vx32

Local 9vx git repository for patches.
git clone git://r-36.net/vx32
Log | Files | Refs

u64.c (3281B)

      1 #include "u.h"
      2 #include "lib.h"
      3 
      4 enum {
      5 	INVAL=	255
      6 };
      7 
      8 static uchar t64d[256] = {
      9    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     10    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     11    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,   62,INVAL,INVAL,INVAL,   63,
     12       52,   53,   54,   55,   56,   57,   58,   59,   60,   61,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     13    INVAL,    0,    1,    2,    3,    4,    5,    6,    7,    8,    9,   10,   11,   12,   13,   14,
     14       15,   16,   17,   18,   19,   20,   21,   22,   23,   24,   25,INVAL,INVAL,INVAL,INVAL,INVAL,
     15    INVAL,   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,   36,   37,   38,   39,   40,
     16       41,   42,   43,   44,   45,   46,   47,   48,   49,   50,   51,INVAL,INVAL,INVAL,INVAL,INVAL,
     17    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     18    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     19    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     20    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     21    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     22    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     23    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,
     24    INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL,INVAL
     25 };
     26 static char t64e[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
     27 
     28 int
     29 dec64(uchar *out, int lim, char *in, int n)
     30 {
     31 	ulong b24;
     32 	uchar *start = out;
     33 	uchar *e = out + lim;
     34 	int i, c;
     35 
     36 	b24 = 0;
     37 	i = 0;
     38 	while(n-- > 0){
     39  
     40 		c = t64d[*(uchar*)in++];
     41 		if(c == INVAL)
     42 			continue;
     43 		switch(i){
     44 		case 0:
     45 			b24 = c<<18;
     46 			break;
     47 		case 1:
     48 			b24 |= c<<12;
     49 			break;
     50 		case 2:
     51 			b24 |= c<<6;
     52 			break;
     53 		case 3:
     54 			if(out + 3 > e)
     55 				goto exhausted;
     56 
     57 			b24 |= c;
     58 			*out++ = b24>>16;
     59 			*out++ = b24>>8;
     60 			*out++ = b24;
     61 			i = -1;
     62 			break;
     63 		}
     64 		i++;
     65 	}
     66 	switch(i){
     67 	case 2:
     68 		if(out + 1 > e)
     69 			goto exhausted;
     70 		*out++ = b24>>16;
     71 		break;
     72 	case 3:
     73 		if(out + 2 > e)
     74 			goto exhausted;
     75 		*out++ = b24>>16;
     76 		*out++ = b24>>8;
     77 		break;
     78 	}
     79 exhausted:
     80 	return out - start;
     81 }
     82 
     83 int
     84 enc64(char *out, int lim, uchar *in, int n)
     85 {
     86 	int i;
     87 	ulong b24;
     88 	char *start = out;
     89 	char *e = out + lim;
     90 
     91 	for(i = n/3; i > 0; i--){
     92 		b24 = (*in++)<<16;
     93 		b24 |= (*in++)<<8;
     94 		b24 |= *in++;
     95 		if(out + 4 >= e)
     96 			goto exhausted;
     97 		*out++ = t64e[(b24>>18)];
     98 		*out++ = t64e[(b24>>12)&0x3f];
     99 		*out++ = t64e[(b24>>6)&0x3f];
    100 		*out++ = t64e[(b24)&0x3f];
    101 	}
    102 
    103 	switch(n%3){
    104 	case 2:
    105 		b24 = (*in++)<<16;
    106 		b24 |= (*in)<<8;
    107 		if(out + 4 >= e)
    108 			goto exhausted;
    109 		*out++ = t64e[(b24>>18)];
    110 		*out++ = t64e[(b24>>12)&0x3f];
    111 		*out++ = t64e[(b24>>6)&0x3f];
    112 		*out++ = '=';
    113 		break;
    114 	case 1:
    115 		b24 = (*in)<<16;
    116 		if(out + 4 >= e)
    117 			goto exhausted;
    118 		*out++ = t64e[(b24>>18)];
    119 		*out++ = t64e[(b24>>12)&0x3f];
    120 		*out++ = '=';
    121 		*out++ = '=';
    122 		break;
    123 	}
    124 exhausted:
    125 	*out = 0;
    126 	return out - start;
    127 }