iOS生成RSA非随机密钥对？

Question

我想每次应用相同的种子时都生成相同的不对称密钥对。

我已经使用iOS RSA加密算法来生成RSA非对称密钥对。 我也每次都用同样的种子。 （公共和私有标签）但是，每次生成时，我都会收到不同的密钥。

- (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

您正在设置的“公共和私有标签”只是标识符，如果您将密钥对存储在密钥链中，则可以稍后使用SecItemCopyMatching搜索。

不幸的是，您不能使用SecKeyGeneratePair或SecKeyGeneratePairAsync密钥对设置“种子”值。 您将始终获得“随机生成的”密钥对。

如果必须这样做，则必须查看提供该功能的其他库。