1 /*++
2 /* NAME
3 /* quote_822_local 3
4 /* SUMMARY
5 /* quote local part of mailbox
6 /* SYNOPSIS
7 /* #include <quote_822_local.h>
8 /*
9 /* VSTRING *quote_822_local(dst, src)
10 /* VSTRING *dst;
11 /* const char *src;
12 /*
13 /* VSTRING *quote_822_local_flags(dst, src, flags)
14 /* VSTRING *dst;
15 /* const char *src;
16 /* int flags;
17 /*
18 /* VSTRING *unquote_822_local(dst, src)
19 /* VSTRING *dst;
20 /* const char *src;
21 /* DESCRIPTION
22 /* quote_822_local() quotes the local part of a mailbox and
23 /* returns a result that can be used in message headers as
24 /* specified by RFC 822 (actually, an 8-bit clean version of
25 /* RFC 822). It implements an 8-bit clean version of RFC 822.
26 /*
27 /* quote_822_local_flags() provides finer control.
28 /*
29 /* unquote_822_local() transforms the local part of a mailbox
30 /* address to unquoted (internal) form.
31 /*
32 /* Arguments:
33 /* .IP dst
34 /* The result.
35 /* .IP src
36 /* The input address.
37 /* .IP flags
38 /* Bit-wise OR of zero or more of the following.
39 /* .RS
40 /* .IP QUOTE_FLAG_8BITCLEAN
41 /* In violation with RFCs, treat 8-bit text as ordinary text.
42 /* .IP QUOTE_FLAG_EXPOSE_AT
43 /* In violation with RFCs, treat `@' as an ordinary character.
44 /* .IP QUOTE_FLAG_APPEND
45 /* Append to the result buffer, instead of overwriting it.
46 /* .IP QUOTE_FLAG_BARE_LOCALPART
47 /* The input is a localpart without @domain part.
48 /* .RE
49 /* STANDARDS
50 /* RFC 822 (ARPA Internet Text Messages)
51 /* BUGS
52 /* The code assumes that the domain is RFC 822 clean.
53 /* LICENSE
54 /* .ad
55 /* .fi
56 /* The Secure Mailer license must be distributed with this software.
57 /* AUTHOR(S)
58 /* Wietse Venema
59 /* IBM T.J. Watson Research
60 /* P.O. Box 704
61 /* Yorktown Heights, NY 10598, USA
62 /*
63 /* Wietse Venema
64 /* Google, Inc.
65 /* 111 8th Avenue
66 /* New York, NY 10011, USA
67 /*--*/
68
69 /* System library. */
70
71 #include <sys_defs.h>
72 #include <string.h>
73 #include <ctype.h>
74
75 /* Utility library. */
76
77 #include <vstring.h>
78
79 /* Global library. */
80
81 /* Application-specific. */
82
83 #include "quote_822_local.h"
84
85 /* Local stuff. */
86
87 #define YES 1
88 #define NO 0
89
90 /* is_822_dot_string - is this local-part an rfc 822 dot-string? */
91
is_822_dot_string(const char * local_part,const char * end,int flags)92 static int is_822_dot_string(const char *local_part, const char *end, int flags)
93 {
94 const char *cp;
95 int ch;
96
97 /*
98 * Detect any deviations from a sequence of atoms separated by dots. We
99 * could use lookup tables to speed up some of the work, but hey, how
100 * large can a local-part be anyway?
101 *
102 * RFC 822 expects 7-bit data. Rather than quoting every 8-bit character
103 * (and still passing it on as 8-bit data) we leave 8-bit data alone.
104 */
105 if (local_part == end || local_part[0] == 0 || local_part[0] == '.')
106 return (NO);
107 for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
108 if (ch == '.' && (cp + 1) < end && cp[1] == '.')
109 return (NO);
110 if (ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
111 return (NO);
112 if (ch == ' ')
113 return (NO);
114 if (ISCNTRL(ch))
115 return (NO);
116 if (ch == '(' || ch == ')'
117 || ch == '<' || ch == '>'
118 || (ch == '@' && !(flags & QUOTE_FLAG_EXPOSE_AT)) || ch == ','
119 || ch == ';' || ch == ':'
120 || ch == '\\' || ch == '"'
121 || ch == '[' || ch == ']')
122 return (NO);
123 }
124 if (cp[-1] == '.')
125 return (NO);
126 return (YES);
127 }
128
129 /* make_822_quoted_string - make quoted-string from local-part */
130
make_822_quoted_string(VSTRING * dst,const char * local_part,const char * end,int flags)131 static VSTRING *make_822_quoted_string(VSTRING *dst, const char *local_part,
132 const char *end, int flags)
133 {
134 const char *cp;
135 int ch;
136
137 /*
138 * Put quotes around the result, and prepend a backslash to characters
139 * that need quoting when they occur in a quoted-string.
140 */
141 VSTRING_ADDCH(dst, '"');
142 for (cp = local_part; cp < end && (ch = *(unsigned char *) cp) != 0; cp++) {
143 if ((ch > 127 && !(flags & QUOTE_FLAG_8BITCLEAN))
144 || ch == '"' || ch == '\\' || ch == '\r')
145 VSTRING_ADDCH(dst, '\\');
146 VSTRING_ADDCH(dst, ch);
147 }
148 VSTRING_ADDCH(dst, '"');
149 return (dst);
150 }
151
152 /* quote_822_local_flags - quote local part of mailbox according to rfc 822 */
153
quote_822_local_flags(VSTRING * dst,const char * mbox,int flags)154 VSTRING *quote_822_local_flags(VSTRING *dst, const char *mbox, int flags)
155 {
156 const char *start; /* first byte of localpart */
157 const char *end; /* first byte after localpart */
158 const char *colon;
159
160 /*
161 * According to RFC 822, a local-part is a dot-string or a quoted-string.
