tiny_md5.c 6.1 KB

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  1. #include "tiny_md5.h"
  2. #include <string.h>
  3. MD5_CTX context;
  4. // 常量表
  5. static const uint8_t PADDING[64] = {
  6. 0x80
  7. };
  8. static void Encode(uint8_t* output, const uint32_t* input, uint32_t len) {
  9. for (uint32_t i = 0, j = 0; j < len; i++, j += 4) {
  10. output[j] = (uint8_t)(input[i] & 0xff);
  11. output[j+1] = (uint8_t)((input[i] >> 8) & 0xff);
  12. output[j+2] = (uint8_t)((input[i] >> 16) & 0xff);
  13. output[j+3] = (uint8_t)((input[i] >> 24) & 0xff);
  14. }
  15. }
  16. static void MD5Transform(uint32_t state[4], const uint8_t block[64]);
  17. void MD5_Calculate(uint8_t* input, uint32_t length, uint8_t output[16]) {
  18. MD5Init(&context);
  19. MD5Update(&context, input, length);
  20. MD5Final(output, &context);
  21. }
  22. /* 下面是核心实现 */
  23. #define S11 7
  24. #define S12 12
  25. #define S13 17
  26. #define S14 22
  27. #define S21 5
  28. #define S22 9
  29. #define S23 14
  30. #define S24 20
  31. #define S31 4
  32. #define S32 11
  33. #define S33 16
  34. #define S34 23
  35. #define S41 6
  36. #define S42 10
  37. #define S43 15
  38. #define S44 21
  39. #define F(x,y,z) (((x)&(y)) | ((~x)&(z)))
  40. #define G(x,y,z) (((x)&(z)) | ((y)&(~z)))
  41. #define H(x,y,z) ((x) ^ (y) ^ (z))
  42. #define I(x,y,z) ((y) ^ ((x) | (~z)))
  43. #define ROTATE_LEFT(x,n) (((x) << (n)) | ((x) >> (32-(n))))
  44. #define FF(a,b,c,d,x,s,ac) { \
  45. (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  46. (a) = ROTATE_LEFT ((a), (s)); \
  47. (a) += (b); \
  48. }
  49. #define GG(a,b,c,d,x,s,ac) { \
  50. (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  51. (a) = ROTATE_LEFT ((a), (s)); \
  52. (a) += (b); \
  53. }
  54. #define HH(a,b,c,d,x,s,ac) { \
  55. (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  56. (a) = ROTATE_LEFT ((a), (s)); \
  57. (a) += (b); \
  58. }
  59. #define II(a,b,c,d,x,s,ac) { \
  60. (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  61. (a) = ROTATE_LEFT ((a), (s)); \
  62. (a) += (b); \
  63. }
  64. static void MD5Transform(uint32_t state[4], const uint8_t block[64]) {
  65. uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
  66. memcpy(x, block, 64);
  67. // Round 1
  68. FF (a, b, c, d, x[ 0], S11, 0xd76aa478);
  69. FF (d, a, b, c, x[ 1], S12, 0xe8c7b756);
  70. FF (c, d, a, b, x[ 2], S13, 0x242070db);
  71. FF (b, c, d, a, x[ 3], S14, 0xc1bdceee);
  72. FF (a, b, c, d, x[ 4], S11, 0xf57c0faf);
  73. FF (d, a, b, c, x[ 5], S12, 0x4787c62a);
  74. FF (c, d, a, b, x[ 6], S13, 0xa8304613);
  75. FF (b, c, d, a, x[ 7], S14, 0xfd469501);
  76. FF (a, b, c, d, x[ 8], S11, 0x698098d8);
  77. FF (d, a, b, c, x[ 9], S12, 0x8b44f7af);
  78. FF (c, d, a, b, x[10], S13, 0xffff5bb1);
  79. FF (b, c, d, a, x[11], S14, 0x895cd7be);
  80. FF (a, b, c, d, x[12], S11, 0x6b901122);
  81. FF (d, a, b, c, x[13], S12, 0xfd987193);
  82. FF (c, d, a, b, x[14], S13, 0xa679438e);
  83. FF (b, c, d, a, x[15], S14, 0x49b40821);
  84. // Round 2
  85. GG (a, b, c, d, x[ 1], S21, 0xf61e2562);
  86. GG (d, a, b, c, x[ 6], S22, 0xc040b340);
  87. GG (c, d, a, b, x[11], S23, 0x265e5a51);
  88. GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa);
  89. GG (a, b, c, d, x[ 5], S21, 0xd62f105d);
  90. GG (d, a, b, c, x[10], S22, 0x02441453);
  91. GG (c, d, a, b, x[15], S23, 0xd8a1e681);
  92. GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8);
  93. GG (a, b, c, d, x[ 9], S21, 0x21e1cde6);
