使用iOS进行Rc4加密解密
搜了一次,网络上绝大部分,都转的是下面的这个封装的:
http://www.cocoachina.com/bbs/read.php?tid-77608.html
首先非常感谢楼主的分享,但是使用后发现这个里面的代码实际上是有问题的:
为了帮后人摆脱此坑的困扰,本人稍微做了一下修正,具体如下:
+(NSString*)HloveyRC4:(NSString*)aInput key:(NSString*)aKey
{
NSMutableArray *iS = [[NSMutableArray alloc] initWithCapacity:256];
NSMutableArray *iK = [[NSMutableArray alloc] initWithCapacity:256];
for (int i= 0; i<256; i++) {
[iS addObject:[NSNumber numberWithInt:i]];
}
int j=1;
//改动1,s-box的长度应当是256,楼主之前写的是255
for (short i=0; i<256; i++) {
UniChar c = [aKey characterAtIndex:i%aKey.length];
[iK addObject:[NSNumber numberWithChar:c]];
}
j=0;
for (int i=0; i<256; i++) {
int is = [[iS objectAtIndex:i] intValue];
UniChar ik = (UniChar)[[iK objectAtIndex:i] charValue];
j = (j + is + ik)%256;
NSNumber *temp = [iS objectAtIndex:i];
[iS replaceObjectAtIndex:i withObject:[iS objectAtIndex:j]];
[iS replaceObjectAtIndex:j withObject:temp];
}
int i=0;
j=0;
Byte byteBuffer[aInput.length];
for (short x=0; x<[aInput length]; x++) {
i = (i+1)%256;
int is = [[iS objectAtIndex:i] intValue];
j = (j+is)%256;
int is_i = [[iS objectAtIndex:i] intValue];
int is_j = [[iS objectAtIndex:j] intValue];
int t = (is_i+is_j) % 256;
int iY = [[iS objectAtIndex:t] intValue];
//改动2:增加交换is_i和is_j的具体内容
[iS exchangeObjectAtIndex:i withObjectAtIndex:j];
UniChar ch = (UniChar)[aInput characterAtIndex:x];
UniChar ch_y = ch^iY;
byteBuffer[x] = ch_y;
}
[iS release];
[iK release];
return result;
}
+ (NSString *)byteToBase64String:(Byte [])byteBuffer lengh:(NSInteger)buffLen
{
NSData *adata = [[NSData alloc] initWithBytes:byteBuffer length:buffLen];
NSString *string = [adata base64EncodedStringWithOptions:0];
return string;
}
参考资料:
http://baike.baidu.com/link?url=GDR7_BqVSKStCioLhfGikGMJ_MBwiGCsuB1bowM3ZRvZ0tNGesVt15AKLPXVjV5qfCaAMxwjolEM9dNy9ca3qa
百度百科,c语言实现