text: /*
   * Copyright (C) 2015-2018 Alibaba Group Holding Limited
   */
  #include "infra_config.h"
  
  #ifdef INFRA_MD5
  
  #include <stdlib.h>
  #include <string.h>
  
  #include "infra_md5.h"
  
  #define MD5_KEY_IOPAD_SIZE  (64)
  #define MD5_DIGEST_SIZE     (16)
  
  /* Implementation that should never be optimized out by the compiler */
  static void utils_md5_zeroize(void *v, size_t n)
  {
      volatile unsigned char *p = v;
      while (n--) {
          *p++ = 0;
      }
  }
  
  /*
   * 32-bit integer manipulation macros (little endian)
   */
  #ifndef IOT_MD5_GET_UINT32_LE
  #define IOT_MD5_GET_UINT32_LE(n,b,i)                            \
      {                                                       \
          (n) = ( (uint32_t) (b)[(i)    ]       )             \
                | ( (uint32_t) (b)[(i) + 1] <<  8 )             \
                | ( (uint32_t) (b)[(i) + 2] << 16 )             \
                | ( (uint32_t) (b)[(i) + 3] << 24 );            \
      }
  #endif
  
  #ifndef IOT_MD5_PUT_UINT32_LE
  #define IOT_MD5_PUT_UINT32_LE(n,b,i)                                    \
      {                                                               \
          (b)[(i)    ] = (unsigned char) ( ( (n)       ) & 0xFF );    \
          (b)[(i) + 1] = (unsigned char) ( ( (n) >>  8 ) & 0xFF );    \
          (b)[(i) + 2] = (unsigned char) ( ( (n) >> 16 ) & 0xFF );    \
          (b)[(i) + 3] = (unsigned char) ( ( (n) >> 24 ) & 0xFF );    \
      }
  #endif
  
  void utils_md5_init(iot_md5_context *ctx)
  {
      memset(ctx, 0, sizeof(iot_md5_context));
  }
  
  void utils_md5_free(iot_md5_context *ctx)
  {
      if (ctx == NULL) {
          return;
      }
  
      utils_md5_zeroize(ctx, sizeof(iot_md5_context));
  }
  
  void utils_md5_clone(iot_md5_context *dst,
                       const iot_md5_context *src)
  {
      *dst = *src;
  }
  
  /*
   * MD5 context setup
   */
  void utils_md5_starts(iot_md5_context *ctx)
  {
      ctx->total[0] = 0;
      ctx->total[1] = 0;
  
      ctx->state[0] = 0x67452301;
      ctx->state[1] = 0xEFCDAB89;
      ctx->state[2] = 0x98BADCFE;
      ctx->state[3] = 0x10325476;
  }
  
  void utils_md5_process(iot_md5_context *ctx, const unsigned char data[64])
  {
      uint32_t X[16], A, B, C, D;
  
      IOT_MD5_GET_UINT32_LE(X[ 0], data,  0);
      IOT_MD5_GET_UINT32_LE(X[ 1], data,  4);
      IOT_MD5_GET_UINT32_LE(X[ 2], data,  8);
      IOT_MD5_GET_UINT32_LE(X[ 3], data, 12);
      IOT_MD5_GET_UINT32_LE(X[ 4], data, 16);
      IOT_MD5_GET_UINT32_LE(X[ 5], data, 20);
      IOT_MD5_GET_UINT32_LE(X[ 6], data, 24);
      IOT_MD5_GET_UINT32_LE(X[ 7], data, 28);
      IOT_MD5_GET_UINT32_LE(X[ 8], data, 32);
      IOT_MD5_GET_UINT32_LE(X[ 9], data, 36);
      IOT_MD5_GET_UINT32_LE(X[10], data, 40);
      IOT_MD5_GET_UINT32_LE(X[11], data, 44);
      IOT_MD5_GET_UINT32_LE(X[12], data, 48);
      IOT_MD5_GET_UINT32_LE(X[13], data, 52);
      IOT_MD5_GET_UINT32_LE(X[14], data, 56);
      IOT_MD5_GET_UINT32_LE(X[15], data, 60);
  
  #define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
  
  #define P(a,b,c,d,k,s,t)                                \
      {                                                       \
          a += F(b,c,d) + X[k] + t; a = S(a,s) + b;           \
      }
  
      A = ctx->state[0];
      B = ctx->state[1];
      C = ctx->state[2];
      D = ctx->state[3];
  
  #define F(x,y,z) (z ^ (x & (y ^ z)))
  
