--- /dev/null
+/* ========================================================================
+ * Copyright 1988-2007 University of Washington
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *
+ * ========================================================================
+ */
+
+/*
+ * Program: UTF-8 auxillary routines (c-client and MIME2 support)
+ *
+ * Author: Mark Crispin
+ * Networks and Distributed Computing
+ * Computing & Communications
+ * University of Washington
+ * Administration Building, AG-44
+ * Seattle, WA 98195
+ * Internet: MRC@CAC.Washington.EDU
+ *
+ * Date: 11 June 1997
+ * Last Edited: 12 October 2007
+ */
+
+
+#include <stdio.h>
+#include <ctype.h>
+#include "c-client.h"
+\f
+/* Convert charset labelled stringlist to UTF-8 in place
+ * Accepts: string list
+ * charset
+ */
+
+static void utf8_stringlist (STRINGLIST *st,char *charset)
+{
+ SIZEDTEXT txt;
+ /* convert entire stringstruct */
+ if (st) do if (utf8_text (&st->text,charset,&txt,U8T_CANONICAL)) {
+ fs_give ((void **) &st->text.data);
+ st->text.data = txt.data; /* transfer this text */
+ st->text.size = txt.size;
+ } while (st = st->next);
+}
+
+
+/* Convert charset labelled searchpgm to UTF-8 in place
+ * Accepts: search program
+ * charset
+ */
+
+void utf8_searchpgm (SEARCHPGM *pgm,char *charset)
+{
+ SIZEDTEXT txt;
+ SEARCHHEADER *hl;
+ SEARCHOR *ol;
+ SEARCHPGMLIST *pl;
+ if (pgm) { /* must have a search program */
+ utf8_stringlist (pgm->bcc,charset);
+ utf8_stringlist (pgm->cc,charset);
+ utf8_stringlist (pgm->from,charset);
+ utf8_stringlist (pgm->to,charset);
+ utf8_stringlist (pgm->subject,charset);
+ for (hl = pgm->header; hl; hl = hl->next) {
+ if (utf8_text (&hl->line,charset,&txt,U8T_CANONICAL)) {
+ fs_give ((void **) &hl->line.data);
+ hl->line.data = txt.data;
+ hl->line.size = txt.size;
+ }
+ if (utf8_text (&hl->text,charset,&txt,U8T_CANONICAL)) {
+ fs_give ((void **) &hl->text.data);
+ hl->text.data = txt.data;
+ hl->text.size = txt.size;
+ }
+ }
+ utf8_stringlist (pgm->body,charset);
+ utf8_stringlist (pgm->text,charset);
+ for (ol = pgm->or; ol; ol = ol->next) {
+ utf8_searchpgm (ol->first,charset);
+ utf8_searchpgm (ol->second,charset);
+ }
+ for (pl = pgm->not; pl; pl = pl->next) utf8_searchpgm (pl->pgm,charset);
+ utf8_stringlist (pgm->return_path,charset);
+ utf8_stringlist (pgm->sender,charset);
+ utf8_stringlist (pgm->reply_to,charset);
+ utf8_stringlist (pgm->in_reply_to,charset);
+ utf8_stringlist (pgm->message_id,charset);
+ utf8_stringlist (pgm->newsgroups,charset);
+ utf8_stringlist (pgm->followup_to,charset);
+ utf8_stringlist (pgm->references,charset);
+ }
+}
+\f
+/* Convert MIME-2 sized text to UTF-8
+ * Accepts: source sized text
+ * charset
+ * flags (same as utf8_text())
+ * Returns: T if successful, NIL if failure
+ */
+
+#define MINENCWORD 9
+#define MAXENCWORD 75
+
+/* This resizing algorithm is stupid, but hopefully it should never be triggered
+ * except for a pathological header. The main concern is that we don't get a
+ * buffer overflow.
+ */
+
+#define DSIZE 65536 /* real headers should never be this big */
+#define FUZZ 10 /* paranoia fuzz */
+
+long utf8_mime2text (SIZEDTEXT *src,SIZEDTEXT *dst,long flags)
+{
+ unsigned char *s,*se,*e,*ee,*t,*te;
+ char *cs,*ce,*ls;
+ SIZEDTEXT txt,rtxt;
+ unsigned long i;
+ size_t dsize = min (DSIZE,((src->size / 4) + 1) * 9);
+ /* always create buffer if canonicalizing */
+ dst->data = (flags & U8T_CANONICAL) ?
