comparison: b64.c
b64.c
- changeset 0
- 3ebc0316f54f
equal
deleted
inserted
replaced
| -1:000000000000 | 0:3ebc0316f54f |
|---|---|
| 1 #include <lua.h> | |
| 2 #include <lauxlib.h> | |
| 3 | |
| 4 #include "b64.h" | |
| 5 | |
| 6 int frombase64(lua_State *L, const unsigned char *str, unsigned int len) { | |
| 7 int d = 0, dlast = 0, phase = 0; | |
| 8 unsigned char c; | |
| 9 static int table[256] = { | |
| 10 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* 00-0F */ | |
| 11 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* 10-1F */ | |
| 12 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63, /* 20-2F */ | |
| 13 52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1, /* 30-3F */ | |
| 14 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14, /* 40-4F */ | |
| 15 15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1, /* 50-5F */ | |
| 16 -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40, /* 60-6F */ | |
| 17 41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1, /* 70-7F */ | |
| 18 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* 80-8F */ | |
| 19 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* 90-9F */ | |
| 20 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* A0-AF */ | |
| 21 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* B0-BF */ | |
| 22 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* C0-CF */ | |
| 23 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* D0-DF */ | |
| 24 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, /* E0-EF */ | |
| 25 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1 /* F0-FF */ | |
| 26 }; | |
| 27 luaL_Buffer b; | |
| 28 | |
| 29 luaL_buffinit(L, &b); | |
| 30 for (; len--; ++str) { | |
| 31 d = table[(int)*str]; | |
| 32 if (d == -1) continue; | |
| 33 switch(phase) { | |
| 34 case 0: | |
| 35 ++phase; | |
| 36 break; | |
| 37 case 1: | |
| 38 c = ((dlast << 2) | ((d & 0x30) >> 4)); | |
| 39 luaL_addchar(&b, c); | |
| 40 ++phase; | |
| 41 break; | |
| 42 case 2: | |
| 43 c = (((dlast & 0xf) << 4) | ((d & 0x3c) >> 2)); | |
| 44 luaL_addchar(&b, c); | |
| 45 ++phase; | |
| 46 break; | |
| 47 case 3: | |
| 48 c = (((dlast & 0x03 ) << 6) | d); | |
| 49 luaL_addchar(&b, c); | |
| 50 phase = 0; | |
| 51 break; | |
| 52 } | |
| 53 dlast = d; | |
| 54 } | |
| 55 luaL_pushresult(&b); | |
| 56 return 1; | |
| 57 } | |
| 58 | |
| 59 static void b64_encode(luaL_Buffer *b, unsigned int c1, unsigned int c2, unsigned int c3, int n) { | |
| 60 static const char code[] = | |
| 61 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
| 62 unsigned long tuple = c3 + 256UL * (c2 + 256UL * c1); | |
| 63 int i; | |
| 64 char s[4]; | |
| 65 | |
| 66 for (i = 0; i < 4; i++) { | |
| 67 s[3-i] = code[tuple % 64]; | |
| 68 tuple /= 64; | |
| 69 } | |
| 70 for (i = n+1; i < 4; i++) s[i] = '='; | |
| 71 luaL_addlstring(b, s, 4); | |
| 72 } | |
| 73 | |
| 74 int tobase64(lua_State *L, int pos) { | |
| 75 size_t l; | |
| 76 const unsigned char *s = (const unsigned char*)luaL_checklstring(L, pos, &l); | |
| 77 luaL_Buffer b; | |
| 78 int n; | |
| 79 | |
| 80 luaL_buffinit(L, &b); | |
| 81 for (n = l / 3; n--; s += 3) | |
| 82 b64_encode(&b, s[0], s[1], s[2], 3); | |
| 83 | |
| 84 switch (l % 3) { | |
| 85 case 1: | |
| 86 b64_encode(&b, s[0], 0, 0, 1); | |
| 87 break; | |
| 88 case 2: | |
| 89 b64_encode(&b, s[0], s[1], 0, 2); | |
| 90 break; | |
| 91 } | |
| 92 luaL_pushresult(&b); | |
| 93 return 1; | |
| 94 } |
