// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
* Copyright (C) 2002-2016, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* file name: ucnv_u7.c
* encoding: UTF-8
* tab size: 8 (not used)
* indentation:4
*
* created on: 2002jul01
* created by: Markus W. Scherer
*
* UTF-7 converter implementation. Used to be in ucnv_utf.c.
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_CONVERSION && !UCONFIG_ONLY_HTML_CONVERSION
#include "cmemory.h"
#include "unicode/ucnv.h"
#include "ucnv_bld.h"
#include "ucnv_cnv.h"
#include "uassert.h"
/* UTF-7 -------------------------------------------------------------------- */
/*
* UTF-7 is a stateful encoding of Unicode.
* It is defined in RFC 2152. (http://www.ietf.org/rfc/rfc2152.txt)
* It was intended for use in Internet email systems, using in its bytewise
* encoding only a subset of 7-bit US-ASCII.
* UTF-7 is deprecated in favor of UTF-8/16/32 and SCSU, but still
* occasionally used.
*
* For converting Unicode to UTF-7, the RFC allows to encode some US-ASCII
* characters directly or in base64. Especially, the characters in set O
* as defined in the RFC (see below) may be encoded directly but are not
* allowed in, e.g., email headers.
* By default, the ICU UTF-7 converter encodes set O directly.
* By choosing the option "version=1", set O will be escaped instead.
* For example:
* utf7Converter=ucnv_open("UTF-7,version=1");
*
* For details about email headers see RFC 2047.
*/
/*
* Tests for US-ASCII characters belonging to character classes
* defined in UTF-7.
*
* Set D (directly encoded characters) consists of the following
* characters: the upper and lower case letters A through Z
* and a through z, the 10 digits 0-9, and the following nine special
* characters (note that "+" and "=" are omitted):
* '(),-./:?
*
* Set O (optional direct characters) consists of the following
* characters (note that "\" and "~" are omitted):
* !"#$%&*;<=>@[]^_`{|}
*
* According to the rules in RFC 2152, the byte values for the following
* US-ASCII characters are not used in UTF-7 and are therefore illegal:
* - all C0 control codes except for CR LF TAB
* - BACKSLASH
* - TILDE
* - DEL
* - all codes beyond US-ASCII, i.e. all >127
*/
#define inSetD(c) \
((uint8_t)((c)-97)<26 || (uint8_t)((c)-65)<26 ||
/* letters */ \
(uint8_t)((c)-48)<10 ||
/* digits */ \
(uint8_t)((c)-39)<3 ||
/* '() */ \
(uint8_t)((c)-44)<4 ||
/* ,-./ */ \
(c)==58 || (c)==63
/* :? */ \
)
#define inSetO(c) \
((uint8_t)((c)-33)<6 ||
/* !"#$%& */ \
(uint8_t)((c)-59)<4 ||
/* ;<=> */ \
(uint8_t)((c)-93)<4 ||
/* ]^_` */ \
(uint8_t)((c)-123)<3 ||
/* {|} */ \
(c)==42 || (c)==64 || (c)==91
/* *@[ */ \
)
#define isCRLFTAB(c) ((c)==13 || (c)==10 || (c)==9)
#define isCRLFSPTAB(c) ((c)==32 || (c)==13 || (c)==10 || (c)==9)
#define PLUS 43
#define MINUS 45
#define BACKSLASH 92
#define TILDE 126
/* legal byte values: all US-ASCII graphic characters from space to before tilde, and CR LF TAB */
#define isLegalUTF7(c) (((uint8_t)((c)-32)<94 && (c)!=BACKSLASH) || isCRLFTAB(c))
/* encode directly sets D and O and CR LF SP TAB */
static const UBool encodeDirectlyMaximum[128]={
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0
};
/* encode directly set D and CR LF SP TAB but not set O */
static const UBool encodeDirectlyRestricted[128]={
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0
};
static const uint8_t
toBase64[64]={
/* A-Z */
65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77,
78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
/* a-z */
97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,
110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
/* 0-9 */
48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
/* +/ */
43, 47
};
static const int8_t
fromBase64[128]={
/* C0 controls, -1 for legal ones (CR LF TAB), -3 for illegal ones */
-3, -3, -3, -3, -3, -3, -3, -3, -3, -1, -1, -3, -3, -1, -3, -3,
-3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
/* general punctuation with + and / and a special value (-2) for - */
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -2, -1, 63,
/* digits */
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
/* A-Z */
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -3, -1, -1, -1,
