mirror of https://github.com/oxen-io/session-ios
Address Indic script crash.
Matthew Chen
7 years ago
parent
c60422e921
commit
abfd333a17
@ -0,0 +1,17 @@
|
||||
//
|
||||
// Copyright (c) 2018 Open Whisper Systems. All rights reserved.
|
||||
//
|
||||
|
||||
NS_ASSUME_NONNULL_BEGIN
|
||||
|
||||
@interface NSString (SSK)
|
||||
|
||||
- (NSString *)ows_stripped;
|
||||
|
||||
- (NSString *)filterStringForDisplay;
|
||||
|
||||
- (BOOL)isValidE164;
|
||||
|
||||
@end
|
||||
|
||||
NS_ASSUME_NONNULL_END
|
||||
@ -0,0 +1,199 @@
|
||||
//
|
||||
// Copyright (c) 2018 Open Whisper Systems. All rights reserved.
|
||||
//
|
||||
|
||||
#import "NSString+SSK.h"
|
||||
|
||||
NS_ASSUME_NONNULL_BEGIN
|
||||
|
||||
@interface UnicodeCodeRange : NSObject
|
||||
|
||||
@property (nonatomic) unichar first;
|
||||
@property (nonatomic) unichar last;
|
||||
|
||||
@end
|
||||
|
||||
#pragma mark -
|
||||
|
||||
@implementation UnicodeCodeRange
|
||||
|
||||
+ (UnicodeCodeRange *)rangeWithStart:(unichar)first last:(unichar)last
|
||||
{
|
||||
OWSAssert(first <= last);
|
||||
|
||||
UnicodeCodeRange *range = [UnicodeCodeRange new];
|
||||
range.first = first;
|
||||
range.last = last;
|
||||
return range;
|
||||
}
|
||||
|
||||
- (NSComparisonResult)compare:(UnicodeCodeRange *)other
|
||||
{
|
||||
|
||||
return self.first > other.first;
|
||||
}
|
||||
|
||||
@end
|
||||
|
||||
#pragma mark -
|
||||
|
||||
@implementation NSString (SSK)
|
||||
|
||||
- (NSString *)ows_stripped
|
||||
{
|
||||
return [self stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
|
||||
}
|
||||
|
||||
+ (BOOL)shouldFilterIndic
|
||||
{
|
||||
static BOOL result = NO;
|
||||
static dispatch_once_t onceToken;
|
||||
dispatch_once(&onceToken, ^{
|
||||
result = (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 0) && !SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 3));
|
||||
});
|
||||
return result;
|
||||
}
|
||||
|
||||
+ (BOOL)isIndicVowel:(unichar)c
|
||||
{
|
||||
static NSArray<UnicodeCodeRange *> *ranges;
|
||||
static dispatch_once_t onceToken;
|
||||
dispatch_once(&onceToken, ^{
|
||||
// From:
|
||||
// https://unicode.org/charts/PDF/U0C00.pdf
|
||||
// https://unicode.org/charts/PDF/U0980.pdf
|
||||
// https://unicode.org/charts/PDF/U0900.pdf
|
||||
ranges = [@[
|
||||
// Telugu:
|
||||
[UnicodeCodeRange rangeWithStart:0xC05 last:0xC14],
|
||||
[UnicodeCodeRange rangeWithStart:0xC3E last:0xC4C],
|
||||
[UnicodeCodeRange rangeWithStart:0xC60 last:0xC63],
|
||||
// Bengali
|
||||
[UnicodeCodeRange rangeWithStart:0x985 last:0x994],
|
||||
[UnicodeCodeRange rangeWithStart:0x9BE last:0x9C8],
|
||||
[UnicodeCodeRange rangeWithStart:0x9CB last:0x9CC],
|
||||
[UnicodeCodeRange rangeWithStart:0x9E0 last:0x9E3],
|
||||
// Devanagari
|
||||
[UnicodeCodeRange rangeWithStart:0x904 last:0x914],
|
||||
[UnicodeCodeRange rangeWithStart:0x93A last:0x93B],
|
||||
[UnicodeCodeRange rangeWithStart:0x93E last:0x94C],
|
||||
[UnicodeCodeRange rangeWithStart:0x94E last:0x94F],
|
||||
[UnicodeCodeRange rangeWithStart:0x955 last:0x957],
|
||||
[UnicodeCodeRange rangeWithStart:0x960 last:0x963],
|
||||
[UnicodeCodeRange rangeWithStart:0x972 last:0x977],
|
||||
] sortedArrayUsingSelector:@selector(compare:)];
|
||||
});
|
||||
|
||||
for (UnicodeCodeRange *range in ranges) {
|
||||
if (c < range.first) {
|
||||
// For perf, we can take advantage of the fact that the
|
||||
// ranges are sorted to exit early if the character lies
|
||||
// before the current range.
