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

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      xtext 3
   6 /* SUMMARY
   7 /*      quote/unquote text, xtext style.
   8 /* SYNOPSIS
   9 /*      #include <xtext.h>
  10 /*
  11 /*      VSTRING *xtext_quote(quoted, unquoted, special)
  12 /*      VSTRING *quoted;
  13 /*      const char *unquoted;
  14 /*      const char *special;
  15 /*
  16 /*      VSTRING *xtext_quote_append(unquoted, quoted, special)
  17 /*      VSTRING *unquoted;
  18 /*      const char *quoted;
  19 /*      const char *special;
  20 /*
  21 /*      VSTRING *xtext_unquote(unquoted, quoted)
  22 /*      VSTRING *unquoted;
  23 /*      const char *quoted;
  24 /* DESCRIPTION
  25 /*      xtext_quote() takes a null-terminated string and replaces characters
  26 /*      +, <33(10) and >126(10), as well as characters specified with "special"
  27 /*      by +XX, XX being the two-digit uppercase hexadecimal equivalent.
  28 /*
  29 /*      xtext_quote_append() is like xtext_quote(), but appends the conversion
  30 /*      result to the result buffer.
  31 /*
  32 /*      xtext_unquote() performs the opposite transformation. This function
  33 /*      understands lowercase, uppercase, and mixed case +XX sequences. The
  34 /*      result value is the unquoted argument in case of success, a null pointer
  35 /*      otherwise.
  36 /* BUGS
  37 /*      This module cannot process null characters in data.
  38 /* LICENSE
  39 /* .ad
  40 /* .fi
  41 /*      The Secure Mailer license must be distributed with this software.
  42 /* AUTHOR(S)
  43 /*      Wietse Venema
  44 /*      IBM T.J. Watson Research
  45 /*      P.O. Box 704
  46 /*      Yorktown Heights, NY 10598, USA
  47 /*--*/
  48
  49 /* System library. */
  50
  51 #include <sys_defs.h>
  52 #include <string.h>
  53 #include <ctype.h>
  54
  55 /* Utility library. */
  56
  57 #include "msg.h"
  58 #include "vstring.h"
  59 #include "xtext.h"
  60
  61 /* Application-specific. */
  62
  63 #define STR(x)  vstring_str(x)
  64 #define LEN(x)  VSTRING_LEN(x)
  65
  66 /* xtext_quote_append - append unquoted data to quoted data */
  67
  68 VSTRING *xtext_quote_append(VSTRING *quoted, const char *unquoted,
  69                                     const char *special)
  70 {
  71     const char *cp;
  72     int     ch;
  73
  74     for (cp = unquoted; (ch = *(unsigned const char *) cp) != 0; cp++) {
  75         if (ch != '+' && ch > 32 && ch < 127
  76             && (*special == 0 || strchr(special, ch) == 0)) {
  77             VSTRING_ADDCH(quoted, ch);
  78         } else {
  79             vstring_sprintf_append(quoted, "+%02X", ch);
  80         }
  81     }
  82     VSTRING_TERMINATE(quoted);
  83     return (quoted);
  84 }
  85
  86 /* xtext_quote - unquoted data to quoted */
  87
  88 VSTRING *xtext_quote(VSTRING *quoted, const char *unquoted, const char *special)
  89 {
  90     VSTRING_RESET(quoted);
  91     xtext_quote_append(quoted, unquoted, special);
  92     return (quoted);
  93 }
  94
  95 /* xtext_unquote - quoted data to unquoted */
  96
  97 VSTRING *xtext_unquote(VSTRING *unquoted, const char *quoted)
  98 {
  99     const char *cp;
 100     int     ch;
 101
 102     VSTRING_RESET(unquoted);
 103     for (cp = quoted; (ch = *cp) != 0; cp++) {
 104         if (ch == '+') {
 105             if (ISDIGIT(cp[1]))
 106                 ch = (cp[1] - '0') << 4;
 107             else if (cp[1] >= 'a' && cp[1] <= 'f')
 108                 ch = (cp[1] - 'a' + 10) << 4;
 109             else if (cp[1] >= 'A' && cp[1] <= 'F')
 110                 ch = (cp[1] - 'A' + 10) << 4;
 111             else
 112                 return (0);
 113             if (ISDIGIT(cp[2]))
 114                 ch |= (cp[2] - '0');
 115             else if (cp[2] >= 'a' && cp[2] <= 'f')
 116                 ch |= (cp[2] - 'a' + 10);
 117             else if (cp[2] >= 'A' && cp[2] <= 'F')
 118                 ch |= (cp[2] - 'A' + 10);
 119             else
 120                 return (0);
 121             cp += 2;
 122         }
 123         VSTRING_ADDCH(unquoted, ch);
 124     }
 125     VSTRING_TERMINATE(unquoted);
 126     return (unquoted);
 127 }
 128
 129 #ifdef TEST
 130
 131  /*
 132   * Proof-of-concept test program: convert to quoted and back.
 133   */
 134 #include <vstream.h>
 135
 136 #define BUFLEN 1024
 137
 138 static ssize_t read_buf(VSTREAM *fp, VSTRING *buf)
 139 {
 140     ssize_t len;
 141
 142     VSTRING_RESET(buf);
 143     len = vstream_fread(fp, STR(buf), vstring_avail(buf));
 144     VSTRING_AT_OFFSET(buf, len);                /* XXX */
 145     VSTRING_TERMINATE(buf);
 146     return (len);
 147 }
 148
 149 int     main(int unused_argc, char **unused_argv)
 150 {
 151     VSTRING *unquoted = vstring_alloc(BUFLEN);
 152     VSTRING *quoted = vstring_alloc(100);
 153     ssize_t len;
 154
 155     while ((len = read_buf(VSTREAM_IN, unquoted)) > 0) {
 156         xtext_quote(quoted, STR(unquoted), "+=");
 157         if (xtext_unquote(unquoted, STR(quoted)) == 0)
 158             msg_fatal("bad input: %.100s", STR(quoted));
 159         if (LEN(unquoted) != len)
 160             msg_fatal("len %ld != unquoted len %ld",
 161                       (long) len, (long) LEN(unquoted));
 162         if (vstream_fwrite(VSTREAM_OUT, STR(unquoted), LEN(unquoted)) != LEN(unquoted))
 163             msg_fatal("write error: %m");
 164     }
 165     vstream_fflush(VSTREAM_OUT);
 166     vstring_free(unquoted);
 167     vstring_free(quoted);
 168     return (0);
 169 }
 170
 171 #endif