Vickate_AES加密与解密（Objective-C版），暂未实现与java的交互（求大神帮助）

</pre><pre name="code" class="objc">
#import <Foundation/Foundation.h>

@class NSString;

@interface NSData (Encryption)

- (NSData *)AES256EncryptWithKey:(NSString *)key;   //加密

- (NSData *)AES256DecryptWithKey:(NSString *)key;   //解密

- (NSString *)newStringInBase64FromData;            //追加64编码

+ (NSString*)base64encode:(NSString*)str;           //同上64编码

@end

#import "NSData+Encryption.h"

#import <CommonCrypto/CommonCryptor.h>
static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

@implementation NSData (Encryption)

- (NSData *)AES256EncryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

// fetch key data
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [self length];

//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);

size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES256,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
//the returned NSData takes ownership of the buffer and will free it on deallocation
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}

free(buffer); //free the buffer;
return nil;
}

- (NSData *)AES256DecryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

// fetch key data
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [self length];

//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);

size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES256,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesDecrypted);

if (cryptStatus == kCCSuccess) {
//the returned NSData takes ownership of the buffer and will free it on deallocation
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}

free(buffer); //free the buffer;
return nil;
}

- (NSString *)newStringInBase64FromData            //追加64编码

{

NSMutableString *dest = [[NSMutableString alloc] initWithString:@""];

unsigned char * working = (unsigned char *)[self bytes];

NSUInteger srcLen = [self length];

for (int i=0; i<srcLen; i += 3) {

for (int nib=0; nib<4; nib++) {

int byt = (nib == 0)?0:nib-1;

int ix = (nib+1)*2;

if (i+byt >= srcLen) break;

unsigned char curr = ((working[i+byt] << (8-ix)) & 0x3F);

if (i+nib < srcLen) curr |= ((working[i+nib] >> ix) & 0x3F);

[dest appendFormat:@"%c", base64[curr]];

}

}

return dest;

}

+ (NSString*)base64encode:(NSString*)str

{

if ([str length] == 0)

return @"";

const char *source = [str UTF8String];

unsigned long strlength  = strlen(source);

char *characters = malloc(((strlength + 2) / 3) * 4);

if (characters == NULL)

return nil;

NSUInteger length = 0;

NSUInteger i = 0;

while (i < strlength) {

char buffer[3] = {0,0,0};

short bufferLength = 0;

while (bufferLength < 3 && i < strlength)

buffer[bufferLength++] = source[i++];

characters[length++] = base64[(buffer[0] & 0xFC) >> 2];

characters[length++] = base64[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];

if (bufferLength > 1)

characters[length++] = base64[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];

else characters[length++] = '=';

if (bufferLength > 2)

characters[length++] = base64[buffer[2] & 0x3F];

else characters[length++] = '=';

}

NSString *g = [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];

return g;

}

@end

NSString *key = @"my password";

NSString *secret = @"你好";

// 加密

NSData *plain = [secret dataUsingEncoding:NSUTF8StringEncoding];

NSData *cipher = [plain AES256EncryptWithKey:key];

NSLog(@"%@",[cipher newStringInBase64FromData]);

//    printf("%s\n", [[cipher description] UTF8String]);

NSLog(@"%@", [[NSString alloc] initWithData:cipher encoding:NSUTF8StringEncoding]);//打印出null,这是因为没有解密。

plain = [cipher AES256DecryptWithKey:key];

//    printf("%s\n", [[plain description] UTF8String]);

NSLog(@"%@", [[NSString alloc] initWithData:plain encoding:NSUTF8StringEncoding]);