  94. GG (d, a, b, c, x[14], S22, 0xc33707d6);
  95. GG (c, d, a, b, x[ 3], S23, 0xf4d50d87);
  96. GG (b, c, d, a, x[ 8], S24, 0x455a14ed);
  97. GG (a, b, c, d, x[13], S21, 0xa9e3e905);
  98. GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8);
  99. GG (c, d, a, b, x[ 7], S23, 0x676f02d9);
  100. GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);
  101. // Round 3
  102. HH (a, b, c, d, x[ 5], S31, 0xfffa3942);
  103. HH (d, a, b, c, x[ 8], S32, 0x8771f681);
  104. HH (c, d, a, b, x[11], S33, 0x6d9d6122);
  105. HH (b, c, d, a, x[14], S34, 0xfde5380c);
  106. HH (a, b, c, d, x[ 1], S31, 0xa4beea44);
  107. HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9);
  108. HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60);
  109. HH (b, c, d, a, x[10], S34, 0xbebfbc70);
  110. HH (a, b, c, d, x[13], S31, 0x289b7ec6);
  111. HH (d, a, b, c, x[ 0], S32, 0xeaa127fa);
  112. HH (c, d, a, b, x[ 3], S33, 0xd4ef3085);
  113. HH (b, c, d, a, x[ 6], S34, 0x04881d05);
  114. HH (a, b, c, d, x[ 9], S31, 0xd9d4d039);
  115. HH (d, a, b, c, x[12], S32, 0xe6db99e5);
  116. HH (c, d, a, b, x[15], S33, 0x1fa27cf8);
  117. HH (b, c, d, a, x[ 2], S34, 0xc4ac5665);
  118. // Round 4
  119. II (a, b, c, d, x[ 0], S41, 0xf4292244);
  120. II (d, a, b, c, x[ 7], S42, 0x432aff97);
  121. II (c, d, a, b, x[14], S43, 0xab9423a7);
  122. II (b, c, d, a, x[ 5], S44, 0xfc93a039);
  123. II (a, b, c, d, x[12], S41, 0x655b59c3);
  124. II (d, a, b, c, x[ 3], S42, 0x8f0ccc92);
  125. II (c, d, a, b, x[10], S43, 0xffeff47d);
  126. II (b, c, d, a, x[ 1], S44, 0x85845dd1);
  127. II (a, b, c, d, x[ 8], S41, 0x6fa87e4f);
  128. II (d, a, b, c, x[15], S42, 0xfe2ce6e0);
  129. II (c, d, a, b, x[ 6], S43, 0xa3014314);
  130. II (b, c, d, a, x[13], S44, 0x4e0811a1);
  131. II (a, b, c, d, x[ 4], S41, 0xf7537e82);
  132. II (d, a, b, c, x[11], S42, 0xbd3af235);
  133. II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb);
  134. II (b, c, d, a, x[ 9], S44, 0xeb86d391);
  135. state[0] += a;
  136. state[1] += b;
  137. state[2] += c;
  138. state[3] += d;
  139. }
  140. void MD5Init(MD5_CTX* context) {
  141. context->count[0] = context->count[1] = 0;
  142. context->state[0] = 0x67452301;
  143. context->state[1] = 0xefcdab89;
  144. context->state[2] = 0x98badcfe;
  145. context->state[3] = 0x10325476;
  146. }
  147. void MD5Update(MD5_CTX* context, const uint8_t* input, uint32_t inputLen) {
  148. uint32_t i, index, partLen;
  149. index = (context->count[0] >> 3) & 0x3F;
  150. context->count[0] += inputLen << 3;
  151. if (context->count[0] < (inputLen << 3))
  152. context->count[1]++;
  153. context->count[1] += inputLen >> 29;
  154. partLen = 64 - index;
  155. if (inputLen >= partLen) {
  156. memcpy(&context->buffer[index], input, partLen);
  157. MD5Transform(context->state, context->buffer);
  158. for (i = partLen; i + 63 < inputLen; i += 64)
  159. MD5Transform(context->state, &input[i]);
  160. index = 0;
  161. } else {
  162. i = 0;
  163. }
  164. memcpy(&context->buffer[index], &input[i], inputLen - i);
  165. }
  166. void MD5Final(uint8_t digest[16], MD5_CTX* context) {
  167. uint8_t bits[8];
  168. uint32_t index, padLen;
  169. Encode(bits, context->count, 8);
  170. index = (context->count[0] >> 3) & 0x3f;
  171. padLen = (index < 56) ? (56 - index) : (120 - index);
  172. MD5Update(context, PADDING, padLen);
  173. MD5Update(context, bits, 8);
  174. Encode(digest, context->state, 16);
  175. }