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Diffstat (limited to 'misc/win32/utf8.c')
| -rw-r--r-- | misc/win32/utf8.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/misc/win32/utf8.c b/misc/win32/utf8.c new file mode 100644 index 0000000..280f406 --- /dev/null +++ b/misc/win32/utf8.c @@ -0,0 +1,259 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "apr.h" +#include "apr_private.h" +#include "apr_errno.h" +#include "apr_arch_utf8.h" + +/* Implementation of RFC 3629, "UTF-8, a transformation format of ISO 10646" + * with particular attention to canonical translation forms (see section 10 + * "Security Considerations" of the RFC for more info). + * + * Since several architectures including Windows support unicode, with UCS2 + * used as the actual storage conventions by that archicture, these functions + * exist to transform or validate UCS2 strings into APR's 'char' type + * convention. It is left up to the operating system to determine the + * validitity of the string, e.g. normative forms, in the context of + * its native language support. Other file systems which support filename + * characters of 0x80-0xff but have no explicit requirement for Unicode + * will find this function useful only for validating the character sequences + * and rejecting poorly encoded UTF8 sequences. + * + * Len UCS-4 range (hex) UTF-8 octet sequence (binary) + * 1:2 00000000-0000007F 0xxxxxxx + * 2:2 00000080-000007FF 110XXXXx 10xxxxxx + * 3:2 00000800-0000FFFF 1110XXXX 10Xxxxxx 10xxxxxx + * 4:4 00010000-001FFFFF 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx + * 00200000-03FFFFFF 111110XX 10XXXxxx 10xxxxxx 10xxxxxx 10xxxxxx + * 04000000-7FFFFFFF 1111110X 10XXXXxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx + * + * One of the X bits must be 1 to avoid overlong representation of ucs2 values. + * + * For conversion into ucs2, the 4th form is limited in range to 0010 FFFF, + * and the final two forms are used only by full ucs4, per RFC 3629; + * + * "Pairs of UCS-2 values between D800 and DFFF (surrogate pairs in + * Unicode parlance), being actually UCS-4 characters transformed + * through UTF-16, need special treatment: the UTF-16 transformation + * must be undone, yielding a UCS-4 character that is then transformed + * as above." + * + * From RFC2781 UTF-16: the compressed ISO 10646 encoding bitmask + * + * U' = U - 0x10000 + * U' = 00000000 0000yyyy yyyyyyxx xxxxxxxx + * W1 = 110110yy yyyyyyyy + * W2 = 110111xx xxxxxxxx + * Max U' = 0000 00001111 11111111 11111111 + * Max U = 0000 00010000 11111111 11111111 + * + * Len is the table above is a mapping of bytes used for utf8:ucs2 values, + * which results in these conclusions of maximum allocations; + * + * apr_conv_utf8_to_ucs2 out bytes:sizeof(in) * 1 <= Req <= sizeof(in) * 2 + * apr_conv_ucs2_to_utf8 out words:sizeof(in) / 2 <= Req <= sizeof(in) * 3 / 2 + */ + +APR_DECLARE(apr_status_t) apr_conv_utf8_to_ucs2(const char *in, + apr_size_t *inbytes, + apr_wchar_t *out, + apr_size_t *outwords) +{ + apr_int64_t newch, mask; + apr_size_t expect, eating; + int ch; + + while (*inbytes && *outwords) + { + ch = (unsigned char)(*in++); + if (!(ch & 0200)) { + /* US-ASCII-7 plain text + */ + --*inbytes; + --*outwords; + *(out++) = ch; + } + else + { + if ((ch & 0300) != 0300) { + /* Multibyte Continuation is out of place + */ + return APR_EINVAL; + } + else + { + /* Multibyte Sequence Lead Character + * + * Compute the expected bytes while adjusting + * or lead byte and leading zeros mask. + */ + mask = 0340; + expect = 1; + while ((ch & mask) == mask) { + mask |= mask >> 1; + if (++expect > 3) /* (truly 5 for ucs-4) */ + return APR_EINVAL; + } + newch = ch & ~mask; + eating = expect + 1; + if (*inbytes <= expect) + return APR_INCOMPLETE; + /* Reject values of excessive leading 0 bits + * utf-8 _demands_ the shortest possible byte length + */ + if (expect == 1) { + if (!