|
||||
return NO;
|
||||
}
|
||||
if (range.first <= c && c <= range.last) {
|
||||
return YES;
|
||||
}
|
||||
}
|
||||
return NO;
|
||||
}
|
||||
|
||||
+ (NSCharacterSet *)problematicCharacterSetForIndicScript
|
||||
{
|
||||
static NSCharacterSet *characterSet;
|
||||
static dispatch_once_t onceToken;
|
||||
dispatch_once(&onceToken, ^{
|
||||
UniChar chars[] = {0x200C};
|
||||
NSString *characterSetString = [[NSString alloc] initWithCharacters:chars
|
||||
length:sizeof(chars) / sizeof(UniChar)];
|
||||
characterSet = [NSCharacterSet characterSetWithCharactersInString:characterSetString];
|
||||
});
|
||||
|
||||
return characterSet;
|
||||
}
|
||||
|
||||
// See: https://manishearth.github.io/blog/2018/02/15/picking-apart-the-crashing-ios-string/
|
||||
- (NSString *)filterForIndicScripts
|
||||
{
|
||||
if (!NSString.shouldFilterIndic) {
|
||||
return self;
|
||||
}
|
||||
|
||||
if ([self rangeOfCharacterFromSet:[[self class] problematicCharacterSetForIndicScript]].location == NSNotFound) {
|
||||
return self;
|
||||
}
|
||||
|
||||
NSMutableString *filteredForIndic = [NSMutableString new];
|
||||
for (NSUInteger index = 0; index < self.length; index++) {
|
||||
unichar c = [self characterAtIndex:index];
|
||||
if (c == 0x200C) {
|
||||
NSUInteger nextIndex = index + 1;
|
||||
if (nextIndex < self.length) {
|
||||
unichar next = [self characterAtIndex:nextIndex];
|
||||
if ([NSString isIndicVowel:next]) {
|
||||
// Discard ZWNJ (zero-width non-joiner) whenever we find a ZWNJ
|
||||
// followed by an Indic (Telugu, Bengali, Devanagari) vowel
|
||||
// and replace it with 0xFFFD, the Unicode "replacement character."
|
||||
[filteredForIndic appendFormat:@"\uFFFD"];
|
||||
DDLogError(@"%@ Filtered unsafe Indic script.", self.logTag);
|
||||
// Then discard the vowel too.
|
||||
index++;
|
||||
continue;
|
||||
}
|
||||
}
|
||||
}
|
||||
[filteredForIndic appendFormat:@"%C", c];
|
||||
}
|
||||
return [filteredForIndic copy];
|
||||
}
|
||||
|
||||
- (NSString *)filterStringForDisplay
|
||||
{
|
||||
return self.ows_stripped.filterForIndicScripts.filterForExcessiveDiacriticals;
|
||||
}
|
||||
|
||||
- (NSString *)filterForExcessiveDiacriticals
|
||||
{
|
||||
if (!self.hasExcessiveDiacriticals) {
|
||||
return self;
|
||||
}
|
||||
return [self stringByFoldingWithOptions:NSDiacriticInsensitiveSearch locale:[NSLocale currentLocale]];
|
||||
}
|
||||
|
||||
- (BOOL)hasExcessiveDiacriticals
|
||||
{
|
||||
// discard any zalgo style text, by detecting maximum number of glyphs per character
|
||||
NSUInteger index = 0;
|
||||
while (index < self.length) {
|
||||
// Walk the grapheme clusters in the string.
|
||||
NSRange range = [self rangeOfComposedCharacterSequenceAtIndex:index];
|
||||
if (range.length > 4) {
|
||||
// There are too many characters in this grapheme cluster.
|
||||
return YES;
|
||||
} else if (range.location != index || range.length < 1) {
|
||||
// This should never happen.
|
||||
OWSFail(
|
||||
@"%@ unexpected composed character sequence: %zd, %@", self.logTag, index, NSStringFromRange(range));
|
||||
return YES;
|
||||
}
|
||||
index = range.location + range.length;
|
||||
}
|
||||
return NO;
|
||||
}
|
||||
|
||||
- (BOOL)isValidE164
|
||||
{
|
||||
NSError *error = nil;
|
||||
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^\\+\\d+$"
|
||||
options:NSRegularExpressionCaseInsensitive
|
||||
error:&error];
|
||||
if (error || !regex) {
|
||||
OWSFail(@"%@ could not compile regex: %@", self.logTag, error);
|
||||
return NO;
|
||||
}
|
||||
return [regex rangeOfFirstMatchInString:self options:0 range:NSMakeRange(0, self.length)].location != NSNotFound;
|
||||
}
|
||||
|
||||
@end
|
||||
|
||||
NS_ASSUME_NONNULL_END
|
||||
Loading…
Reference in New Issue