RSA加密使用现有的公共密钥

Question

我想的NSData以下方法进行加密：

- (NSData *) encryptWithData:(NSData *)content { 

size_t plainLen = [content length]; 

void *plain = malloc(plainLen); 
[content getBytes:plain 
      length:plainLen]; 

size_t cipherLen = 256; 
void *cipher = malloc(cipherLen); 

OSStatus returnCode = SecKeyEncrypt("PUBLIC KEY HERE", kSecPaddingPKCS1, plain, 
            plainLen, cipher, &cipherLen); 

NSData *result = nil; 
if (returnCode != 0) { 
    NSLog(@"SecKeyEncrypt fail. Error Code: %ld", returnCode); 
} 
else { 
    result = [NSData dataWithBytes:cipher 
          length:cipherLen]; 
} 

free(plain); 
free(cipher); 

return result; 

}

，里面写到“公用钥匙HERE”我要加载现有的公共键我已经复制到我的包。我怎样才能做到这一点？

Answer 1

例如使用含有公钥证书文件：

NSData *certificateData = [NSData dataWithContentsOfURL:certificateURL options:0 error:&error]; 
if (certificateData) { 
    SecCertificateRef certificate = SecCertificateCreateWithData(NULL, (__bridge CFDataRef)(certificateData)); 
    // ... 
    SecKeyRef publicKey; 
    SecCertificateCopyPublicKey(certificate, &publicKey); 
    // ... 
} 

若要从包中加载数据：

NSArray *certificateURLs = [[NSBundle mainBundle] URLsForResourcesWithExtension:@"cer" subdirectory:@"myCertificates"]; 
for (NSURL *certificateURL in certificateURLs) { 
    NSData *certificateData = [NSData dataWithContentsOfURL:certificateURL options:0 error:&error]; 
    // ... 
}