/* a-z */
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -3, -3
};
/*
* converter status values:
*
* toUnicodeStatus:
* 24 inDirectMode (boolean)
* 23..16 base64Counter (-1..7)
* 15..0 bits (up to 14 bits incoming base64)
*
* fromUnicodeStatus:
* 31..28 version (0: set O direct 1: set O escaped)
* 24 inDirectMode (boolean)
* 23..16 base64Counter (0..2)
* 7..0 bits (6 bits outgoing base64)
*
*/
U_CDECL_BEGIN
static void U_CALLCONV
_UTF7Reset(UConverter *cnv, UConverterResetChoice choice) {
if(choice<=UCNV_RESET_TO_UNICODE) {
/* reset toUnicode */
cnv->toUnicodeStatus=0x1000000;
/* inDirectMode=true */
cnv->toULength=0;
}
if(choice!=UCNV_RESET_TO_UNICODE) {
/* reset fromUnicode */
cnv->fromUnicodeStatus=(cnv->fromUnicodeStatus&0xf0000000)|0x1000000;
/* keep version, inDirectMode=true */
}
}
static void U_CALLCONV
_UTF7Open(UConverter *cnv,
UConverterLoadArgs *pArgs,
UErrorCode *pErrorCode) {
(
void)pArgs;
if(UCNV_GET_VERSION(cnv)<=1) {
/* TODO(markus): Should just use cnv->options rather than copying the version number. */
cnv->fromUnicodeStatus=UCNV_GET_VERSION(cnv)<<28;
_UTF7Reset(cnv, UCNV_RESET_BOTH);
}
else {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
}
}
static void U_CALLCONV
_UTF7ToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
const uint8_t *source, *sourceLimit;
char16_t *target;
const char16_t *targetLimit;
int32_t *offsets;
uint8_t *bytes;
uint8_t byteIndex;
int32_t length, targetCapacity;
/* UTF-7 state */
uint16_t bits;
int8_t base64Counter;
UBool inDirectMode;
int8_t base64Value;
int32_t sourceIndex, nextSourceIndex;
uint8_t b;
/* set up the local pointers */
cnv=pArgs->converter;
source=(
const uint8_t *)pArgs->source;
sourceLimit=(
const uint8_t *)pArgs->sourceLimit;
target=pArgs->target;
targetLimit=pArgs->targetLimit;
offsets=pArgs->offsets;
/* get the state machine state */
{
uint32_t status=cnv->toUnicodeStatus;
inDirectMode=(UBool)((status>>24)&1);
base64Counter=(int8_t)(status>>16);
bits=(uint16_t)status;
}
bytes=cnv->toUBytes;
byteIndex=cnv->toULength;
/* sourceIndex=-1 if the current character began in the previous buffer */
sourceIndex=byteIndex==0 ? 0 : -1;
nextSourceIndex=0;
if(inDirectMode) {
directMode:
/*
* In Direct Mode, most US-ASCII characters are encoded directly, i.e.,
* with their US-ASCII byte values.
* Backslash and Tilde and most control characters are not allowed in UTF-7.
* A plus sign starts Unicode (or "escape") Mode.
*
* In Direct Mode, only the sourceIndex is used.
*/
byteIndex=0;
length=(int32_t)(sourceLimit-source);
targetCapacity=(int32_t)(targetLimit-target);
if(length>targetCapacity) {
length=targetCapacity;
}
while(length>0) {
b=*source++;
if(!isLegalUTF7(b)) {
/* illegal */
bytes[0]=b;
byteIndex=1;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
else if(b!=PLUS) {
/* write directly encoded character */
*target++=b;
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
}
else /* PLUS */ {
/* switch to Unicode mode */
nextSourceIndex=++sourceIndex;
inDirectMode=
false;
byteIndex=0;
bits=0;
base64Counter=-1;
goto unicodeMode;
}
--length;
}
if(source<sourceLimit && target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
}
else {
unicodeMode:
/*
* In Unicode (or "escape") Mode, UTF-16BE is base64-encoded.
* The base64 sequence ends with any character that is not in the base64 alphabet.
* A terminating minus sign is consumed.
*
* In Unicode Mode, the sourceIndex has the index to the start of the current
* base64 bytes, while nextSourceIndex is precisely parallel to source,
* keeping the index to the following byte.
* Note that in 2 out of 3 cases, UChars overlap within a base64 byte.
*/
while(source<sourceLimit) {
if(target<targetLimit) {
bytes[byteIndex++]=b=*source++;
++nextSourceIndex;
base64Value = -3;
/* initialize as illegal */
if(b>=126 || (base64Value=fromBase64[b])==-3 || base64Value==-1) {
/* either
* base64Value==-1 for any legal character except base64 and minus sign, or
* base64Value==-3 for illegal characters:
* 1. In either case, leave Unicode mode.
* 2.1. If we ended with an incomplete char16_t or none after the +, then
* generate an error for the preceding erroneous sequence and deal with
* the current (possibly illegal) character next time through.
