external/ibm-public/postfix/dist/src/global/quote_821_local.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      quote_821_local 3
   6 /* SUMMARY
   7 /*      quote local part of address
   8 /* SYNOPSIS
   9 /*      #include "quote_821_local.h"
  10 /*
  11 /*      VSTRING *quote_821_local(dst, src)
  12 /*      VSTRING *dst;
  13 /*      char    *src;
  14 /*
  15 /*      VSTRING *quote_821_local_flags(dst, src, flags)
  16 /*      VSTRING *dst;
  17 /*      const char *src;
  18 /*      int     flags;
  19 /* DESCRIPTION
  20 /*      quote_821_local() quotes the local part of a mailbox address and
  21 /*      returns a result that can be used in SMTP commands as specified
  22 /*      by RFC 821. It implements an 8-bit clean version of RFC 821.
  23 /*
  24 /*      quote_821_local_flags() provides finer control.
  25 /*
  26 /*      Arguments:
  27 /* .IP dst
  28 /*      The result.
  29 /* .IP src
  30 /*      The input address.
  31 /* .IP flags
  32 /*      Bit-wise OR of zero or more of the following.
  33 /* .RS
  34 /* .IP QUOTE_FLAG_8BITCLEAN
  35 /*      In violation with RFCs, treat 8-bit text as ordinary text.
  36 /* .IP QUOTE_FLAG_EXPOSE_AT
  37 /*      In violation with RFCs, treat `@' as an ordinary character.
  38 /* .IP QUOTE_FLAG_APPEND
  39 /*      Append to the result buffer, instead of overwriting it.
  40 /* .RE
  41 /* STANDARDS
  42 /*      RFC 821 (SMTP protocol)
  43 /* BUGS
  44 /*      The code assumes that the domain is RFC 821 clean.
  45 /* LICENSE
  46 /* .ad
  47 /* .fi
  48 /*      The Secure Mailer license must be distributed with this software.
  49 /* AUTHOR(S)
  50 /*      Wietse Venema
  51 /*      IBM T.J. Watson Research
  52 /*      P.O. Box 704
  53 /*      Yorktown Heights, NY 10598, USA
  54 /*--*/
  55
  56 /* System library. */
  57
  58 #include <sys_defs.h>
  59 #include <string.h>
  60 #include <ctype.h>
  61
  62 /* Utility library. */
  63
  64 #include <vstring.h>
  65
  66 /* Global library. */
  67
  68 #include "quote_821_local.h"
  69
  70 /* Application-specific. */
  71
  72 #define YES     1
  73 #define NO      0
  74
  75 /* is_821_dot_string - is this local-part an rfc 821 dot-string? */
  76
  77 static int is_821_dot_string(const char *local_part, const char *end, int flags)
  78 {
  79     const char *cp;
  80     int     ch;
  81
  82     /*
  83      * Detect any deviations from the definition of dot-string. We could use
  84      * lookup tables to speed up some of the work, but hey, how large can a
  85      * local-part be anyway?
  86      */
  87     if (local_part == end || local_part[0] == 0 || local_part[0] == '.')
  88         return (NO);
  89     for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
  90         if (ch == '.' && cp[1] == '.')
  91             return (NO);
  92         if (ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
  93             return (NO);
  94         if (ch == ' ')
  95             return (NO);
  96         if (ISCNTRL(ch))
  97             return (NO);
  98         if (ch == '<' || ch == '>'
  99             || ch == '(' || ch == ')'
 100             || ch == '[' || ch == ']'
 101             || ch == '\\' || ch == ','
 102             || ch == ';' || ch == ':'
 103             || (ch == '@' && !(flags & QUOTE_FLAG_EXPOSE_AT)) || ch == '"')
 104             return (NO);
 105     }
 106     if (cp[-1] == '.')
 107         return (NO);
 108     return (YES);
 109 }
 110
 111 /* make_821_quoted_string - make quoted-string from local-part */
 112
 113 static VSTRING *make_821_quoted_string(VSTRING *dst, const char *local_part,
 114                                                const char *end, int flags)
 115 {
 116     const char *cp;
 117     int     ch;
 118
 119     /*
 120      * Put quotes around the result, and prepend a backslash to characters
 121      * that need quoting when they occur in a quoted-string.
 122      */
 123     VSTRING_ADDCH(dst, '"');
 124     for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
 125         if ((ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
 126             || ch == '\r' || ch == '\n' || ch == '"' || ch == '\\')
 127             VSTRING_ADDCH(dst, '\\');
 128         VSTRING_ADDCH(dst, ch);
 129     }
 130     VSTRING_ADDCH(dst, '"');
 131     VSTRING_TERMINATE(dst);
 132     return (dst);
 133 }
 134
 135 /* quote_821_local_flags - quote local part of address according to rfc 821 */
 136
 137 VSTRING *quote_821_local_flags(VSTRING *dst, const char *addr, int flags)
 138 {
 139     const char   *at;
 140
 141     /*
 142      * According to RFC 821, a local-part is a dot-string or a quoted-string.
 143      * We first see if the local-part is a dot-string. If it is not, we turn
 144      * it into a quoted-string. Anything else would be too painful.
 145      */
 146     if ((at = strrchr(addr, '@')) == 0)         /* just in case */
 147         at = addr + strlen(addr);               /* should not happen */
 148     if ((flags & QUOTE_FLAG_APPEND) == 0)
 149         VSTRING_RESET(dst);
 150     if (is_821_dot_string(addr, at, flags)) {
 151         return (vstring_strcat(dst, addr));
 152     } else {
 153         make_821_quoted_string(dst, addr, at, flags & QUOTE_FLAG_8BITCLEAN);
 154         return (vstring_strcat(dst, at));
 155     }
 156 }
 157
 158 #ifdef TEST
 159
 160  /*
 161   * Test program for local-part quoting as per rfc 821
 162   */
 163 #include <stdlib.h>
 164 #include <vstream.h>
 165 #include <vstring_vstream.h>
 166 #include "quote_821_local.h"
 167
 168 int     main(void)
 169 {
 170     VSTRING *src = vstring_alloc(100);
 171     VSTRING *dst = vstring_alloc(100);
 172
 173     while (vstring_fgets_nonl(src, VSTREAM_IN)) {
 174         vstream_fprintf(VSTREAM_OUT, "%s\n",
 175                         vstring_str(quote_821_local(dst, vstring_str(src))));
 176         vstream_fflush(VSTREAM_OUT);
 177     }
 178     exit(0);
 179 }
 180
 181 #endif