IOS加密 AES 256算法(EncryptAndDecrypt.h)
陈誉
EncryptAndDecrypt.h
#import <Foundation/Foundation.h>
@class NSString;
@interface NSData (Encryption)
- (NSData *)AES256EncryptWithKey:(NSData *)key; //加密
- (NSData *)AES256DecryptWithKey:(NSData *)key; //解密
- (NSString *)newStringInBase64FromData; //追加64编码
+ (NSString*)base64encode:(NSString*)str; //同上64编码
+(NSData*)stringToByte:(NSString*)string;
+(NSString*)byteToString:(NSData*)data;
@end
///EncryptAndDecrypt.m
#import "EncryptAndDecrypt.h"
#import <CommonCrypto/CommonCrypto.h>
static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
@implementation NSData (Encryption)
- (NSData *)AES256EncryptWithKey:(NSData *)key //加密
{
//AES256加密，密钥应该是32位的
const void * keyPtr2 = [key bytes];
char (*keyPtr)[32] = keyPtr2;
//对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
//所以在下边需要再加上一个块的大小
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
[key bytes], kCCKeySizeAES256,
NULL,/* 初始化向量(可选) */
[self bytes], dataLength,/*输入*/
buffer, bufferSize,/* 输出 */
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);//释放buffer
return nil;
}
- (NSData *)AES256DecryptWithKey:(NSData *)key //解密
{
//同理，解密中，密钥也是32位的
const void * keyPtr2 = [key bytes];
char (*keyPtr)[32] = keyPtr2;
//对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
//所以在下边需要再加上一个块的大小
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
keyPtr, kCCKeySizeAES256,
NULL,/* 初始化向量(可选) */
[self bytes], dataLength,/* 输入 */
buffer, bufferSize,/* 输出 */
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
- (NSString *)newStringInBase64FromData //追加64编码
{
NSMutableString *dest = [[NSMutableString alloc] initWithString:@""];
unsigned char * working = (unsigned char *)[self bytes];
int 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];
int 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;
}
+(NSData*)stringToByte:(NSString*)string
{
NSString *hexString=[[string uppercaseString] stringByReplacingOccurrencesOfString:@" " withString:@""];
if ([hexString length]%2!=0) {
return nil;
}
Byte tempbyt[1]={0};
NSMutableData* bytes=[NSMutableData data];
for(int i=0;i<[hexString length];i++)
{
unichar hex_char1 = [hexString characterAtIndex:i]; 两位16进制数中的第一位(高位*16)
int int_ch1;
if(hex_char1 >= '0' && hex_char1 <='9')
int_ch1 = (hex_char1-48)*16; 0 的Ascll - 48
else if(hex_char1 >= 'A' && hex_char1 <='F')
int_ch1 = (hex_char1-55)*16; A 的Ascll - 65
else
return nil;
i++;
unichar hex_char2 = [hexString characterAtIndex:i]; ///两位16进制数中的第二位(低位)
int int_ch2;
if(hex_char2 >= '0' && hex_char2 <='9')
int_ch2 = (hex_char2-48); 0 的Ascll - 48
else if(hex_char2 >= 'A' && hex_char2 <='F')
int_ch2 = hex_char2-55; A 的Ascll - 65
else
return nil;
tempbyt[0] = int_ch1+int_ch2; ///将转化后的数放入Byte数组里
[bytes appendBytes:tempbyt length:1];
}
return bytes;
}
+(NSString*)byteToString:(NSData*)data
{
Byte *plainTextByte = (Byte *)[data bytes];
NSString *hexStr=@"";
for(int i=0;i<[data length];i++)
{
NSString *newHexStr = [NSString stringWithFormat:@"%x",plainTextByte[i]&0xff];///16进制数
if([newHexStr length]==1)
hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr];
else
hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr];
}
return hexStr;
}
@end使用
-(void)Jiami
{
NSString *plainText = @"AES中国";//明文
NSData *plainTextData = [plainText dataUsingEncoding:NSUTF8StringEncoding];
NSString *keyStr = @"12345678901234567890123456789012";
NSData *keyDataStr = [keyStr dataUsingEncoding:NSUTF8StringEncoding];
NSData *cipherTextData = [plainTextData AES256EncryptWithKey:keyDataStr];
NSString *hexStr = [NSData byteToString:cipherTextData];
NSLog(@"密文:%@",hexStr);
[self Jiemi:hexStr];
}
-(void)Jiemi:(NSString *)hexString
{
NSString *keyStr = @"12345678901234567890123456789012";
NSData *keyDataStr = [keyStr dataUsingEncoding:NSUTF8StringEncoding];
NSData *data = [NSData stringToByte:hexString];
/
NSData *datas = [data AES256DecryptWithKey:keyDataStr];
NSLog([[NSString alloc]initWithData:datas encoding:NSUTF8StringEncoding]);
}
http://blog.csdn.net/pjk1129/article/details/8489550
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