diff options
Diffstat (limited to 'src/lib9/u64.c')
| -rw-r--r-- | src/lib9/u64.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/lib9/u64.c b/src/lib9/u64.c new file mode 100644 index 00000000..a17bdf1d --- /dev/null +++ b/src/lib9/u64.c @@ -0,0 +1,126 @@ +#include <lib9.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; +} |