* 2.2. Else the current char comes after a complete char16_t, which was already
* pushed to the output buf, so:
* 2.2.1. If the current char is legal, just save it for processing next time.
* It may be for example, a plus which we need to deal with in direct mode.
* 2.2.2. Else if the current char is illegal, we might as well deal with it here.
*/
inDirectMode=
true;
if(base64Counter==-1) {
/* illegal: + immediately followed by something other than base64 or minus sign */
/* include the plus sign in the reported sequence, but not the subsequent char */
--source;
bytes[0]=PLUS;
byteIndex=1;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
else if(bits!=0) {
/* bits are illegally left over, a char16_t is incomplete */
/* don't include current char (legal or illegal) in error seq */
--source;
--byteIndex;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
else {
/* previous char16_t was complete */
if(base64Value==-3) {
/* current character is illegal, deal with it here */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
else {
/* un-read the current character in case it is a plus sign */
--source;
sourceIndex=nextSourceIndex-1;
goto directMode;
}
}
}
else if(base64Value>=0) {
/* collect base64 bytes into UChars */
switch(base64Counter) {
case -1:
/* -1 is immediately after the + */
case 0:
bits=base64Value;
base64Counter=1;
break;
case 1:
case 3:
case 4:
case 6:
bits=(uint16_t)((bits<<6)|base64Value);
++base64Counter;
break;
case 2:
*target++=(char16_t)((bits<<4)|(base64Value>>2));
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex-1;
}
bytes[0]=b;
/* keep this byte in case an error occurs */
byteIndex=1;
bits=(uint16_t)(base64Value&3);
base64Counter=3;
break;
case 5:
*target++=(char16_t)((bits<<2)|(base64Value>>4));
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex-1;
}
bytes[0]=b;
/* keep this byte in case an error occurs */
byteIndex=1;
bits=(uint16_t)(base64Value&15);
base64Counter=6;
break;
case 7:
*target++=(char16_t)((bits<<6)|base64Value);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex;
}
byteIndex=0;
bits=0;
base64Counter=0;
break;
default:
/* will never occur */
break;
}
}
else /*base64Value==-2*/ {
/* minus sign terminates the base64 sequence */
inDirectMode=
true;
if(base64Counter==-1) {
/* +- i.e. a minus immediately following a plus */
*target++=PLUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
}
else {
/* absorb the minus and leave the Unicode Mode */
if(bits!=0) {
/* bits are illegally left over, a char16_t is incomplete */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
}
sourceIndex=nextSourceIndex;
goto directMode;
}
}
else {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
}
}
if(U_SUCCESS(*pErrorCode) && pArgs->flush && source==sourceLimit && bits==0) {
/*
* if we are in Unicode mode, then the byteIndex might not be 0,
* but that is ok if bits==0
* -> we set byteIndex=0 at the end of the stream to avoid a truncated error
* (not true for IMAP-mailbox-name where we must end in direct mode)
*/
byteIndex=0;
}
/* set the converter state back into UConverter */
cnv->toUnicodeStatus=((uint32_t)inDirectMode<<24)|((uint32_t)((uint8_t)base64Counte
r)<<16)|(uint32_t)bits;
cnv->toULength=byteIndex;
/* write back the updated pointers */
pArgs->source=(const char *)source;
pArgs->target=target;
pArgs->offsets=offsets;
}
static void U_CALLCONV
_UTF7FromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
const char16_t *source, *sourceLimit;
uint8_t *target, *targetLimit;
int32_t *offsets;
int32_t length, targetCapacity, sourceIndex;
char16_t c;
/* UTF-7 state */
const UBool *encodeDirectly;
uint8_t bits;
int8_t base64Counter;
UBool inDirectMode;
/* set up the local pointers */
cnv=pArgs->converter;
/* set up the local pointers */
source=pArgs->source;
sourceLimit=pArgs->sourceLimit;
target=(uint8_t *)pArgs->target;
targetLimit=(uint8_t *)pArgs->targetLimit;
offsets=pArgs->offsets;
/* get the state machine state */
{
uint32_t status=cnv->fromUnicodeStatus;
encodeDirectly= status<0x10000000 ? encodeDirectlyMaximum : encodeDirectlyRestricted;
inDirectMode=(UBool)((status>>24)&1);
base64Counter=(int8_t)(status>>16);
bits=(uint8_t)status;
U_ASSERT(bits<=UPRV_LENGTHOF(toBase64));
}
/* UTF-7 always encodes UTF-16 code units, therefore we need only a simple sourceIndex */
sourceIndex=0;
if(inDirectMode) {
directMode:
length=(int32_t)(sourceLimit-source);
targetCapacity=(int32_t)(targetLimit-target);
if(length>targetCapacity) {
length=targetCapacity;
}
while(length>0) {
c=*source++;
/* currently always encode CR LF SP TAB directly */
if(c<=127 && encodeDirectly[c]) {
/* encode directly */
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
} else if(c==PLUS) {
/* output +- for + */
*target++=PLUS;
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
/* realign length and targetCapacity */
goto directMode;
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=MINUS;
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
} else {
/* un-read this character and switch to Unicode Mode */
--source;
*target++=PLUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
inDirectMode=false;
base64Counter=0;
goto unicodeMode;
}
--length;
}
if(source<sourceLimit && target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
unicodeMode:
while(source<sourceLimit) {
if(target<targetLimit) {
c=*source++;
if(c<=127 && encodeDirectly[c]) {
/* encode directly */
inDirectMode=true;
/* trick: back out this character to make this easier */
--source;
/* terminate the base64 sequence */
if(base64Counter!=0) {
/* write remaining bits for the previous character */
*target++=toBase64[bits];
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
}
if(fromBase64[c]!=-1) {
/* need to terminate with a minus */
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[0]=MINUS;
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
}
goto directMode;
} else {
/*
* base64 this character:
* Output 2 or 3 base64 bytes for the remaining bits of the previous character
* and the bits of this character, each implicitly in UTF-16BE.