162 * We first see if the local-part is a dot-string. If it is not, we turn
163 * it into a quoted-string. Anything else would be too painful. But
164 * first, skip over any source route that precedes the local-part.
165 */
166 if (mbox[0] == '@' && (colon = strchr(mbox, ':')) != 0)
167 start = colon + 1;
168 else
169 start = mbox;
170 if ((flags & QUOTE_FLAG_BARE_LOCALPART) != 0
171 || (end = strrchr(start, '@')) == 0)
172 end = start + strlen(start);
173 if ((flags & QUOTE_FLAG_APPEND) == 0)
174 VSTRING_RESET(dst);
175 if (is_822_dot_string(start, end, flags)) {
176 return (vstring_strcat(dst, mbox));
177 } else {
178 vstring_strncat(dst, mbox, start - mbox);
179 make_822_quoted_string(dst, start, end, flags & QUOTE_FLAG_8BITCLEAN);
180 return (vstring_strcat(dst, end));
181 }
182 }
183
184 /* unquote_822_local - unquote local part of mailbox according to rfc 822 */
185
unquote_822_local(VSTRING * dst,const char * mbox)186 VSTRING *unquote_822_local(VSTRING *dst, const char *mbox)
187 {
188 const char *start; /* first byte of localpart */
189 const char *colon;
190 const char *cp;
191 int in_quote = 0;
192 const char *bare_at_src;
193 int bare_at_dst_pos = -1;
194
195 /* Don't unquote a routing prefix. Is this still possible? */
196 if (mbox[0] == '@' && (colon = strchr(mbox, ':')) != 0) {
197 start = colon + 1;
198 vstring_strncpy(dst, mbox, start - mbox);
199 } else {
200 start = mbox;
201 VSTRING_RESET(dst);
202 }
203 /* Locate the last unquoted '@'. */
204 for (cp = start; *cp; cp++) {
205 if (*cp == '"') {
206 in_quote = !in_quote;
207 continue;
208 } else if (*cp == '@') {
209 if (!in_quote) {
210 bare_at_dst_pos = VSTRING_LEN(dst);
211 bare_at_src = cp;
212 }
213 } else if (*cp == '\\') {
214 if (cp[1] == 0)
215 continue;
216 cp++;
217 }
218 VSTRING_ADDCH(dst, *cp);
219 }
220 /* Don't unquote text after the last unquoted '@'. */
221 if (bare_at_dst_pos >= 0) {
222 vstring_truncate(dst, bare_at_dst_pos);
223 vstring_strcat(dst, bare_at_src);
224 } else
225 VSTRING_TERMINATE(dst);
226 return (dst);
227 }
228
229 #ifdef TEST
230
231 /*
232 * Proof-of-concept test program. Read an unquoted address from stdin, and
233 * show the quoted and unquoted results. Specify <> to test behavior for an
234 * empty unquoted adress.
235 */
236 #include <ctype.h>
237 #include <string.h>
238
239 #include <msg.h>
240 #include <name_mask.h>
241 #include <stringops.h>
242 #include <vstream.h>
243 #include <vstring_vstream.h>
244
245 #define STR vstring_str
246
main(int unused_argc,char ** argv)247 int main(int unused_argc, char **argv)
248 {
249 VSTRING *in = vstring_alloc(100);
250 VSTRING *out = vstring_alloc(100);
251 char *cmd;
252 char *bp;
253 int flags;
254
255 while (vstring_fgets_nonl(in, VSTREAM_IN)) {
256 bp = STR(in);
257 if ((cmd = mystrtok(&bp, CHARS_SPACE)) != 0) {
258 while (ISSPACE(*bp))
259 bp++;
260 if (*bp == 0) {
261 msg_warn("missing argument");
262 continue;
263 }
264 if (strcmp(bp, "<>") == 0)
265 bp = "";
266 if (strcmp(cmd, "quote") == 0) {
267 quote_822_local(out, bp);
268 vstream_printf("'%s' quoted '%s'\n", bp, STR(out));
269 } else if (strcmp(cmd, "quote_with_flags") == 0) {
270 if ((cmd = mystrtok(&bp, CHARS_SPACE)) == 0) {
271 msg_warn("missing flags");
272 continue;
273 }
274 while (ISSPACE(*bp))
275 bp++;
276 flags = quote_flags_from_string(cmd);
277 quote_822_local_flags(out, bp, flags);
278 vstream_printf("'%s' quoted flags=%s '%s'\n",
279 bp, quote_flags_to_string((VSTRING *) 0, flags), STR(out));
280 } else if (strcmp(cmd, "unquote") == 0) {
281 unquote_822_local(out, bp);
282 vstream_printf("'%s' unquoted '%s'\n", bp, STR(out));
283 } else {
284 msg_warn("unknown command: %s", cmd);
285 }
286 vstream_fflush(VSTREAM_OUT);
287 }
288 }
289 vstring_free(in);
290 vstring_free(out);
291 return (0);
292 }
293
294 #endif
295