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c语言如何实现blowfish算法及实例

2019-11-08 22:41 必威体育 云澈114°c
A+ A-

  0x5a88f54c, 0xe029ac71, 0xe019a5e6, 0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc, 0xf8d56629, 0x79132e28,

  0x6f3f3b82, 0x3520ab82, 0x011a1d4b, 0x277227f8, 0x611560b1, 0xe7933fdc, 0xbb3a792b, 0x344525bd, 0xa08839e1,

  0xde966292, 0x81b949d0, 0x4c50901b, 0x71c65614, 0xe6c6c7bd, 0x327a140a, 0x45e1d006, 0xc3f27b9a, 0xc9aa53fd,

  0xb8db38ef, 0x8e79dcb0, 0x603a180e, 0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda, 0x55605c60,

  2)用自己选择的key8个一组地去异或pbox,用异或的结果填充key_pbox。key可以循环使用。

  0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07, 0xefe830f5, 0x4d2d38e6, 0xf0255dc1, 0x4cdd2086, 0x8470eb26, 0x6382e9c6,

  BlowFish算法使用两个“盒”——ungigned long pbox[18]和unsigned long sbox[4,256]。

  BlowFish算法中,有一个核心加密函数:BF_En(后文详细介绍)。该函数输入64位信息,运算后, 以64位密文的形式输出。 用BlowFish算法加密信息,需要两个过程:

  0x6841e7f7, 0xca7820fb, 0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527, 0x55533a3a, 0x20838d87, 0xfe6ba9b7,

  0x021ecc5e, 0x09686b3f, 0x3ebaefc9, 0x3c971814, 0x6b6a70a1, 0x687f3584, 0x52a0e286, 0xb79c5305, 0xaa500737,

  0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f, 0xf79e59b7, 0x43f5bb3a, 0xf2d519ff,

  0xa1ebddf8, 0x991be14c, 0xdb6e6b0d, 0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,

  0x34c6ffea, 0xfe28ed61, 0xee7c3c73, 0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0, 0x45eee2b6, 0xa3aaabea,

  0x39720a3d, 0x7c927c24, 0x86e3725f, 0x724d9db9, 0x1ac15bb4, 0xd39eb8fc, 0xed545578, 0x08fca5b5, 0xd83d7cd3,

  0x0a121386, 0xd90cec6e, 0xd5abea2a, 0x64af674e, 0xda86a85f, 0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086,

  0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0, 0x7745ae04, 0xd736fccc, 0x83426b33, 0xf01eab71, 0xb0804187,

  datal = 0x00000000; datar = 0x00000000;

  0x51ce794b, 0x2f32c9b7, 0xa01fbac9, 0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7, 0x1a908749, 0xd44fbd9a,

  信息解密的过程就是把信息加密过程的key_pbox逆序使用即可。

  b = x & 0x00FF; x 》》= 8;

  3)用BF_En加密一个全0的64位信息,用输出的结果替换key_pbox[0]和key_pbox[1]。i=0

  0xbf0f7315, 0xd62d1c7e, 0xc700c47b, 0xb78c1b6b, 0x21a19045, 0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79,

  0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a, 0x1b510052, 0x9a532915, 0xd60f573f, 0xbc9bc6e4, 0x2b60a476,

  0x5266c825, 0x2e4cc978, 0x9c10b36a, 0xc6150eba, 0x94e2ea78, 0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d,

  0x3d816250, 0xcf62a1f2, 0x5b8d2646, 0xfc8883a0, 0xc1c7b6a3, 0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285,

  for (i = 0; i 《 4; ++i) {

  0x409f60c4, 0x5e5c9ec2, 0x196a2463, 0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c,

  0x5f11199b, 0x043556f1, 0xd7a3c76b, 0x3c11183b, 0x5924a509, 0xf28fe6ed, 0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e,

  0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2, 0x5a04abfc, 0x800bcadc, 0x9e447a2e, 0xc3453484, 0xfdd56705,

  0x699a17ff, 0x5664526c, 0xc2b19ee1, 0x193602a5, 0x75094c29, 0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65,

  0x623d7da8, 0xf837889a, 0x97e32d77, 0x11ed935f, 0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99,

  0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33, 0x62fb1341, 0xcee4c6e8, 0xef20cada, 0x36774c01, 0xd07e9efe, 0x2bf11fb4,

