/* Conversion module for UTF-7. Copyright (C) 2000-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Bruno Haible <haible@clisp.cons.org>, 2000. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ /* UTF-7 is a legacy encoding used for transmitting Unicode within the ASCII character set, used primarily by mail agents. New programs are encouraged to use UTF-8 instead. UTF-7 is specified in RFC 2152 (and old RFC 1641, RFC 1642). The original Base64 encoding is defined in RFC 2045. */ #include <dlfcn.h> #include <gconv.h> #include <stdint.h> #include <stdlib.h> /* Define this to 1 if you want the so-called "optional direct" characters ! " # $ % & * ; < = > @ [ ] ^ _ ` { | } to be encoded. Define to 0 if you want them to be passed straight through, like the so-called "direct" characters. We set this to 1 because it's safer. */ #define UTF7_ENCODE_OPTIONAL_CHARS 1 /* The set of "direct characters": A-Z a-z 0-9 ' ( ) , - . / : ? space tab lf cr */ static const unsigned char direct_tab[128 / 8] = { 0x00, 0x26, 0x00, 0x00, 0x81, 0xf3, 0xff, 0x87, 0xfe, 0xff, 0xff, 0x07, 0xfe, 0xff, 0xff, 0x07 }; static int isdirect (uint32_t ch) { return (ch < 128 && ((direct_tab[ch >> 3] >> (ch & 7)) & 1)); } /* The set of "direct and optional direct characters": A-Z a-z 0-9 ' ( ) , - . / : ? space tab lf cr ! " # $ % & * ; < = > @ [ ] ^ _ ` { | } */ static const unsigned char xdirect_tab[128 / 8] = { 0x00, 0x26, 0x00, 0x00, 0xff, 0xf7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xef, 0xff, 0xff, 0xff, 0x3f }; static int isxdirect (uint32_t ch) { return (ch < 128 && ((xdirect_tab[ch >> 3] >> (ch & 7)) & 1)); } /* The set of "extended base64 characters": A-Z a-z 0-9 + / - */ static const unsigned char xbase64_tab[128 / 8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0xa8, 0xff, 0x03, 0xfe, 0xff, 0xff, 0x07, 0xfe, 0xff, 0xff, 0x07 }; static int isxbase64 (uint32_t ch) { return (ch < 128 && ((xbase64_tab[ch >> 3] >> (ch & 7)) & 1)); } /* Converts a value in the range 0..63 to a base64 encoded char. */ static unsigned char base64 (unsigned int i) { if (i < 26) return i + 'A'; else if (i < 52) return i - 26 + 'a'; else if (i < 62) return i - 52 + '0'; else if (i == 62) return '+'; else if (i == 63) return '/'; else abort (); } /* Definitions used in the body of the `gconv' function. */ #define CHARSET_NAME "UTF-7//" #define DEFINE_INIT 1 #define DEFINE_FINI 1 #define FROM_LOOP from_utf7_loop #define TO_LOOP to_utf7_loop #define MIN_NEEDED_FROM 1 #define MAX_NEEDED_FROM 6 #define MIN_NEEDED_TO 4 #define MAX_NEEDED_TO 4 #define ONE_DIRECTION 0 #define PREPARE_LOOP \ mbstate_t saved_state; \ mbstate_t *statep = data->__statep; #define EXTRA_LOOP_ARGS , statep /* Since we might have to reset input pointer we must be able to save and restore the state. */ #define SAVE_RESET_STATE(Save) \ if (Save) \ saved_state = *statep; \ else \ *statep = saved_state /* First define the conversion function from UTF-7 to UCS4. The state is structured as follows: __count bit 2..0: zero __count bit 8..3: shift __wch: data Precise meaning: shift data 0 -- not inside base64 encoding 1..32 XX..XX00..00 inside base64, (32 - shift) bits pending This state layout is simpler than relying on STORE_REST/UNPACK_BYTES. When shift = 0, __wch needs to store at most one lookahead byte (see __GCONV_INCOMPLETE_INPUT below). */ #define MIN_NEEDED_INPUT MIN_NEEDED_FROM #define MAX_NEEDED_INPUT MAX_NEEDED_FROM #define MIN_NEEDED_OUTPUT MIN_NEEDED_TO #define MAX_NEEDED_OUTPUT MAX_NEEDED_TO #define LOOPFCT FROM_LOOP #define BODY \ { \ uint_fast8_t ch = *inptr; \ \ if ((statep->__count >> 3) == 0) \ { \ /* base64 encoding inactive. */ \ if (isxdirect (ch)) \ { \ inptr++; \ put32 (outptr, ch); \ outptr += 4; \ } \ else if (__glibc_likely (ch == '+')) \ { \ if (__glibc_unlikely (inptr + 2 > inend)) \ { \ /* Not enough input available. */ \ result = __GCONV_INCOMPLETE_INPUT; \ break; \ } \ if (inptr[1] == '-') \ { \ inptr += 2; \ put32 (outptr, ch); \ outptr += 4; \ } \ else \ { \ /* Switch into base64 mode. */ \ inptr++; \ statep->__count = (32 << 3); \ statep->__value.__wch = 0; \ } \ } \ else \ { \ /* The input is invalid. */ \ STANDARD_FROM_LOOP_ERR_HANDLER (1); \ } \ } \ else \ { \ /* base64 encoding active. */ \ uint32_t i; \ int shift; \ \ if (ch >= 'A' && ch <= 'Z') \ i = ch - 'A'; \ else if (ch >= 'a' && ch <= 'z') \ i = ch - 'a' + 26; \ else if (ch >= '0' && ch <= '9') \ i = ch - '0' + 52; \ else if (ch == '+') \ i = 62; \ else if (ch == '/') \ i = 63; \ else \ { \ /* Terminate base64 encoding. */ \ \ /* If accumulated data is nonzero, the input is invalid. */ \ /* Also, partial UTF-16 characters are invalid. */ \ if (__builtin_expect (statep->__value.__wch != 0, 0) \ || __builtin_expect ((statep->__count >> 3) <= 26, 0)) \ { \ STANDARD_FROM_LOOP_ERR_HANDLER ((statep->__count = 0, 1)); \ } \ \ if (ch == '-') \ inptr++; \ \ statep->__count = 0; \ continue; \ } \ \ /* Concatenate the base64 integer i to the accumulator. */ \ shift = (statep->__count >> 3); \ if (shift > 6) \ { \ uint32_t wch; \ \ shift -= 6; \ wch = statep->__value.__wch | (i << shift); \ \ if (shift <= 16 && shift > 10) \ { \ /* An UTF-16 character has just been completed. */ \ uint32_t wc1 = wch >> 16; \ \ /* UTF-16: When we see a High Surrogate, we must also decode \ the following Low Surrogate. */ \ if (!(wc1 >= 0xd800 && wc1 < 0xdc00)) \ { \ wch = wch << 16; \ shift += 16; \ put32 (outptr, wc1); \ outptr += 4; \ } \ } \ else if (shift <= 10 && shift > 4) \ { \ /* After a High Surrogate, verify that the next 16 bit \ indeed form a Low Surrogate. */ \ uint32_t wc2 = wch & 0xffff; \ \ if (! __builtin_expect (wc2 >= 0xdc00 && wc2 < 0xe000, 1)) \ { \ STANDARD_FROM_LOOP_ERR_HANDLER ((statep->__count = 0, 1));\ } \ } \ \ statep->__value.__wch = wch; \ } \ else \ { \ /* An UTF-16 surrogate pair has just been completed. */ \ uint32_t wc1 = (uint32_t) statep->__value.__wch >> 16; \ uint32_t wc2 = ((uint32_t) statep->__value.__wch & 0xffff) \ | (i >> (6 - shift)); \ \ statep->__value.