*
* Here, bits is an 8-bit variable because only 6 bits need to be kept from one
* character to the next. The actual 2 or 4 bits are shifted to the left edge
* of the 6-bits field 5..0 to make the termination of the base64 sequence easier.
*/
switch(base64Counter) {
case 0:
*target++=toBase64[c>>10];
if(target<targetLimit) {
*target++=toBase64[(c>>4)&0x3f];
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=toBase64[(c>>4)&0x3f];
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=(uint8_t)((c&15)<<2);
base64Counter=1;
break;
case 1:
*target++=toBase64[bits|(c>>14)];
if(target<targetLimit) {
*target++=toBase64[(c>>8)&0x3f];
if(target<targetLimit) {
*target++=toBase64[(c>>2)&0x3f];
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=toBase64[(c>>2)&0x3f];
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=toBase64[(c>>8)&0x3f];
cnv->charErrorBuffer[1]=toBase64[(c>>2)&0x3f];
cnv->charErrorBufferLength=2;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=(uint8_t)((c&3)<<4);
base64Counter=2;
break;
case 2:
*target++=toBase64[bits|(c>>12)];
if(target<targetLimit) {
*target++=toBase64[(c>>6)&0x3f];
if(target<targetLimit) {
*target++=toBase64[c&0x3f];
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=toBase64[c&0x3f];
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=toBase64[(c>>6)&0x3f];
cnv->charErrorBuffer[1]=toBase64[c&0x3f];
cnv->charErrorBufferLength=2;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=0;
base64Counter=0;
break;
default:
/* will never occur */
break;
}
}
} else {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
}
}
if(pArgs->flush && source>=sourceLimit) {
/* flush remaining bits to the target */
if(!inDirectMode) {
if (base64Counter!=0) {
if(target<targetLimit) {
*target++=toBase64[bits];
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[cnv->charErrorBufferLength++]=toBase64[bits];
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
}
/* Add final MINUS to terminate unicodeMode */
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[cnv->charErrorBufferLength++]=MINUS;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
}
/* reset the state for the next conversion */
cnv->fromUnicodeStatus=(cnv->fromUnicodeStatus&0xf0000000)|0x1000000; /* keep version, inDirectMode=true */
} else {
/* set the converter state back into UConverter */
cnv->fromUnicodeStatus=
(cnv->fromUnicodeStatus&0xf0000000)| /* keep version*/
((uint32_t)inDirectMode<<24)|((uint32_t)base64Counter<<16)|(uint32_t)bits;
}
/* write back the updated pointers */
pArgs->source=source;
pArgs->target=(char *)target;
pArgs->offsets=offsets;
}
static const char * U_CALLCONV
_UTF7GetName(const UConverter *cnv) {
switch(cnv->fromUnicodeStatus>>28) {
case 1:
return "UTF-7,version=1";
default:
return "UTF-7";
}
}
U_CDECL_END
static const UConverterImpl _UTF7Impl={
UCNV_UTF7,
nullptr,
nullptr,
_UTF7Open,
nullptr,
_UTF7Reset,
_UTF7ToUnicodeWithOffsets,
_UTF7ToUnicodeWithOffsets,
_UTF7FromUnicodeWithOffsets,
_UTF7FromUnicodeWithOffsets,
nullptr,
nullptr,
_UTF7GetName,
nullptr, /* we don't need writeSub() because we never call a callback at fromUnicode() */
nullptr,
ucnv_getCompleteUnicodeSet,
nullptr,
nullptr
};
static const UConverterStaticData _UTF7StaticData={
sizeof(UConverterStaticData),
"UTF-7",
0, /* TODO CCSID for UTF-7 */
UCNV_IBM, UCNV_UTF7,
1, 4,
{ 0x3f, 0, 0, 0 }, 1, /* the subchar is not used */
false, false,
0,
0,
{ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
};
const UConverterSharedData _UTF7Data=
UCNV_IMMUTABLE_SHARED_DATA_INITIALIZER(&_UTF7StaticData, &_UTF7Impl);
/* IMAP mailbox name encoding ----------------------------------------------- */
/*
* RFC 2060: INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1
* http://www.ietf.org/rfc/rfc2060.txt
*
* 5.1.3. Mailbox International Naming Convention
*
* By convention, international mailbox names are specified using a
* modified version of the UTF-7 encoding described in [UTF-7]. The
* purpose of these modifications is to correct the following problems
* with UTF-7:
*
* 1) UTF-7 uses the "+" character for shifting; this conflicts with
* the common use of "+" in mailbox names, in particular USENET
* newsgroup names.
