code/trunk/pcre_valid_utf8.c

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
           Copyright (c) 1997-2013 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/


/* This module contains an internal function for validating UTF-8 character
strings. */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pcre_internal.h"


/*************************************************
*         Validate a UTF-8 string                *
*************************************************/

/* This function is called (optionally) at the start of compile or match, to
check that a supposed UTF-8 string is actually valid. The early check means
that subsequent code can assume it is dealing with a valid string. The check
can be turned off for maximum performance, but the consequences of supplying an
invalid string are then undefined.

Originally, this function checked according to RFC 2279, allowing for values in
the range 0 to 0x7fffffff, up to 6 bytes long, but ensuring that they were in
the canonical format. Once somebody had pointed out RFC 3629 to me (it
obsoletes 2279), additional restrictions were applied. The values are now
limited to be between 0 and 0x0010ffff, no more than 4 bytes long, and the
subrange 0xd000 to 0xdfff is excluded. However, the format of 5-byte and 6-byte
characters is still checked.

From release 8.13 more information about the details of the error are passed
back in the returned value:

PCRE_UTF8_ERR0   No error
PCRE_UTF8_ERR1   Missing 1 byte at the end of the string
PCRE_UTF8_ERR2   Missing 2 bytes at the end of the string
PCRE_UTF8_ERR3   Missing 3 bytes at the end of the string
PCRE_UTF8_ERR4   Missing 4 bytes at the end of the string
PCRE_UTF8_ERR5   Missing 5 bytes at the end of the string
PCRE_UTF8_ERR6   2nd-byte's two top bits are not 0x80
PCRE_UTF8_ERR7   3rd-byte's two top bits are not 0x80
PCRE_UTF8_ERR8   4th-byte's two top bits are not 0x80
PCRE_UTF8_ERR9   5th-byte's two top bits are not 0x80
PCRE_UTF8_ERR10  6th-byte's two top bits are not 0x80
PCRE_UTF8_ERR11  5-byte character is not permitted by RFC 3629
PCRE_UTF8_ERR12  6-byte character is not permitted by RFC 3629
PCRE_UTF8_ERR13  4-byte character with value > 0x10ffff is not permitted
PCRE_UTF8_ERR14  3-byte character with value 0xd000-0xdfff is not permitted
PCRE_UTF8_ERR15  Overlong 2-byte sequence
PCRE_UTF8_ERR16  Overlong 3-byte sequence
PCRE_UTF8_ERR17  Overlong 4-byte sequence
PCRE_UTF8_ERR18  Overlong 5-byte sequence (won't ever occur)
PCRE_UTF8_ERR19  Overlong 6-byte sequence (won't ever occur)
PCRE_UTF8_ERR20  Isolated 0x80 byte (not within UTF-8 character)
PCRE_UTF8_ERR21  Byte with the illegal value 0xfe or 0xff
PCRE_UTF8_ERR22  Unused (was non-character)

Arguments:
  string       points to the string
  length       length of string, or -1 if the string is zero-terminated
  errp         pointer to an error position offset variable

Returns:       = 0    if the string is a valid UTF-8 string
               > 0    otherwise, setting the offset of the bad character
*/

int
PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
{
#ifdef SUPPORT_UTF
register PCRE_PUCHAR p;

if (length < 0)
  {
  for (p = string; *p != 0; p++);
  length = (int)(p - string);
  }

for (p = string; length-- > 0; p++)
  {
  register pcre_uchar ab, c, d;

  c = *p;
  if (c < 128) continue;                /* ASCII character */

  if (c < 0xc0)                         /* Isolated 10xx xxxx byte */
    {
    *erroroffset = (int)(p - string);
    return PCRE_UTF8_ERR20;
    }

  if (c >= 0xfe)                        /* Invalid 0xfe or 0xff bytes */
    {
    *erroroffset = (int)(p - string);
    return PCRE_UTF8_ERR21;
    }

  ab = PRIV(utf8_table4)[c & 0x3f];     /* Number of additional bytes */
  if (length < ab)
    {
    *erroroffset = (int)(p - string);          /* Missing bytes */
    return ab - length;                 /* Codes ERR1 to ERR5 */
    }
  length -= ab;                         /* Length remaining */