__wch = (i << shift) << 26; \ shift += 26; \ \ assert (wc1 >= 0xd800 && wc1 < 0xdc00); \ assert (wc2 >= 0xdc00 && wc2 < 0xe000); \ put32 (outptr, \ 0x10000 + ((wc1 - 0xd800) << 10) + (wc2 - 0xdc00)); \ outptr += 4; \ } \ \ statep->__count = shift << 3; \ \ /* Now that we digested the input increment the input pointer. */ \ inptr++; \ } \ } #define LOOP_NEED_FLAGS #define EXTRA_LOOP_DECLS , mbstate_t *statep #include <iconv/loop.c> /* Next, define the conversion from UCS4 to UTF-7. The state is structured as follows: __count bit 2..0: zero __count bit 4..3: shift __count bit 8..5: data Precise meaning: shift data 0 0 not inside base64 encoding 1 0 inside base64, no pending bits 2 XX00 inside base64, 2 bits known for next byte 3 XXXX inside base64, 4 bits known for next byte __count bit 2..0 and __wch are always zero, because this direction never returns __GCONV_INCOMPLETE_INPUT. */ #define MIN_NEEDED_INPUT MIN_NEEDED_TO #define MAX_NEEDED_INPUT MAX_NEEDED_TO #define MIN_NEEDED_OUTPUT MIN_NEEDED_FROM #define MAX_NEEDED_OUTPUT MAX_NEEDED_FROM #define LOOPFCT TO_LOOP #define BODY \ { \ uint32_t ch = get32 (inptr); \ \ if ((statep->__count & 0x18) == 0) \ { \ /* base64 encoding inactive */ \ if (UTF7_ENCODE_OPTIONAL_CHARS ? isdirect (ch) : isxdirect (ch)) \ { \ *outptr++ = (unsigned char) ch; \ } \ else \ { \ size_t count; \ \ if (ch == '+') \ count = 2; \ else if (ch < 0x10000) \ count = 3; \ else if (ch < 0x110000) \ count = 6; \ else \ STANDARD_TO_LOOP_ERR_HANDLER (4); \ \ if (__glibc_unlikely (outptr + count > outend)) \ { \ result = __GCONV_FULL_OUTPUT; \ break; \ } \ \ *outptr++ = '+'; \ if (ch == '+') \ *outptr++ = '-'; \ else if (ch < 0x10000) \ { \ *outptr++ = base64 (ch >> 10); \ *outptr++ = base64 ((ch >> 4) & 0x3f); \ statep->__count = ((ch & 15) << 5) | (3 << 3); \ } \ else if (ch < 0x110000) \ { \ uint32_t ch1 = 0xd800 + ((ch - 0x10000) >> 10); \ uint32_t ch2 = 0xdc00 + ((ch - 0x10000) & 0x3ff); \ \ ch = (ch1 << 16) | ch2; \ *outptr++ = base64 (ch >> 26); \ *outptr++ = base64 ((ch >> 20) & 0x3f); \ *outptr++ = base64 ((ch >> 14) & 0x3f); \ *outptr++ = base64 ((ch >> 8) & 0x3f); \ *outptr++ = base64 ((ch >> 2) & 0x3f); \ statep->__count = ((ch & 3) << 7) | (2 << 3); \ } \ else \ abort (); \ } \ } \ else \ { \ /* base64 encoding active */ \ if (UTF7_ENCODE_OPTIONAL_CHARS ? isdirect (ch) : isxdirect (ch)) \ { \ /* deactivate base64 encoding */ \ size_t count; \ \ count = ((statep->__count & 0x18) >= 0x10) + isxbase64 (ch) + 1; \ if (__glibc_unlikely (outptr + count > outend)) \ { \ result = __GCONV_FULL_OUTPUT; \ break; \ } \ \ if ((statep->__count & 0x18) >= 0x10) \ *outptr++ = base64 ((statep->__count >> 3) & ~3); \ if (isxbase64 (ch)) \ *outptr++ = '-'; \ *outptr++ = (unsigned char) ch; \ statep->__count = 0; \ } \ else \ { \ size_t count; \ \ if (ch < 0x10000) \ count = ((statep->__count & 0x18) >= 0x10 ? 3 : 2); \ else if (ch < 0x110000) \ count = ((statep->__count & 0x18) >= 0x18 ? 