+ (unsigned char *) fs_get ((size_t) dsize) : NIL;
+ dst->size = 0; /* nothing written yet */
+ /* look for encoded words */
+ for (s = src->data, se = src->data + src->size; s < se; s++) {
+ if (((se - s) > MINENCWORD) && (*s == '=') && (s[1] == '?') &&
+ (cs = (char *) mime2_token (s+2,se,(unsigned char **) &ce)) &&
+ (e = mime2_token ((unsigned char *) ce+1,se,&ee)) &&
+ (te = mime2_text (t = e+2,se)) && (ee == e + 1) &&
+ ((te - s) < MAXENCWORD)) {
+ if (mime2_decode (e,t,te,&txt)) {
+ *ce = '\0'; /* temporarily tie off charset */
+ if (ls = strchr (cs,'*')) *ls = '\0';
+ /* convert to UTF-8 as best we can */
+ if (!utf8_text (&txt,cs,&rtxt,flags)) utf8_text (&txt,NIL,&rtxt,flags);
+ if (dst->data) { /* make sure existing buffer fits */
+ while (dsize <= (dst->size + rtxt.size + FUZZ)) {
+ dsize += DSIZE; /* kick it up */
+ fs_resize ((void **) &dst->data,dsize);
+ }
+ }
+ else { /* make a new buffer */
+ while (dsize <= (dst->size + rtxt.size)) dsize += DSIZE;
+ memcpy (dst->data = (unsigned char *) fs_get (dsize),src->data,
+ dst->size = s - src->data);
+ }
+ for (i = 0; i < rtxt.size; i++) dst->data[dst->size++] = rtxt.data[i];
+\f
+ /* all done with converted text */
+ if (rtxt.data != txt.data) fs_give ((void **) &rtxt.data);
+ if (ls) *ls = '*'; /* restore language tag delimiter */
+ *ce = '?'; /* restore charset delimiter */
+ /* all done with decoded text */
+ fs_give ((void **) &txt.data);
+ s = te+1; /* continue scan after encoded word */
+ /* skip leading whitespace */
+ for (t = s + 1; (t < se) && ((*t == ' ') || (*t == '\t')); t++);
+ /* see if likely continuation encoded word */
+ if (t < (se - MINENCWORD)) switch (*t) {
+ case '=': /* possible encoded word? */
+ if (t[1] == '?') s = t - 1;
+ break;
+ case '\015': /* CR, eat a following LF */
+ if (t[1] == '\012') t++;
+ case '\012': /* possible end of logical line */
+ if ((t[1] == ' ') || (t[1] == '\t')) {
+ do t++;
+ while ((t < (se - MINENCWORD)) && ((t[1] == ' ')||(t[1] == '\t')));
+ if ((t < (se - MINENCWORD)) && (t[1] == '=') && (t[2] == '?'))
+ s = t; /* definitely looks like continuation */
+ }
+ }
+ }
+ else { /* restore original text */
+ if (dst->data) fs_give ((void **) &dst->data);
+ dst->data = src->data;
+ dst->size = src->size;
+ return NIL; /* syntax error: MIME-2 decoding failure */
+ }
+ }
+ else do if (dst->data) { /* stash ASCII characters until LWSP */
+ if (dsize < (dst->size + FUZZ)) {
+ dsize += DSIZE; /* kick it up */
+ fs_resize ((void **) &dst->data,dsize);
+ }
+ /* kludge: assumes ASCII doesn't decompose and titlecases to one byte */
+ dst->data[dst->size++] = (flags & U8T_CASECANON) ?
