1*9a747e4fSDavid du Colombier #include <u.h>
2*9a747e4fSDavid du Colombier #include <libc.h>
3*9a747e4fSDavid du Colombier
4*9a747e4fSDavid du Colombier int
dec32(uchar * dest,int ndest,char * src,int nsrc)5*9a747e4fSDavid du Colombier dec32(uchar *dest, int ndest, char *src, int nsrc)
6*9a747e4fSDavid du Colombier {
7*9a747e4fSDavid du Colombier char *s, *tab;
8*9a747e4fSDavid du Colombier uchar *start;
9*9a747e4fSDavid du Colombier int i, u[8];
10*9a747e4fSDavid du Colombier
11*9a747e4fSDavid du Colombier if(ndest+1 < (5*nsrc+7)/8)
12*9a747e4fSDavid du Colombier return -1;
13*9a747e4fSDavid du Colombier start = dest;
14*9a747e4fSDavid du Colombier tab = "23456789abcdefghijkmnpqrstuvwxyz";
15*9a747e4fSDavid du Colombier while(nsrc>=8){
16*9a747e4fSDavid du Colombier for(i=0; i<8; i++){
17*9a747e4fSDavid du Colombier s = strchr(tab,(int)src[i]);
18*9a747e4fSDavid du Colombier u[i] = s ? s-tab : 0;
19*9a747e4fSDavid du Colombier }
20*9a747e4fSDavid du Colombier *dest++ = (u[0]<<3) | (0x7 & (u[1]>>2));
21*9a747e4fSDavid du Colombier *dest++ = ((0x3 & u[1])<<6) | (u[2]<<1) | (0x1 & (u[3]>>4));
22*9a747e4fSDavid du Colombier *dest++ = ((0xf & u[3])<<4) | (0xf & (u[4]>>1));
23*9a747e4fSDavid du Colombier *dest++ = ((0x1 & u[4])<<7) | (u[5]<<2) | (0x3 & (u[6]>>3));
24*9a747e4fSDavid du Colombier *dest++ = ((0x7 & u[6])<<5) | u[7];
25*9a747e4fSDavid du Colombier src += 8;
26*9a747e4fSDavid du Colombier nsrc -= 8;
27*9a747e4fSDavid du Colombier }
28*9a747e4fSDavid du Colombier if(nsrc > 0){
29*9a747e4fSDavid du Colombier if(nsrc == 1 || nsrc == 3 || nsrc == 6)
30*9a747e4fSDavid du Colombier return -1;
31*9a747e4fSDavid du Colombier for(i=0; i<nsrc; i++){
32*9a747e4fSDavid du Colombier s = strchr(tab,(int)src[i]);
33*9a747e4fSDavid du Colombier u[i] = s ? s-tab : 0;
34*9a747e4fSDavid du Colombier }
35*9a747e4fSDavid du Colombier *dest++ = (u[0]<<3) | (0x7 & (u[1]>>2));
36*9a747e4fSDavid du Colombier if(nsrc == 2)
37*9a747e4fSDavid du Colombier goto out;
38*9a747e4fSDavid du Colombier *dest++ = ((0x3 & u[1])<<6) | (u[2]<<1) | (0x1 & (u[3]>>4));
39*9a747e4fSDavid du Colombier if(nsrc == 4)
40*9a747e4fSDavid du Colombier goto out;
41*9a747e4fSDavid du Colombier *dest++ = ((0xf & u[3])<<4) | (0xf & (u[4]>>1));
42*9a747e4fSDavid du Colombier if(nsrc == 5)
43*9a747e4fSDavid du Colombier goto out;
44*9a747e4fSDavid du Colombier *dest++ = ((0x1 & u[4])<<7) | (u[5]<<2) | (0x3 & (u[6]>>3));
45*9a747e4fSDavid du Colombier }
46*9a747e4fSDavid du Colombier out:
47*9a747e4fSDavid du Colombier return dest-start;
48*9a747e4fSDavid du Colombier }
49*9a747e4fSDavid du Colombier
50*9a747e4fSDavid du Colombier int
enc32(char * dest,int ndest,uchar * src,int nsrc)51*9a747e4fSDavid du Colombier enc32(char *dest, int ndest, uchar *src, int nsrc)
52*9a747e4fSDavid du Colombier {
53*9a747e4fSDavid du Colombier char *tab, *start;
54*9a747e4fSDavid du Colombier int j;