*
* 2) UTF-7's encoding is BASE64 which uses the "/" character; this
* conflicts with the use of "/" as a popular hierarchy delimiter.
*
* 3) UTF-7 prohibits the unencoded usage of "\"; this conflicts with
* the use of "\" as a popular hierarchy delimiter.
*
* 4) UTF-7 prohibits the unencoded usage of "~"; this conflicts with
* the use of "~" in some servers as a home directory indicator.
*
* 5) UTF-7 permits multiple alternate forms to represent the same
* string; in particular, printable US-ASCII characters can be
* represented in encoded form.
*
* In modified UTF-7, printable US-ASCII characters except for "&"
* represent themselves; that is, characters with octet values 0x20-0x25
* and 0x27-0x7e. The character "&" (0x26) is represented by the two-
* octet sequence "&-".
*
* All other characters (octet values 0x00-0x1f, 0x7f-0xff, and all
* Unicode 16-bit octets) are represented in modified BASE64, with a
* further modification from [UTF-7] that "," is used instead of "/".
* Modified BASE64 MUST NOT be used to represent any printing US-ASCII
* character which can represent itself.
*
* "&" is used to shift to modified BASE64 and "-" to shift back to US-
* ASCII. All names start in US-ASCII, and MUST end in US-ASCII (that
* is, a name that ends with a Unicode 16-bit octet MUST end with a "-
* ").
*
* For example, here is a mailbox name which mixes English, Japanese,
* and Chinese text: ~peter/mail/&ZeVnLIqe-/&U,BTFw-
*/
/*
* Tests for US-ASCII characters belonging to character classes
* defined in UTF-7.
*
* Set D (directly encoded characters) consists of the following
* characters: the upper and lower case letters A through Z
* and a through z, the 10 digits 0-9, and the following nine special
* characters (note that "+" and "=" are omitted):
* '(),-./:?
*
* Set O (optional direct characters) consists of the following
* characters (note that "\" and "~" are omitted):
* !"#$%&*;<=>@[]^_`{|}
*
* According to the rules in RFC 2152, the byte values for the following
* US-ASCII characters are not used in UTF-7 and are therefore illegal:
* - all C0 control codes except for CR LF TAB
* - BACKSLASH
* - TILDE
* - DEL
* - all codes beyond US-ASCII, i.e. all >127
*/
/* uses '&' not '+' to start a base64 sequence */
#define AMPERSAND 0x26
#define COMMA 0x2c
#define SLASH 0x2f
/* legal byte values: all US-ASCII graphic characters 0x20..0x7e */
#define isLegalIMAP(c) (0x20<=(c) && (c)<=0x7e)
/* direct-encode all of printable ASCII 0x20..0x7e except '&' 0x26 */
#define inSetDIMAP(c) (isLegalIMAP(c) && c!=AMPERSAND)
#define TO_BASE64_IMAP(n) ((n)<63 ? toBase64[n] : COMMA)
#define FROM_BASE64_IMAP(c) ((c)==COMMA ? 63 : (c)==SLASH ? -1 : fromBase64[c])
/*
* converter status values:
*
* toUnicodeStatus:
* 24 inDirectMode (boolean)
* 23..16 base64Counter (-1..7)
* 15..0 bits (up to 14 bits incoming base64)
*
* fromUnicodeStatus:
* 24 inDirectMode (boolean)
* 23..16 base64Counter (0..2)
* 7..0 bits (6 bits outgoing base64)
*
* ignore bits 31..25
*/
U_CDECL_BEGIN
static void U_CALLCONV
_IMAPToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
const uint8_t *source, *sourceLimit;
char16_t *target;
const char16_t *targetLimit;
int32_t *offsets;
uint8_t *bytes;
uint8_t byteIndex;
int32_t length, targetCapacity;
/* UTF-7 state */
uint16_t bits;
int8_t base64Counter;
UBool inDirectMode;
int8_t base64Value;
int32_t sourceIndex, nextSourceIndex;
char16_t c;
uint8_t b;
/* set up the local pointers */
cnv=pArgs->converter;
source=(const uint8_t *)pArgs->source;
sourceLimit=(const uint8_t *)pArgs->sourceLimit;
target=pArgs->target;
targetLimit=pArgs->targetLimit;
offsets=pArgs->offsets;
/* get the state machine state */
{
uint32_t status=cnv->toUnicodeStatus;
inDirectMode=(UBool)((status>>24)&1);
base64Counter=(int8_t)(status>>16);
bits=(uint16_t)status;
}
bytes=cnv->toUBytes;
byteIndex=cnv->toULength;
/* sourceIndex=-1 if the current character began in the previous buffer */
sourceIndex=byteIndex==0 ? 0 : -1;
nextSourceIndex=0;
if(inDirectMode) {
directMode:
/*
* In Direct Mode, US-ASCII characters are encoded directly, i.e.,
* with their US-ASCII byte values.
