Objective C 中的 RSA 实现

RSA算法是一种非对称加密算法，广泛应用于信息安全领域。在Objective C中，我们可以使用第三方库来实现RSA加解密功能。本文将介绍如何在Objective C中使用RSA进行加解密，并提供一个简单的代码示例。

objective-c
- (void)generateRSAKeyPair {
    NSDictionary *privateKeyAttributes = @{ (id)kSecAttrIsPermanent : @YES };
    NSDictionary *publicKeyAttributes = @{ (id)kSecAttrIsPermanent : @YES };
    NSDictionary *keyPairAttributes = @{ (id)kSecAttrKeyType : (id)kSecAttrKeyTypeRSA,
                                          (id)kSecAttrKeySizeInBits : @2048,
                                          (id)kSecPrivateKeyAttrs : privateKeyAttributes,
                                          (id)kSecPublicKeyAttrs : publicKeyAttributes };
    
    SecKeyRef publicKey, privateKey;
    OSStatus status = SecKeyGeneratePair((__bridge CFDictionaryRef)keyPairAttributes, &publicKey, &privateKey);
    
    if (status == errSecSuccess) {
        NSLog(@"RSA key pair generated successfully.");
        // 密钥对生成成功，可以保存密钥或者进行加解密操作
    } else {
        NSLog(@"Failed to generate RSA key pair. Error code: %d", (int)status);
    }
}

objective-c
- (NSData *)encryptData:(NSData *)data withPublicKey:(SecKeyRef)publicKey {
    size_t cipherBufferSize = SecKeyGetBlockSize(publicKey);
    uint8_t *cipherBuffer = malloc(cipherBufferSize);
    uint8_t *plainBuffer = (uint8_t *)[data bytes];
    size_t plainBufferSize = data.length;
    
    OSStatus status = SecKeyEncrypt(publicKey, kSecPaddingPKCS1, plainBuffer, plainBufferSize, cipherBuffer, &cipherBufferSize);
    
    if (status == errSecSuccess) {
        return [NSData dataWithBytes:cipherBuffer length:cipherBufferSize];
    } else {
        NSLog(@"RSA encryption failed. Error code: %d", (int)status);
        return nil;
    }
}
- (NSData *)decryptData:(NSData *)data withPrivateKey:(SecKeyRef)privateKey {
    size_t plainBufferSize = SecKeyGetBlockSize(privateKey);
    uint8_t *plainBuffer = malloc(plainBufferSize);
    uint8_t *cipherBuffer = (uint8_t *)[data bytes];
    size_t cipherBufferSize = data.length;
    
    OSStatus status = SecKeyDecrypt(privateKey, kSecPaddingPKCS1, cipherBuffer, cipherBufferSize, plainBuffer, &plainBufferSize);
    
    if (status == errSecSuccess) {
        return [NSData dataWithBytes:plainBuffer length:plainBufferSize];
    } else {
        NSLog(@"RSA decryption failed. Error code: %d", (int)status);
        return nil;
    }
}