55*9a747e4fSDavid du Colombier
56*9a747e4fSDavid du Colombier if(ndest <= (8*nsrc+4)/5 )
57*9a747e4fSDavid du Colombier return -1;
58*9a747e4fSDavid du Colombier start = dest;
59*9a747e4fSDavid du Colombier tab = "23456789abcdefghijkmnpqrstuvwxyz";
60*9a747e4fSDavid du Colombier while(nsrc>=5){
61*9a747e4fSDavid du Colombier j = (0x1f & (src[0]>>3));
62*9a747e4fSDavid du Colombier *dest++ = tab[j];
63*9a747e4fSDavid du Colombier j = (0x1c & (src[0]<<2)) | (0x03 & (src[1]>>6));
64*9a747e4fSDavid du Colombier *dest++ = tab[j];
65*9a747e4fSDavid du Colombier j = (0x1f & (src[1]>>1));
66*9a747e4fSDavid du Colombier *dest++ = tab[j];
67*9a747e4fSDavid du Colombier j = (0x10 & (src[1]<<4)) | (0x0f & (src[2]>>4));
68*9a747e4fSDavid du Colombier *dest++ = tab[j];
69*9a747e4fSDavid du Colombier j = (0x1e & (src[2]<<1)) | (0x01 & (src[3]>>7));
70*9a747e4fSDavid du Colombier *dest++ = tab[j];
71*9a747e4fSDavid du Colombier j = (0x1f & (src[3]>>2));
72*9a747e4fSDavid du Colombier *dest++ = tab[j];
73*9a747e4fSDavid du Colombier j = (0x18 & (src[3]<<3)) | (0x07 & (src[4]>>5));
74*9a747e4fSDavid du Colombier *dest++ = tab[j];
75*9a747e4fSDavid du Colombier j = (0x1f & (src[4]));
76*9a747e4fSDavid du Colombier *dest++ = tab[j];
77*9a747e4fSDavid du Colombier src += 5;
78*9a747e4fSDavid du Colombier nsrc -= 5;
79*9a747e4fSDavid du Colombier }
80*9a747e4fSDavid du Colombier if(nsrc){
81*9a747e4fSDavid du Colombier j = (0x1f & (src[0]>>3));
82*9a747e4fSDavid du Colombier *dest++ = tab[j];
83*9a747e4fSDavid du Colombier j = (0x1c & (src[0]<<2));
84*9a747e4fSDavid du Colombier if(nsrc == 1)
85*9a747e4fSDavid du Colombier goto out;
86*9a747e4fSDavid du Colombier j |= (0x03 & (src[1]>>6));
87*9a747e4fSDavid du Colombier *dest++ = tab[j];
88*9a747e4fSDavid du Colombier j = (0x1f & (src[1]>>1));
89*9a747e4fSDavid du Colombier if(nsrc == 2)
90*9a747e4fSDavid du Colombier goto out;
91*9a747e4fSDavid du Colombier *dest++ = tab[j];
92*9a747e4fSDavid du Colombier j = (0x10 & (src[1]<<4));
93*9a747e4fSDavid du Colombier if(nsrc == 3)
94*9a747e4fSDavid du Colombier goto out;
95*9a747e4fSDavid du Colombier j |= (0x0f & (src[2]>>4));
96*9a747e4fSDavid du Colombier *dest++ = tab[j];
97*9a747e4fSDavid du Colombier j = (0x1e & (src[2]<<1));
98*9a747e4fSDavid du Colombier if(nsrc == 4)
99*9a747e4fSDavid du Colombier goto out;
100*9a747e4fSDavid du Colombier j |= (0x01 & (src[3]>>7));
101*9a747e4fSDavid du Colombier *dest++ = tab[j];
102*9a747e4fSDavid du Colombier j = (0x1f & (src[3]>>2));
103*9a747e4fSDavid du Colombier *dest++ = tab[j];
104*9a747e4fSDavid du Colombier j = (0x18 & (src[3]<<3));
105*9a747e4fSDavid du Colombier out:
106*9a747e4fSDavid du Colombier *dest++ = tab[j];
107*9a747e4fSDavid du Colombier }
108*9a747e4fSDavid du Colombier *dest = 0;
109*9a747e4fSDavid du Colombier return dest-start;
110*9a747e4fSDavid du Colombier }
111