* An ampersand starts Unicode (or "escape") Mode.
*
* In Direct Mode, only the sourceIndex is used.
*/
byteIndex=0;
length=(int32_t)(sourceLimit-source);
targetCapacity=(int32_t)(targetLimit-target);
if(length>targetCapacity) {
length=targetCapacity;
}
while(length>0) {
b=*source++;
if(!isLegalIMAP(b)) {
/* illegal */
bytes[0]=b;
byteIndex=1;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
} else if(b!=AMPERSAND) {
/* write directly encoded character */
*target++=b;
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
} else /* AMPERSAND */ {
/* switch to Unicode mode */
nextSourceIndex=++sourceIndex;
inDirectMode=false;
byteIndex=0;
bits=0;
base64Counter=-1;
goto unicodeMode;
}
--length;
}
if(source<sourceLimit && target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
unicodeMode:
/*
* In Unicode (or "escape") Mode, UTF-16BE is base64-encoded.
* The base64 sequence ends with any character that is not in the base64 alphabet.
* A terminating minus sign is consumed.
* US-ASCII must not be base64-ed.
*
* In Unicode Mode, the sourceIndex has the index to the start of the current
* base64 bytes, while nextSourceIndex is precisely parallel to source,
* keeping the index to the following byte.
* Note that in 2 out of 3 cases, UChars overlap within a base64 byte.
*/
while(source<sourceLimit) {
if(target<targetLimit) {
bytes[byteIndex++]=b=*source++;
++nextSourceIndex;
if(b>0x7e) {
/* illegal - test other illegal US-ASCII values by base64Value==-3 */
inDirectMode=true;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
} else if((base64Value=FROM_BASE64_IMAP(b))>=0) {
/* collect base64 bytes into UChars */
switch(base64Counter) {
case -1: /* -1 is immediately after the & */
case 0:
bits=base64Value;
base64Counter=1;
break;
case 1:
case 3:
case 4:
case 6:
bits=(uint16_t)((bits<<6)|base64Value);
++base64Counter;
break;
case 2:
c=(char16_t)((bits<<4)|(base64Value>>2));
if(isLegalIMAP(c)) {
/* illegal */
inDirectMode=true;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
*target++=c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex-1;
}
bytes[0]=b; /* keep this byte in case an error occurs */
byteIndex=1;
bits=(uint16_t)(base64Value&3);
base64Counter=3;
break;
case 5:
c=(char16_t)((bits<<2)|(base64Value>>4));
if(isLegalIMAP(c)) {
/* illegal */
inDirectMode=true;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
*target++=c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex-1;
}
bytes[0]=b; /* keep this byte in case an error occurs */
byteIndex=1;
bits=(uint16_t)(base64Value&15);
base64Counter=6;
break;
case 7:
c=(char16_t)((bits<<6)|base64Value);
if(isLegalIMAP(c)) {
/* illegal */
inDirectMode=true;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
*target++=c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
sourceIndex=nextSourceIndex;
}
byteIndex=0;
bits=0;
base64Counter=0;
break;
default:
/* will never occur */
break;
}
} else if(base64Value==-2) {
/* minus sign terminates the base64 sequence */
inDirectMode=true;
if(base64Counter==-1) {
/* &- i.e. a minus immediately following an ampersand */
*target++=AMPERSAND;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
/* absorb the minus and leave the Unicode Mode */
if(bits!=0 || (base64Counter!=0 && base64Counter!=3 && base64Counter!=6)) {
/* bits are illegally left over, a char16_t is incomplete */
/* base64Counter other than 0, 3, 6 means non-minimal zero-padding, also illegal */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
}
sourceIndex=nextSourceIndex;
goto directMode;
} else {
if(base64Counter==-1) {
/* illegal: & immediately followed by something other than base64 or minus sign */
/* include the ampersand in the reported sequence */
--sourceIndex;
bytes[0]=AMPERSAND;
bytes[1]=b;
byteIndex=2;
}
/* base64Value==-1 for characters that are illegal only in Unicode mode */
/* base64Value==-3 for illegal characters */
/* illegal */
inDirectMode=true;
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