  0x5dec8032, 0xef845d5d, 0xe98575b1, 0xdc262302, 0xeb651b88, 0x23893e81, 0xd396acc5, 0x0f6d6ff3, 0x83f44239,

  void blf_key(blf_ctx *c, char *k, int len){ InitializeBlowfish(c,k,len); }

  //y = ((S[0][a] + S[1][b]) ^ S[2][c]) + S[3][d]; y = bc-》S[0][a] + bc-》S[1][b]; y = y ^ bc-》S[2][c]; y = y + bc-》S[3][d];

  #ifdef little_endian /* Eg: Intel */ #include #endif

  Affects : AX, BX, CX, DX, SI, DI, direcTIon Flag

  0xebcdaf0c, 0x7b3e89a0, 0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e, 0x226800bb, 0x57b8e0af, 0x2464369b,

  由于Blowfish算法采用变长密钥,这在给用户带来极大便利的同时也有隐患。由于算法加/解密核心在于密钥的选择和保密,但在实际应用中经常使用一些弱密钥对信息资源进行加密,导致存在着很大的安全隐患

  if (j 》= keybytes) { j = 0; } }

  0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5, 0x654f3b1d, 0x41cd2105, 0xd81e799e, 0x86854dc7, 0xe44b476a,

  0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6, 0xaace1e7c, 0xd3375fec, 0xce78a399, 0x406b2a42, 0x20fe9e35,

  0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0, 0x006058aa, 0x30dc7d62, 0x11e69ed7,

  可以看出,选择不同的key,用BlowFish算法加密同样的信息,可以得出不同的结果。 要破解BlowFish算法,就是要得到BlowFish算法的key。所以,使用BlowFish算法进行加密,最重要的也就是key的选择以及key的保密。其中key的选择可以使用bf_sdk中的_WeakKey函数进行检验。以下是该函数的说明:

  附:C语言实现实例

  0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10, 0x1ab93d1d, 0x0ba5a4df, 0xa186f20f,

  2.信息加密

  0x5449a36f, 0x877d48fa, 0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74, 0x3a6f6eab, 0xf4f8fd37, 0xa812dc60,

  void blf_enc(blf_ctx *c, unsigned long *data, int blocks){ unsigned long *d; int i;

  void Blowfish_encipher(blf_ctx *c,unsigned long *xl, unsigned long *xr) {

  xR=xR^P17 xL=xL^P18

  return y; }

  0xc8b57634, 0x9af3dda7, 0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41, 0xe238cd99, 0x3bea0e2f, 0x3280bba1,

  0x3320f46a, 0x43b7d4b7, 0x500061af, 0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840, 0x4d95fc1d, 0x96b591af,

  重新合并xL和xR 函数F见下图:

  unsigned long ks0[] = {

  --------------------------------------------------------------------------------------- _WeakKey

  0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7}; unsigned long ks2[] = {

  6)用key_pbox[16]和key_pbox[17]做首次输入(相当于上面的全0的输入),用类似的方法,替换key_sbox 信息加密。信息加密就是用函数把待加密信息x分成32位的两部分:xL,xR BF_En对输入信息进行变换,BF_En函数详细过程如下: 对于i=1至16 xL=xL^Pi xR=F(xL)^xR

  #include #include #include #include

  0xf2122b64, 0x8888b812, 0x900df01c, 0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad, 0x2f2f2218, 0xbe0e1777,

  0xd096954b, 0x55a867bc, 0xa1159a58, 0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c,

  0xdd433b37, 0x24c2ba16, 0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd, 0x71dff89e, 0x10314e55, 0x81ac77d6,

  如此循环,直到key_box填充完毕。

  Blowfish算法的源密钥——pbox和sbox是固定的,而我们要加密一个信息,需要自己选择一个key,用这个key对pbox和sbox进行变换,得到下一步信息加密所要用的key_pbox和key_sbox。解密亦是如此,由于Blowfish是对称加密算法,解密方在得到key后根据key生成解密所需的key_box和key_sbox。对同一个信息加密解密,选取的key的不同会导致密文的不同。因此,Blowfish算法的关键在于key的选择以及保密。

  0x4b7a70e9, 0xb5b32944, 0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d, 0x9cee60b8, 0x8fedb266, 0xecaa8c71,

  0xd9f385b9, 0xee39d7ab, 0x3b124e8b, 0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332,

