(IOS) 공개키를 이용한 RSA 암호화 클래스

Java 플랫폼의 서버와 IOS&Android 간의 RSA암호화 문자열을 주고받아야 하는 상황이 발생되었다.
구글링과 맥부기 카페의 도움으로 아래의 IOS용 RSA암호화클래스를 작성했다. 

인터페이스 RSAEncryptor.h

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#import <Foundation/Foundation.h> #import <Security/Security.h> #import "SecKeyWrapper.h"   @interface RSAEncryptor : SecKeyWrapper {     SecKeyRef keyref; } + (RSAEncryptor *)sharedSingleton; -(NSString*)encrypt:(NSString *)str;   @end

구현클래스 RSAEncryptor.h

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#import "RSAEncryptor.h" #import "SecKeyWrapper.h" #import "BasicEncodingRules.h" #import "Base64.h"   //공개키-modulus (바이너리를 BASE64로 인코딩한 문자열) #define PUBLICKEY_MODULUS @"AMQJe/E1jYwMhyGfrFULikXkiwAMyN2mmb1dYn8F15ELwK6obGIfDiOaVQGqItO+xrWWZHNi9KA39+MmsNc2pSUzLSaNCjaWWNmeKQ4K08CctUVIkTRg4YG6Q/ZDAy5vaZkzNFPSUJLWw7dRLsyQW3H4zJanLKYIetxu3ILkQ471"   //공개키-exponent (바이너리를 BASE64로 인코딩한 문자열) #define PUBLICKEY_EXPONENT @"AQAB"   @implementation RSAEncryptor   static RSAEncryptor *rsaEncryptor = nil;   + (RSAEncryptor *)sharedSingleton {     @synchronized(self)     {         if (rsaEncryptor == NULL)             rsaEncryptor = [[self alloc] init];     }     return(rsaEncryptor); } - (id)init {     if (self = [super init]) {                   //공개키 생성         NSData *pubKeyModData = [Base64 decode:PUBLICKEY_MODULUS];         NSData *pubKeyExpData = [Base64 decode:PUBLICKEY_EXPONENT];                   NSString *peerName = @"thisissometagname";  //태그명         NSMutableArray *pubKeyArray = [[NSMutableArray alloc] init];         [pubKeyArray addObject:pubKeyModData];         [pubKeyArray addObject:pubKeyExpData];         NSData *pubKeys = [pubKeyArray berData];                   keyref = [self addPeerPublicKey:peerName keyBits:pubKeys];     }     return self; } - (void)dealloc {     // Should never be called, but just here for clarity really.     if (false) {    //ignore warning         [super dealloc];     } }   -(NSString*)encrypt:(NSString *)str {     if (keyref) {         size_t cipherBufferSize;         uint8_t *cipherBuffer;                     // 1 암호화 된 텍스트를 저장할 버퍼를 할당합니다.         const char *dataToEncrypt = [str UTF8String];         size_t dataLength = strlen(dataToEncrypt);         cipherBufferSize = SecKeyGetBlockSize(keyref);         cipherBuffer = malloc(cipherBufferSize);         //NSLog(@"RSA암호화할 문자열 : %s", dataToEncrypt);         OSStatus status = SecKeyEncrypt(keyref,                                         kSecPaddingPKCS1,                                         (uint8_t*)dataToEncrypt,                                         (size_t) dataLength,                                         cipherBuffer,                                         &cipherBufferSize                                         );                   if (status==0) {             [Base64 initialize];             NSString *encoded = [Base64 encode:cipherBuffer length:cipherBufferSize];             //NSLog(@"RSA암호화(BASE64문자열) : %@", encoded);             return encoded;         }     }     return @""; }     @end

사용방법

1	[[RSAEncryptor sharedSingleton] encrypt:@"암호화할 문자열"];

ps) SecKeyWrapper 클래스를 시뮬레이터에서 작동시키려면 시뮬레이터에서만 빌드되게 해놓은 코드를 돌지않게끔 수정해야한다. 아래코드 참고

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#if FALSE #error This sample is designed to run on a device, not in the simulator. To run this sample, \ choose Project > Set Active SDK > Device and connect a device. Then click Build and Go.