--- /dev/null
+/*************************************************
+* 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
+ Original API code Copyright (c) 1997-2012 University of Cambridge
+ New API code Copyright (c) 2016-2017 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 character
+strings. This file is also #included by the pcre2test program, which uses
+macros to change names from _pcre2_xxx to xxxx, thereby avoiding name clashes
+with the library. In this case, PCRE2_PCRE2TEST is defined. */
+
+#ifndef PCRE2_PCRE2TEST /* We're compiling the library */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "pcre2_internal.h"
+#endif /* PCRE2_PCRE2TEST */
+
+
+#ifndef SUPPORT_UNICODE
+/*************************************************
+* Dummy function when Unicode is not supported *
+*************************************************/
+
+/* This function should never be called when Unicode is not supported. */
+
+int
+PRIV(valid_utf)(PCRE2_SPTR string, PCRE2_SIZE length, PCRE2_SIZE *erroroffset)
+{
+(void)string;
+(void)length;
+(void)erroroffset;
+return 0;
+}
+#else /* UTF is supported */
+
+
+
+/*************************************************
+* Validate a UTF string *
+*************************************************/
+
+/* This function is called (optionally) at the start of compile or match, to
+check that a supposed UTF 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.
+
+Arguments:
+ string points to the string
+ length length of string
+ errp pointer to an error position offset variable
+
+Returns: == 0 if the string is a valid UTF string
+ != 0 otherwise, setting the offset of the bad character
+*/
+
+int
+PRIV(valid_utf)(PCRE2_SPTR string, PCRE2_SIZE length, PCRE2_SIZE *erroroffset)
+{
+PCRE2_SPTR p;
+uint32_t c;
+
+/* ----------------- Check a UTF-8 string ----------------- */
+
+#if PCRE2_CODE_UNIT_WIDTH == 8
+
+/* 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. Error returns are as follows:
+
+PCRE2_ERROR_UTF8_ERR1 Missing 1 byte at the end of the string
+PCRE2_ERROR_UTF8_ERR2 Missing 2 bytes at the end of the string
+PCRE2_ERROR_UTF8_ERR3 Missing 3 bytes at the end of the string
+PCRE2_ERROR_UTF8_ERR4 Missing 4 bytes at the end of the string
+PCRE2_ERROR_UTF8_ERR5 Missing 5 bytes at the end of the string
+PCRE2_ERROR_UTF8_ERR6 2nd-byte's two top bits are not 0x80
+PCRE2_ERROR_UTF8_ERR7 3rd-byte's two top bits are not 0x80
+PCRE2_ERROR_UTF8_ERR8 4th-byte's two top bits are not 0x80
+PCRE2_ERROR_UTF8_ERR9 5th-byte's two top bits are not 0x80
+PCRE2_ERROR_UTF8_ERR10 6th-byte's two top bits are not 0x80
+PCRE2_ERROR_UTF8_ERR11 5-byte character is not permitted by RFC 3629
+PCRE2_ERROR_UTF8_ERR12 6-byte character is not permitted by RFC 3629
+PCRE2_ERROR_UTF8_ERR13 4-byte character with value > 0x10ffff is not permitted
+PCRE2_ERROR_UTF8_ERR14 3-byte character with value 0xd800-0xdfff is not permitted
+PCRE2_ERROR_UTF8_ERR15 Overlong 2-byte sequence
+PCRE2_ERROR_UTF8_ERR16 Overlong 3-byte sequence
+PCRE2_ERROR_UTF8_ERR17 Overlong 4-byte sequence
+PCRE2_ERROR_UTF8_ERR18 Overlong 5-byte sequence (won't ever occur)
+PCRE2_ERROR_UTF8_ERR19 Overlong 6-byte sequence (won't ever occur)
+PCRE2_ERROR_UTF8_ERR20 Isolated 0x80 byte (not within UTF-8 character)
+PCRE2_ERROR_UTF8_ERR21 Byte with the illegal value 0xfe or 0xff
+*/
+
+for (p = string; length > 0; p++)
+ {
+ uint32_t ab, d;
+
+ c = *p;
+ length--;
+
+ if (c < 128) continue; /* ASCII character */
+
+ if (c < 0xc0) /* Isolated 10xx xxxx byte */
+ {
+ *erroroffset = (PCRE2_SIZE)(p - string);
+ return PCRE2_ERROR_UTF8_ERR20;
+ }
+
+ if (c >= 0xfe) /* Invalid 0xfe or 0xff bytes */
+ {
+ *erroroffset = (PCRE2_SIZE)(p - string);
+ return PCRE2_ERROR_UTF8_ERR21;
+ }
+
+ ab = PRIV(utf8_table4)[c & 0x3f]; /* Number of additional bytes (1-5) */
+ if (length < ab) /* Missing bytes */
+ {
+ *erroroffset = (PCRE2_SIZE)(p - string);
+ switch(ab - length)
+ {
+ case 1: return PCRE2_ERROR_UTF8_ERR1;
+ case 2: return PCRE2_ERROR_UTF8_ERR2;