  /* Check top bits in the second byte */

  if (((d = *(++p)) & 0xc0) != 0x80)
    {
    *erroroffset = (int)(p - string) - 1;
    return PCRE_UTF8_ERR6;
    }

  /* For each length, check that the remaining bytes start with the 0x80 bit
  set and not the 0x40 bit. Then check for an overlong sequence, and for the
  excluded range 0xd800 to 0xdfff. */

  switch (ab)
    {
    /* 2-byte character. No further bytes to check for 0x80. Check first byte
    for for xx00 000x (overlong sequence). */

    case 1: if ((c & 0x3e) == 0)
      {
      *erroroffset = (int)(p - string) - 1;
      return PCRE_UTF8_ERR15;
      }
    break;

    /* 3-byte character. Check third byte for 0x80. Then check first 2 bytes
      for 1110 0000, xx0x xxxx (overlong sequence) or
          1110 1101, 1010 xxxx (0xd800 - 0xdfff) */

    case 2:
    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR7;
      }
    if (c == 0xe0 && (d & 0x20) == 0)
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR16;
      }
    if (c == 0xed && d >= 0xa0)
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR14;
      }
    break;

    /* 4-byte character. Check 3rd and 4th bytes for 0x80. Then check first 2
       bytes for for 1111 0000, xx00 xxxx (overlong sequence), then check for a
       character greater than 0x0010ffff (f4 8f bf bf) */

    case 3:
    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR7;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
      {
      *erroroffset = (int)(p - string) - 3;
      return PCRE_UTF8_ERR8;
      }
    if (c == 0xf0 && (d & 0x30) == 0)
      {
      *erroroffset = (int)(p - string) - 3;
      return PCRE_UTF8_ERR17;
      }
    if (c > 0xf4 || (c == 0xf4 && d > 0x8f))
      {
      *erroroffset = (int)(p - string) - 3;
      return PCRE_UTF8_ERR13;
      }
    break;

    /* 5-byte and 6-byte characters are not allowed by RFC 3629, and will be
    rejected by the length test below. However, we do the appropriate tests
    here so that overlong sequences get diagnosed, and also in case there is
    ever an option for handling these larger code points. */

    /* 5-byte character. Check 3rd, 4th, and 5th bytes for 0x80. Then check for
    1111 1000, xx00 0xxx */

    case 4:
    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR7;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
      {
      *erroroffset = (int)(p - string) - 3;
      return PCRE_UTF8_ERR8;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Fifth byte */
      {
      *erroroffset = (int)(p - string) - 4;
      return PCRE_UTF8_ERR9;
      }
    if (c == 0xf8 && (d & 0x38) == 0)
      {
      *erroroffset = (int)(p - string) - 4;
      return PCRE_UTF8_ERR18;
      }
    break;

    /* 6-byte character. Check 3rd-6th bytes for 0x80. Then check for
    1111 1100, xx00 00xx. */

    case 5:
    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
      {
      *erroroffset = (int)(p - string) - 2;
      return PCRE_UTF8_ERR7;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
      {
      *erroroffset = (int)(p - string) - 3;
      return PCRE_UTF8_ERR8;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Fifth byte */
      {
      *erroroffset = (int)(p - string) - 4;
      return PCRE_UTF8_ERR9;
      }
    if ((*(++p) & 0xc0) != 0x80)     /* Sixth byte */
      {
      *erroroffset = (int)(p - string) - 5;
      return PCRE_UTF8_ERR10;
      }
    if (c == 0xfc && (d & 0x3c) == 0)
      {
      *erroroffset = (int)(p - string) - 5;
      return PCRE_UTF8_ERR19;
      }
    break;
    }

