将 NSData 转换为 SecKeyRef

Question

>我用SecKeyGeneratePair生成了私钥和公钥我已经将SecKeyRef转换为NSData

size_t keySize = SecKeyGetBlockSize（publicKey）;

NSData *keyData = [NSData dataWithBytes：publicKey length：keySize];

但不幸的是，我无法将keyData重新转换为SecKeyRef类型。

问题来了：如何重新转换 SecKeyRef 类型的 NSData？

这是代码！

    //
    //  RSA.m
    //  example
    //
    //  Created by Ferdinando Picone on 07/11/13.
    //  Copyright (c) 2013 Ferdinando Picone. All rights reserved.
    //
    #import "RSA.h"
    #import <Security/Security.h>
    #import "NSData+Base64.h"
    static const UInt8 publicKeyIdentifier[] = "com.apple.sample.publickey";
    static const UInt8 privateKeyIdentifier[] = "com.apple.sample.privatekey";
    
    SecKeyRef publicKey = NULL;
    SecKeyRef privateKey = NULL;
    @implementation RSA
    -(void)start{
RSA *one = [[RSA alloc]init];

// Generate public and private key
[one generateKeyPairPlease];
NSLog(@" %@", publicKey);
NSLog(@" %@", privateKey);
//Convert public key in NSData Type
size_t  keySize = SecKeyGetBlockSize(publicKey);
NSData  *keyData = [NSData dataWithBytes:publicKey length:keySize];
NSLog (@" %@", keyData);
//Convert public key in NSString Type
NSString *keyStringB64 =[keyData base64EncodedString];

//Reconvert NSString in a NSData Type (newKeyData)
NSData *newKeyData = [NSData dataFromBase64String:keyStringB64];
NSLog(@" %@", newKeyData);
// In the debug you can see that keyData==newKeyData
// NOW I NEED TO RECONVERT newKeyData in a SecKeyRef newPublicKey
SecKeyRef newPublicKey=NULL;
    }
    -(void) generateKeyPairPlease{
OSStatus status = noErr;
NSMutableDictionary *privateKeyAttr = [[NSMutableDictionary alloc] init];
NSMutableDictionary *publicKeyAttr = [[NSMutableDictionary alloc] init];
NSMutableDictionary *keyPairAttr = [[NSMutableDictionary alloc] init];
NSData * publicTag = [NSData dataWithBytes:publicKeyIdentifier
                                    length:strlen((const char *)publicKeyIdentifier)];
NSData * privateTag = [NSData dataWithBytes:privateKeyIdentifier
                                     length:strlen((const char *)privateKeyIdentifier)];

[keyPairAttr setObject:(__bridge id)kSecAttrKeyTypeRSA
                forKey:(__bridge id)kSecAttrKeyType];
[keyPairAttr setObject:[NSNumber numberWithInt:1024]
                forKey:(__bridge id)kSecAttrKeySizeInBits];
[privateKeyAttr setObject:[NSNumber numberWithBool:YES]
                   forKey:(__bridge id)kSecAttrIsPermanent];
[privateKeyAttr setObject:privateTag
                   forKey:(__bridge id)kSecAttrApplicationTag];
[publicKeyAttr setObject:[NSNumber numberWithBool:YES]
                  forKey:(__bridge id)kSecAttrIsPermanent];
[publicKeyAttr setObject:publicTag
                  forKey:(__bridge id)kSecAttrApplicationTag];
[keyPairAttr setObject:privateKeyAttr
                forKey:(__bridge id)kSecPrivateKeyAttrs];
[keyPairAttr setObject:publicKeyAttr
                forKey:(__bridge id)kSecPublicKeyAttrs];
status = SecKeyGeneratePair((__bridge CFDictionaryRef)keyPairAttr,
                            &publicKey, &privateKey);

    }

    @end

Answer 1

您可以使用

iOS 10.10中提供的API从NSData创建SecKeyRef

。

- (SecKeyRef)secKeyRefFromFrivateKeyData:(NSData *)privateKeyData
{
    NSDictionary *attributes = @{(__bridge NSString*)kSecAttrKeyType : (__bridge NSString*)kSecAttrKeyTypeRSA,
                                 (__bridge NSString*)kSecAttrKeyClass : (__bridge NSString*)kSecAttrKeyClassPrivate};
    return SecKeyCreateWithData((__bridge CFDataRef)privateKeyData, (__bridge CFDictionaryRef)attributes, NULL);
}