如何在iOS中使用ECC

问题描述

在iOS中是否有使用ECC的示例？

Is there any example for use ECC in iOS?

我注意到Apple Developer Documents中的kSecAttrKeyTypeEC，但我不能将它用于通用密钥对。

I noticed that the kSecAttrKeyTypeEC in Apple Developer Documents, but I can't use it to generic Key pair.

下面的代码是从示例中修改的CryptoExercise

Below code is modified from the example CryptoExercise

// 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)kSecAttrKeyTypeEC 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: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." );

sanityCheck总是返回-50，这意味着'errSecParam'。

The sanityCheck always return -50 which means 'errSecParam'.

我真的不知道怎么用它，谢谢你读这个。

I really don't know how to use it, thank you for read this.

推荐答案

NSDictionary *parameters = @{
                             (__bridge id)kSecAttrKeyType: (__bridge id)kSecAttrKeyTypeEC,
                             (__bridge id)kSecAttrKeySizeInBits: @256,
                             (__bridge id)kSecPrivateKeyAttrs: @{
                                     (__bridge id)kSecAttrIsPermanent: @YES,
                                     (__bridge id)kSecAttrApplicationTag: [@"my.key.tag" dataUsingEncoding:NSUTF8StringEncoding],
                                     },
                             (__bridge id)kSecPublicKeyAttrs: @{
                                     (__bridge id)kSecAttrIsPermanent: @YES,
                                     (__bridge id)kSecAttrApplicationTag: [@"my.key.pubtag" dataUsingEncoding:NSUTF8StringEncoding],
                                     }
                             };

SecKeyRef publicKey, privateKey;
OSStatus status = SecKeyGeneratePair((__bridge CFDictionaryRef)parameters, &publicKey, &privateKey);

这样可行，请仔细检查您的密钥大小参数。

This works, double check your key size parameter.

只需注意，目前EC密钥只能用于签名/验证数据。加密/解密返回 errSecUnimplemented = -4。

Just a note, currently EC keys can only be used for signing/verifying data. Encryption/decryption returns errSecUnimplemented = -4.

这篇关于如何在iOS中使用ECC的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！