  密钥预处理的过程与加密时完全相同

  0x763bd6eb, 0x37392eb3, 0xcc115979, 0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b, 0x12754ccc, 0x782ef11c,

  0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66, 0xe3bc4595, 0xa67bc883, 0xb17f37d1,

  0x7a325381, 0x28958677, 0x3b8f4898, 0x6b4bb9af, 0xc4bfe81b, 0x66282193, 0x61d809cc, 0xfb21a991, 0x487cac60,

  short InitializeBlowfish(blf_ctx *c, char key[], short keybytes) {

  0xd2ada8d9, 0x165fa266, 0x80957705, 0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf,

  Return : AX = Status (1=weak, 0=good)

  0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a}; unsigned long ks1[] = {

  0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7, 0xe3fe501a, 0xb6794c3b, 0x976ce0bd, 0x04c006ba, 0xc1a94fb6,

  把xL分成4个8位分组:a,b,c和d

  /* Exchange Xl and Xr */ temp = Xl; Xl = Xr; Xr = temp; }

  0x1b588d40, 0xccd2017f, 0x6bb4e3bb, 0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb,

  0x56c16aa6, 0x4ed3aa62, 0x363f7706, 0x1bfedf72, 0x429b023d, 0x37d0d724, 0xd00a1248, 0xdb0fead3, 0x49f1c09b,

  typedef struct {

  0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96, 0xba7c9045, 0xf12c7f99, 0x24a19947,

  0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d, 0xf01c1f04, 0x0200b3ff, 0xae0cf51a,

  c-》S[0][i] = ks0[i]; c-》S[1][i] = ks1[i]; c-》S[2][i] = ks2[i]; c-》S[3][i] = ks3[i]; }

  0x9320f991, 0xea7a90c2, 0xfb3e7bce, 0x5121ce64, 0x774fbe32, 0xa8b6e37e, 0xc3293d46, 0x48de5369, 0x6413e680,

  ---------------------------------------------------------------------------------------

  

c语言如何实现blowfish算法及实例

  temp = Xl; Xl = Xr; Xr = temp; }

  0xc6a376d2, 0x6549c2c8, 0x530ff8ee, 0x468dde7d, 0xd5730a1d, 0x4cd04dc6, 0x2939bbdb, 0xa9ba4650, 0xac9526e8,

  比如说:选的key是“abcdefghijklmn”。则异或过程为: key_pbox[0]=pbox[0]^abcdefgh key_pbox[1]=pbox[1]^ijklmnab „„„„ „„„„

  0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6};

  0x7c72e993, 0xb3ee1411, 0x636fbc2a, 0x2ba9c55d, 0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c,

  分别说明如下: 密钥预处理:

  0x6a124237, 0xb79251e7, 0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa, 0x3d25bdd8, 0xe2e1c3c9, 0x44421659,

  0x3c005e5f, 0x77a057be, 0xbde8ae24, 0x55464299, 0xbf582e61, 0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2,

  0x2338ea63, 0x53c2dd94, 0xc2c21634, 0xbbcbee56, 0x90bcb6de, 0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188,

  0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e, 0xaec2771b, 0xf64e6370, 0x740e0d8d, 0xe75b1357, 0xf8721671,

  0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504, 0x96eb27b3, 0x55fd3941, 0xda2547e6,

  交换xL和xR(最后一轮取消该运算)

  0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b, 0x9a53e479, 0xb6f84565, 0xd28e49bc,

  #define N 16

  c-》P[i] = c-》P[i] ^ data; }

  for (i = 0; i 《 N + 2; ++i) {

  

c语言如何实现blowfish算法及实例

  0x3cb574b2, 0x25837a58, 0xdc0921bd, 0xd19113f9, 0x7ca92ff6, 0x94324773, 0x22f54701, 0x3ae5e581, 0x37c2dadc,

  0xca6f8ca0, 0x1a87562e, 0xdf1769db, 0xd542a8f6, 0x287effc3, 0xac6732c6, 0x8c4f5573, 0x695b27b0, 0xbbca58c8,

  5)i+2,继续第4步,直到key_pbox全部被替换

  0x0e1e9ec9, 0xdb73dbd3, 0x105588cd, 0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,

  0x2868f169, 0xdcb7da83, 0x573906fe, 0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa, 0xa002b5c4, 0x0de6d027,