      P(A, B, C, D,  0,  7, 0xD76AA478);
      P(D, A, B, C,  1, 12, 0xE8C7B756);
      P(C, D, A, B,  2, 17, 0x242070DB);
      P(B, C, D, A,  3, 22, 0xC1BDCEEE);
      P(A, B, C, D,  4,  7, 0xF57C0FAF);
      P(D, A, B, C,  5, 12, 0x4787C62A);
      P(C, D, A, B,  6, 17, 0xA8304613);
      P(B, C, D, A,  7, 22, 0xFD469501);
      P(A, B, C, D,  8,  7, 0x698098D8);
      P(D, A, B, C,  9, 12, 0x8B44F7AF);
      P(C, D, A, B, 10, 17, 0xFFFF5BB1);
      P(B, C, D, A, 11, 22, 0x895CD7BE);
      P(A, B, C, D, 12,  7, 0x6B901122);
      P(D, A, B, C, 13, 12, 0xFD987193);
      P(C, D, A, B, 14, 17, 0xA679438E);
      P(B, C, D, A, 15, 22, 0x49B40821);
  
  #undef F
  
  #define F(x,y,z) (y ^ (z & (x ^ y)))
  
      P(A, B, C, D,  1,  5, 0xF61E2562);
      P(D, A, B, C,  6,  9, 0xC040B340);
      P(C, D, A, B, 11, 14, 0x265E5A51);
      P(B, C, D, A,  0, 20, 0xE9B6C7AA);
      P(A, B, C, D,  5,  5, 0xD62F105D);
      P(D, A, B, C, 10,  9, 0x02441453);
      P(C, D, A, B, 15, 14, 0xD8A1E681);
      P(B, C, D, A,  4, 20, 0xE7D3FBC8);
      P(A, B, C, D,  9,  5, 0x21E1CDE6);
      P(D, A, B, C, 14,  9, 0xC33707D6);
      P(C, D, A, B,  3, 14, 0xF4D50D87);
      P(B, C, D, A,  8, 20, 0x455A14ED);
      P(A, B, C, D, 13,  5, 0xA9E3E905);
      P(D, A, B, C,  2,  9, 0xFCEFA3F8);
      P(C, D, A, B,  7, 14, 0x676F02D9);
      P(B, C, D, A, 12, 20, 0x8D2A4C8A);
  
  #undef F
  
  #define F(x,y,z) (x ^ y ^ z)
  
      P(A, B, C, D,  5,  4, 0xFFFA3942);
      P(D, A, B, C,  8, 11, 0x8771F681);
      P(C, D, A, B, 11, 16, 0x6D9D6122);
      P(B, C, D, A, 14, 23, 0xFDE5380C);
      P(A, B, C, D,  1,  4, 0xA4BEEA44);
      P(D, A, B, C,  4, 11, 0x4BDECFA9);
      P(C, D, A, B,  7, 16, 0xF6BB4B60);
      P(B, C, D, A, 10, 23, 0xBEBFBC70);
      P(A, B, C, D, 13,  4, 0x289B7EC6);
      P(D, A, B, C,  0, 11, 0xEAA127FA);
      P(C, D, A, B,  3, 16, 0xD4EF3085);
      P(B, C, D, A,  6, 23, 0x04881D05);
      P(A, B, C, D,  9,  4, 0xD9D4D039);
      P(D, A, B, C, 12, 11, 0xE6DB99E5);
      P(C, D, A, B, 15, 16, 0x1FA27CF8);
      P(B, C, D, A,  2, 23, 0xC4AC5665);
  
  #undef F
  
  #define F(x,y,z) (y ^ (x | ~z))
  
      P(A, B, C, D,  0,  6, 0xF4292244);
      P(D, A, B, C,  7, 10, 0x432AFF97);
      P(C, D, A, B, 14, 15, 0xAB9423A7);
      P(B, C, D, A,  5, 21, 0xFC93A039);
      P(A, B, C, D, 12,  6, 0x655B59C3);
      P(D, A, B, C,  3, 10, 0x8F0CCC92);
      P(C, D, A, B, 10, 15, 0xFFEFF47D);
      P(B, C, D, A,  1, 21, 0x85845DD1);
      P(A, B, C, D,  8,  6, 0x6FA87E4F);
      P(D, A, B, C, 15, 10, 0xFE2CE6E0);
      P(C, D, A, B,  6, 15, 0xA3014314);
      P(B, C, D, A, 13, 21, 0x4E0811A1);
      P(A, B, C, D,  4,  6, 0xF7537E82);
      P(D, A, B, C, 11, 10, 0xBD3AF235);
      P(C, D, A, B,  2, 15, 0x2AD7D2BB);
      P(B, C, D, A,  9, 21, 0xEB86D391);
  
  #undef F
  
      ctx->state[0] += A;
      ctx->state[1] += B;
      ctx->state[2] += C;
      ctx->state[3] += D;
  }
  
