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/*++
/* NAME
/* uxtext 3
/* SUMMARY
/* quote/unquote text, xtext style.
/* SYNOPSIS
/* #include <uxtext.h>
/*
/* VSTRING *uxtext_quote(quoted, unquoted, special)
/* VSTRING *quoted;
/* const char *unquoted;
/* const char *special;
/*
/* VSTRING *uxtext_quote_append(unquoted, quoted, special)
/* VSTRING *unquoted;
/* const char *quoted;
/* const char *special;
/*
/* VSTRING *uxtext_unquote(unquoted, quoted)
/* VSTRING *unquoted;
/* const char *quoted;
/*
/* VSTRING *uxtext_unquote_append(unquoted, quoted)
/* VSTRING *unquoted;
/* const char *quoted;
/* DESCRIPTION
/* uxtext_quote() takes a null-terminated UTF8 string and
/* replaces characters \, <33(10) and >126(10), as well as
/* characters specified with "special" with \x{XX}, XX being
/* a 2-6-digit uppercase hexadecimal equivalent.
/*
/* uxtext_quote_append() is like uxtext_quote(), but appends
/* the conversion result to the result buffer.
/*
/* uxtext_unquote() performs the opposite transformation. This
/* function understands lowercase, uppercase, and mixed case
/* \x{XX...} sequences. The result value is the unquoted
/* argument in case of success, a null pointer otherwise.
/*
/* uxtext_unquote_append() is like uxtext_unquote(), but appends
/* the conversion result to the result buffer.
/* BUGS
/* This module cannot process null characters in data.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Arnt Gulbrandsen
/*
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <string.h>
#include <ctype.h>
/* Utility library. */
#include "msg.h"
#include "vstring.h"
#include "uxtext.h"
/* Application-specific. */
#define STR(x) vstring_str(x)
#define LEN(x) VSTRING_LEN(x)
/* uxtext_quote_append - append unquoted data to quoted data */
VSTRING *uxtext_quote_append(VSTRING *quoted, const char *unquoted,
const char *special)
{
unsigned const char *cp;
int ch;
for (cp = (unsigned const char *) unquoted; (ch = *cp) != 0; cp++) {
/* Fix 20140709: the '\' character must always be quoted. */
if (ch != '\\' && ch > 32 && ch < 127
&& (*special == 0 || strchr(special, ch) == 0)) {
VSTRING_ADDCH(quoted, ch);
} else {
/*
* had RFC6533 been written like 6531 and 6532, this else clause
* would be one line long.
*/
int unicode = 0;
int pick = 0;
if (ch < 0x80) {
//0000 0000 - 0000 007 F 0x xxxxxx
unicode = ch;
} else if ((ch & 0xe0) == 0xc0) {
//0000 0080 - 0000 07 FF 110 xxxxx 10 xxxxxx
unicode = (ch & 0x1f);
pick = 1;
} else if ((ch & 0xf0) == 0xe0) {
//0000 0800 - 0000 FFFF 1110 xxxx 10 xxxxxx 10 xxxxxx
unicode = (ch & 0x0f);
pick = 2;
} else if ((ch & 0xf8) == 0xf0) {
//0001 0000 - 001 F FFFF 11110 xxx 10 xxxxxx 10 xxxxxx 10 xxxxxx
unicode = (ch & 0x07);
pick = 3;
} else if ((ch & 0xfc) == 0xf8) {
//0020 0000 - 03 FF FFFF 111110 xx 10 xxxxxx 10 xxxxxx...10 xxxxxx
unicode = (ch & 0x03);
pick = 4;
} else if ((ch & 0xfe) == 0xfc) {
//0400 0000 - 7 FFF FFFF 1111110 x 10 xxxxxx...10 xxxxxx
unicode = (ch & 0x01);
pick = 5;
} else {
return (0);
}
while (pick > 0) {
ch = *++cp;
if ((ch & 0xc0) != 0x80)
return (0);
unicode = unicode << 6 | (ch & 0x3f);
pick--;
}
vstring_sprintf_append(quoted, "\\x{%02X}", unicode);
}
}
VSTRING_TERMINATE(quoted);
return (quoted);
}
/* uxtext_quote - unquoted data to quoted */
VSTRING *uxtext_quote(VSTRING *quoted, const char *unquoted, const char *special)
{
VSTRING_RESET(quoted);
uxtext_quote_append(quoted, unquoted, special);
return (quoted);
}
/* uxtext_unquote_append - quoted data to unquoted */
VSTRING *uxtext_unquote_append(VSTRING *unquoted, const char *quoted)
{
const unsigned char *cp;
int ch;
for (cp = (const unsigned char *) quoted; (ch = *cp) != 0; cp++) {
if (ch == '\\' && cp[1] == 'x' && cp[2] == '{') {
int unicode = 0;
cp += 2;
while ((ch = *++cp) != '}') {
if (ISDIGIT(ch))
unicode = (unicode << 4) + (ch - '0');
else if (ch >= 'a' && ch <= 'f')
unicode = (unicode << 4) + (ch - 'a' + 10);
else if (ch >= 'A' && ch <= 'F')
unicode = (unicode << 4) + (ch - 'A' + 10);
else
return (0); /* also covers the null
* terminator */
if (unicode > 0x10ffff)
return (0);
}
/*
* the following block is from
* https://github.com/aox/aox/blob/master/encodings/utf.cpp, with
* permission by the authors.
