Import Debian changes 4.89-2+deb9u4

[hcoop/debian/exim4.git] / src / imap_utf7.c

diff --git a/src/imap_utf7.c b/src/imap_utf7.c
new file mode 100644 (file)
index 0000000..0c3d5a2
--- /dev/null
+++ b/src/imap_utf7.c
@@ -0,0 +1,209 @@
+#include "exim.h"
+
+#ifdef SUPPORT_I18N
+
+uschar *
+imap_utf7_encode(uschar *string, const uschar *charset, uschar sep,
+  uschar *specials, uschar **error)
+{
+static uschar encode_base64[64] =
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+int ptr = 0;
+int size = 0;
+size_t slen;
+uschar *sptr, *yield = NULL;
+int i = 0, j;  /* compiler quietening */
+uschar c = 0;  /* compiler quietening */
+BOOL base64mode = FALSE;
+BOOL lastsep = FALSE;
+uschar utf16buf[256];
+uschar *utf16ptr;
+uschar *s;
+uschar outbuf[256];
+uschar *outptr = outbuf;
+#if HAVE_ICONV
+iconv_t icd;
+#endif
+
+if (!specials) specials = US"";
+
+/* Pass over the string. If it consists entirely of "normal" characters
+   (possibly with leading seps), return it as is. */
+for (s = string; *s; s++)
+  {
+  if (s == string && *s == sep)
+    string++;
+  if (  *s >= 0x7f
+     || *s < 0x20
+     || strchr("./&", *s)
+     || *s == sep
+     || Ustrchr(specials, *s)
+     )
+    break;
+  }
+
+if (!*s)
+  return string;
+
+sptr = string;
+slen = Ustrlen(string);
+
+#if HAVE_ICONV
+if ((icd = iconv_open("UTF-16BE", CCS charset)) == (iconv_t)-1)
+  {
+  *error = string_sprintf(
+       "imapfolder: iconv_open(\"UTF-16BE\", \"%s\") failed: %s%s",
+    charset, strerror(errno),
+    errno == EINVAL ? " (maybe unsupported conversion)" : "");
+  return NULL;
+  }
+#endif
+
+while (slen > 0)
+  {
+#if HAVE_ICONV
+  size_t left = sizeof(utf16buf);
+  utf16ptr = utf16buf;
+
+  if (  iconv(icd, (ICONV_ARG2_TYPE)&sptr, &slen, CSS &utf16ptr, &left)
+               == (size_t)-1
+     && errno != E2BIG
+        )
+    {
+    *error = string_sprintf("imapfolder: iconv() failed to convert from %s: %s",
+                             charset, strerror(errno));
+    iconv_close(icd);
+    return NULL;
+    }
+#else
+  for (utf16ptr = utf16buf;
+       slen > 0 && (utf16ptr - utf16buf) < sizeof(utf16buf);
+       utf16ptr += 2, slen--, sptr++)
+    {
+    *utf16ptr = *sptr;
+    *(utf16ptr+1) = '\0';
+    }
+#endif
+
+  s = utf16buf;
+  while (s < utf16ptr)
+    {
+    /* Now encode utf16buf as modified UTF-7 */
+    if (  s[0] != 0
+       || s[1] >= 0x7f
+       || s[1] < 0x20
+       || (Ustrchr(specials, s[1]) && s[1] != sep)
+       )
+      {
+      lastsep = FALSE;
+      /* Encode as modified BASE64 */
+      if (!base64mode)
+        {
+        *outptr++ = '&';
+        base64mode = TRUE;
+        i = 0;
+        }
+
+      for (j = 0; j < 2; j++, s++) switch (i++)
+       {
+       case 0:
+         /* Top 6 bits of the first octet */
+         *outptr++ = encode_base64[(*s >> 2) & 0x3F];
+         c = (*s & 0x03); break;
+       case 1:
+         /* Bottom 2 bits of the first octet, and top 4 bits of the second */
+         *outptr++ = encode_base64[(c << 4) | ((*s >> 4) & 0x0F)];
+         c = (*s & 0x0F); break;
+       case 2:
+         /* Bottom 4 bits of the second octet and top 2 bits of the third */
+         *outptr++ = encode_base64[(c << 2) | ((*s >> 6) & 0x03)];
+         /* Bottom 6 bits of the third octet */
+         *outptr++ = encode_base64[*s & 0x3F];
+         i = 0;
+       }
+      }
+
+    else if (  (s[1] != '.' && s[1] != '/')
+           || s[1] == sep
+           )
+      {
+      /* Encode as self (almost) */
+      if (base64mode)
+        {
+        switch (i)
+          {
+          case 1:
+               /* Remaining bottom 2 bits of the last octet */
+               *outptr++ = encode_base64[c << 4];
+               break;
+         case 2:
+               /* Remaining bottom 4 bits of the last octet */
+               *outptr++ = encode_base64[c << 2];
+         }
+       *outptr++ = '-';
+       base64mode = FALSE;
+       }
+
+      if (*++s == sep)
+       {
+       if (!lastsep)
+         {
+         *outptr++ = '.';
+         lastsep = TRUE;
+         }
+       }
+      else
+        {
+        *outptr++ = *s;
+        if (*s == '&')
+         *outptr++ = '-';
+       lastsep = FALSE;
+        }
+
+      s++;
+      }
+    else
+      {
+      *error = string_sprintf("imapfolder: illegal character '%c'", s[1]);
+      return NULL;
+      }
+
+    if (outptr > outbuf + sizeof(outbuf) - 3)
+      {
+      yield = string_catn(yield, &size, &ptr, outbuf, outptr - outbuf);
+      outptr = outbuf;
+      }
+
+    }
+  } /* End of input string */
+
+if (base64mode)
+  {
+  switch (i)
+    {
+    case 1:
+      /* Remaining bottom 2 bits of the last octet */
+      *outptr++ = encode_base64[c << 4];
+      break;
+    case 2:
+      /* Remaining bottom 4 bits of the last octet */
+      *outptr++ = encode_base64[c << 2];
+    }
+  *outptr++ = '-';
+  }
+
+#if HAVE_ICONV
+iconv_close(icd);
+#endif
+
+yield = string_catn(yield, &size, &ptr, outbuf, outptr - outbuf);
+if (yield[ptr-1] == '.')
+  ptr--;
+yield[ptr] = '\0';
+
+return yield;
+}
+
+#endif /* whole file */
+/* vi: aw ai sw=2
+*/