| /************************************************* |
| * 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) 1997-2012 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. */ |
| |
| |
| #include "config.h" |
| |
| #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 |
| |
| 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 |
| PCRE_PUCHAR p; |
| |
| if (length < 0) |
| { |
| for (p = string; *p != 0; p++); |
| length = (int)(p - string); |
| } |
| |
| for (p = string; length-- > 0; p++) |
| { |
| int 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 /* SUPPORT_UTF */ |
| (void)(string); /* Keep picky compilers happy */ |
| (void)(length); |
| #endif |
| |
| return PCRE_UTF8_ERR0; /* This indicates success */ |
| } |
| |
| /* End of pcre_valid_utf8.c */ |