  /* Character is valid under RFC 2279, but 4-byte and 5-byte characters are
  excluded by RFC 3629. The pointer p is currently at the last byte of the
  character. */

  if (ab > 3)
    {
    *erroroffset = (int)(p - string) - ab;
    return (ab == 4)? PCRE_UTF8_ERR11 : PCRE_UTF8_ERR12;
    }
  }

#else  /* Not SUPPORT_UTF */
(void)(string);  /* Keep picky compilers happy */
(void)(length);
(void)(erroroffset);
#endif

return PCRE_UTF8_ERR0;   /* This indicates success */
}

/* End of pcre_valid_utf8.c */
1	/*************************************************
2	* Perl-Compatible Regular Expressions *
3	*************************************************/
4
5	/* PCRE is a library of functions to support regular expressions whose syntax
6	and semantics are as close as possible to those of the Perl 5 language.
7
8	Written by Philip Hazel
9	Copyright (c) 1997-2013 University of Cambridge
10
11	-----------------------------------------------------------------------------
12	Redistribution and use in source and binary forms, with or without
13	modification, are permitted provided that the following conditions are met:
14
15	* Redistributions of source code must retain the above copyright notice,
16	this list of conditions and the following disclaimer.
17
18	* Redistributions in binary form must reproduce the above copyright
19	notice, this list of conditions and the following disclaimer in the
20	documentation and/or other materials provided with the distribution.
21
22	* Neither the name of the University of Cambridge nor the names of its
23	contributors may be used to endorse or promote products derived from
24	this software without specific prior written permission.
25
26	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29	ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36	POSSIBILITY OF SUCH DAMAGE.
37	-----------------------------------------------------------------------------
38	*/
39
40
41	/* This module contains an internal function for validating UTF-8 character
42	strings. */
43
44
45	#ifdef HAVE_CONFIG_H
46	#include "config.h"
47	#endif
48
49	#include "pcre_internal.h"
50
51
52	/*************************************************
53	* Validate a UTF-8 string *
54	*************************************************/
55
56	/* This function is called (optionally) at the start of compile or match, to
57	check that a supposed UTF-8 string is actually valid. The early check means
58	that subsequent code can assume it is dealing with a valid string. The check
59	can be turned off for maximum performance, but the consequences of supplying an
60	invalid string are then undefined.
61
62	Originally, this function checked according to RFC 2279, allowing for values in
63	the range 0 to 0x7fffffff, up to 6 bytes long, but ensuring that they were in
64	the canonical format. Once somebody had pointed out RFC 3629 to me (it
65	obsoletes 2279), additional restrictions were applied. The values are now
66	limited to be between 0 and 0x0010ffff, no more than 4 bytes long, and the
67	subrange 0xd000 to 0xdfff is excluded. However, the format of 5-byte and 6-byte
68	characters is still checked.
69
70	From release 8.13 more information about the details of the error are passed
71	back in the returned value:
72
73	PCRE_UTF8_ERR0 No error
74	PCRE_UTF8_ERR1 Missing 1 byte at the end of the string
