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-rw-r--r--src/global/uxtext.c278
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diff --git a/src/global/uxtext.c b/src/global/uxtext.c
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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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