sha1 加密解密

#include "sha1.h" // 32bit字左循环移位的宏 //C++中单斜杠（\）的意思：转义字符；换行的标志（一般在宏定义中） #define SHA1CircularShift(bits,word) \ (((word) << (bits)) | ((word) >> (32-(bits)))) ////////////////////////////////////////////////////////////////////////// // 局部函数原型 ////////////////////////////////////////////////////////////////////////// void SHA1PadMessage(SHA1Context *); /* 定义填充信息指针 */ void SHA1ProcessMessageBlock(SHA1Context *); //数据初始化操作 int SHA1Reset(SHA1Context *context) { if (!context) { return shaNull; } context->Length_Low = 0; context->Length_High = 0; context->Message_Block_Index = 0; context->Intermediate_Hash[0] = 0x67452301; context->Intermediate_Hash[1] = 0xEFCDAB89; context->Intermediate_Hash[2] = 0x98BADCFE; context->Intermediate_Hash[3] = 0x10325476; context->Intermediate_Hash[4] = 0xC3D2E1F0; context->Computed = 0; context->Corrupted = 0; return shaSuccess; } //接收单位长度为8字节倍数的消息，处理最后一个分组前面的所有分组 //调用SHA1ProcessMessage int SHA1Input(SHA1Context *context, const uint8_t *message_array, unsigned length) { if (!length) { return shaSuccess; } if (!context || !message_array) { return shaNull; } if (context->Computed) { context->Corrupted = shaStateError; return shaStateError; } if (context->Corrupted) { return context->Corrupted; } while(length-- && !context->Corrupted) //执行while循环，读取message_array中的每一个字符 { context->Message_Block[context->Message_Block_Index++] = (*message_array & 0xFF); context->Length_Low += 8; if (context->Length_Low == 0) { context->Length_High++; if (context->Length_High == 0) { context->Corrupted = 1; // Message is too long } } if (context->Message_Block_Index == 64) { SHA1ProcessMessageBlock(context); //处理每一个512bit消息块 } message_array++; //指针指向下一个字符 } return shaSuccess; } //返回一个160bit的消息摘要队列 //调用SHA1PadMessage int SHA1Result( SHA1Context *context, uint8_t Message_Digest[SHA1HashSize]) { int i; if (!context || !Message_Digest) { return shaNull; } if (context->Corrupted) { return context->Corrupted; } if (!context->Computed) //执行此处 { SHA1PadMessage(context); //数据填充模块 for(i=0; i<64; ++i) { context->Message_Block[i] = 0; //消息清零 } context->Length_Low = 0; // 长度清零 context->Length_High = 0; context->Computed = 1; } for(i = 0; i < SHA1HashSize; ++i) { //由Intermediate_Hash[0 ~ 4]得到Message_Digest[0 ~ 40] Message_Digest[i] = context->Intermediate_Hash[i>>2] >> 8 * ( 3 - ( i & 0x03 ) ); } return shaSuccess; } //数据填充模块，被SHA1Result调用 //调用SHA1ProcessMessage void SHA1PadMessage(SHA1Context *context) { if (context->Message_Block_Index > 55) { context->Message_Block[context->Message_Block_Index++] = 0x80; while(context->Message_Block_Index < 64) { context->Message_Block[context->Message_Block_Index++] = 0; } SHA1ProcessMessageBlock(context); //处理最后一个（含消息长度）512bit消息块 //处理后context->Message_Block_Index = 0; while(context->Message_Block_Index < 56) { context->Message_Block[context->Message_Block_Index++] = 0; } } else { context->Message_Block[context->Message_Block_Index++] = 0x80; while(context->Message_Block_Index < 56) { context->Message_Block[context->Message_Block_Index++] = 0; } } //最后64位保存为数据长度 context->Message_Block[56] = context->Length_High >> 24; context->Message_Block[57] = context->Length_High >> 16; context->Message_Block[58] = context->Length_High >> 8; context->Message_Block[59] = context->Length_High; context->Message_Block[60] = context->Length_Low >> 24; context->Message_Block[61] = context->Length_Low >> 16; context->Message_Block[62] = context->Length_Low >> 8; context->Message_Block[63] = context->Length_Low; SHA1ProcessMessageBlock(context); //处理最后一个（含消息长度）512bit消息块 } // 消息块（固定长度512bit）处理，被SHA1Input，SHA1PadMessage调用 void SHA1ProcessMessageBlock(SHA1Context *context) { const uint32_t K[] = { 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6 }; int t; // 循环计数 uint32_t temp; // 临时缓存 uint32_t W[80]; // 字顺序 uint32_t A, B, C, D, E; // 设置系统磁盘缓存块 //初始化W队列中的头16个字数据 for(t = 0; t < 16; t++) { W[t] = context->Message_Block[t * 4] << 24; W[t] |= context->Message_Block[t * 4 + 1] << 16; W[t] |= context->Message_Block[t * 4 + 2] << 8; W[t] |= context->Message_Block[t * 4 + 3]; } //字W[16]~W[79]的生成 for(t = 16; t < 80; t++) { W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]); } A = context->Intermediate_Hash[0]; B = context->Intermediate_Hash[1]; C = context->Intermediate_Hash[2]; D = context->Intermediate_Hash[3]; E = context->Intermediate_Hash[4]; // 定义算法所用之数学函数及其迭代算法描述 for(t = 0; t < 20; t++) { temp = SHA1CircularShift(5,A) + ((B & C) | ((~B) & D)) + E + W[t] + K[0]; E = D; D = C; C = SHA1CircularShift(30,B); B = A; A = temp; } for(t = 20; t < 40; t++) { temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1]; E = D; D = C; C = SHA1CircularShift(30,B); B = A; A = temp; } for(t = 40; t < 60; t++) { temp = SHA1CircularShift(5,A) + ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2]; E = D; D = C; C = SHA1CircularShift(30,B); B = A; A = temp; } for(t = 60; t < 80; t++) { temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3]; E = D; D = C; C = SHA1CircularShift(30,B); B = A; A = temp; } // 迭代算法第80步（最后一步）描述 context->Intermediate_Hash[0] += A; context->Intermediate_Hash[1] += B; context->Intermediate_Hash[2] += C; context->Intermediate_Hash[3] += D; context->Intermediate_Hash[4] += E; context->Message_Block_Index = 0; }