scuffed-code/icu4c/source/common/punycode.c
2003-03-28 19:44:29 +00:00

564 lines
17 KiB
C

/*
*******************************************************************************
*
* Copyright (C) 2002, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: punycode.c
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 2002jan31
* created by: Markus W. Scherer
*/
/* This ICU code derived from: */
/*
punycode.c 0.4.0 (2001-Nov-17-Sat)
http://www.cs.berkeley.edu/~amc/idn/
Adam M. Costello
http://www.nicemice.net/amc/
*/
/*
* ICU modifications:
* - ICU data types and coding conventions
* - ICU string buffer handling with implicit source lengths
* and destination preflighting
* - UTF-16 handling
*/
#include "unicode/utypes.h"
#include "ustr_imp.h"
#include "cstring.h"
#include "cmemory.h"
#include "punycode.h"
#include "unicode/ustring.h"
/* Punycode ----------------------------------------------------------------- */
/* Punycode parameters for Bootstring */
#define BASE 36
#define TMIN 1
#define TMAX 26
#define SKEW 38
#define DAMP 700
#define INITIAL_BIAS 72
#define INITIAL_N 0x80
/* "Basic" Unicode/ASCII code points */
#define _HYPHEN 0X2d
#define DELIMITER _HYPHEN
#define _ZERO 0X30
#define _NINE 0x39
#define _SMALL_A 0X61
#define _SMALL_Z 0X7a
#define _CAPITAL_A 0X41
#define _CAPITAL_Z 0X5a
#define IS_BASIC(c) ((c)<0x80)
#define IS_BASIC_UPPERCASE(c) (_CAPITAL_A<=(c) && (c)<=_CAPITAL_Z)
/**
* digitToBasic() returns the basic code point whose value
* (when used for representing integers) is d, which must be in the
* range 0 to BASE-1. The lowercase form is used unless the uppercase flag is
* nonzero, in which case the uppercase form is used.
*/
U_INLINE char
digitToBasic(int32_t digit, UBool uppercase) {
/* 0..25 map to ASCII a..z or A..Z */
/* 26..35 map to ASCII 0..9 */
if(digit<26) {
if(uppercase) {
return (char)(_CAPITAL_A+digit);
} else {
return (char)(_SMALL_A+digit);
}
} else {
return (char)((_ZERO-26)+digit);
}
}
/**
* basicToDigit[] contains the numeric value of a basic code
* point (for use in representing integers) in the range 0 to
* BASE-1, or -1 if b is does not represent a value.
*/
static const int8_t
basicToDigit[256]={
-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,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1, -1,
-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, -1, -1, -1, -1,
-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, -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, -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, -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
};
U_INLINE char
asciiCaseMap(char b, UBool uppercase) {
if(uppercase) {
if(_SMALL_A<=b && b<=_SMALL_Z) {
b-=(_SMALL_A-_CAPITAL_A);
}
} else {
if(_CAPITAL_A<=b && b<=_CAPITAL_Z) {
b+=(_SMALL_A-_CAPITAL_A);
}
}
return b;
}
/* Punycode-specific Bootstring code ---------------------------------------- */
/*
* The following code omits the {parts} of the pseudo-algorithm in the spec
* that are not used with the Punycode parameter set.
*/
/* Bias adaptation function. */
static int32_t
adaptBias(int32_t delta, int32_t length, UBool firstTime) {
int32_t count;
if(firstTime) {
delta/=DAMP;
} else {
delta/=2;
}
delta+=delta/length;
for(count=0; delta>((BASE-TMIN)*TMAX)/2; count+=BASE) {
delta/=(BASE-TMIN);
}
return count+(((BASE-TMIN+1)*delta)/(delta+SKEW));
}
#define MAX_CP_COUNT 200
U_CFUNC int32_t
u_strToPunycode(const UChar *src, int32_t srcLength,
UChar *dest, int32_t destCapacity,
const UBool *caseFlags,
UErrorCode *pErrorCode) {
int32_t cpBuffer[MAX_CP_COUNT];
int32_t n, delta, handledCPCount, basicLength, destLength, bias, j, m, q, k, t, srcCPCount;
UChar c, c2;
/* argument checking */
if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
return 0;
}
if(src==NULL || srcLength<-1 || (dest==NULL && destCapacity!=0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
/*
* Handle the basic code points and
* convert extended ones to UTF-32 in cpBuffer (caseFlag in sign bit):
*/
srcCPCount=destLength=0;
if(srcLength==-1) {
/* NUL-terminated input */
for(j=0; /* no condition */; ++j) {
if((c=src[j])==0) {
break;
}
if(srcCPCount==MAX_CP_COUNT) {
/* too many input code points */
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
if(IS_BASIC(c)) {
cpBuffer[srcCPCount++]=0;
if(destLength<destCapacity) {
dest[destLength]=
caseFlags!=NULL ?
