google身份验证器C语言接口

#include <stdlib.h> #include <stdio.h> #include <assert.h> #include <stdint.h> #include <time.h> #include "ga.h" #pragma warning(disable:4996) // typedef unsigned int size_t; // typedef int ptrdiff_t; // typedef int intptr_t; /****************************** Base32 Encoding ******************************/ static const size_t BASE32_ENCODE_INPUT = 5; static const size_t BASE32_ENCODE_OUTPUT = 8; static const char* const BASE32_ENCODE_TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567="; //返回输出缓冲区需要的大小 size_t base32EncodeGetLength(size_t size) { /* * output 8 bytes for every 5 input: * 1 2 3 4 5 * 1 = ---11111 = 11111--- * 2 = ---111XX = -----111 XX------ * 3 = ---11111 = --11111- * 4 = ---1XXXX = -------1 XXXX---- * 5 = ---1111X = ----1111 X------- * 6 = ---11111 = -11111-- * 7 = ---11XXX = ------11 XXX----- * 8 = ---11111 = ---11111 */ return (((size + BASE32_ENCODE_INPUT - 1) / BASE32_ENCODE_INPUT) * BASE32_ENCODE_OUTPUT) + 1; /*plus terminator*/ } //base32编码，size是src字符串的长度不包括结尾的'\0' size_t base32Encode(char* dest, const void* src, size_t size) { if (dest && src) { unsigned char* pSrc = (unsigned char*)src; size_t dwSrcSize = size; size_t dwDestSize = 0; size_t dwBlockSize; unsigned char n1, n2, n3, n4, n5, n6, n7, n8; while (dwSrcSize >= 1) { /* Encode inputs */ dwBlockSize = (dwSrcSize < BASE32_ENCODE_INPUT ? dwSrcSize : BASE32_ENCODE_INPUT); n1 = n2 = n3 = n4 = n5 = n6 = n7 = n8 = 0; switch (dwBlockSize) { case 5: n8 = (pSrc[4] & 0x1f); n7 = ((unsigned char)(pSrc[4] & 0xe0) >> 5); case 4: n7 |= ((unsigned char)(pSrc[3] & 0x03) << 3); n6 = ((unsigned char)(pSrc[3] & 0x7c) >> 2); n5 = ((unsigned char)(pSrc[3] & 0x80) >> 7); case 3: n5 |= ((unsigned char)(pSrc[2] & 0x0f) << 1); n4 = ((unsigned char)(pSrc[2] & 0xf0) >> 4); case 2: n4 |= ((unsigned char)(pSrc[1] & 0x01) << 4); n3 = ((unsigned char)(pSrc[1] & 0x3e) >> 1); n2 = ((unsigned char)(pSrc[1] & 0xc0) >> 6); case 1: n2 |= ((unsigned char)(pSrc[0] & 0x07) << 2); n1 = ((unsigned char)(pSrc[0] & 0xf8) >> 3); break; default: assert(0); } pSrc += dwBlockSize; dwSrcSize -= dwBlockSize; /* Validate */ assert(n1 <= 31); assert(n2 <= 31); assert(n3 <= 31); assert(n4 <= 31); assert(n5 <= 31); assert(n6 <= 31); assert(n7 <= 31); assert(n8 <= 31); /* Padding */ switch (dwBlockSize) { case 1: n3 = n4 = 32; case 2: n5 = 32; case 3: n6 = n7 = 32; case 4: n8 = 32; case 5: break; default: assert(0); } /* 8 outputs */ *dest++ = BASE32_ENCODE_TABLE[n1]; *dest++ = BASE32_ENCODE_TABLE[n2]; *dest++ = BASE32_ENCODE_TABLE[n3]; *dest++ = BASE32_ENCODE_TABLE[n4]; *dest++ = BASE32_ENCODE_TABLE[n5]; *dest++ = BASE32_ENCODE_TABLE[n6]; *dest++ = BASE32_ENCODE_TABLE[n7]; *dest++ = BASE32_ENCODE_TABLE[n8]; dwDestSize += BASE32_ENCODE_OUTPUT; } *dest++ = '\x0'; /*append terminator*/ return dwDestSize; } else return 0; /*ERROR - null pointer*/ } /****************************** Base32 Decoding ******************************/ static const size_t BASE32_DECODE_INPUT = 8; static const size_t BASE32_DECODE_OUTPUT = 5; static const size_t BASE32_DECODE_MAX_PADDING = 6; static const unsigned char BASE32_DECODE_MAX = 31; static const unsigned char BASE32_DECODE_TABLE[0x80] = { /*00-07*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*08-0f*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*10-17*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*18-1f*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*20-27*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*28-2f*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*30-37*/ 0xFF, 0xFF, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /*6 = '2'-'7'*/ /*38-3f*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x20, 0xFF, 0xFF, /*1 = '='*/ /*40-47*/ 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, /*7 = 'A'-'G'*/ /*48-4f*/ 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, /*8 = 'H'-'O'*/ /*50-57*/ 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, /*8 = 'P'-'W'*/ /*58-5f*/ 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /*3 = 'X'-'Z'*/ /*60-67*/ 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, /*7 = 'a'-'g' (same as 'A'-'G')*/ /*68-6f*/ 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, /*8 = 'h'-'o' (same as 'H'-'O')*/ /*70-77*/ 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, /*8 = 'p'-'w' (same as 'P'-'W')*/ /*78-7f*/ 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF /*3 = 'x'-'z' (same as 'X'-'Z')*/ }; int cyoBase32Validate(const char* src, size_t size) { /* * returns 0 if the source is a valid base32 encoding */ if (size % BASE32_DECODE_INPUT != 0) return -1; /*ERROR - size isn't a multiple of 8*/ for (; size >= 1; --size, ++src) { unsigned char ch = *src; if ((ch >= 0x80) || (BASE32_DECODE_TABLE[ch] > BASE32_DECODE_MAX)) break; } for (; 1 <= size && size <= BASE32_DECODE_MAX_PADDING; --size, ++src) { unsigned char ch = *src; if ((ch >= 0x80) || (BASE32_DECODE_TABLE[ch] != BASE32_DECODE_MAX + 1)) break; } if (size != 0) return -2; /*ERROR - invalid base32 character*/ return 0; /*OK*/ } size_t base32DecodeGetLength(size_t size) { /* * output 5 bytes for every 8 input: * 1 2 3 4 5 * 1 = ---11111 = 11111--- * 2 = ---111XX = -----111 XX------ * 3 = ---11111 = --11111- * 4 = ---1XXXX = -------1 XXXX---- * 5 = ---1111X = ----1111 X------- * 6 = ---11111 = -11111-- * 7 = ---11XXX = ------11 XXX----- * 8 = ---11111 = ---11111 */ if (size % BASE32_DECODE_INPUT == 0) return (((size + BASE32_DECODE_INPUT - 1) / BASE32_DECODE_INPUT) * BASE32_DECODE_OUTPUT) + 1; /*plus terminator*/ else return 0; /*ERROR - size isn't a multiple of 8*/ } size_t base32Decode(void* dest, const char* src, size_t size) { if (dest && src && (size % BASE32_DECODE_INPUT == 0)) { unsigned char* pDest = (unsigned char*)dest; size_t dwSrcSize = size; size_t dwDestSize = 0; unsigned char in1, in2, in3, in4, in5, in6, in7, in8; while (dwSrcSize >= 1) { /* 8 inputs */ in1 = *src++; in2 = *src++; in3 = *src++; in4 = *src++; in5 = *src++; in6 = *src++; in7 = *src++; in8 = *src++; dwSrcSize -= BASE32_DECODE_INPUT; /* Validate ascii */ if (in1 >= 0x80 || in2 >= 0x80 || in3 >= 0x80 || in4 >= 0x80 || in5 >= 0x80 || in6 >= 0x80 || in7 >= 0x80 || in8 >= 0x80) return 0; /*ERROR - invalid base32 character*/ /* Convert ascii to base16 */ in1 = BASE32_DECODE_TABLE[in1]; in2 = BASE32_DECODE_TABLE[in2]; in3 = BASE32_DECODE_TABLE[in3]; in4 = BASE32_DECODE_TABLE[in4]; in5 = BASE32_DECODE_TABLE[in5]; in6 = BASE32_DECODE_TABLE[in6]; in7 = BASE32_DECODE_TABLE[in7]; in8 = BASE32_DECODE_TABLE[in8]; /* Validate base32 */ if (in1 > BASE32_DECODE_MAX || in2 > BASE32_DECODE_MAX) return 0; /*ERROR - invalid base32 character*/ /*the following can be padding*/ if ((int)in3 > (int)BASE32_DECODE_MAX + 1 || (int)in4 > (int)BASE32_DECODE_MAX + 1 || (int)in5 > (int)BASE32_DECODE_MAX + 1 || (int)in6 > (int)BASE32_DECODE_MAX + 1 || (int)in7 > (int)BASE32_DECODE_MAX + 1 || (int)in8 > (int)BASE32_DECODE_MAX + 1) return 0; /*ERROR - invalid base32 character*/ /* 5 outputs */ *pDest++ = ((unsigned char)(in1 & 0x1f) << 3) | ((unsigned char)(in2 & 0x1c) >> 2); *pDest++ = ((unsigned char)(in2 & 0x03) << 6) | ((unsigned char)(in3 & 0x1f) << 1) | ((unsigned char)(in4 & 0x10) >> 4); *pDest++ = ((unsigned char)(in4 & 0x0f) << 4) | ((unsigned char)(in5 & 0x1e) >> 1); *pDest++ = ((