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+/*++
+/* NAME
+/* midna_domain 3
+/* SUMMARY
+/* ASCII/UTF-8 domain name conversion
+/* SYNOPSIS
+/* #include <midna_domain.h>
+/*
+/* int midna_domain_cache_size;
+/* int midna_domain_transitional;
+/*
+/* const char *midna_domain_to_ascii(
+/* const char *name)
+/*
+/* const char *midna_domain_to_utf8(
+/* const char *name)
+/*
+/* const char *midna_domain_suffix_to_ascii(
+/* const char *name)
+/*
+/* const char *midna_domain_suffix_to_utf8(
+/* const char *name)
+/* AUXILIARY FUNCTIONS
+/* void midna_domain_pre_chroot(void)
+/* DESCRIPTION
+/* The functions in this module transform domain names from/to
+/* ASCII and UTF-8 form. The result is cached to avoid repeated
+/* conversion.
+/*
+/* This module builds on the ICU library implementation of the
+/* UTS #46 specification, using default ICU library options
+/* because those are likely best tested: with transitional
+/* processing, with case mapping, with normalization, with
+/* limited IDNA2003 compatibility, without STD3 ASCII rules.
+/*
+/* midna_domain_to_ascii() converts an UTF-8 or ASCII domain
+/* name to ASCII. The result is a null pointer in case of
+/* error. This function verifies that the result passes
+/* valid_hostname().
+/*
+/* midna_domain_to_utf8() converts an UTF-8 or ASCII domain
+/* name to UTF-8. The result is a null pointer in case of
+/* error. This function verifies that the result, after
+/* conversion to ASCII, passes valid_hostname().
+/*
+/* midna_domain_suffix_to_ascii() and midna_domain_suffix_to_utf8()
+/* take a name that starts with '.' and otherwise perform the
+/* same operations as midna_domain_to_ascii() and
+/* midna_domain_to_utf8().
+/*
+/* midna_domain_cache_size specifies the size of the conversion
+/* result cache. This value is used only once, upon the first
+/* lookup request.
+/*
+/* midna_domain_transitional enables transitional conversion
+/* between UTF8 and ASCII labels.
+/*
+/* midna_domain_pre_chroot() does some pre-chroot initialization.
+/* SEE ALSO
+/* http://unicode.org/reports/tr46/ Unicode IDNA Compatibility processing
+/* msg(3) diagnostics interface
+/* DIAGNOSTICS
+/* Fatal errors: memory allocation problem.
+/* Warnings: conversion error or result validation error.
+/* 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>
+
+#ifndef NO_EAI
+#include <unicode/uidna.h>
+
+ /*
+ * Utility library.
+ */
+#include <mymalloc.h>
+#include <msg.h>
+#include <ctable.h>
+#include <stringops.h>
+#include <valid_hostname.h>
+#include <name_mask.h>
+#include <midna_domain.h>
+
+ /*
+ * Application-specific.
+ */
+#define DEF_MIDNA_CACHE_SIZE 256
+
+int midna_domain_cache_size = DEF_MIDNA_CACHE_SIZE;
+int midna_domain_transitional = 0;
+static VSTRING *midna_domain_buf; /* x.suffix */
+
+#define STR(x) vstring_str(x)
+
+/* midna_domain_strerror - pick one for error reporting */
+
+static const char *midna_domain_strerror(UErrorCode error, int info_errors)
+{
+
+ /*
+ * XXX The UIDNA_ERROR_EMPTY_LABEL etc. names are defined in an ENUM, so
+ * we can't use #ifdef to dynamically determine which names exist.