6 : 5); \ else \ STANDARD_TO_LOOP_ERR_HANDLER (4); \ \ if (__glibc_unlikely (outptr + count > outend)) \ { \ result = __GCONV_FULL_OUTPUT; \ break; \ } \ \ if (ch < 0x10000) \ { \ switch ((statep->__count >> 3) & 3) \ { \ case 1: \ *outptr++ = base64 (ch >> 10); \ *outptr++ = base64 ((ch >> 4) & 0x3f); \ statep->__count = ((ch & 15) << 5) | (3 << 3); \ break; \ case 2: \ *outptr++ = \ base64 (((statep->__count >> 3) & ~3) | (ch >> 12)); \ *outptr++ = base64 ((ch >> 6) & 0x3f); \ *outptr++ = base64 (ch & 0x3f); \ statep->__count = (1 << 3); \ break; \ case 3: \ *outptr++ = \ base64 (((statep->__count >> 3) & ~3) | (ch >> 14)); \ *outptr++ = base64 ((ch >> 8) & 0x3f); \ *outptr++ = base64 ((ch >> 2) & 0x3f); \ statep->__count = ((ch & 3) << 7) | (2 << 3); \ break; \ default: \ abort (); \ } \ } \ else if (ch < 0x110000) \ { \ uint32_t ch1 = 0xd800 + ((ch - 0x10000) >> 10); \ uint32_t ch2 = 0xdc00 + ((ch - 0x10000) & 0x3ff); \ \ ch = (ch1 << 16) | ch2; \ switch ((statep->__count >> 3) & 3) \ { \ case 1: \ *outptr++ = base64 (ch >> 26); \ *outptr++ = base64 ((ch >> 20) & 0x3f); \ *outptr++ = base64 ((ch >> 14) & 0x3f); \ *outptr++ = base64 ((ch >> 8) & 0x3f); \ *outptr++ = base64 ((ch >> 2) & 0x3f); \ statep->__count = ((ch & 3) << 7) | (2 << 3); \ break; \ case 2: \ *outptr++ = \ base64 (((statep->__count >> 3) & ~3) | (ch >> 28)); \ *outptr++ = base64 ((ch >> 22) & 0x3f); \ *outptr++ = base64 ((ch >> 16) & 0x3f); \ *outptr++ = base64 ((ch >> 10) & 0x3f); \ *outptr++ = base64 ((ch >> 4) & 0x3f); \ statep->__count = ((ch & 15) << 5) | (3 << 3); \ break; \ case 3: \ *outptr++ = \ base64 (((statep->__count >> 3) & ~3) | (ch >> 30)); \ *outptr++ = base64 ((ch >> 24) & 0x3f); \ *outptr++ = base64 ((ch >> 18) & 0x3f); \ *outptr++ = base64 ((ch >> 12) & 0x3f); \ *outptr++ = base64 ((ch >> 6) & 0x3f); \ *outptr++ = base64 (ch & 0x3f); \ statep->__count = (1 << 3); \ break; \ default: \ abort (); \ } \ } \ else \ abort (); \ } \ } \ \ /* Now that we wrote the output increment the input pointer. */ \ inptr += 4; \ } #define LOOP_NEED_FLAGS #define EXTRA_LOOP_DECLS , mbstate_t *statep #include <iconv/loop.c> /* Since this is a stateful encoding we have to provide code which resets the output state to the initial state. This has to be done during the flushing. */ #define EMIT_SHIFT_TO_INIT \ if (FROM_DIRECTION) \ /* Nothing to emit. */ \ memset (data->__statep, '\0', sizeof (mbstate_t)); \ else \ { \ /* The "to UTF-7" direction. Flush the remaining bits and terminate \ with a '-' byte. This will guarantee correct decoding if more \ UTF-7 encoded text is added afterwards. */ \ int state = data->__statep->__count; \ \ if (state & 0x18) \ { \ /* Deactivate base64 encoding. */ \ size_t count = ((state & 0x18) >= 0x10) + 1; \ \ if (__glibc_unlikely (outbuf + count > outend)) \ /* We don't have enough room in the output buffer. */ \ status = __GCONV_FULL_OUTPUT; \ else \ { \ /* Write out the shift sequence. */ \ if ((state & 0x18) >= 0x10) \ *outbuf++ = base64 ((state >> 3) & ~3); \ *outbuf++ = '-'; \ \ data->__statep->__count = 0; \ } \ } \ else \ data->__statep->__count = 0; \ } /* Now define the toplevel functions. */ #include <iconv/skeleton.c>