asciiCaseMap((char)c, caseFlags[j]) :
(char)c;
}
++destLength;
} else {
n=(caseFlags!=NULL && caseFlags[j])<<31L;
if(UTF_IS_SINGLE(c)) {
n|=c;
} else if(UTF_IS_LEAD(c) && UTF_IS_TRAIL(c2=src[j+1])) {
++j;
n|=(int32_t)UTF16_GET_PAIR_VALUE(c, c2);
} else {
/* error: unmatched surrogate */
*pErrorCode=U_INVALID_CHAR_FOUND;
return 0;
}
cpBuffer[srcCPCount++]=n;
}
}
} else {
/* length-specified input */
for(j=0; j<srcLength; ++j) {
if(srcCPCount==MAX_CP_COUNT) {
/* too many input code points */
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
c=src[j];
if(IS_BASIC(c)) {
if(destLength<destCapacity) {
cpBuffer[srcCPCount++]=0;
dest[destLength]=
caseFlags!=NULL ?
asciiCaseMap((char)c, caseFlags[j]) :
(char)c;
}
++destLength;
} else {
n=(caseFlags!=NULL && caseFlags[j])<<31L;
if(UTF_IS_SINGLE(c)) {
n|=c;
} else if(UTF_IS_LEAD(c) && (j+1)<srcLength && UTF_IS_TRAIL(c2=src[j+1])) {
++j;
n|=(int32_t)UTF16_GET_PAIR_VALUE(c, c2);
} else {
/* error: unmatched surrogate */
*pErrorCode=U_INVALID_CHAR_FOUND;
return 0;
}
cpBuffer[srcCPCount++]=n;
}
}
}
/* Finish the basic string - if it is not empty - with a delimiter. */
basicLength=destLength;
if(basicLength>0) {
if(destLength<destCapacity) {
dest[destLength]=DELIMITER;
}
++destLength;
}
/*
* handledCPCount is the number of code points that have been handled
* basicLength is the number of basic code points
* destLength is the number of chars that have been output
*/
/* Initialize the state: */
n=INITIAL_N;
delta=0;
bias=INITIAL_BIAS;
/* Main encoding loop: */
for(handledCPCount=basicLength; handledCPCount<srcCPCount; /* no op */) {
/*
* All non-basic code points < n have been handled already.
* Find the next larger one:
*/
for(m=0x7fffffff, j=0; j<srcCPCount; ++j) {
q=cpBuffer[j]&0x7fffffff; /* remove case flag from the sign bit */
if(n<=q && q<m) {
m=q;
}
}
/*
* Increase delta enough to advance the decoder's
* <n,i> state to <m,0>, but guard against overflow:
*/
if(m-n>(0x7fffffff-MAX_CP_COUNT-delta)/(handledCPCount+1)) {
*pErrorCode=U_INTERNAL_PROGRAM_ERROR;
return 0;
}
delta+=(m-n)*(handledCPCount+1);
n=m;
/* Encode a sequence of same code points n */
for(j=0; j<srcCPCount; ++j) {
q=cpBuffer[j]&0x7fffffff; /* remove case flag from the sign bit */
if(q<n) {
++delta;
} else if(q==n) {
/* Represent delta as a generalized variable-length integer: */
for(q=delta, k=BASE; /* no condition */; k+=BASE) {
/** RAM: comment out the old code for conformance with draft-ietf-idn-punycode-03.txt
t=k-bias;
if(t<TMIN) {
t=TMIN;
} else if(t>TMAX) {
t=TMAX;
}
*/
t=k-bias;
if(t<TMIN) {
t=TMIN;
} else if(k>=(bias+TMAX)) {
t=TMAX;
}
if(q<t) {
break;
}
if(destLength<destCapacity) {
dest[destLength++]=digitToBasic(t+(q-t)%(BASE-t), 0);
}
q=(q-t)/(BASE-t);
}
if(destLength<destCapacity) {
dest[destLength++]=digitToBasic(q, (UBool)(cpBuffer[j]<0));
}
bias=adaptBias(delta, handledCPCount+1, (UBool)(handledCPCount==basicLength));
delta=0;
++handledCPCount;
}
}
++delta;
++n;
}
return u_terminateUChars(dest, destCapacity, destLength, pErrorCode);
}
U_CFUNC int32_t
u_strFromPunycode(const UChar *src, int32_t srcLength,
UChar *dest, int32_t destCapacity,
UBool *caseFlags,
UErrorCode *pErrorCode) {
int32_t n, destLength, i, bias, basicLength, j, in, oldi, w, k, digit, t,
destCPCount, firstSupplementaryIndex, cpLength;
UChar b;
/* argument checking */
if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
return 0;
}
if(src==NULL || srcLength<-1 || (dest==NULL && destCapacity!=0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
if(srcLength==-1) {
srcLength=u_strlen(src);
}
/*
* Handle the basic code points:
* Let basicLength be the number of input code points
* before the last delimiter, or 0 if there is none,
* then copy the first basicLength code points to the output.
*
* The two following loops iterate backward.
