本人在开发中遇到一个des加解密的问题。先上代码
#import "DesEncryption.h"
#import
#import "GTMBase64.h"
@implementation DesEncryption
#pragma mark +++++
//8位key解密有效(已验证)
+(NSString*) DecryptUseDES:(NSString*)cipherText key:(NSString*)key {
// 利用 GTMBase64 解碼 Base64 字串
NSData* cipherData = [GTMBase64 decodeString:cipherText];
unsigned char buffer[1024];
memset(buffer, 0, sizeof(char));
size_t numBytesDecrypted = 0;
// IV 偏移量不需使用
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
kCCAlgorithmDES,
kCCOptionPKCS7Padding| kCCOptionECBMode,
[key UTF8String],
kCCKeySizeDES,
nil,
[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] autorelease];
}
return plainText;
}
////8位key加密有效(已验证)
+(NSString *) EncryptUseDES:(NSString *)clearText key:(NSString *)key
{
NSData *data = [clearText dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
unsigned char buffer[1024];
memset(buffer, 0, sizeof(char));
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
kCCAlgorithmDES,
kCCOptionPKCS7Padding| kCCOptionECBMode,
[key UTF8String],
kCCKeySizeDES,
nil,
[data bytes],
[data length],
buffer,
1024,
&numBytesEncrypted);
NSString* plainText = nil;
if (cryptStatus == kCCSuccess) {
NSData *dataTemp = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
plainText = [GTMBase64 stringByEncodingData:dataTemp];
}else{
NSLog(@"DES加密失败");
}
return plainText;
}
例如:秘钥:abcdefgh
明文:123456
密文:sHTd/9exYuk=
如果秘钥换成:abcdefghabcdefgh
明文:123456
密文:WcbWa42yxuo=
不做任何改动,依旧用上面的解密方法 ,返回的plainText 是nil
期间试图改变kCCKeySizeDES为kCCKeySizeAES128(因为考虑到秘钥长度变为16位),可是结果还是徒劳,
本人尝试改变CCCryptorStatus里面的各种参数,一无所获,特发此贴求助