1*8ccd4a63SDavid du Colombier #include <u.h>
2*8ccd4a63SDavid du Colombier #include <libc.h>
3*8ccd4a63SDavid du Colombier
4*8ccd4a63SDavid du Colombier int
dec32(uchar * dest,int ndest,char * src,int nsrc)5*8ccd4a63SDavid du Colombier dec32(uchar *dest, int ndest, char *src, int nsrc)
6*8ccd4a63SDavid du Colombier {
7*8ccd4a63SDavid du Colombier char *s, *tab;
8*8ccd4a63SDavid du Colombier uchar *start;
9*8ccd4a63SDavid du Colombier int i, u[8];
10*8ccd4a63SDavid du Colombier
11*8ccd4a63SDavid du Colombier if(ndest+1 < (5*nsrc+7)/8)
12*8ccd4a63SDavid du Colombier return -1;
13*8ccd4a63SDavid du Colombier start = dest;
14*8ccd4a63SDavid du Colombier tab = "23456789abcdefghijkmnpqrstuvwxyz";
15*8ccd4a63SDavid du Colombier while(nsrc>=8){
16*8ccd4a63SDavid du Colombier for(i=0; i<8; i++){
17*8ccd4a63SDavid du Colombier s = strchr(tab,(int)src[i]);
18*8ccd4a63SDavid du Colombier u[i] = s ? s-tab : 0;
19*8ccd4a63SDavid du Colombier }
20*8ccd4a63SDavid du Colombier *dest++ = (u[0]<<3) | (0x7 & (u[1]>>2));
21*8ccd4a63SDavid du Colombier *dest++ = ((0x3 & u[1])<<6) | (u[2]<<1) | (0x1 & (u[3]>>4));
22*8ccd4a63SDavid du Colombier *dest++ = ((0xf & u[3])<<4) | (0xf & (u[4]>>1));
23*8ccd4a63SDavid du Colombier *dest++ = ((0x1 & u[4])<<7) | (u[5]<<2) | (0x3 & (u[6]>>3));
24*8ccd4a63SDavid du Colombier *dest++ = ((0x7 & u[6])<<5) | u[7];
25*8ccd4a63SDavid du Colombier src += 8;
26*8ccd4a63SDavid du Colombier nsrc -= 8;
27*8ccd4a63SDavid du Colombier }
28*8ccd4a63SDavid du Colombier if(nsrc > 0){
29*8ccd4a63SDavid du Colombier if(nsrc == 1 || nsrc == 3 || nsrc == 6)
30*8ccd4a63SDavid du Colombier return -1;
31*8ccd4a63SDavid du Colombier for(i=0; i<nsrc; i++){
32*8ccd4a63SDavid du Colombier s = strchr(tab,(int)src[i]);
33*8ccd4a63SDavid du Colombier u[i] = s ? s-tab : 0;
34*8ccd4a63SDavid du Colombier }
35*8ccd4a63SDavid du Colombier *dest++ = (u[0]<<3) | (0x7 & (u[1]>>2));
36*8ccd4a63SDavid du Colombier if(nsrc == 2)
37*8ccd4a63SDavid du Colombier goto out;
38*8ccd4a63SDavid du Colombier *dest++ = ((0x3 & u[1])<<6) | (u[2]<<1) | (0x1 & (u[3]>>4));
39*8ccd4a63SDavid du Colombier if(nsrc == 4)
40*8ccd4a63SDavid du Colombier goto out;
41*8ccd4a63SDavid du Colombier *dest++ = ((0xf & u[3])<<4) | (0xf & (u[4]>>1));
42*8ccd4a63SDavid du Colombier if(nsrc == 5)
43*8ccd4a63SDavid du Colombier goto out;
44*8ccd4a63SDavid du Colombier *dest++ = ((0x1 & u[4])<<7) | (u[5]<<2) | (0x3 & (u[6]>>3));
45*8ccd4a63SDavid du Colombier }
46*8ccd4a63SDavid du Colombier out:
47*8ccd4a63SDavid du Colombier return dest-start;
48*8ccd4a63SDavid du Colombier }
49*8ccd4a63SDavid du Colombier
50*8ccd4a63SDavid du Colombier int
enc32(char * dest,int ndest,uchar * src,int nsrc)51*8ccd4a63SDavid du Colombier enc32(char *dest, int ndest, uchar *src, int nsrc)
52*8ccd4a63SDavid du Colombier {
53*8ccd4a63SDavid du Colombier char *tab, *start;
54*8ccd4a63SDavid du Colombier int j;
