup sketch
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‎examples/Tools/ECCX08JWSPublicKey/ECCX08JWSPublicKey.ino

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/*
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ArduinoECCX08 - JWS Public Key
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This sketch can be used to generate a PEM public key for a private key
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generated in an ECC508/ECC608 crypto chip slot.
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If the ECC508/ECC608 is not configured and locked it prompts
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the user to configure and lock the chip with a default TLS
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configuration.
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The user can also select a slot number to use for the private key
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A new private key can also be generated in this slot.
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The circuit:
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- Arduino MKR board equipped with ECC508 or ECC608 chip
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This example code is in the public domain.
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*/
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#include <ArduinoECCX08.h>
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#include <utility/ECCX08JWS.h>
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#include <utility/ECCX08DefaultTLSConfig.h>
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void setup() {
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Serial.begin(9600);
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while (!Serial);
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if (!ECCX08.begin()) {
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Serial.println("No ECCX08 present!");
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while (1);
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}
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if (!ECCX08.locked()) {
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String lock = promptAndReadLine("The ECCX08 on your board is not locked, would you like to PERMANENTLY configure and lock it now? (y/N)", "N");
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lock.toLowerCase();
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if (!lock.startsWith("y")) {
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Serial.println("Unfortunately you can't proceed without locking it :(");
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while (1);
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}
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if (!ECCX08.writeConfiguration(ECCX08_DEFAULT_TLS_CONFIG)) {
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Serial.println("Writing ECCX08 configuration failed!");
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while (1);
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}
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if (!ECCX08.lock()) {
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Serial.println("Locking ECCX08 configuration failed!");
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while (1);
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}
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Serial.println("ECCX08 locked successfully");
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Serial.println();
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}
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Serial.println("Hi there, in order to generate a PEM public key for your board, we'll need the following information ...");
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Serial.println();
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String slot = promptAndReadLine("What slot would you like to use? (0 - 4)", "0");
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String generateNewKey = promptAndReadLine("Would you like to generate a new private key? (Y/n)", "Y");
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Serial.println();
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generateNewKey.toLowerCase();
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String publicKeyPem = ECCX08JWS.publicKey(slot.toInt(), generateNewKey.startsWith("y"));
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if (!publicKeyPem || publicKeyPem == "") {
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Serial.println("Error generating public key!");
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while (1);
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}
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Serial.println("Here's your public key PEM, enjoy!");
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Serial.println();
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Serial.println(publicKeyPem);
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}
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void loop() {
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// do nothing
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}
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String promptAndReadLine(const char* prompt, const char* defaultValue) {
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Serial.print(prompt);
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Serial.print(" [");
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Serial.print(defaultValue);
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Serial.print("]: ");
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String s = readLine();
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if (s.length() == 0) {
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s = defaultValue;
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}
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Serial.println(s);
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return s;
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}
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String readLine() {
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String line;
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while (1) {
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if (Serial.available()) {
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char c = Serial.read();
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if (c == '\r') {
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// ignore
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continue;
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} else if (c == '\n') {
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break;
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}
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line += c;
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}
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}
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return line;
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}

‎src/utility/ECCX08JWS.cpp

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/*
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This file is part of the ArduinoECCX08 library.
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Copyright (c) 2019 Arduino SA. All rights reserved.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "ECCX08.h"
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#include "ASN1Utils.h"
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#include "PEMUtils.h"
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#include "ECCX08JWS.h"
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static String base64urlEncode(const byte in[], unsigned int length)
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{
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static const char* CODES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_=";
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int b;
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String out;
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int reserveLength = 4 * ((length + 2) / 3);
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out.reserve(reserveLength);
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for (unsigned int i = 0; i < length; i += 3) {
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b = (in[i] & 0xFC) >> 2;
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out += CODES[b];
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b = (in[i] & 0x03) << 4;
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if (i + 1 < length) {
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b |= (in[i + 1] & 0xF0) >> 4;
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out += CODES[b];
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b = (in[i + 1] & 0x0F) << 2;
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if (i + 2 < length) {
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b |= (in[i + 2] & 0xC0) >> 6;
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out += CODES[b];
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b = in[i + 2] & 0x3F;
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out += CODES[b];
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} else {
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out += CODES[b];
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}
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} else {
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out += CODES[b];
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}
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}
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while (out.lastIndexOf('=') != -1) {
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out.remove(out.length() - 1);
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}
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return out;
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}
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ECCX08JWSClass::ECCX08JWSClass()
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{
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}
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ECCX08JWSClass::~ECCX08JWSClass()
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{
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}
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String ECCX08JWSClass::publicKey(int slot, bool newPrivateKey)
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{
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if (slot < 0 || slot > 8) {
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return "";
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}
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byte publicKey[64];
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if (newPrivateKey) {
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if (!ECCX08.generatePrivateKey(slot, publicKey)) {
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return "";
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}
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} else {
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if (!ECCX08.generatePublicKey(slot, publicKey)) {
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return "";
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}
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}
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int length = ASN1Utils.publicKeyLength();
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byte out[length];
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ASN1Utils.appendPublicKey(publicKey, out);
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return PEMUtils.base64Encode(out, length, "-----BEGIN PUBLIC KEY-----\n", "\n-----END PUBLIC KEY-----\n");
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}
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String ECCX08JWSClass::sign(int slot, const char* header, const char* payload)
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{
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if (slot < 0 || slot > 8) {
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return "";
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}
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String encodedHeader = base64urlEncode((const byte*)header, strlen(header));
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String encodedPayload = base64urlEncode((const byte*)payload, strlen(payload));
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String toSign;
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toSign.reserve(encodedHeader.length() + 1 + encodedPayload.length());
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toSign += encodedHeader;
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toSign += '.';
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toSign += encodedPayload;
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byte toSignSha256[32];
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byte signature[64];
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if (!ECCX08.beginSHA256()) {
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return "";
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}
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for (unsigned int i = 0; i < toSign.length(); i += 64) {
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int chunkLength = toSign.length() - i;
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if (chunkLength > 64) {
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chunkLength = 64;
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}
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if (chunkLength == 64) {
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if (!ECCX08.updateSHA256((const byte*)toSign.c_str() + i)) {
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return "";
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}
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} else {
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if (!ECCX08.endSHA256((const byte*)toSign.c_str() + i, chunkLength, toSignSha256)) {
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return "";
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}
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}
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}
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if (!ECCX08.ecSign(slot, toSignSha256, signature)) {
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return "";
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}
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String encodedSignature = base64urlEncode(signature, sizeof(signature));
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String result;
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result.reserve(toSign.length() + 1 + encodedSignature.length());
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result += toSign;
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result += '.';
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result += encodedSignature;
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return result;
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}
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String ECCX08JWSClass::sign(int slot, const String& header, const String& payload)
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{
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return sign(slot, header.c_str(), payload.c_str());
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}
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ECCX08JWSClass ECCX08JWS;

‎src/utility/ECCX08JWS.h

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/*
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This file is part of the ArduinoECCX08 library.
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Copyright (c) 2019 Arduino SA. All rights reserved.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef _ECCX08_JWS_H_
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#define _ECCX08_JWS_H_
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#include <Arduino.h>
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class ECCX08JWSClass {
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public:
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ECCX08JWSClass();
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virtual ~ECCX08JWSClass();
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String publicKey(int slot, bool newPrivateKey = true);
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String sign(int slot, const char* header, const char* payload);
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String sign(int slot, const String& header, const String& payload);
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};
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extern ECCX08JWSClass ECCX08JWS;
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#endif

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