break;
}
} else {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
}
}
endloop:
/*
* the end of the input stream and detection of truncated input
* are handled by the framework, but here we must check if we are in Unicode
* mode and byteIndex==0 because we must end in direct mode
*
* conditions:
* successful
* in Unicode mode and byteIndex==0
* end of input and no truncated input
*/
if( U_SUCCESS(*pErrorCode) &&
!inDirectMode && byteIndex==0 &&
pArgs->flush && source>=sourceLimit
) {
if(base64Counter==-1) {
/* & at the very end of the input */
/* make the ampersand the reported sequence */
bytes[0]=AMPERSAND;
byteIndex=1;
}
/* else if(base64Counter!=-1) byteIndex remains 0 because there is no particular byte sequence */
inDirectMode=true; /* avoid looping */
*pErrorCode=U_TRUNCATED_CHAR_FOUND;
}
/* set the converter state back into UConverter */
cnv->toUnicodeStatus=((uint32_t)inDirectMode<<24)|((uint32_t)((uint8_t)base64Counter)<<16)|(uint32_t)bits;
cnv->toULength=byteIndex;
/* write back the updated pointers */
pArgs->source=(const char *)source;
pArgs->target=target;
pArgs->offsets=offsets;
}
static void U_CALLCONV
_IMAPFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
const char16_t *source, *sourceLimit;
uint8_t *target, *targetLimit;
int32_t *offsets;
int32_t length, targetCapacity, sourceIndex;
char16_t c;
uint8_t b;
/* UTF-7 state */
uint8_t bits;
int8_t base64Counter;
UBool inDirectMode;
/* set up the local pointers */
cnv=pArgs->converter;
/* set up the local pointers */
source=pArgs->source;
sourceLimit=pArgs->sourceLimit;
target=(uint8_t *)pArgs->target;
targetLimit=(uint8_t *)pArgs->targetLimit;
offsets=pArgs->offsets;
/* get the state machine state */
{
uint32_t status=cnv->fromUnicodeStatus;
inDirectMode=(UBool)((status>>24)&1);
base64Counter=(int8_t)(status>>16);
bits=(uint8_t)status;
}
/* UTF-7 always encodes UTF-16 code units, therefore we need only a simple sourceIndex */
sourceIndex=0;
if(inDirectMode) {
directMode:
length=(int32_t)(sourceLimit-source);
targetCapacity=(int32_t)(targetLimit-target);
if(length>targetCapacity) {
length=targetCapacity;
}
while(length>0) {
c=*source++;
/* encode 0x20..0x7e except '&' directly */
if(inSetDIMAP(c)) {
/* encode directly */
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
} else if(c==AMPERSAND) {
/* output &- for & */
*target++=AMPERSAND;
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
/* realign length and targetCapacity */
goto directMode;
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
cnv->charErrorBuffer[0]=MINUS;
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
} else {
/* un-read this character and switch to Unicode Mode */
--source;
*target++=AMPERSAND;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
inDirectMode=false;
base64Counter=0;
goto unicodeMode;
}
--length;
}
if(source<sourceLimit && target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
unicodeMode:
while(source<sourceLimit) {
if(target<targetLimit) {
c=*source++;
if(isLegalIMAP(c)) {
/* encode directly */
inDirectMode=true;
/* trick: back out this character to make this easier */
--source;
/* terminate the base64 sequence */
if(base64Counter!=0) {
/* write remaining bits for the previous character */
*target++=TO_BASE64_IMAP(bits);
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
}
/* need to terminate with a minus */
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[0]=MINUS;
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
goto directMode;
} else {
/*
* base64 this character:
* Output 2 or 3 base64 bytes for the remaining bits of the previous character
* and the bits of this character, each implicitly in UTF-16BE.
*
* Here, bits is an 8-bit variable because only 6 bits need to be kept from one
* character to the next. The actual 2 or 4 bits are shifted to the left edge
* of the 6-bits field 5..0 to make the termination of the base64 sequence easier.