75	PCRE_UTF8_ERR2 Missing 2 bytes at the end of the string
76	PCRE_UTF8_ERR3 Missing 3 bytes at the end of the string
77	PCRE_UTF8_ERR4 Missing 4 bytes at the end of the string
78	PCRE_UTF8_ERR5 Missing 5 bytes at the end of the string
79	PCRE_UTF8_ERR6 2nd-byte's two top bits are not 0x80
80	PCRE_UTF8_ERR7 3rd-byte's two top bits are not 0x80
81	PCRE_UTF8_ERR8 4th-byte's two top bits are not 0x80
82	PCRE_UTF8_ERR9 5th-byte's two top bits are not 0x80
83	PCRE_UTF8_ERR10 6th-byte's two top bits are not 0x80
84	PCRE_UTF8_ERR11 5-byte character is not permitted by RFC 3629
85	PCRE_UTF8_ERR12 6-byte character is not permitted by RFC 3629
86	PCRE_UTF8_ERR13 4-byte character with value > 0x10ffff is not permitted
87	PCRE_UTF8_ERR14 3-byte character with value 0xd000-0xdfff is not permitted
88	PCRE_UTF8_ERR15 Overlong 2-byte sequence
89	PCRE_UTF8_ERR16 Overlong 3-byte sequence
90	PCRE_UTF8_ERR17 Overlong 4-byte sequence
91	PCRE_UTF8_ERR18 Overlong 5-byte sequence (won't ever occur)
92	PCRE_UTF8_ERR19 Overlong 6-byte sequence (won't ever occur)
93	PCRE_UTF8_ERR20 Isolated 0x80 byte (not within UTF-8 character)
94	PCRE_UTF8_ERR21 Byte with the illegal value 0xfe or 0xff
95	PCRE_UTF8_ERR22 Unused (was non-character)
96
97	Arguments:
98	string points to the string
99	length length of string, or -1 if the string is zero-terminated
100	errp pointer to an error position offset variable
101
102	Returns: = 0 if the string is a valid UTF-8 string
103	> 0 otherwise, setting the offset of the bad character
104	*/
105
106	int
107	PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
108	{
109	#ifdef SUPPORT_UTF
110	register PCRE_PUCHAR p;
111
112	if (length < 0)
113	{
114	for (p = string; *p != 0; p++);
115	length = (int)(p - string);
116	}
117
118	for (p = string; length-- > 0; p++)
119	{
120	register pcre_uchar ab, c, d;
121
122	c = *p;
123	if (c < 128) continue; /* ASCII character */
124
125	if (c < 0xc0) /* Isolated 10xx xxxx byte */
126	{
127	*erroroffset = (int)(p - string);
128	return PCRE_UTF8_ERR20;
129	}
130
131	if (c >= 0xfe) /* Invalid 0xfe or 0xff bytes */
132	{
133	*erroroffset = (int)(p - string);
134	return PCRE_UTF8_ERR21;
135	}
136
137	ab = PRIV(utf8_table4)[c & 0x3f]; /* Number of additional bytes */
138	if (length < ab)
139	{
140	erroroffset = (int)(p - string); / Missing bytes */
141	return ab - length; /* Codes ERR1 to ERR5 */
142	}
143	length -= ab; /* Length remaining */
144
145	/* Check top bits in the second byte */
146
147	if (((d = *(++p)) & 0xc0) != 0x80)
148	{
149	*erroroffset = (int)(p - string) - 1;
150	return PCRE_UTF8_ERR6;
151	}
152
153	/* For each length, check that the remaining bytes start with the 0x80 bit
154	set and not the 0x40 bit. Then check for an overlong sequence, and for the
155	excluded range 0xd800 to 0xdfff. */
156
157	switch (ab)
158	{
159	/* 2-byte character. No further bytes to check for 0x80. Check first byte
160	for for xx00 000x (overlong sequence). */
161
162	case 1: if ((c & 0x3e) == 0)
163	{
164	*erroroffset = (int)(p - string) - 1;
165	return PCRE_UTF8_ERR15;
166	}
167	break;
168
169	/* 3-byte character. Check third byte for 0x80. Then check first 2 bytes
170	for 1110 0000, xx0x xxxx (overlong sequence) or
171	1110 1101, 1010 xxxx (0xd800 - 0xdfff) */
172
173	case 2:
174	if (((++p) & 0xc0) != 0x80) / Third byte */
175	{
176	*erroroffset = (int)(p - string) - 2;
177	return PCRE_UTF8_ERR7;