*/
for(j=srcLength; j>0;) {
if(src[--j]==DELIMITER) {
break;
}
}
destLength=basicLength=destCPCount=j;
while(j>0) {
b=src[--j];
if(!IS_BASIC(b)) {
*pErrorCode=U_INVALID_CHAR_FOUND;
return 0;
}
if(j<destCapacity) {
dest[j]=(UChar)b;
if(caseFlags!=NULL) {
caseFlags[j]=IS_BASIC_UPPERCASE(b);
}
}
}
/* Initialize the state: */
n=INITIAL_N;
i=0;
bias=INITIAL_BIAS;
firstSupplementaryIndex=1000000000;
/*
* Main decoding loop:
* Start just after the last delimiter if any
* basic code points were copied; start at the beginning otherwise.
*/
for(in=basicLength>0 ? basicLength+1 : 0; in<srcLength; /* no op */) {
/*
* in is the index of the next character to be consumed, and
* destCPCount is the number of code points in the output array.
*
* Decode a generalized variable-length integer into delta,
* which gets added to i. The overflow checking is easier
* if we increase i as we go, then subtract off its starting
* value at the end to obtain delta.
*/
for(oldi=i, w=1, k=BASE; /* no condition */; k+=BASE) {
if(in>=srcLength) {
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
return 0;
}
digit=basicToDigit[(uint8_t)src[in++]];
if(digit<0) {
*pErrorCode=U_INVALID_CHAR_FOUND;
return 0;
}
if(digit>(0x7fffffff-i)/w) {
/* integer overflow */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
return 0;
}
i+=digit*w;
/** RAM: comment out the old code for conformance with draft-ietf-idn-punycode-03.txt
t=k-bias;
if(t<TMIN) {
t=TMIN;
} else if(t>TMAX) {
t=TMAX;
}
*/
t=k-bias;
if(t<TMIN) {
t=TMIN;
} else if(k>=(bias+TMAX)) {
t=TMAX;
}
if(digit<t) {
break;
}
if(w>0x7fffffff/(BASE-t)) {
/* integer overflow */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
return 0;
}
w*=BASE-t;
}
/*
* Modification from sample code:
* Increments destCPCount here,
* where needed instead of in for() loop tail.
*/
++destCPCount;
bias=adaptBias(i-oldi, destCPCount, (UBool)(oldi==0));
/*
* i was supposed to wrap around from (incremented) destCPCount to 0,
* incrementing n each time, so we'll fix that now:
*/
if(i/destCPCount>(0x7fffffff-n)) {
/* integer overflow */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
return 0;
}
n+=i/destCPCount;
i%=destCPCount;
/* not needed for Punycode: */
/* if (decode_digit(n) <= BASE) return punycode_invalid_input; */
if(n>0x10ffff || UTF_IS_SURROGATE(n)) {
/* Unicode code point overflow */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
return 0;
}
/* Insert n at position i of the output: */
cpLength=UTF_CHAR_LENGTH(n);
if((destLength+cpLength)<destCapacity) {
int32_t codeUnitIndex;
/*
* Handle indexes when supplementary code points are present.
*
* In almost all cases, there will be only BMP code points before i
* and even in the entire string.
* This is handled with the same efficiency as with UTF-32.
*
* Only the rare cases with supplementary code points are handled
* more slowly - but not too bad since this is an insertion anyway.
*/
if(i<=firstSupplementaryIndex) {
codeUnitIndex=i;
if(cpLength>1) {
firstSupplementaryIndex=codeUnitIndex;
} else {
++firstSupplementaryIndex;
}
} else {
codeUnitIndex=firstSupplementaryIndex;
UTF_FWD_N(dest, codeUnitIndex, destLength, i-codeUnitIndex);
}
/* use the UChar index codeUnitIndex instead of the code point index i */
if(codeUnitIndex<destLength) {
uprv_memmove(dest+codeUnitIndex+cpLength,
dest+codeUnitIndex,
(destLength-codeUnitIndex)*U_SIZEOF_UCHAR);
if(caseFlags!=NULL) {
uprv_memmove(caseFlags+codeUnitIndex+cpLength,
caseFlags+codeUnitIndex,
destLength-codeUnitIndex);
}
}
if(cpLength==1) {
/* BMP, insert one code unit */
dest[codeUnitIndex]=(UChar)n;
} else {
/* supplementary character, insert two code units */
dest[codeUnitIndex]=UTF16_LEAD(n);
dest[codeUnitIndex+1]=UTF16_TRAIL(n);
}
if(caseFlags!=NULL) {
/* Case of last character determines uppercase flag: */
caseFlags[codeUnitIndex]=IS_BASIC_UPPERCASE(src[in-1]);
if(cpLength==2) {
caseFlags[codeUnitIndex+1]=FALSE;
}
}
}
destLength+=cpLength;
++i;
}
return u_terminateUChars(dest, destCapacity, destLength, pErrorCode);
}
/* ### check notes on overflow handling - only necessary if not IDNA? are these Punycode functions to be public? */