iOS|iOS 自定义加密算法 iOS自定义加密算法

开发中除了常见的RSA加密、MD5加密等，可以实现自动以算法配合加密方法使用，代码如下:

// 自定义加密算法 + (NSString *)archlyEncryptionAlgorithmWithData:(NSString *)data key:(NSString *)key isDecode:(BOOL)isDecode{ int len = 128; if (key == nil || key.length == 0) { key = @""; }if (data.length < 1) { return @""; }NSString *md5Key = [key md5Hash]; NSString *keyA = [[md5Key substringToIndex:16] md5Hash]; NSString *keyB = [[md5Key substringFromIndex:16] md5Hash]; NSString *keyC; if (isDecode == YES) { // 解密 keyC = [data substringToIndex:4]; }else{ // 加密 NSString *nowTime = [self getNowTimeTimestampms]; NSString *md5Time = [nowTime md5Hash]; keyC = [md5Time substringFromIndex:md5Time.length - 4]; } NSString *cryptkey = [NSString stringWithFormat:@"%@%@",keyA,[[NSString stringWithFormat:@"%@%@",keyA,keyC] md5Hash]]; NSInteger cryptkeyLength = cryptkey.length; NSString *newData; if (isDecode == YES) { // 解密 NSString *preparStr = [data substringFromIndex:4]; if (preparStr.length % 4 != 0) { NSInteger coverLength = 4 - preparStr.length % 4; for (int i = 0; i < coverLength ; i ++) { preparStr = [preparStr stringByAppendingString:@"="]; } } newData = https://www.it610.com/article/[preparStr base64Dencode]; }else{ // 加密 NSString *sub = [[[NSString stringWithFormat:@"%@%@",data,keyB] md5Hash] substringToIndex:16]; newData = https://www.it610.com/article/[NSString stringWithFormat:@"0000000000%@%@",sub,data]; } NSString *result = @""; NSMutableArray *box = [NSMutableArray array]; for (int i = 0; i < len; i++) { [box addObject:@(i)]; }NSMutableArray *rndkArray = [NSMutableArray array]; for (int i = 0; i < len; i ++) { unichar c =[cryptkey characterAtIndex:i % cryptkeyLength]; [rndkArray addObject:@([self ascIIToNumber:[NSString stringWithFormat:@"%C",c]])]; } int j1 = 0; for (int i = 0; i < len; i ++) { int boxNum = [box[i] intValue]; int rndkArrayNum = [rndkArray[i] intValue]; j1 = (j1 + boxNum +rndkArrayNum) % len; [box exchangeObjectAtIndex:i withObjectAtIndex:j1]; }int a2 = 0; int j2 = 0; for (int i = 0; i < newData.length; i ++) { a2 = (a2 +1) % len; int boxNum = [box[a2] intValue]; j2 = (j2 + boxNum) % len; [box exchangeObjectAtIndex:a2 withObjectAtIndex:j2]; unichar c =[newData characterAtIndex:i]; int ASCIIC = [self ascIIToNumber:[NSString stringWithFormat:@"%C",c]]; int value = https://www.it610.com/article/([box[a2] intValue] + [box[j2] intValue]) % len; int boxValue = [box[value] intValue]; int newValue = ASCIIC ^ boxValue; NSString *charStr = [self numberToASCII:newValue]; result = [NSString stringWithFormat:@"%@%@",result,charStr]; }if (isDecode == YES) { // 解密 if (result.length < 1) { NSLog(@"result 为空"); return @""; } BOOL bool1 = [[result substringToIndex:10] isEqualToString:@"0000000000"]; BOOL bool2 = [[result substringToIndex:10] intValue] > [[self getNowTimeTimestamp] intValue]; NSString *string1 = [result substringWithRange:NSMakeRange(10, 16)]; NSString *md5Str = [[NSString stringWithFormat:@"%@%@",[result substringFromIndex:26],keyB] md5Hash]; NSString *string2 = [md5Str substringToIndex:16]; BOOL bool3 = [string2 isEqualToString:string1]; if ((bool1 || bool2) && bool3) { return [result substringFromIndex:26]; }else { return @""; }}else{ // 加密 NSString *baseStr = [[result base64Encode] stringByReplacingOccurrencesOfString:@"=" withString:@""]; return [NSString stringWithFormat:@"%@%@",keyC,baseStr]; }}

调用的辅助方法如下：
实现NSStirng 分类

- (NSString *)md5Hash { const char *plain = self.UTF8String; unsigned char *digest; digest = malloc(CC_MD5_DIGEST_LENGTH); CC_MD5(plain, (CC_LONG)strlen(plain), digest); NSString *encode = [self stringFromBytes:digest length:CC_MD5_DIGEST_LENGTH]; free(digest); return encode; }#pragma mark - Bytes转字符串 /** 字符大小写可以通过修改“%02X”中的x修改,下面采用的是大写X小写用 x */ - (NSString *)stringFromBytes:(uint8_t *)bytes length:(int)length { NSMutableString *strM = [NSMutableString string]; for (int i = 0; i < length; i++) { [strM appendFormat:@"%02x", bytes[i]]; }return [strM copy]; }// base64编码 - (NSString *)base64Encode{ NSData * body = [self dataUsingEncoding:NSUTF8StringEncoding]; return [body base64EncodedStringWithOptions:0]; }// base64解码 - (NSString *)base64Dencode {NSData *decodeData = [[NSData alloc] initWithBase64EncodedString:self options:0]; //解码NSString *decodeString = [[NSString alloc] initWithData:decodeData encoding:NSUTF8StringEncoding]; return decodeString; }

实例方法如下：

// 获取当前时间戳毫秒 - (NSString *)getNowTimeTimestampms{NSDate *datenow = [NSDate date]; NSString *timeSp = [NSString stringWithFormat:@"%ld", (long)([datenow timeIntervalSince1970]*1000)]; return timeSp; }// 获取当前时间戳秒 - (NSString *)getNowTimeTimestamp{NSDate *datenow = [NSDate date]; NSString *timeSp = [NSString stringWithFormat:@"%ld", (long)[datenow timeIntervalSince1970]]; return timeSp; }- (int)ascIIToNumber:(NSString *)c{ return [c characterAtIndex:0]; }- (NSString *)numberToASCII:(int) number{ return [NSString stringWithFormat:@"%C",(unichar)number]; }

【iOS|iOS 自定义加密算法】同一套算法实现加密解密，data为需要加密或解密字符串，key为盐值（可以为空），isDecode控制加密或解密