通过ios实现RSA加密解密中的 RSAEncryptor.h/m相关代码

//
//  RSAEncryptor.h
//  121mai
//
//  Created by 薛XX on 16/2/16.
//
//

#import <Foundation/Foundation.h>

@interface RSAEncryptor : NSObject

#pragma mark - Instance Methods
-(void) loadPublicKeyFromFile: (NSString*) derFilePath;
-(void) loadPublicKeyFromData: (NSData*) derData;
-(void) loadPrivateKeyFromFile: (NSString*) p12FilePath password:(NSString*)p12Password;
-(void) loadPrivateKeyFromData: (NSData*) p12Data password:(NSString*)p12Password;-(NSString*) rsaEncryptString:(NSString*)string;
-(NSData*) rsaEncryptData:(NSData*)data ;
-(NSString*) rsaDecryptString:(NSString*)string;
-(NSData*) rsaDecryptData:(NSData*)data;
#pragma mark - Class Methods+(void) setSharedInstance: (RSAEncryptor*)instance;
+(RSAEncryptor*) sharedInstance;
@end

//
//  RSAEncryptor.m
//  121mai
//
//  Created by 薛XX on 16/2/16.
//
//

#import "RSAEncryptor.h"
#import <Security/Security.h>
#import "NSData+Base64.h"
@implementation RSAEncryptor
{    SecKeyRef publicKey;
SecKeyRef privateKey;
}
-(void)dealloc{    CFRelease(publicKey);
CFRelease(privateKey);
}
-(SecKeyRef) getPublicKey {    return publicKey;
}
-(SecKeyRef) getPrivateKey {    return privateKey;
}
-(void) loadPublicKeyFromFile: (NSString*) derFilePath{    NSData *derData = [[NSData alloc] initWithContentsOfFile:derFilePath];
[self loadPublicKeyFromData: derData];
}
-(void) loadPublicKeyFromData: (NSData*) derData{    publicKey = [self getPublicKeyRefrenceFromeData: derData];
}
-(void) loadPrivateKeyFromFile: (NSString*) p12FilePath password:(NSString*)p12Password{    NSData *p12Data = [NSData dataWithContentsOfFile:p12FilePath];
[self loadPrivateKeyFromData: p12Data password:p12Password];
}
-(void) loadPrivateKeyFromData: (NSData*) p12Data password:(NSString*)p12Password{    privateKey = [self getPrivateKeyRefrenceFromData: p12Data password: p12Password];
}
#pragma mark - Private Methods
-(SecKeyRef) getPublicKeyRefrenceFromeData: (NSData*)derData{    SecCertificateRef myCertificate = SecCertificateCreateWithData(kCFAllocatorDefault, (__bridge CFDataRef)derData);
SecPolicyRef myPolicy = SecPolicyCreateBasicX509();
SecTrustRef myTrust;
OSStatus status = SecTrustCreateWithCertificates(myCertificate,myPolicy,&myTrust);
SecTrustResultType trustResult;
if (status == noErr) {        status = SecTrustEvaluate(myTrust, &trustResult);
}
SecKeyRef securityKey = SecTrustCopyPublicKey(myTrust);
CFRelease(myCertificate);
CFRelease(myPolicy);
CFRelease(myTrust);
return securityKey;
}
-(SecKeyRef) getPrivateKeyRefrenceFromData: (NSData*)p12Data password:(NSString*)password{    SecKeyRef privateKeyRef = NULL;
NSMutableDictionary * options = [[NSMutableDictionary alloc] init];
[options setObject: password forKey:(__bridge id)kSecImportExportPassphrase];
CFArrayRef items = CFArrayCreate(NULL, 0, 0, NULL);
OSStatus securityError = SecPKCS12Import((__bridge CFDataRef) p12Data, (__bridge CFDictionaryRef)options, &items);
if (securityError == noErr && CFArrayGetCount(items) > 0) {        CFDictionaryRef identityDict = CFArrayGetValueAtIndex(items, 0);
SecIdentityRef identityApp = (SecIdentityRef)CFDictionaryGetValue(identityDict, kSecImportItemIdentity);
securityError = SecIdentityCopyPrivateKey(identityApp, &privateKeyRef);
if (securityError != noErr) {            privateKeyRef = NULL;        }    }    CFRelease(items);
return privateKeyRef;
}
#pragma mark - Encrypt
-(NSString*) rsaEncryptString:(NSString*)string {    NSData* data = [string dataUsingEncoding:NSUTF8StringEncoding];
NSData* encryptedData = [self rsaEncryptData: data];
NSString* base64EncryptedString = [encryptedData base64EncodedString];
return base64EncryptedString;
}// 加密的大小受限于SecKeyEncrypt函数，SecKeyEncrypt要求明文和密钥的长度一致，如果要加密更长的内容，需要把内容按密钥长度分成多份，然后多次调用SecKeyEncrypt来实现
-(NSData*) rsaEncryptData:(NSData*)data {    SecKeyRef key = [self getPublicKey];    size_t cipherBufferSize = SecKeyGetBlockSize(key);
uint8_t *cipherBuffer = malloc(cipherBufferSize * sizeof(uint8_t));
size_t blockSize = cipherBufferSize - 11;
// 分段加密
size_t blockCount = (size_t)ceil([data length] / (double)blockSize);
NSMutableData *encryptedData = [[NSMutableData alloc] init] ;
for (int i=0; i<blockCount; i++) {        int bufferSize = MIN(blockSize,[data length] - i * blockSize);
NSData *buffer = [data subdataWithRange:NSMakeRange(i * blockSize, bufferSize)];
OSStatus status = SecKeyEncrypt(key, kSecPaddingPKCS1, (const uint8_t *)[buffer bytes], [buffer length], cipherBuffer, &cipherBufferSize);
if (status == noErr){            NSData *encryptedBytes = [[NSData alloc] initWithBytes:(const void *)cipherBuffer length:cipherBufferSize];
[encryptedData appendData:encryptedBytes];
}else{            if (cipherBuffer) {                free(cipherBuffer);            }            return nil;
}    }    if (cipherBuffer){        free(cipherBuffer);
}    return encryptedData;
}
#pragma mark - Decrypt
-(NSString*) rsaDecryptString:(NSString*)string {    NSData* data = [NSData dataFromBase64String: string];

NSData* decryptData = [self rsaDecryptData: data];
NSString* result = [[NSString alloc] initWithData: decryptData encoding:NSUTF8StringEncoding];
return result;
}
-(NSData*) rsaDecryptData:(NSData*)data {    SecKeyRef key = [self getPrivateKey];
size_t cipherLen = [data length];
void *cipher = malloc(cipherLen);
[data getBytes:cipher length:cipherLen];
size_t plainLen = SecKeyGetBlockSize(key) - 12;
void *plain = malloc(plainLen);
OSStatus status = SecKeyDecrypt(key, kSecPaddingPKCS1, cipher, cipherLen, plain, &plainLen);
if (status != noErr) {        return nil;    }
NSData *decryptedData = [[NSData alloc] initWithBytes:(const void *)plain length:plainLen];
return decryptedData;
}
#pragma mark- Class Methodsstatic
RSAEncryptor* sharedInstance = nil;
+(void) setSharedInstance: (RSAEncryptor*)instance{    sharedInstance = instance;}+(RSAEncryptor*) sharedInstance{    return sharedInstance;
}
@end