55*8ccd4a63SDavid du Colombier
56*8ccd4a63SDavid du Colombier if(ndest <= (8*nsrc+4)/5 )
57*8ccd4a63SDavid du Colombier return -1;
58*8ccd4a63SDavid du Colombier start = dest;
59*8ccd4a63SDavid du Colombier tab = "23456789abcdefghijkmnpqrstuvwxyz";
60*8ccd4a63SDavid du Colombier while(nsrc>=5){
61*8ccd4a63SDavid du Colombier j = (0x1f & (src[0]>>3));
62*8ccd4a63SDavid du Colombier *dest++ = tab[j];
63*8ccd4a63SDavid du Colombier j = (0x1c & (src[0]<<2)) | (0x03 & (src[1]>>6));
64*8ccd4a63SDavid du Colombier *dest++ = tab[j];
65*8ccd4a63SDavid du Colombier j = (0x1f & (src[1]>>1));
66*8ccd4a63SDavid du Colombier *dest++ = tab[j];
67*8ccd4a63SDavid du Colombier j = (0x10 & (src[1]<<4)) | (0x0f & (src[2]>>4));
68*8ccd4a63SDavid du Colombier *dest++ = tab[j];
69*8ccd4a63SDavid du Colombier j = (0x1e & (src[2]<<1)) | (0x01 & (src[3]>>7));
70*8ccd4a63SDavid du Colombier *dest++ = tab[j];
71*8ccd4a63SDavid du Colombier j = (0x1f & (src[3]>>2));
72*8ccd4a63SDavid du Colombier *dest++ = tab[j];
73*8ccd4a63SDavid du Colombier j = (0x18 & (src[3]<<3)) | (0x07 & (src[4]>>5));
74*8ccd4a63SDavid du Colombier *dest++ = tab[j];
75*8ccd4a63SDavid du Colombier j = (0x1f & (src[4]));
76*8ccd4a63SDavid du Colombier *dest++ = tab[j];
77*8ccd4a63SDavid du Colombier src += 5;
78*8ccd4a63SDavid du Colombier nsrc -= 5;
79*8ccd4a63SDavid du Colombier }
80*8ccd4a63SDavid du Colombier if(nsrc){
81*8ccd4a63SDavid du Colombier j = (0x1f & (src[0]>>3));
82*8ccd4a63SDavid du Colombier *dest++ = tab[j];
83*8ccd4a63SDavid du Colombier j = (0x1c & (src[0]<<2));
84*8ccd4a63SDavid du Colombier if(nsrc == 1)
85*8ccd4a63SDavid du Colombier goto out;
86*8ccd4a63SDavid du Colombier j |= (0x03 & (src[1]>>6));
87*8ccd4a63SDavid du Colombier *dest++ = tab[j];
88*8ccd4a63SDavid du Colombier j = (0x1f & (src[1]>>1));
89*8ccd4a63SDavid du Colombier if(nsrc == 2)
90*8ccd4a63SDavid du Colombier goto out;
91*8ccd4a63SDavid du Colombier *dest++ = tab[j];
92*8ccd4a63SDavid du Colombier j = (0x10 & (src[1]<<4));
93*8ccd4a63SDavid du Colombier if(nsrc == 3)
94*8ccd4a63SDavid du Colombier goto out;
95*8ccd4a63SDavid du Colombier j |= (0x0f & (src[2]>>4));
96*8ccd4a63SDavid du Colombier *dest++ = tab[j];
97*8ccd4a63SDavid du Colombier j = (0x1e & (src[2]<<1));
98*8ccd4a63SDavid du Colombier if(nsrc == 4)
99*8ccd4a63SDavid du Colombier goto out;
100*8ccd4a63SDavid du Colombier j |= (0x01 & (src[3]>>7));
101*8ccd4a63SDavid du Colombier *dest++ = tab[j];
102*8ccd4a63SDavid du Colombier j = (0x1f & (src[3]>>2));
103*8ccd4a63SDavid du Colombier *dest++ = tab[j];
104*8ccd4a63SDavid du Colombier j = (0x18 & (src[3]<<3));
105*8ccd4a63SDavid du Colombier out:
106*8ccd4a63SDavid du Colombier *dest++ = tab[j];
107*8ccd4a63SDavid du Colombier }
108*8ccd4a63SDavid du Colombier *dest = 0;
109*8ccd4a63SDavid du Colombier return dest-start;
110*8ccd4a63SDavid du Colombier }
111