src/core/auth.c

   1 /*!@file
   2   \brief  Password Encyption and Storing
   3   \details hashes password using SHA256 and saves result in a file on VFS using
   4            hashing algorithm provided by wolfcrypt(wc), a subsystem of wolfSSL
   5   \author  JEL
   6   \date    2016
   7   -----------------------------------------------------------------------------*/
   8 #include <stddef.h>
   9 #include <stdio.h>
  10 #include <wolfssl/wolfcrypt/sha256.h>
  11 #include <emscripten.h>
  12
  13 word32 str_len(const char*);
  14 int auth_encrypt(int argc, char** argv);
  15 void store_password(byte*);
  16
  17 /* Should come with wolfcrypt type.h */
  18 /* typedef unsigned int word32; */
  19
  20 word32
  21 str_len (const char* str)
  22 {
  23   const char* strl;
  24
  25   for (strl = str; *strl != '\0'; ++strl)
  26   {
  27   /* nothing to be done */;
  28   }
  29   return strl - str;
  30 }
  31
  32
  33 /* Takes a string and hashes it, returning
  34    the encrypted string as a result */
  35
  36 int
  37 auth_encrypt(int argc, char** argv)
  38 {
  39   /* Determine length of password */
  40   word32 len = 0;
  41   char* password;
  42   byte hash[32]; /* 32bytes * 8 = 256, the # bits of hash */
  43   const unsigned char c_password[32]; /* Passwords are between 8-32 chars */
  44   Sha256 sha256[1]; /* Init a Sha256 type for wc */
  45
  46
  47   password = argv[0];
  48   len = str_len(password);
  49
  50   /* Converting password to unsigned const char* for wc_functions */
  51   memcpy( (void*) c_password, (void*) password, len+1);
  52
  53   if (wc_InitSha256(sha256) != 0 )
  54    {
  55      printf("wc_InitSha256 failed\n");
  56    }
  57    else
  58    {
  59      wc_Sha256Update(sha256, c_password, len);
  60      wc_Sha256Final(sha256, hash);
  61    }
  62
  63   printf("password is: %s\n", c_password);
  64   printf("password length is: %d\n", len);
  65   for(len = 0; len < 32; len++){
  66     printf("hash is %x\n",hash[len]);
  67   }
  68
  69   store_password(hash);
  70   free((void*) c_password);
  71
  72
  73   return 0;
  74 }
  75
  76 void
  77 store_password(byte* hash)
  78 {
  79   byte b;
  80   /* Save hash to a file on emscripten VFS */
  81   FILE *fp;
  82   int i;
  83   byte buff[32] = {0};
  84
  85   printf("=====Storing Password in auth/password========\n");
  86   /* for(i = 0; i < 32; i++){ */
  87   /*   printf("hash is %x\n",hash[i]); */
  88   /* } */
  89
  90   fp = fopen("/auth/password", "w+");
  91   if(!fp)
  92   {
  93     printf("cannot open file\n");
  94   }
  95   else
  96   {
  97     fwrite(hash, 1, 32, fp);
  98   }
  99
 100   printf("========Stored Password=========\n");
 101
 102   fseek(fp, 0, SEEK_SET);
 103
 104   for(i = 0; i < 32; i++)
 105   {
 106     fread(buff, 1, 32, fp) ;
 107     printf("buff is %x\n",buff[i]);
 108   }
 109
 110   fclose(fp);
 111 }