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#include <u.h>
#include <libc.h>
#include <bio.h>
#include <auth.h>
#include "imap4d.h"
/*
* modified utf-7, as per imap4 spec
* like utf-7, but substitues , for / in base 64,
* does not allow escaped ascii characters.
*
* /lib/rfc/rfc2152 is utf-7
* /lib/rfc/rfc1642 is obsolete utf-7
*
* test sequences from rfc1642
* 'A≢Α.' 'A&ImIDkQ-.'
* 'Hi Mom ☺!" 'Hi Mom &Jjo-!'
* '日本語' '&ZeVnLIqe-'
*/
static uchar mt64d[256];
static char mt64e[64];
static void
initm64(void)
{
int c, i;
memset(mt64d, 255, 256);
memset(mt64e, '=', 64);
i = 0;
for(c = 'A'; c <= 'Z'; c++){
mt64e[i] = c;
mt64d[c] = i++;
}
for(c = 'a'; c <= 'z'; c++){
mt64e[i] = c;
mt64d[c] = i++;
}
for(c = '0'; c <= '9'; c++){
mt64e[i] = c;
mt64d[c] = i++;
}
mt64e[i] = '+';
mt64d['+'] = i++;
mt64e[i] = ',';
mt64d[','] = i;
}
int
encmutf7(char *out, int lim, char *in)
{
Rune rr;
ulong r, b;
char *start = out;
char *e = out + lim;
int nb;
if(mt64e[0] == 0)
initm64();
for(;;){
r = *(uchar*)in;
if(r < ' ' || r >= Runeself){
if(r == '\0')
break;
if(out + 1 >= e)
return -1;
*out++ = '&';
b = 0;
nb = 0;
for(;;){
in += chartorune(&rr, in);
r = rr;
if(r == '\0' || r >= ' ' && r < Runeself)
break;
b = (b << 16) | r;
for(nb += 16; nb >= 6; nb -= 6){
if(out + 1 >= e)
return -1;
*out++ = mt64e[(b>>(nb-6))&0x3f];
}
}
for(; nb >= 6; nb -= 6){
if(out + 1 >= e)
return -1;
*out++ = mt64e[(b>>(nb-6))&0x3f];
}
if(nb){
if(out + 1 >= e)
return -1;
*out++ = mt64e[(b<<(6-nb))&0x3f];
}
if(out + 1 >= e)
return -1;
*out++ = '-';
if(r == '\0')
break;
}else
in++;
if(out + 1 >= e)
return -1;
*out = r;
out++;
if(r == '&')
*out++ = '-';
}
if(out >= e)
return -1;
*out = '\0';
return out - start;
}
int
decmutf7(char *out, int lim, char *in)
{
Rune rr;
char *start = out;
char *e = out + lim;
int c, b, nb;
if(mt64e[0] == 0)
initm64();
for(;;){
c = *in;
if(c < ' ' || c >= Runeself){
if(c == '\0')
break;
return -1;
}
if(c != '&'){
if(out + 1 >= e)
return -1;
*out++ = c;
in++;
continue;
}
in++;
if(*in == '-'){
if(out + 1 >= e)
return -1;
*out++ = '&';
in++;
continue;
}
b = 0;
nb = 0;
while((c = *in++) != '-'){
c = mt64d[c];
if(c >= 64)
return -1;
b = (b << 6) | c;
nb += 6;
if(nb >= 16){
rr = b >> (nb - 16);
nb -= 16;
if(out + UTFmax + 1 >= e && out + runelen(rr) + 1 >= e)
return -1;
out += runetochar(out, &rr);
}
}
if(b & ((1 << nb) - 1))
return -1;
}
if(out >= e)
return -1;
*out = '\0';
return out - start;
}
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