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/*++
/* NAME
/* quote_821_local 3
/* SUMMARY
/* quote local part of address
/* SYNOPSIS
/* #include "quote_821_local.h"
/*
/* VSTRING *quote_821_local(dst, src)
/* VSTRING *dst;
/* char *src;
/*
/* VSTRING *quote_821_local_flags(dst, src, flags)
/* VSTRING *dst;
/* const char *src;
/* int flags;
/* DESCRIPTION
/* quote_821_local() quotes the local part of a mailbox address and
/* returns a result that can be used in SMTP commands as specified
/* by RFC 821. It implements an 8-bit clean version of RFC 821.
/*
/* quote_821_local_flags() provides finer control.
/*
/* Arguments:
/* .IP dst
/* The result.
/* .IP src
/* The input address.
/* .IP flags
/* Bit-wise OR of zero or more of the following.
/* .RS
/* .IP QUOTE_FLAG_8BITCLEAN
/* In violation with RFCs, treat 8-bit text as ordinary text.
/* .IP QUOTE_FLAG_EXPOSE_AT
/* In violation with RFCs, treat `@' as an ordinary character.
/* .IP QUOTE_FLAG_APPEND
/* Append to the result buffer, instead of overwriting it.
/* .RE
/* STANDARDS
/* RFC 821 (SMTP protocol)
/* BUGS
/* The code assumes that the domain is RFC 821 clean.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <string.h>
#include <ctype.h>
/* Utility library. */
#include <vstring.h>
/* Global library. */
#include "quote_821_local.h"
/* Application-specific. */
#define YES 1
#define NO 0
/* is_821_dot_string - is this local-part an rfc 821 dot-string? */
static int is_821_dot_string(const char *local_part, const char *end, int flags)
{
const char *cp;
int ch;
/*
* Detect any deviations from the definition of dot-string. We could use
* lookup tables to speed up some of the work, but hey, how large can a
* local-part be anyway?
*/
if (local_part == end || local_part[0] == 0 || local_part[0] == '.')
return (NO);
for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
if (ch == '.' && cp[1] == '.')
return (NO);
if (ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
return (NO);
if (ch == ' ')
return (NO);
if (ISCNTRL(ch))
return (NO);
if (ch == '<' || ch == '>'
|| ch == '(' || ch == ')'
|| ch == '[' || ch == ']'
|| ch == '\\' || ch == ','
|| ch == ';' || ch == ':'
|| (ch == '@' && !(flags & QUOTE_FLAG_EXPOSE_AT)) || ch == '"')
return (NO);
}
if (cp[-1] == '.')
return (NO);
return (YES);
}
/* make_821_quoted_string - make quoted-string from local-part */
static VSTRING *make_821_quoted_string(VSTRING *dst, const char *local_part,
const char *end, int flags)
{
const char *cp;
int ch;
/*
* Put quotes around the result, and prepend a backslash to characters
* that need quoting when they occur in a quoted-string.
*/
VSTRING_ADDCH(dst, '"');
for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
if ((ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
|| ch == '\r' || ch == '\n' || ch == '"' || ch == '\\')
VSTRING_ADDCH(dst, '\\');
VSTRING_ADDCH(dst, ch);
}
VSTRING_ADDCH(dst, '"');
VSTRING_TERMINATE(dst);
return (dst);
}
/* quote_821_local_flags - quote local part of address according to rfc 821 */
VSTRING *quote_821_local_flags(VSTRING *dst, const char *addr, int flags)
{
const char *at;
/*
* According to RFC 821, a local-part is a dot-string or a quoted-string.
* We first see if the local-part is a dot-string. If it is not, we turn
* it into a quoted-string. Anything else would be too painful.
*/
if ((at = strrchr(addr, '@')) == 0) /* just in case */
at = addr + strlen(addr); /* should not happen */
if ((flags & QUOTE_FLAG_APPEND) == 0)
VSTRING_RESET(dst);
if (is_821_dot_string(addr, at, flags)) {
return (vstring_strcat(dst, addr));
} else {
make_821_quoted_string(dst, addr, at, flags & QUOTE_FLAG_8BITCLEAN);
return (vstring_strcat(dst, at));
}
}
#ifdef TEST
/*
* Test program for local-part quoting as per rfc 821
*/
#include <stdlib.h>
#include <vstream.h>
#include <vstring_vstream.h>
#include "quote_821_local.h"
int main(void)
{
VSTRING *src = vstring_alloc(100);
VSTRING *dst = vstring_alloc(100);
while (vstring_fgets_nonl(src, VSTREAM_IN)) {
vstream_fprintf(VSTREAM_OUT, "%s\n",
vstring_str(quote_821_local(dst, vstring_str(src))));
vstream_fflush(VSTREAM_OUT);
}
exit(0);
}
#endif
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