+ (unsigned char) ucs4_titlecase (*s) : *s;
+ }
+ while ((*s != ' ') && (*s != '\t') && (*s != '\015') && (*s != '\012') &&
+ (++s < se));
+ }
+ if (dst->data) dst->data[dst->size] = '\0';
+ else { /* nothing converted, return identity */
+ dst->data = src->data;
+ dst->size = src->size;
+ }
+ return T; /* success */
+}
+\f
+/* Decode MIME-2 text
+ * Accepts: Encoding
+ * text
+ * text end
+ * destination sized text
+ * Returns: T if successful, else NIL
+ */
+
+long mime2_decode (unsigned char *e,unsigned char *t,unsigned char *te,
+ SIZEDTEXT *txt)
+{
+ unsigned char *q;
+ txt->data = NIL; /* initially no returned data */
+ switch (*e) { /* dispatch based upon encoding */
+ case 'Q': case 'q': /* sort-of QUOTED-PRINTABLE */
+ txt->data = (unsigned char *) fs_get ((size_t) (te - t) + 1);
+ for (q = t,txt->size = 0; q < te; q++) switch (*q) {
+ case '=': /* quoted character */
+ /* both must be hex */
+ if (!isxdigit (q[1]) || !isxdigit (q[2])) {
+ fs_give ((void **) &txt->data);
+ return NIL; /* syntax error: bad quoted character */
+ }
+ /* assemble character */
+ txt->data[txt->size++] = hex2byte (q[1],q[2]);
+ q += 2; /* advance past quoted character */
+ break;
+ case '_': /* convert to space */
+ txt->data[txt->size++] = ' ';
+ break;
+ default: /* ordinary character */
+ txt->data[txt->size++] = *q;
+ break;
+ }
+ txt->data[txt->size] = '\0';
+ break;
+ case 'B': case 'b': /* BASE64 */
+ if (txt->data = (unsigned char *) rfc822_base64 (t,te - t,&txt->size))
+ break;
+ default: /* any other encoding is unknown */
+ return NIL; /* syntax error: unknown encoding */
+ }
+ return T;
+}
+\f
+/* Get MIME-2 token from encoded word
+ * Accepts: current text pointer
+ * text limit pointer
+ * pointer to returned end pointer
+ * Returns: current text pointer & end pointer if success, else NIL
+ */
+
+unsigned char *mime2_token (unsigned char *s,unsigned char *se,
+ unsigned char **t)
+{
+ for (*t = s; **t != '?'; ++*t) {
+ if ((*t < se) && isgraph (**t)) switch (**t) {
+ case '(': case ')': case '<': case '>': case '@': case ',': case ';':
+ case ':': case '\\': case '"': case '/': case '[': case ']': case '.':
+ case '=':
+ return NIL; /* none of these are valid in tokens */
+ }
+ else return NIL; /* out of text or CTL or space */
+ }
+ return s;
+}
+
+
+/* Get MIME-2 text from encoded word
+ * Accepts: current text pointer
+ * text limit pointer
+ * pointer to returned end pointer
+ * Returns: end pointer if success, else NIL
+ */
+
+unsigned char *mime2_text (unsigned char *s,unsigned char *se)
+{
+ unsigned char *t = se - 1;
+ /* search for closing ?, make sure valid */
+ while ((s < t) && (*s != '?') && isgraph (*s++));
+ return ((s < t) && (*s == '?') && (s[1] == '=') &&
+ ((se == (s + 2)) || (s[2] == ' ') || (s[2] == '\t') ||
+ (s[2] == '\015') || (s[2] == '\012'))) ? s : NIL;
+}
+\f
+/* Convert UTF-16 string to Modified Base64
+ * Accepts: destination pointer
+ * source string
+ * source length in octets
+ * Returns: updated destination pointer
+ */
+
+static unsigned char *utf16_to_mbase64 (unsigned char *t,unsigned char *s,
+ size_t i)
+{
+ char *v = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+ *t++ = '&'; /* write shift-in */
+ while (i >= 3) { /* process tuplets */
+ *t++ = v[s[0] >> 2]; /* byte 1: high 6 bits (1) */
+ /* byte 2: low 2 bits (1), high 4 bits (2) */
+ *t++ = v[((s[0] << 4) + (s[1] >> 4)) & 0x3f];
+ /* byte 3: low 4 bits (2), high 2 bits (3) */
+ *t++ = v[((s[1] << 2) + (s[2] >> 6)) & 0x3f];
+ *t++ = v[s[2] & 0x3f]; /* byte 4: low 6 bits (3) */
+ s += 3;
+ i -= 3;
+ }
+ if (i) {
+ *t++ = v[s[0] >> 2]; /* byte 1: high 6 bits (1) */
+ /* byte 2: low 2 bits (1), high 4 bits (2) */
+ *t++ = v[((s[0] << 4) + (--i ? (s[1] >> 4) : 0)) & 0x3f];
+ /* byte 3: low 4 bits (2) */
+ if (i) *t++ = v[(s[1] << 2) & 0x3f];
+ }
+ *t++ = '-'; /* write shift-out */
+ return t;
+}
+
+
+/* Poot a UTF-16 value to a buffer
+ * Accepts: buffer pointer