  0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e, 0xaf664fd1, 0xcad18115, 0x6b2395e0, 0x333e92e1, 0x3b240b62,

  0x018cff28, 0xc332ddef, 0xbe6c5aa5, 0x65582185, 0x68ab9802, 0xeecea50f, 0xdb2f953b, 0x2aef7dad, 0x5b6e2f84,

  0xe60b6f47, 0x0fe3f11d, 0xe54cda54, 0x1edad891, 0xce6279cf, 0xcd3e7e6f, 0x1618b166, 0xfd2c1d05, 0x848fd2c5,

  0xcc814544, 0xaf5ebd09, 0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3, 0xc0cba857, 0x45c8740f, 0xd20b5f39,

  0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6, 0x2826a2f9, 0xa73a3ae1, 0x4ba99586, 0xef5562e9, 0xc72fefd3,

  unsigned long Xl; unsigned long Xr; unsigned long temp; short i;

  0x5366f9c3, 0xc8b38e74, 0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84, 0x846a0e79, 0x915f95e2, 0x466e598e,

  unsigned long Xl; unsigned long Xr; unsigned long temp; short i; Xl = *xl; Xr = *xr;

  BlowFish算法的源密钥——pbox和sbox是固定的。我们要加密一个信息,需要自己选择一个key, 用这个key对pbox和sbox进行变换,得到下一步信息加密所要用的key_pbox和key_sbox。具体的变化算法如下: 1)用sbox填充key_sbox

  0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6, 0xce89e299, 0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81,

  for (j = 0; j 《 256; j += 2) {

  0xf752f7da, 0x3f046f69, 0x77fa0a59, 0x80e4a915, 0x87b08601, 0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797,

  0xf009b91e, 0x5563911d, 0x59dfa6aa, 0x78c14389, 0xd95a537f, 0x207d5ba2, 0x02e5b9c5, 0x83260376, 0x6295cfa9,

  void Blowfish_decipher(blf_ctx *,unsigned long *xl, unsigned long *xr);

  unsigned long F(blf_ctx *bc, unsigned long x) {

  data = 0x00000000; for (k = 0; k 《 4; ++k) {

  void Blowfish_decipher(blf_ctx *c, unsigned long *xl, unsigned long *xr) {

  #define noErr 0 #define DATAERROR -1 #define KEYBYTES 8

  *xl = Xl; *xr = Xr;

  #ifdef little_endian /* Eg: Intel */ #include #include #endif

  0x41041f0f, 0x404779a4, 0x5d886e17, 0x325f51eb, 0xd59bc0d1, 0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60,

  0xd79a3234, 0x92638212, 0x670efa8e, 0x406000e0}; unsigned long ks3[] = {

  4)用BF_En加密替换后的key_pbox[i],key_pbox[i+1],用输出替代key_pbox[i+2]和key_pbox[i+3]

  0xb3916cf7, 0x0801f2e2, 0x858efc16, 0x636920d8, 0x71574e69, 0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658,

  Blowfish_encipher(c,&datal, &datar);

  0x20b45770, 0x8cd55591, 0xc902de4c, 0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e, 0xb77f19b6, 0xe0a9dc09,

  0x8d937e41, 0xd65fecf1, 0x6c223bdb, 0x7cde3759, 0xcbee7460, 0x4085f2a7, 0xce77326e, 0xa6078084, 0x19f8509e,

  short i; short j; short k; short error; short numread; unsigned long data; unsigned long datal; unsigned long datar;

  #define MAXKEYBYTES 56 /* 448 bits */ // #define little_endian 1 /* Eg: Intel */ #define big_endian 1 /* Eg: Motorola */

  Blowfish算法是一种对称的分组加密算法,算法核心在于子密钥生成,它将变长密钥扩展成总长4168 Byte的子密钥数组。算法中使用了大量的子密钥,而子密钥又依赖于用户密钥,实际加/解密过程中使用的是更新后的子密钥数组,子密钥即P数组和S盒。Blowfish算法有一个核心加密函数:BF_En(),该函数的输人是64位明文信息,经过运算,以64位密文信息的形式输出。用Blowfish算法加密信息,需要两个过程:密钥预处理和信息加密。同样,解密亦需要两个过程,密钥预处理和信息解密。

  0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8, 0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837,

  0x4c70a239, 0xd59e9e0b, 0xcbaade14, 0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf, 0x19bdf0ca,