  /*
   * MD5 process buffer
   */
  void utils_md5_update(iot_md5_context *ctx, const unsigned char *input, uint32_t ilen)
  {
      uint32_t fill;
      uint32_t left;
  
      if (ilen == 0) {
          return;
      }
  
      left = ctx->total[0] & 0x3F;
      fill = 64 - left;
  
      ctx->total[0] += (uint32_t) ilen;
      ctx->total[0] &= 0xFFFFFFFF;
  
      if (ctx->total[0] < (uint32_t) ilen) {
          ctx->total[1]++;
      }
  
      if (left && ilen >= fill) {
          memcpy((void *)(ctx->buffer + left), input, fill);
          utils_md5_process(ctx, ctx->buffer);
          input += fill;
          ilen  -= fill;
          left = 0;
      }
  
      while (ilen >= 64) {
          utils_md5_process(ctx, input);
          input += 64;
          ilen  -= 64;
      }
  
      if (ilen > 0) {
          memcpy((void *)(ctx->buffer + left), input, ilen);
      }
  }
  
  static const unsigned char iot_md5_padding[64] = {
      0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  };
  
  /*
   * MD5 final digest
   */
  void utils_md5_finish(iot_md5_context *ctx, unsigned char output[16])
  {
      uint32_t last, padn;
      uint32_t high, low;
      unsigned char msglen[8];
  
      high = (ctx->total[0] >> 29)
             | (ctx->total[1] <<  3);
      low  = (ctx->total[0] <<  3);
  
      IOT_MD5_PUT_UINT32_LE(low,  msglen, 0);
      IOT_MD5_PUT_UINT32_LE(high, msglen, 4);
  
      last = ctx->total[0] & 0x3F;
      padn = (last < 56) ? (56 - last) : (120 - last);
  
      utils_md5_update(ctx, iot_md5_padding, padn);
      utils_md5_update(ctx, msglen, 8);
  
      IOT_MD5_PUT_UINT32_LE(ctx->state[0], output,  0);
      IOT_MD5_PUT_UINT32_LE(ctx->state[1], output,  4);
      IOT_MD5_PUT_UINT32_LE(ctx->state[2], output,  8);
      IOT_MD5_PUT_UINT32_LE(ctx->state[3], output, 12);
  }
  
  
  /*
   * output = MD5( input buffer )
   */
  void utils_md5(const unsigned char *input, uint32_t ilen, unsigned char output[16])
  {
      iot_md5_context ctx;
  
      utils_md5_init(&ctx);
      utils_md5_starts(&ctx);
      utils_md5_update(&ctx, input, ilen);
      utils_md5_finish(&ctx, output);
      utils_md5_free(&ctx);
  }
  
  static int8_t utils_hb2hex(uint8_t hb)
  {
      hb = hb & 0xF;
      return (int8_t)(hb < 10 ? '0' + hb : hb - 10 + 'a');
  }
  
  void utils_hmac_md5(const char *msg, int msg_len, char *digest, const char *key, int key_len)
  {
      iot_md5_context context;
      unsigned char k_ipad[MD5_KEY_IOPAD_SIZE];    /* inner padding - key XORd with ipad  */
      unsigned char k_opad[MD5_KEY_IOPAD_SIZE];    /* outer padding - key XORd with opad */
      unsigned char out[MD5_DIGEST_SIZE];
      int i;
  
      if ((NULL == msg) || (NULL == digest) || (NULL == key)) {
          return;
      }
  
      if (key_len > MD5_KEY_IOPAD_SIZE) {
          return;
      }
  
      /* start out by storing key in pads */
      memset(k_ipad, 0, sizeof(k_ipad));
      memset(k_opad, 0, sizeof(k_opad));
      memcpy(k_ipad, key, key_len);
      memcpy(k_opad, key, key_len);
  
      /* XOR key with ipad and opad values */
      for (i = 0; i < MD5_KEY_IOPAD_SIZE; i++) {
          k_ipad[i] ^= 0x36;
          k_opad[i] ^= 0x5c;
      }
  
      /* perform inner MD5 */
      utils_md5_init(&context);                                      /* init context for 1st pass */
      utils_md5_starts(&context);                                    /* setup context for 1st pass */
      utils_md5_update(&context, k_ipad, MD5_KEY_IOPAD_SIZE);            /* start with inner pad */
      utils_md5_update(&context, (unsigned char *) msg, msg_len);    /* then text of datagram */
      utils_md5_finish(&context, out);                               /* finish up 1st pass */
  
      /* perform outer MD5 */
      utils_md5_init(&context);                              /* init context for 2nd pass */
      utils_md5_starts(&context);                            /* setup context for 2nd pass */
      utils_md5_update(&context, k_opad, MD5_KEY_IOPAD_SIZE);    /* start with outer pad */
      utils_md5_update(&context, out, MD5_DIGEST_SIZE);      /* then results of 1st hash */
      utils_md5_finish(&context, out);                       /* finish up 2nd pass */
  
      for (i = 0; i < MD5_DIGEST_SIZE; ++i) {
          digest[i * 2] = utils_hb2hex(out[i] >> 4);
          digest[i * 2 + 1] = utils_hb2hex(out[i]);
      }
  }
  
  #endif
  
  