iOS 生成 RSA 非随 secret 钥对？

Question

我想在每次应用相同的种子时生成相同的非对称 key 对。

我已经使用 iOS RSA 加密练习来生成 RSA 非对称 key 对。我也每次都使用相同的种子。 (公共(public)和私有(private)标签)但是，我每次生成时都会收到不同的 key 。

- (void)generateKeyPair:(NSUInteger)keySize {
    OSStatus sanityCheck = noErr;
    publicKeyRef = NULL;
    privateKeyRef = NULL;

    LOGGING_FACILITY1( keySize == 512 || keySize == 1024 || keySize == 2048, @"%d is an invalid and unsupported key size.", keySize );

    // First delete current keys.
    [self deleteAsymmetricKeys];

    // Container dictionaries.
    NSMutableDictionary * privateKeyAttr = [[NSMutableDictionary alloc] init];
    NSMutableDictionary * publicKeyAttr = [[NSMutableDictionary alloc] init];
    NSMutableDictionary * keyPairAttr = [[NSMutableDictionary alloc] init];

    // Set top level dictionary for the keypair.
    [keyPairAttr setObject:(id)kSecAttrKeyTypeRSA forKey:(id)kSecAttrKeyType];
    [keyPairAttr setObject:[NSNumber numberWithUnsignedInteger:keySize] forKey:(id)kSecAttrKeySizeInBits];

    // Set the private key dictionary.
    [privateKeyAttr setObject:[NSNumber numberWithBool:YES] forKey:(id)kSecAttrIsPermanent];
    [privateKeyAttr setObject:[NSNumber numberWithBool:YES] forKey:(id)kSecAttrCanEncrypt];
    [privateKeyAttr setObject:[NSNumber numberWithBool:YES] forKey:(id)kSecAttrCanDecrypt];

     [privateKeyAttr setObject:privateTag forKey:(id)kSecAttrApplicationTag];
    // See SecKey.h to set other flag values.

    // Set the public key dictionary.
    [publicKeyAttr setObject:[NSNumber numberWithBool:YES] forKey:(id)kSecAttrIsPermanent];
    [publicKeyAttr setObject:publicTag forKey:(id)kSecAttrApplicationTag];
    // See SecKey.h to set other flag values.

    // Set attributes to top level dictionary.
    [keyPairAttr setObject:privateKeyAttr forKey:(id)kSecPrivateKeyAttrs];
    [keyPairAttr setObject:publicKeyAttr forKey:(id)kSecPublicKeyAttrs];

    // SecKeyGeneratePair returns the SecKeyRefs just for educational purposes.
    sanityCheck = SecKeyGeneratePair((CFDictionaryRef)keyPairAttr, &publicKeyRef, &privateKeyRef);
    LOGGING_FACILITY( sanityCheck == noErr && publicKeyRef != NULL && privateKeyRef != NULL, @"Something really bad went wrong with generating the key pair." );


    NSLog(@"getPublicKeyBits: %@", [self getPublicKeyBits]);

    NSLog(@"getPublicKeyExp: %@", [self getPublicKeyExp]);
    NSLog(@"getPublicKeyMod: %@", [self getPublicKeyMod]);


   // NSLog(@"keyPairAttr: %@" , keyPairAttr);
    [privateKeyAttr release];
    [publicKeyAttr release];
    [keyPairAttr release];
}

Answer 1

您设置的“公共(public)和私有(private)标签”只是标识符，如果您将 key 对存储在 key 链中，您稍后可以使用 SecItemCopyMatching 搜索这些标识符。

遗憾的是，您无法使用 SecKeyGeneratePair 或 SecKeyGeneratePairAsync 为非对称 key 对设置“种子”值。您将始终获得“随机生成”的 key 对。

如果您必须这样做，您将不得不查看提供该功能的其他库。