Adding upstream version 4.96.upstream/4.96upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 278 insertions, 0 deletions

diff --git a/src/utf8.c b/src/utf8.c
new file mode 100644
index 0000000..bc7adb8
--- /dev/null
+++ b/src/utf8.c
@@ -0,0 +1,278 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) The Exim Maintainers 2022 */
+/* Copyright (c) Jeremy Harris 2015 - 2018 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+
+#include "exim.h"
+
+#ifdef SUPPORT_I18N
+
+#ifdef SUPPORT_I18N_2008
+# include <idn2.h>
+#else
+# include <idna.h>
+#endif
+
+#include <punycode.h>
+#include <stringprep.h>
+
+static uschar *
+string_localpart_alabel_to_utf8_(const uschar * alabel, uschar ** err);
+
+/**************************************************/
+
+BOOL
+string_is_utf8(const uschar * s)
+{
+uschar c;
+if (s) while ((c = *s++)) if (c & 0x80) return TRUE;
+return FALSE;
+}
+
+static BOOL
+string_is_alabel(const uschar * s)
+{
+return s[0] == 'x' && s[1] == 'n' && s[2] == '-' && s[3] == '-';
+}
+
+/**************************************************/
+/* Domain conversions.
+The *err string pointer should be null before the call
+
+Return NULL for error, with optional errstr pointer filled in
+*/
+
+uschar *
+string_domain_utf8_to_alabel(const uschar * utf8, uschar ** err)
+{
+uschar * s1, * s;
+int rc;
+
+#ifdef SUPPORT_I18N_2008
+/* Avoid lowercasing plain-ascii domains */
+if (!string_is_utf8(utf8))
+  return string_copy(utf8);
+
+/* Only lowercase is accepted by the library call.  A pity since we lose
+any mixed-case annotation.  This does not really matter for a domain. */
+  {
+  uschar c;
+  for (s1 = s = US utf8; (c = *s1); s1++) if (!(c & 0x80) && isupper(c))
+    {
+    s = string_copy(utf8);
+    for (s1 = s + (s1 - utf8); (c = *s1); s1++) if (!(c & 0x80) && isupper(c))
+      *s1 = tolower(c);
+    break;
+    }
+  }
+if ((rc = idn2_lookup_u8((const uint8_t *) s, &s1, IDN2_NFC_INPUT)) != IDN2_OK)
+  {
+  if (err) *err = US idn2_strerror(rc);
+  return NULL;
+  }
+#else
+s = US stringprep_utf8_nfkc_normalize(CCS utf8, -1);
+if (  (rc = idna_to_ascii_8z(CCS s, CSS &s1, IDNA_ALLOW_UNASSIGNED))
+   != IDNA_SUCCESS)
+  {
+  free(s);
+  if (err) *err = US idna_strerror(rc);
+  return NULL;
+  }
+free(s);
+#endif
+s = string_copy(s1);
+free(s1);
+return s;
+}
+
+
+
+uschar *
+string_domain_alabel_to_utf8(const uschar * alabel, uschar ** err)
+{
+#ifdef SUPPORT_I18N_2008
+const uschar * label;
+int sep = '.';
+gstring * g = NULL;
+
+while (label = string_nextinlist(&alabel, &sep, NULL, 0))
+  if (  string_is_alabel(label)
+     && !(label = string_localpart_alabel_to_utf8_(label, err))
+     )
+    return NULL;
+  else
+    g = string_append_listele(g, '.', label);
+return string_from_gstring(g);
+
+#else
+
+uschar * s1, * s;
+int rc;
+
+if (  (rc = idna_to_unicode_8z8z(CCS alabel, CSS &s1, IDNA_USE_STD3_ASCII_RULES))
+   != IDNA_SUCCESS)
+  {
+  if (err) *err = US idna_strerror(rc);
+  return NULL;
+  }
+s = string_copy(s1);
+free(s1);
+return s;
+#endif
+}
+
+/**************************************************/
+/* localpart conversions */
+/* the *err string pointer should be null before the call */
+
+
+uschar *
+string_localpart_utf8_to_alabel(const uschar * utf8, uschar ** err)
+{
+size_t ucs4_len = 0;
+punycode_uint * p;
+size_t p_len;
+uschar * res;
+int rc;
+
+if (!string_is_utf8(utf8)) return string_copy(utf8);