178	}
179	if (c == 0xe0 && (d & 0x20) == 0)
180	{
181	*erroroffset = (int)(p - string) - 2;
182	return PCRE_UTF8_ERR16;
183	}
184	if (c == 0xed && d >= 0xa0)
185	{
186	*erroroffset = (int)(p - string) - 2;
187	return PCRE_UTF8_ERR14;
188	}
189	break;
190
191	/* 4-byte character. Check 3rd and 4th bytes for 0x80. Then check first 2
192	bytes for for 1111 0000, xx00 xxxx (overlong sequence), then check for a
193	character greater than 0x0010ffff (f4 8f bf bf) */
194
195	case 3:
196	if (((++p) & 0xc0) != 0x80) / Third byte */
197	{
198	*erroroffset = (int)(p - string) - 2;
199	return PCRE_UTF8_ERR7;
200	}
201	if (((++p) & 0xc0) != 0x80) / Fourth byte */
202	{
203	*erroroffset = (int)(p - string) - 3;
204	return PCRE_UTF8_ERR8;
205	}
206	if (c == 0xf0 && (d & 0x30) == 0)
207	{
208	*erroroffset = (int)(p - string) - 3;
209	return PCRE_UTF8_ERR17;
210	}
211	if (c > 0xf4 \|\| (c == 0xf4 && d > 0x8f))
212	{
213	*erroroffset = (int)(p - string) - 3;
214	return PCRE_UTF8_ERR13;
215	}
216	break;
217
218	/* 5-byte and 6-byte characters are not allowed by RFC 3629, and will be
219	rejected by the length test below. However, we do the appropriate tests
220	here so that overlong sequences get diagnosed, and also in case there is
221	ever an option for handling these larger code points. */
222
223	/* 5-byte character. Check 3rd, 4th, and 5th bytes for 0x80. Then check for
224	1111 1000, xx00 0xxx */
225
226	case 4:
227	if (((++p) & 0xc0) != 0x80) / Third byte */
228	{
229	*erroroffset = (int)(p - string) - 2;
230	return PCRE_UTF8_ERR7;
231	}
232	if (((++p) & 0xc0) != 0x80) / Fourth byte */
233	{
234	*erroroffset = (int)(p - string) - 3;
235	return PCRE_UTF8_ERR8;
236	}
237	if (((++p) & 0xc0) != 0x80) / Fifth byte */
238	{
239	*erroroffset = (int)(p - string) - 4;
240	return PCRE_UTF8_ERR9;
241	}
242	if (c == 0xf8 && (d & 0x38) == 0)
243	{
244	*erroroffset = (int)(p - string) - 4;
245	return PCRE_UTF8_ERR18;
246	}
247	break;
248
249	/* 6-byte character. Check 3rd-6th bytes for 0x80. Then check for
250	1111 1100, xx00 00xx. */
251
252	case 5:
253	if (((++p) & 0xc0) != 0x80) / Third byte */
254	{
255	*erroroffset = (int)(p - string) - 2;
256	return PCRE_UTF8_ERR7;
257	}
258	if (((++p) & 0xc0) != 0x80) / Fourth byte */
259	{
260	*erroroffset = (int)(p - string) - 3;
261	return PCRE_UTF8_ERR8;
262	}
263	if (((++p) & 0xc0) != 0x80) / Fifth byte */
264	{
265	*erroroffset = (int)(p - string) - 4;
266	return PCRE_UTF8_ERR9;
267	}
268	if (((++p) & 0xc0) != 0x80) / Sixth byte */
269	{
270	*erroroffset = (int)(p - string) - 5;
271	return PCRE_UTF8_ERR10;
272	}
273	if (c == 0xfc && (d & 0x3c) == 0)
274	{
275	*erroroffset = (int)(p - string) - 5;
276	return PCRE_UTF8_ERR19;
277	}
278	break;
279	}
280
281	/* Character is valid under RFC 2279, but 4-byte and 5-byte characters are
282	excluded by RFC 3629. The pointer p is currently at the last byte of the
283	character. */
284
285	if (ab > 3)
286	{
287	*erroroffset = (int)(p - string) - ab;
288	return (ab == 4)? PCRE_UTF8_ERR11 : PCRE_UTF8_ERR12;
289	}
290	}
291
292	#else /* Not SUPPORT_UTF */
293	(void)(string); /* Keep picky compilers happy */
294	(void)(length);
295	(void)(erroroffset);
296	#endif
297
298	return PCRE_UTF8_ERR0; /* This indicates success */
299	}
300
301	/* End of pcre_valid_utf8.c */
Name	Value
svn:eol-style	native
svn:keywords	"Author Date Id Revision Url"