+ */
+ static LONG_NAME_MASK uidna_errors[] = {
+ "UIDNA_ERROR_EMPTY_LABEL", UIDNA_ERROR_EMPTY_LABEL,
+ "UIDNA_ERROR_LABEL_TOO_LONG", UIDNA_ERROR_LABEL_TOO_LONG,
+ "UIDNA_ERROR_DOMAIN_NAME_TOO_LONG", UIDNA_ERROR_DOMAIN_NAME_TOO_LONG,
+ "UIDNA_ERROR_LEADING_HYPHEN", UIDNA_ERROR_LEADING_HYPHEN,
+ "UIDNA_ERROR_TRAILING_HYPHEN", UIDNA_ERROR_TRAILING_HYPHEN,
+ "UIDNA_ERROR_HYPHEN_3_4", UIDNA_ERROR_HYPHEN_3_4,
+ "UIDNA_ERROR_LEADING_COMBINING_MARK", UIDNA_ERROR_LEADING_COMBINING_MARK,
+ "UIDNA_ERROR_DISALLOWED", UIDNA_ERROR_DISALLOWED,
+ "UIDNA_ERROR_PUNYCODE", UIDNA_ERROR_PUNYCODE,
+ "UIDNA_ERROR_LABEL_HAS_DOT", UIDNA_ERROR_LABEL_HAS_DOT,
+ "UIDNA_ERROR_INVALID_ACE_LABEL", UIDNA_ERROR_INVALID_ACE_LABEL,
+ "UIDNA_ERROR_BIDI", UIDNA_ERROR_BIDI,
+ "UIDNA_ERROR_CONTEXTJ", UIDNA_ERROR_CONTEXTJ,
+ /* The above errors are defined with ICU 46 and later. */
+ 0,
+ };
+
+ if (info_errors) {
+ return (str_long_name_mask_opt((VSTRING *) 0, "idna error",
+ uidna_errors, info_errors,
+ NAME_MASK_NUMBER | NAME_MASK_COMMA));
+ } else {
+ return u_errorName(error);
+ }
+}
+
+/* midna_domain_pre_chroot - pre-chroot initialization */
+
+void midna_domain_pre_chroot(void)
+{
+ UErrorCode error = U_ZERO_ERROR;
+ UIDNAInfo info = UIDNA_INFO_INITIALIZER;
+ UIDNA *idna;
+
+ idna = uidna_openUTS46(midna_domain_transitional ? UIDNA_DEFAULT
+ : UIDNA_NONTRANSITIONAL_TO_ASCII, &error);
+ if (U_FAILURE(error))
+ msg_warn("ICU library initialization failed: %s",
+ midna_domain_strerror(error, info.errors));
+ uidna_close(idna);
+}
+
+/* midna_domain_to_ascii_create - convert domain to ASCII */
+
+static void *midna_domain_to_ascii_create(const char *name, void *unused_context)
+{
+ static const char myname[] = "midna_domain_to_ascii_create";
+ char buf[1024]; /* XXX */
+ UErrorCode error = U_ZERO_ERROR;
+ UIDNAInfo info = UIDNA_INFO_INITIALIZER;
+ UIDNA *idna;
+ int anl;
+
+ /*
+ * Paranoia: do not expose uidna_*() to unfiltered network data.
+ */
+ if (allascii(name) == 0 && valid_utf8_string(name, strlen(name)) == 0) {
+ msg_warn("%s: Problem translating domain \"%.100s\" to ASCII form: %s",
+ myname, name, "malformed UTF-8");
+ return (0);
+ }
+
+ /*
+ * Perform the requested conversion.
+ */
+ idna = uidna_openUTS46(midna_domain_transitional ? UIDNA_DEFAULT
+ : UIDNA_NONTRANSITIONAL_TO_ASCII, &error);
+ anl = uidna_nameToASCII_UTF8(idna,
+ name, strlen(name),
+ buf, sizeof(buf) - 1,
+ &info,
+ &error);
+ uidna_close(idna);
+
+ /*
+ * Paranoia: verify that the result passes valid_hostname(). A quick
+ * check shows that UTS46 ToASCII by default rejects inputs with labels
+ * that start or end in '-', with names or labels that are over-long, or
+ * "fake" A-labels, as required by UTS 46 section 4.1, but we rely on
+ * valid_hostname() on the output side just to be sure.
