ios - 将 PEM 文件中的公钥加载到 NSData

Question

我有一个存储在 PEM 文件中的公钥，我想加载这个文件并将公钥提取到一个 NSData 中，然后我可以将其发送到 [SecKeyWrapper addPeerPublicKey:keyBits:](参见 http://developer.apple.com/library/ios/#samplecode/CryptoExercise/Listings/Classes_SecKeyWrapper_h.html)。

我如何在 Objective-C(在 iOS 上)中做到这一点？

Answer 1

假设您知道公钥存在并且以“-----BEGIN PUBLIC KEY-----”开头并以“-----END PUBLIC KEY-----”结尾，您可以执行以下操作以下:

NSString *startPublicKey = @"-----BEGIN PUBLIC KEY-----";
NSString *endPublicKey = @"-----END PUBLIC KEY-----";
NSString* path = [[NSBundle mainBundle] pathForResource:@"mykey"
                                                     ofType:@"pem"];
NSString* content = [NSString stringWithContentsOfFile:path
                                                  encoding:NSUTF8StringEncoding
                                                     error:NULL];
NSString *publicKey;
NSScanner *scanner = [NSScanner scannerWithString:content];
[scanner scanUpToString:startPublicKey intoString:nil];
[scanner scanString:startPublicKey intoString:nil];
[scanner scanUpToString:endPublicKey intoString:&publicKey];

NSData *data = [NSData base64DataFromString:publicKey];