需要初始化iv的DES加密。（CBC模式）
两个iv任选其一，必须要和你的后台对应。（CBC模式）
const Byte iv[] = {1,2,3,4,5,6,7,8};
const Byte iv[] = {0,1,2,3,4,5,6,7};
/// 需要初始化iv的DES加密。（CBC模式）
+ (NSString *)encodeDesCBCWithString:(NSString*)stringCBC {
NSData*data;
// NSString*ciphertext =nil;
NSData *textData = [stringCBC dataUsingEncoding:NSUTF8StringEncoding];
NSUInteger dataLength = [textData length];
unsigned char buffer[1024];
memset(buffer,0,sizeof(char));
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding ,
[kASDESKEY UTF8String],kCCKeySizeDES,
iv,
[textData bytes], dataLength,
buffer,1024,
&numBytesEncrypted);
if(cryptStatus ==kCCSuccess) {
data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
}
NSString *result = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
return result;
}
需要初始化iv的DES解密。（CBC模式）
/// 需要初始化iv的DES解密。（CBC模式）
+ (NSString*)decodeDesCBCWithString:(NSString *)stringCBC {
// NSData*plaindata =nil;
NSString*plaintext =nil;
// NSData *cipherdata = [GTMBase64 decodeString:stringCBC];
NSData *cipherdata = [[NSData alloc] initWithBase64EncodedString:stringCBC options:NSDataBase64DecodingIgnoreUnknownCharacters];
unsigned char buffer[1024];
memset(buffer,0,sizeof(char));
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding ,
[kASDESKEY UTF8String],kCCKeySizeDES,
iv,
[cipherdata bytes], [cipherdata length],
buffer,1024,
&numBytesDecrypted);
if (cryptStatus ==kCCSuccess) {
NSData*plaindata = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];
plaintext = [[NSString alloc]initWithData:plaindata encoding:NSUTF8StringEncoding];
}
return plaintext;
}
不需要初始化iv的DES加密。（ECB模式）
/// 不需要初始化iv的DES加密。（ECB模式）
+ (NSString *)encodeDesECBWithString:(NSString*)stringECB {
NSData*data;
// NSString*ciphertext =nil;
NSData *textData = [stringECB dataUsingEncoding:NSUTF8StringEncoding];
NSUInteger dataLength = [textData length];
unsigned char buffer[1024];
memset(buffer,0,sizeof(char));
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
[kASDESKEY UTF8String],kCCKeySizeDES,
NULL,
[textData bytes], dataLength,
buffer,1024,
&numBytesEncrypted);
if(cryptStatus ==kCCSuccess) {
data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
}
NSString *result = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
return result;
}
不需要初始化iv的DES解密。（ECB模式）
/// 不需要初始化iv的DES解密。（ECB模式）
+ (NSString*)decodeDesECBWithString:(NSString *)stringECB {
// NSData*plaindata = nil;
NSString*plaintext = nil;
// NSData *cipherdata = [GTMBase64 decodeString:stringECB];
NSData *cipherdata = [[NSData alloc] initWithBase64EncodedString:stringECB options:NSDataBase64DecodingIgnoreUnknownCharacters];
unsigned char buffer[1024];
memset(buffer,0,sizeof(char));
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
[kASDESKEY UTF8String],kCCKeySizeDES,
NULL,
[cipherdata bytes], [cipherdata length],
buffer,1024,
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
NSData*plaindata = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];
plaintext = [[NSString alloc]initWithData:plaindata encoding:NSUTF8StringEncoding];
}
return plaintext;
}
DES16进制加密
/// 使用DES加密方法
+ (NSString *)encodeDesWithString:(NSString *)string {
NSString *ciphertext = nil;
const char *textBytes = [string UTF8String];
size_t dataLength = [string length];
//==================
uint8_t *bufferPtr = NULL;
size_t bufferPtrSize = 0;
size_t movedBytes = 0;
bufferPtrSize = (dataLength + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);
bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
memset((void *)bufferPtr, 0x0, bufferPtrSize);
NSString *testString = kASDESKEY;
NSData *testData = [testString dataUsingEncoding: NSUTF8StringEncoding];
Byte *iv = (Byte *)[testData bytes];
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding,
[kASDESKEY UTF8String], kCCKeySizeDES,
iv,
textBytes, dataLength,
(void *)bufferPtr, bufferPtrSize,
&movedBytes);
if (cryptStatus == kCCSuccess) {
ciphertext= [ASKDESTools parseByte2HexString:bufferPtr :(int)movedBytes];
}
ciphertext=[ciphertext uppercaseString];//字符变大写
return ciphertext;
}
DES16进制解密
/// 使用DES进行解密计算
+ (NSString *)decodeDesWithString:(NSString *)string {
NSData* cipherData = [ASKDESTools convertHexStrToData:[string lowercaseString]];
unsigned char buffer[1024];
memset(buffer, 0, sizeof(char));
size_t numBytesDecrypted = 0;
NSString *testString = kASDESKEY;
NSData *testData = [testString dataUsingEncoding: NSUTF8StringEncoding];
Byte *iv = (Byte *)[testData bytes];
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
kCCAlgorithmDES,
kCCOptionPKCS7Padding,
[kASDESKEY UTF8String],
kCCKeySizeDES,
iv,
[cipherData bytes],
[cipherData length],
buffer,
1024,
&numBytesDecrypted);
NSString* plainText = nil;
if (cryptStatus == kCCSuccess) {
NSData* data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];
plainText = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
}
return plainText;
}
加密解密中有两个方法调用，其实是为了16进制与data之间的转换。有些公司并未转换成16进制，而是需要跟base64共同加解密。方法适用，只需要将得出的plainText 的值转成base64即可。
加密时转成16进制
+ (NSString *) parseByte2HexString:(Byte *) bytes :(int)len {
NSString *hexStr = @"";
if(bytes)
{
for(int i = 0; i < len ; i++)
{
NSString *newHexStr = [NSString stringWithFormat:@"%x",bytes[i]&0xff]; ///16进制数
if([newHexStr length]==1)
hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr];
else
{
hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr];
}
}
}
return hexStr;
}
解密时转回data
+ (NSData *)convertHexStrToData:(NSString *)str {
if (!str || [str length] == 0) {
return nil;
}
NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:8];
NSRange range;
if ([str length] % 2 == 0) {
range = NSMakeRange(0, 2);
} else {
range = NSMakeRange(0, 1);
}
for (NSInteger i = range.location; i < [str length]; i += 2) {
unsigned int anInt;
NSString *hexCharStr = [str substringWithRange:range];
NSScanner *scanner = [[NSScanner alloc] initWithString:hexCharStr];
[scanner scanHexInt:&anInt];
NSData *entity = [[NSData alloc] initWithBytes:&anInt length:1];
[hexData appendData:entity];
range.location += range.length;
range.length = 2;
}
return hexData;
}
注意：
1、DES的加密模式有ECB和CBC。
2、iOS的填充模式只有 kCCOptionPKCS7Padding 和kCCOptionPKCS7Padding | kCCOptionECBMode两种。而后台填充模式就多了，这就需要一一对应才能实现加密和解密。
3、具体的对应模式是java的DES/ECB/PKCS5Padding对应iOS的kCCOptionPKCS7Padding | kCCOptionECBMode；DES/CBC/PKCS5Padding对应ios的kCCOptionPKCS7Padding 。
Simulator Screen Shot - iPhone 11 Pro Max - 2020-04-30 at 16.17.14.png
Demo下载地址