+ */
+ if (U_SUCCESS(error) && info.errors == 0 && anl > 0) {
+ buf[anl] = 0; /* XXX */
+ if (!valid_hostname(buf, DONT_GRIPE)) {
+ msg_warn("%s: Problem translating domain \"%.100s\" to ASCII form: %s",
+ myname, name, "malformed ASCII label(s)");
+ return (0);
+ }
+ return (mystrndup(buf, anl));
+ } else {
+ msg_warn("%s: Problem translating domain \"%.100s\" to ASCII form: %s",
+ myname, name, midna_domain_strerror(error, info.errors));
+ return (0);
+ }
+}
+
+/* midna_domain_to_utf8_create - convert domain to UTF8 */
+
+static void *midna_domain_to_utf8_create(const char *name, void *unused_context)
+{
+ static const char myname[] = "midna_domain_to_utf8_create";
+ char buf[1024]; /* XXX */
+ UErrorCode error = U_ZERO_ERROR;
+ UIDNAInfo info = UIDNA_INFO_INITIALIZER;
+ UIDNA *idna;
+ int anl;
+
+ /*
+ * Paranoia: do not expose uidna_*() to unfiltered network data.
+ */
+ if (allascii(name) == 0 && valid_utf8_string(name, strlen(name)) == 0) {
+ msg_warn("%s: Problem translating domain \"%.100s\" to UTF-8 form: %s",
+ myname, name, "malformed UTF-8");
+ return (0);
+ }
+
+ /*
+ * Perform the requested conversion.
+ */
+ idna = uidna_openUTS46(midna_domain_transitional ? UIDNA_DEFAULT
+ : UIDNA_NONTRANSITIONAL_TO_UNICODE, &error);
+ anl = uidna_nameToUnicodeUTF8(idna,
+ name, strlen(name),
+ buf, sizeof(buf) - 1,
+ &info,
+ &error);
+ uidna_close(idna);
+
+ /*
+ * Paranoia: UTS46 toUTF8 by default accepts and produces an over-long
+ * name or a name that contains an over-long NR-LDH label (and perhaps
+ * other invalid forms that are not covered in UTS 46, section 4.1). We
+ * rely on midna_domain_to_ascii() to validate the output.
+ */
+ if (U_SUCCESS(error) && info.errors == 0 && anl > 0) {
+ buf[anl] = 0; /* XXX */
+ if (midna_domain_to_ascii(buf) == 0)
+ return (0);
+ return (mystrndup(buf, anl));
+ } else {
+ msg_warn("%s: Problem translating domain \"%.100s\" to UTF8 form: %s",
+ myname, name, midna_domain_strerror(error, info.errors));
+ return (0);
+ }
+}
+
+/* midna_domain_cache_free - cache element destructor */
+
+static void midna_domain_cache_free(void *value, void *unused_context)
+{
+ if (value)
+ myfree(value);
+}
+
+/* midna_domain_to_ascii - convert name to ASCII */
+
+const char *midna_domain_to_ascii(const char *name)
+{
+ static CTABLE *midna_domain_to_ascii_cache = 0;
+
+ if (midna_domain_to_ascii_cache == 0)
+ midna_domain_to_ascii_cache = ctable_create(midna_domain_cache_size,
+ midna_domain_to_ascii_create,
+ midna_domain_cache_free,
+ (void *) 0);
+ return (ctable_locate(midna_domain_to_ascii_cache, name));
+}
+
+/* midna_domain_to_utf8 - convert name to UTF8 */
+
+const char *midna_domain_to_utf8(const char *name)
+{
+ static CTABLE *midna_domain_to_utf8_cache = 0;
+
+ if (midna_domain_to_utf8_cache == 0)
+ midna_domain_to_utf8_cache = ctable_create(midna_domain_cache_size,
+ midna_domain_to_utf8_create,
+ midna_domain_cache_free,
+ (void *) 0);
+ return (ctable_locate(midna_domain_to_utf8_cache, name));
+}
+
+/* midna_domain_suffix_to_ascii - convert .name to ASCII */
+
+const char *midna_domain_suffix_to_ascii(const char *suffix)
+{
+ const char *cache_res;
+
+ /*
+ * If prepending x to .name causes the result to become too long, then
+ * the suffix is bad.