*/
if (unicode < 0x80) {
VSTRING_ADDCH(unquoted, (char) unicode);
} else if (unicode < 0x800) {
VSTRING_ADDCH(unquoted, 0xc0 | ((char) (unicode >> 6)));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode & 0x3f)));
} else if (unicode < 0x10000) {
VSTRING_ADDCH(unquoted, 0xe0 | ((char) (unicode >> 12)));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 6) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode & 0x3f)));
} else if (unicode < 0x200000) {
VSTRING_ADDCH(unquoted, 0xf0 | ((char) (unicode >> 18)));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 12) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 6) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode & 0x3f)));
} else if (unicode < 0x4000000) {
VSTRING_ADDCH(unquoted, 0xf8 | ((char) (unicode >> 24)));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 18) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 12) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 6) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode & 0x3f)));
} else {
VSTRING_ADDCH(unquoted, 0xfc | ((char) (unicode >> 30)));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 24) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 18) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 12) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode >> 6) & 0x3f));
VSTRING_ADDCH(unquoted, 0x80 | ((char) (unicode & 0x3f)));
}
} else {
VSTRING_ADDCH(unquoted, ch);
}
}
VSTRING_TERMINATE(unquoted);
return (unquoted);
}
/* uxtext_unquote - quoted data to unquoted */
VSTRING *uxtext_unquote(VSTRING *unquoted, const char *quoted)
{
VSTRING_RESET(unquoted);
return (uxtext_unquote_append(unquoted, quoted) ? unquoted : 0);
}
#ifdef TEST
/*
* Proof-of-concept test program: convert to quoted and back.
*/
#include <vstream.h>
#define BUFLEN 1024
static ssize_t read_buf(VSTREAM *fp, VSTRING *buf)
{
ssize_t len;
len = vstream_fread_buf(fp, buf, BUFLEN);
VSTRING_TERMINATE(buf);
return (len);
}
int main(int unused_argc, char **unused_argv)
{
VSTRING *unquoted = vstring_alloc(BUFLEN);
VSTRING *quoted = vstring_alloc(100);
ssize_t len;
/*
* Negative tests.
*/
if (uxtext_unquote(unquoted, "\\x{x1}") != 0)
msg_warn("undetected error pattern 1");
if (uxtext_unquote(unquoted, "\\x{2x}") != 0)
msg_warn("undetected error pattern 2");
if (uxtext_unquote(unquoted, "\\x{33") != 0)
msg_warn("undetected error pattern 3");
/*
* Positive tests.
*/
while ((len = read_buf(VSTREAM_IN, unquoted)) > 0) {
uxtext_quote(quoted, STR(unquoted), "+=");
if (uxtext_unquote(unquoted, STR(quoted)) == 0)
msg_fatal("bad input: %.100s", STR(quoted));
if (LEN(unquoted) != len)
msg_fatal("len %ld != unquoted len %ld",
(long) len, (long) LEN(unquoted));
if (vstream_fwrite(VSTREAM_OUT, STR(unquoted), LEN(unquoted)) != LEN(unquoted))
msg_fatal("write error: %m");
}
vstream_fflush(VSTREAM_OUT);
vstring_free(unquoted);
vstring_free(quoted);
return (0);
}
#endif
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