The base64 encode formatted output from Arduino HMAC-SHA1 does not match with JAVA/python/online tool - twitter

Question

I am working on an Arduino project which is required an authorized authentication based on OAuth 1.0 to connects to the cloud. This is alike [Authorizing a request to Twitter API][1], and I am stuck in the step of [Creating a signature][2]. The whole process of creating a signature requires algorithms like encodeURL, base64encode, and hmac-sha1. On my Arduino project, I use Cryptosuite(link 3) library for hmac-sha1 and arduino-base64(link 4) library for base64encode. Both of them are working fine separately. However, I need to get a base64-formatted output of hmac-sha1. So I have tried this:
#include <avr/pgmspace.h>
#include <sha1.h>
#include <Base64.h>
uint8_t *in, out, i;
char b64[29];
static const char PROGMEM b64chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
char key[] = "testKey";
char basestring[] = "testing";
void printHash(uint8_t* hash) {
int i;
for (i=0; i<20; i++) {
Serial.print("0123456789abcdef"[hash[i]>>4]);
Serial.print("0123456789abcdef"[hash[i]&0xf]);
}
Serial.println();
}
void setup() {
Serial.begin(115200);
Serial.print("Result:");
Sha1.initHmac((uint8_t*)key, strlen(key));
Sha1.print(basestring);
printHash(Sha1.resultHmac());
Serial.println();
// encoding
char* input;
input = (char*)(Sha1.resultHmac());
int inputLen = strlen(input);
int encodedLen = base64_enc_len(inputLen);
char encoded[encodedLen];
// note input is consumed in this step: it will be empty afterwards
base64_encode(encoded, input, inputLen);
Serial.print("base64 result: ");
Serial.println(encoded);
}
void loop() {
}
The output of printHash that I got is 60d41271d43b875b791e2d54c34bf3f018a29763, which is exactly same with the online verification tool(link 5).
However, I supposed to get YNQScdQ7h1t5Hi1Uw0vz8Biil2M= for the base64 result. But I got L18B0HicKRhuxmB6SIFpZP+DpHxU which seems wrong. I have also tried to write a JAVA program and a python program, which also said that the output of the base64 result should be YNQScdQ7h1t5Hi1Uw0vz8Biil2M=
I also found this post: Issues talking between Arduino SHA1-HMAC and base64 encoding and Python(link 6). I have also tried the tidy function it mentioned from Adafruit-Tweet-Receipt(link 7).
// base64-encode SHA-1 hash output. This is NOT a general-purpose base64
// encoder! It's stripped down for the fixed-length hash -- always 20
// bytes input, always 27 chars output + '='.
for(in = Sha1.resultHmac(), out=0; ; in += 3) { // octets to sextets
b64[out++] = in[0] >> 2;
b64[out++] = ((in[0] & 0x03) << 4) | (in[1] >> 4);
if(out >= 26) break;
b64[out++] = ((in[1] & 0x0f) << 2) | (in[2] >> 6);
b64[out++] = in[2] & 0x3f;
}
b64[out] = (in[1] & 0x0f) << 2;
// Remap sextets to base64 ASCII chars
for(i=0; i<=out; i++) b64[i] = pgm_read_byte(&b64chars[b64[i]]);
b64[i++] = '=';
b64[i++] = 0;
Is there any mistake I've made in here?
Thanks!

Answer 1

So full example will be:
#include <avr/pgmspace.h>
#include <sha1.h>
#include <Base64.h>
char key[] = "testKey";
char basestring[] = "testing";
void printHash(uint8_t* hash) {
for (int i=0; i<20; i++) {
Serial.print("0123456789abcdef"[hash[i]>>4]);
Serial.print("0123456789abcdef"[hash[i]&0xf]);
}
Serial.println();
}
void setup() {
Serial.begin(115200);
Serial.print("Input: ");
Serial.println(basestring);
Serial.print("Key: ");
Serial.println(key);
Serial.print("Hmac-sha1 (hex): ");
Sha1.initHmac((uint8_t*)key, strlen(key));
Sha1.print(basestring);
uint8_t *hash;
hash = Sha1.resultHmac();
printHash(hash);
// base64 encoding
char* input = (char*) hash;
int inputLen = strlen(input) - 1; // skip null termination
int encodedLen = base64_enc_len(inputLen);
char encoded[encodedLen];
// note input is consumed in this step: it will be empty afterwards
base64_encode(encoded, input, inputLen);
Serial.print("Hmac-sha1 (base64): ");
Serial.println(encoded);
}
void loop() { }
which outputs:
Input: testing
Key: testKey
Hmac-sha1 (hex): 60d41271d43b875b791e2d54c34bf3f018a29763
Hmac-sha1 (base64): YNQScdQ7h1t5Hi1Uw0vz8Biil2M=