+ */
+ if (midna_domain_buf == 0)
+ midna_domain_buf = vstring_alloc(100);
+ vstring_sprintf(midna_domain_buf, "x%s", suffix);
+ if ((cache_res = midna_domain_to_ascii(STR(midna_domain_buf))) == 0)
+ return (0);
+ else
+ return (cache_res + 1);
+}
+
+/* midna_domain_suffix_to_utf8 - convert .name to UTF8 */
+
+const char *midna_domain_suffix_to_utf8(const char *name)
+{
+ const char *cache_res;
+
+ /*
+ * If prepending x to .name causes the result to become too long, then
+ * the suffix is bad.
+ */
+ if (midna_domain_buf == 0)
+ midna_domain_buf = vstring_alloc(100);
+ vstring_sprintf(midna_domain_buf, "x%s", name);
+ if ((cache_res = midna_domain_to_utf8(STR(midna_domain_buf))) == 0)
+ return (0);
+ else
+ return (cache_res + 1);
+}
+
+#ifdef TEST
+
+ /*
+ * Test program - reads names from stdin, reports invalid names to stderr.
+ */
+#include <unistd.h>
+#include <stdlib.h>
+#include <locale.h>
+
+#include <stringops.h> /* XXX util_utf8_enable */
+#include <vstring.h>
+#include <vstream.h>
+#include <vstring_vstream.h>
+#include <msg_vstream.h>
+
+int main(int argc, char **argv)
+{
+ VSTRING *buffer = vstring_alloc(1);
+ const char *bp;
+ const char *ascii;
+ const char *utf8;
+
+ if (setlocale(LC_ALL, "C") == 0)
+ msg_fatal("setlocale(LC_ALL, C) failed: %m");
+
+ msg_vstream_init(argv[0], VSTREAM_ERR);
+ /* msg_verbose = 1; */
+ util_utf8_enable = 1;
+
+ if (geteuid() == 0) {
+ midna_domain_pre_chroot();
+ if (chroot(".") != 0)
+ msg_fatal("chroot(\".\"): %m");
+ }
+ while (vstring_fgets_nonl(buffer, VSTREAM_IN)) {
+ bp = STR(buffer);
+ msg_info("> %s", bp);
+ while (ISSPACE(*bp))
+ bp++;
+ if (*bp == '#' || *bp == 0)
+ continue;
+ msg_info("unconditional conversions:");
+ utf8 = midna_domain_to_utf8(bp);
+ msg_info("\"%s\" ->utf8 \"%s\"", bp, utf8 ? utf8 : "(error)");
+ ascii = midna_domain_to_ascii(bp);
+ msg_info("\"%s\" ->ascii \"%s\"", bp, ascii ? ascii : "(error)");
+ msg_info("conditional conversions:");
+ if (!allascii(bp)) {
+ if (ascii != 0) {
+ utf8 = midna_domain_to_utf8(ascii);
+ msg_info("\"%s\" ->ascii \"%s\" ->utf8 \"%s\"",
+ bp, ascii, utf8 ? utf8 : "(error)");
+ if (utf8 != 0) {
+ if (strcmp(utf8, bp) != 0)
+ msg_warn("\"%s\" != \"%s\"", bp, utf8);
+ }
+ }
+ } else {
+ if (utf8 != 0) {
+ ascii = midna_domain_to_ascii(utf8);
+ msg_info("\"%s\" ->utf8 \"%s\" ->ascii \"%s\"",
+ bp, utf8, ascii ? ascii : "(error)");
+ if (ascii != 0) {
+ if (strcmp(ascii, bp) != 0)
+ msg_warn("\"%s\" != \"%s\"", bp, ascii);
+ }
+ }
+ }
+ }
+ exit(0);
+}
+
+#endif /* TEST */
+
+#endif /* NO_EAI */