+ * value
+ * Returns: updated pointer
+ */
+
+static unsigned char *utf16_poot (unsigned char *s,unsigned long c)
+{
+ *s++ = (unsigned char) (c >> 8);
+ *s++ = (unsigned char) (c & 0xff);
+ return s;
+}
+\f
+/* Convert UTF-8 to Modified UTF-7
+ * Accepts: UTF-8 string
+ * Returns: Modified UTF-7 string on success, NIL if invalid UTF-8
+ */
+
+#define MAXUNIUTF8 4 /* maximum length of Unicode UTF-8 sequence */
+
+unsigned char *utf8_to_mutf7 (unsigned char *src)
+{
+ unsigned char *u16buf,*utf16;
+ unsigned char *ret,*t;
+ unsigned long j,c;
+ unsigned char *s = src;
+ unsigned long i = 0;
+ int nonascii = 0;
+ while (*s) { /* pass one: count destination octets */
+ if (*s & 0x80) { /* non-ASCII character? */
+ j = MAXUNIUTF8; /* get single UCS-4 codepoint */
+ if ((c = utf8_get (&s,&j)) & U8G_ERROR) return NIL;
+ /* tally number of UTF-16 octets */
+ nonascii += (c & U8GM_NONBMP) ? 4 : 2;
+ }
+ else { /* ASCII character */
+ if (nonascii) { /* add pending Modified BASE64 size + shifts */
+ i += ((nonascii / 3) * 4) + ((j = nonascii % 3) ? j + 1 : 0) + 2;
+ nonascii = 0; /* back to ASCII */
+ }
+ if (*s == '&') i += 2; /* two octets if the escape */
+ else ++i; /* otherwise just count another octet */
+ ++s; /* advance to next source octet */
+ }
+ }
+ if (nonascii) /* add pending Modified BASE64 size + shifts */
+ i += ((nonascii / 3) * 4) + ((j = nonascii % 3) ? j + 1 : 0) + 2;
+\f
+ /* create return buffer */
+ t = ret = (unsigned char *) fs_get (i + 1);
+ /* and scratch buffer */
+ utf16 = u16buf = (unsigned char *) fs_get (i + 1);
+ for (s = src; *s;) { /* pass two: copy destination octets */
+ if (*s & 0x80) { /* non-ASCII character? */
+ j = MAXUNIUTF8; /* get single UCS-4 codepoint */
+ if ((c = utf8_get (&s,&j)) & U8G_ERROR) return NIL;
+ if (c & U8GM_NONBMP) { /* non-BMP? */
+ c -= UTF16_BASE; /* yes, convert to surrogate */
+ utf16 = utf16_poot (utf16_poot (utf16,(c >> UTF16_SHIFT)+UTF16_SURRH),
+ (c & UTF16_MASK) + UTF16_SURRL);
+ }
+ else utf16 = utf16_poot (utf16,c);
+ }
+ else { /* ASCII character */
+ if (utf16 != u16buf) { /* add pending Modified BASE64 size + shifts */
+ t = utf16_to_mbase64 (t,u16buf,utf16 - u16buf);
+ utf16 = u16buf; /* reset buffer */
+ }
+ *t++ = *s; /* copy the character */
+ if (*s == '&') *t++ = '-';/* special sequence if the escape */
+ ++s; /* advance to next source octet */
+ }
+ }
+ /* add pending Modified BASE64 size + shifts */
+ if (utf16 != u16buf) t = utf16_to_mbase64 (t,u16buf,utf16 - u16buf);
+ *t = '\0'; /* tie off destination */
+ if (i != (t - ret)) fatal ("utf8_to_mutf7 botch");
+ fs_give ((void **) &u16buf);
+ return ret;
+}
+\f
+/* Convert Modified UTF-7 to UTF-8
+ * Accepts: Modified UTF-7 string
+ * Returns: UTF-8 string on success, NIL if invalid Modified UTF-7
+ */
+
+unsigned char *utf8_from_mutf7 (unsigned char *src)
+{
+ SIZEDTEXT utf8,utf7;
+ unsigned char *s;
+ int mbase64 = 0;
+ /* disallow bogus strings */
+ if (mail_utf7_valid (src)) return NIL;
+ /* initialize SIZEDTEXTs */
+ memset (&utf7,0,sizeof (SIZEDTEXT));
+ memset (&utf8,0,sizeof (SIZEDTEXT));
+ /* make copy of source */
+ for (s = cpytxt (&utf7,src,strlen (src)); *s; ++s) switch (*s) {
+ case '&': /* Modified UTF-7 uses & instead of + */
+ *s = '+';
+ mbase64 = T; /* note that we are in Modified BASE64 */
+ break;
+ case '+': /* temporarily swap text + to & */
+ if (!mbase64) *s = '&';
+ break;
+ case '-': /* shift back to ASCII */
+ mbase64 = NIL;
+ break;
+ case ',': /* Modified UTF-7 uses , instead of / ... */
+ if (mbase64) *s = '/'; /* ...in Modified BASE64 */
+ break;
+ }
+ /* do the conversion */
+ utf8_text_utf7 (&utf7,&utf8,NIL,NIL);
+ /* no longer need copy of source */
+ fs_give ((void **) &utf7.data);
+ /* post-process: switch & and + */
+ for (s = utf8.data; *s; ++s) switch (*s) {
+ case '&':
+ *s = '+';
+ break;
+ case '+':
+ *s = '&';
+ break;
+ }
+ return utf8.data;
+}
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