(newch & 0036)) + return APR_EINVAL; + } + else { + /* Reject values of excessive leading 0 bits + */ + if (!newch && !((unsigned char)*in & 0077 & (mask << 1))) + return APR_EINVAL; + if (expect == 2) { + /* Reject values D800-DFFF when not utf16 encoded + * (may not be an appropriate restriction for ucs-4) + */ + if (newch == 0015 && ((unsigned char)*in & 0040)) + return APR_EINVAL; + } + else if (expect == 3) { + /* Short circuit values > 110000 + */ + if (newch > 4) + return APR_EINVAL; + if (newch == 4 && ((unsigned char)*in & 0060)) + return APR_EINVAL; + } + } + /* Where the boolean (expect > 2) is true, we will need + * an extra word for the output. + */ + if (*outwords < (apr_size_t)(expect > 2) + 1) + break; /* buffer full */ + while (expect--) + { + /* Multibyte Continuation must be legal */ + if (((ch = (unsigned char)*(in++)) & 0300) != 0200) + return APR_EINVAL; + newch <<= 6; + newch |= (ch & 0077); + } + *inbytes -= eating; + /* newch is now a true ucs-4 character + * + * now we need to fold to ucs-2 + */ + if (newch < 0x10000) + { + --*outwords; + *(out++) = (apr_wchar_t) newch; + } + else + { + *outwords -= 2; + newch -= 0x10000; + *(out++) = (apr_wchar_t) (0xD800 | (newch >> 10)); + *(out++) = (apr_wchar_t) (0xDC00 | (newch & 0x03FF)); + } + } + } + } + /* Buffer full 'errors' aren't errors, the client must inspect both + * the inbytes and outwords values + */ + return APR_SUCCESS; +} + +APR_DECLARE(apr_status_t) apr_conv_ucs2_to_utf8(const apr_wchar_t *in, + apr_size_t *inwords, + char *out, + apr_size_t *outbytes) +{ + apr_int64_t newch, require; + apr_size_t need; + char *invout; + int ch; + + while (*inwords && *outbytes) + { + ch = (unsigned short)(*in++); + if (ch < 0x80) + { + --*inwords; + --*outbytes; + *(out++) = (unsigned char) ch; + } + else + { + if ((ch & 0xFC00) == 0xDC00) { + /* Invalid Leading ucs-2 Multiword Continuation Character + */ + return APR_EINVAL; + } + if ((ch & 0xFC00) == 0xD800) { + /* Leading ucs-2 Multiword Character + */ + if (*inwords < 2) { + /* Missing ucs-2 Multiword Continuation Character + */ + return APR_INCOMPLETE; + } + if (((unsigned short)(*in) & 0xFC00) != 0xDC00) { + /* Invalid ucs-2 Multiword Continuation Character + */ + return APR_EINVAL; + } + newch = (ch & 0x03FF) << 10 | ((unsigned short)(*in++) & 0x03FF); + newch += 0x10000; + } + else { + /* ucs-2 Single Word Character + */ + newch = ch; + } + /* Determine the absolute minimum utf-8 bytes required + */ + require = newch >> 11; + need = 1; + while (require) + require >>= 5, ++need; + if (need >= *outbytes) + break; /* Insufficient buffer */ + *inwords -= (need > 2) + 1; + *outbytes -= need + 1; + /* Compute the utf-8 characters in last to first order, + * calculating the lead character length bits along the way. + */ + ch = 0200; + out += need + 1; + invout = out; + while (need--) { + ch |= ch >> 1; + *(--invout) = (unsigned char)(0200 | (newch & 0077)); + newch >>= 6; + } + /* Compute the lead utf-8 character and move the dest offset + */ + *(--invout) = (unsigned char)(ch | newch); + } + } + /* Buffer full 'errors' aren't errors, the client must inspect both + * the inwords and outbytes values + */ + return APR_SUCCESS; +} |