RSA加密如何讓字符串NSString如何轉成SecKeyRef？
RSA加密如何讓字符串NSString如何轉成SecKeyRef？
註意：此方法只適用於服務器生成的der格式的公鑰字符串，dem格式的會在SecTrustCreateWithCertificates函數處崩潰。 
看到網上有很多朋友都提出過這個問題，也沒有詳細的解答，感覺挺坑的，因為我之前也在為這個問題糾結了好久，之後是在技術群有高人相助才解決掉的，廢話不多說直接上代碼吧！
這是當時後臺提供給我的公鑰字符串：服務器是java
#defineRSA_PUBLIC_KEY @"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"
註意：跟後臺服務器一定要溝通好，用什麽格式 不然會有很多坑等著你去跳，編碼格式建議采用（utf-8）
//獲取公鑰
static SecKeyRef _public_key=nil;
- (SecKeyRef) getPublicKey{// 從公鑰證書文件中獲取到公鑰的SecKeyRef指針
if(_public_key == nil){
//由於後臺給我的字符串時base過的所以要轉回來，沒有的請忽視
NSData *certificateData = [GTMBase64 decodeString:RSA_PUBLIC_KEY];
SecCertificateRef myCertificate = SecCertificateCreateWithData(kCFAllocatorDefault, (CFDataRef)certificateData);
SecPolicyRef myPolicy = SecPolicyCreateBasicX509();
SecTrustRef myTrust;
OSStatus status = SecTrustCreateWithCertificates(myCertificate,myPolicy,&myTrust);
SecTrustResultType trustResult;
if (status == noErr) {
status = SecTrustEvaluate(myTrust, &trustResult);
}
_public_key = SecTrustCopyPublicKey(myTrust);
CFRelease(myCertificate);
CFRelease(myPolicy);
CFRelease(myTrust);
}
return _public_key;
}
RSA加密如何讓字符串NSString如何轉成SecKeyRef？