+
+p = (punycode_uint *) stringprep_utf8_to_ucs4(CCS utf8, -1, &ucs4_len);
+if (!p || !ucs4_len)
+  {
+  if (err) *err = US"l_u2a: bad UTF-8 input";
+  return NULL;
+  }
+p_len = ucs4_len*4;	/* this multiplier is pure guesswork */
+res = store_get(p_len+5, utf8);
+
+res[0] = 'x'; res[1] = 'n'; res[2] = res[3] = '-';
+
+if ((rc = punycode_encode(ucs4_len, p, NULL, &p_len, CS res+4)) != PUNYCODE_SUCCESS)
+  {
+  DEBUG(D_expand) debug_printf("l_u2a: bad '%s'\n", punycode_strerror(rc));
+  free(p);
+  if (err) *err = US punycode_strerror(rc);
+  return NULL;
+  }
+p_len += 4;
+free(p);
+res[p_len] = '\0';
+return res;
+}
+
+
+static uschar *
+string_localpart_alabel_to_utf8_(const uschar * alabel, uschar ** err)
+{
+size_t p_len;
+punycode_uint * p;
+int rc;
+uschar * s, * res;
+
+DEBUG(D_expand) debug_printf("l_a2u: '%s'\n", alabel);
+alabel += 4;
+p_len = Ustrlen(alabel);
+p = store_get((p_len+1) * sizeof(*p), alabel);
+
+if ((rc = punycode_decode(p_len, CCS alabel, &p_len, p, NULL)) != PUNYCODE_SUCCESS)
+  {
+  if (err) *err = US punycode_strerror(rc);
+  return NULL;
+  }
+
+s = US stringprep_ucs4_to_utf8(p, p_len, NULL, &p_len);
+res = string_copyn(s, p_len);
+free(s);
+return res;
+}
+
+
+uschar *
+string_localpart_alabel_to_utf8(const uschar * alabel, uschar ** err)
+{
+if (string_is_alabel(alabel))
+  return string_localpart_alabel_to_utf8_(alabel, err);
+
+if (err) *err = US"bad alabel prefix";
+return NULL;
+}
+
+
+/**************************************************/
+/* Whole address conversion.
+The *err string pointer should be null before the call.
+
+Return NULL on error, with (optional) errstring pointer filled in
+*/
+
+uschar *
+string_address_utf8_to_alabel(const uschar * utf8, uschar ** err)
+{
+uschar * l, * d;
+
+if (!*utf8) return string_copy(utf8);
+
+DEBUG(D_expand) debug_printf("addr from utf8 <%s>", utf8);
+
+for (const uschar * s = utf8; *s; s++)
+  if (*s == '@')
+    {
+    l = string_copyn(utf8, s - utf8);
+    if (  !(l = string_localpart_utf8_to_alabel(l, err))
+       || !(d = string_domain_utf8_to_alabel(++s, err))
+       )
+      return NULL;
+    l = string_sprintf("%s@%s", l, d);
+    DEBUG(D_expand) debug_printf(" -> <%s>\n", l);
+    return l;
+    }
+
+l =  string_localpart_utf8_to_alabel(utf8, err);
+DEBUG(D_expand) debug_printf(" -> <%s>\n", l);
+return l;
+}
+
+
+
+/*************************************************
+*         Report the library versions.           *
+*************************************************/
+
+/* See a description in tls-openssl.c for an explanation of why this exists.
+
+Arguments:   string to append to
+Returns:     string
+*/
+
+gstring *
+utf8_version_report(gstring * g)
+{
+#ifdef SUPPORT_I18N_2008
+g = string_fmt_append(g, "Library version: IDN2: Compile: %s\n"
+           "                       Runtime: %s\n",
+	IDN2_VERSION,
+	idn2_check_version(NULL));
+g = string_fmt_append(g, "Library version: Stringprep: Compile: %s\n"
+           "                             Runtime: %s\n",
+	STRINGPREP_VERSION,
+	stringprep_check_version(NULL));
+#else
+g = string_fmt_append(g, "Library version: IDN: Compile: %s\n"
+           "                      Runtime: %s\n",
+	STRINGPREP_VERSION,
+	stringprep_check_version(NULL));
+#endif
+return g;
+}
+
+#endif	/* whole file */
+
+/* vi: aw ai sw=2
+*/
+/* End of utf8.c */