+ case 3: return PCRE2_ERROR_UTF8_ERR3;
+ case 4: return PCRE2_ERROR_UTF8_ERR4;
+ case 5: return PCRE2_ERROR_UTF8_ERR5;
+ }
+ }
+ length -= ab; /* Length remaining */
+
+ /* Check top bits in the second byte */
+
+ if (((d = *(++p)) & 0xc0) != 0x80)
+ {
+ *erroroffset = (int)(p - string) - 1;
+ return PCRE2_ERROR_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 PCRE2_ERROR_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 PCRE2_ERROR_UTF8_ERR7;
+ }
+ if (c == 0xe0 && (d & 0x20) == 0)
+ {
+ *erroroffset = (int)(p - string) - 2;
+ return PCRE2_ERROR_UTF8_ERR16;
+ }
+ if (c == 0xed && d >= 0xa0)
+ {
+ *erroroffset = (int)(p - string) - 2;
+ return PCRE2_ERROR_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 PCRE2_ERROR_UTF8_ERR7;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Fourth byte */
+ {
+ *erroroffset = (int)(p - string) - 3;
+ return PCRE2_ERROR_UTF8_ERR8;
+ }
+ if (c == 0xf0 && (d & 0x30) == 0)
+ {
+ *erroroffset = (int)(p - string) - 3;
+ return PCRE2_ERROR_UTF8_ERR17;
+ }
+ if (c > 0xf4 || (c == 0xf4 && d > 0x8f))
+ {
+ *erroroffset = (int)(p - string) - 3;
+ return PCRE2_ERROR_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 PCRE2_ERROR_UTF8_ERR7;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Fourth byte */
+ {
+ *erroroffset = (int)(p - string) - 3;
+ return PCRE2_ERROR_UTF8_ERR8;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Fifth byte */
+ {
+ *erroroffset = (int)(p - string) - 4;
+ return PCRE2_ERROR_UTF8_ERR9;
+ }
+ if (c == 0xf8 && (d & 0x38) == 0)
+ {
+ *erroroffset = (int)(p - string) - 4;
+ return PCRE2_ERROR_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 PCRE2_ERROR_UTF8_ERR7;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Fourth byte */
+ {
+ *erroroffset = (int)(p - string) - 3;
+ return PCRE2_ERROR_UTF8_ERR8;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Fifth byte */
+ {
+ *erroroffset = (int)(p - string) - 4;
+ return PCRE2_ERROR_UTF8_ERR9;
+ }
+ if ((*(++p) & 0xc0) != 0x80) /* Sixth byte */
+ {
+ *erroroffset = (int)(p - string) - 5;
+ return PCRE2_ERROR_UTF8_ERR10;
+ }
+ if (c == 0xfc && (d & 0x3c) == 0)
+ {
+ *erroroffset = (int)(p - string) - 5;
+ return PCRE2_ERROR_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)? PCRE2_ERROR_UTF8_ERR11 : PCRE2_ERROR_UTF8_ERR12;
+ }
+ }
+return 0;
+
+
+/* ----------------- Check a UTF-16 string ----------------- */
+
+#elif PCRE2_CODE_UNIT_WIDTH == 16
+
+/* There's not so much work, nor so many errors, for UTF-16.
+PCRE2_ERROR_UTF16_ERR1 Missing low surrogate at the end of the string
+PCRE2_ERROR_UTF16_ERR2 Invalid low surrogate
+PCRE2_ERROR_UTF16_ERR3 Isolated low surrogate
+*/
+
+for (p = string; length > 0; p++)
+ {
+ c = *p;
+ length--;
+
+ if ((c & 0xf800) != 0xd800)
+ {
+ /* Normal UTF-16 code point. Neither high nor low surrogate. */
+ }
+ else if ((c & 0x0400) == 0)
+ {
+ /* High surrogate. Must be a followed by a low surrogate. */
+ if (length == 0)
+ {
+ *erroroffset = p - string;
+ return PCRE2_ERROR_UTF16_ERR1;
+ }
+ p++;
+ length--;
+ if ((*p & 0xfc00) != 0xdc00)
+ {
+ *erroroffset = p - string;
+ return PCRE2_ERROR_UTF16_ERR2;
+ }
+ }
+ else
+ {
+ /* Isolated low surrogate. Always an error. */
+ *erroroffset = p - string;
+ return PCRE2_ERROR_UTF16_ERR3;
+ }
+ }
+return 0;
+
+
+
+/* ----------------- Check a UTF-32 string ----------------- */
+
+#else
+
+/* There is very little to do for a UTF-32 string.
+PCRE2_ERROR_UTF32_ERR1 Surrogate character
+PCRE2_ERROR_UTF32_ERR2 Character > 0x10ffff
+*/
+
+for (p = string; length > 0; length--, p++)
+ {
+ c = *p;
+ if ((c & 0xfffff800u) != 0xd800u)
+ {
+ /* Normal UTF-32 code point. Neither high nor low surrogate. */
+ if (c > 0x10ffffu)
+ {
+ *erroroffset = p - string;
+ return PCRE2_ERROR_UTF32_ERR2;
+ }
+ }
+ else
+ {
+ /* A surrogate */
+ *erroroffset = p - string;
+ return PCRE2_ERROR_UTF32_ERR1;
+ }
+ }
+return 0;
+#endif /* CODE_UNIT_WIDTH */
+}
+#endif /* SUPPORT_UNICODE */
+
+/* End of pcre2_valid_utf.c */
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