verify the pinAuth parameter with hmac

crypto.c

@@ -54,6 +54,44 @@ void crypto_sha256_final(uint8_t * hash)
     sha256_final(&sha256_ctx, hash);
 }
 
+void crypto_sha256_hmac(uint8_t * key, uint32_t klen, uint8_t * data, uint32_t datalen, uint8_t * hmac)
+{
+    uint8_t buf[64];
+    int i;
+    memset(buf, 0, sizeof(buf));
+
+    if(klen > 64)
+    {
+        printf("Error, key size must be <= 64\n");
+        exit(1);
+    }
+
+    memmove(buf, key, klen);
+
+    for (i = 0; i < sizeof(buf); i++)
+    {
+        buf[i] = buf[i] ^ 0x36;
+    }
+
+    crypto_sha256_init();
+    crypto_sha256_update(buf, 64);
+    crypto_sha256_update(data, datalen);
+    crypto_sha256_final(hmac);
+
+    memset(buf, 0, sizeof(buf));
+    memmove(buf, key, klen);
+
+    for (i = 0; i < sizeof(buf); i++)
+    {
+        buf[i] = buf[i] ^ 0x5c;
+    }
+
+    crypto_sha256_init();
+    crypto_sha256_update(buf, 64);
+    crypto_sha256_update(hmac, 32);
+    crypto_sha256_final(hmac);
+}
+
 
 void crypto_ecc256_init()
 {