123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127 |
- #include <u.h>
- #include <libc.h>
- enum {
- INVAL= 255
- };
- static uchar t64d[256] = {
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL, 62,INVAL,INVAL,INVAL, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
- 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
- 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
- INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL
- };
- static char t64e[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
- int
- dec64(uchar *out, int lim, char *in, int n)
- {
- ulong b24;
- uchar *start = out;
- uchar *e = out + lim;
- int i, c;
- b24 = 0;
- i = 0;
- while(n-- > 0){
-
- c = t64d[*(uchar*)in++];
- if(c == INVAL)
- continue;
- switch(i){
- case 0:
- b24 = c<<18;
- break;
- case 1:
- b24 |= c<<12;
- break;
- case 2:
- b24 |= c<<6;
- break;
- case 3:
- if(out + 3 > e)
- goto exhausted;
- b24 |= c;
- *out++ = b24>>16;
- *out++ = b24>>8;
- *out++ = b24;
- i = -1;
- break;
- }
- i++;
- }
- switch(i){
- case 2:
- if(out + 1 > e)
- goto exhausted;
- *out++ = b24>>16;
- break;
- case 3:
- if(out + 2 > e)
- goto exhausted;
- *out++ = b24>>16;
- *out++ = b24>>8;
- break;
- }
- exhausted:
- return out - start;
- }
- int
- enc64(char *out, int lim, uchar *in, int n)
- {
- int i;
- ulong b24;
- char *start = out;
- char *e = out + lim;
- for(i = n/3; i > 0; i--){
- b24 = (*in++)<<16;
- b24 |= (*in++)<<8;
- b24 |= *in++;
- if(out + 4 >= e)
- goto exhausted;
- *out++ = t64e[(b24>>18)];
- *out++ = t64e[(b24>>12)&0x3f];
- *out++ = t64e[(b24>>6)&0x3f];
- *out++ = t64e[(b24)&0x3f];
- }
- switch(n%3){
- case 2:
- b24 = (*in++)<<16;
- b24 |= (*in)<<8;
- if(out + 4 >= e)
- goto exhausted;
- *out++ = t64e[(b24>>18)];
- *out++ = t64e[(b24>>12)&0x3f];
- *out++ = t64e[(b24>>6)&0x3f];
- *out++ = '=';
- break;
- case 1:
- b24 = (*in)<<16;
- if(out + 4 >= e)
- goto exhausted;
- *out++ = t64e[(b24>>18)];
- *out++ = t64e[(b24>>12)&0x3f];
- *out++ = '=';
- *out++ = '=';
- break;
- }
- exhausted:
- *out = 0;
- return out - start;
- }
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