*/
switch(base64Counter) {
case 0:
b=(uint8_t)(c>>10);
*target++=TO_BASE64_IMAP(b);
if(target<targetLimit) {
b=(uint8_t)((c>>4)&0x3f);
*target++=TO_BASE64_IMAP(b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
b=(uint8_t)((c>>4)&0x3f);
cnv->charErrorBuffer[0]=TO_BASE64_IMAP(b);
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=(uint8_t)((c&15)<<2);
base64Counter=1;
break;
case 1:
b=(uint8_t)(bits|(c>>14));
*target++=TO_BASE64_IMAP(b);
if(target<targetLimit) {
b=(uint8_t)((c>>8)&0x3f);
*target++=TO_BASE64_IMAP(b);
if(target<targetLimit) {
b=(uint8_t)((c>>2)&0x3f);
*target++=TO_BASE64_IMAP(b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
b=(uint8_t)((c>>2)&0x3f);
cnv->charErrorBuffer[0]=TO_BASE64_IMAP(b);
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
b=(uint8_t)((c>>8)&0x3f);
cnv->charErrorBuffer[0]=TO_BASE64_IMAP(b);
b=(uint8_t)((c>>2)&0x3f);
cnv->charErrorBuffer[1]=TO_BASE64_IMAP(b);
cnv->charErrorBufferLength=2;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=(uint8_t)((c&3)<<4);
base64Counter=2;
break;
case 2:
b=(uint8_t)(bits|(c>>12));
*target++=TO_BASE64_IMAP(b);
if(target<targetLimit) {
b=(uint8_t)((c>>6)&0x3f);
*target++=TO_BASE64_IMAP(b);
if(target<targetLimit) {
b=(uint8_t)(c&0x3f);
*target++=TO_BASE64_IMAP(b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex++;
}
b=(uint8_t)(c&0x3f);
cnv->charErrorBuffer[0]=TO_BASE64_IMAP(b);
cnv->charErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
} else {
if(offsets!=nullptr) {
*offsets++=sourceIndex++;
}
b=(uint8_t)((c>>6)&0x3f);
cnv->charErrorBuffer[0]=TO_BASE64_IMAP(b);
b=(uint8_t)(c&0x3f);
cnv->charErrorBuffer[1]=TO_BASE64_IMAP(b);
cnv->charErrorBufferLength=2;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
bits=0;
base64Counter=0;
break;
default:
/* will never occur */
break;
}
}
} else {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
}
}
if(pArgs->flush && source>=sourceLimit) {
/* flush remaining bits to the target */
if(!inDirectMode) {
if(base64Counter!=0) {
if(target<targetLimit) {
*target++=TO_BASE64_IMAP(bits);
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[cnv->charErrorBufferLength++]=TO_BASE64_IMAP(bits);
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
}
/* need to terminate with a minus */
if(target<targetLimit) {
*target++=MINUS;
if(offsets!=nullptr) {
*offsets++=sourceIndex-1;
}
} else {
cnv->charErrorBuffer[cnv->charErrorBufferLength++]=MINUS;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
}
}
/* reset the state for the next conversion */
cnv->fromUnicodeStatus=(cnv->fromUnicodeStatus&0xf0000000)|0x1000000; /* keep version, inDirectMode=true */
} else {
/* set the converter state back into UConverter */
cnv->fromUnicodeStatus=
(cnv->fromUnicodeStatus&0xf0000000)| /* keep version*/
((uint32_t)inDirectMode<<24)|((uint32_t)base64Counter<<16)|(uint32_t)bits;
}
/* write back the updated pointers */
pArgs->source=source;
pArgs->target=(char *)target;
pArgs->offsets=offsets;
}
U_CDECL_END
static const UConverterImpl _IMAPImpl={
UCNV_IMAP_MAILBOX,
nullptr,
nullptr,
_UTF7Open,
nullptr,
_UTF7Reset,
_IMAPToUnicodeWithOffsets,
_IMAPToUnicodeWithOffsets,
_IMAPFromUnicodeWithOffsets,
_IMAPFromUnicodeWithOffsets,
nullptr,
nullptr,
nullptr,
nullptr, /* we don't need writeSub() because we never call a callback at fromUnicode() */
nullptr,
ucnv_getCompleteUnicodeSet,
nullptr,
nullptr
};
static const UConverterStaticData _IMAPStaticData={
sizeof(UConverterStaticData),
"IMAP-mailbox-name",
0, /* TODO CCSID for IMAP-mailbox-name */
UCNV_IBM, UCNV_IMAP_MAILBOX,
1, 4,
{ 0x3f, 0, 0, 0 }, 1, /* the subchar is not used */
false, false,
0,
0,
{ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
};
const UConverterSharedData _IMAPData=
UCNV_IMMUTABLE_SHARED_DATA_INITIALIZER(&_IMAPStaticData, &_IMAPImpl);
#endif
