SecKeyRawVerify verifies on mac but fails with -98

问题:

I need to digitally sign on mac some data and then verify it on iOS. So I generated RSA keypair and certificate for public key in DER format with open ssl (tried generation with SecKeyGeneratePair but then it is harder to import Public key to iOS and SecKeyRawVerify still doesn't work with the same result), and signed my data on Mac app. Then if I verify this data on iOS verification fails with -9809 error code, but if execute the same code on mac verification succeeds.

Here is my code for verification:

NSString* certPath = [[NSBundle mainBundle] pathForResource: @"Public" ofType:@"der"];
NSData* certificateData = [NSData dataWithContentsOfFile: certPath];

SecCertificateRef certificateFromFile = SecCertificateCreateWithData(NULL, (__bridge CFDataRef)certificateData); // load the certificate

SecPolicyRef secPolicy = SecPolicyCreateBasicX509();

SecTrustRef trust;
OSStatus statusTrust = SecTrustCreateWithCertificates( certificateFromFile, secPolicy, &trust);
SecTrustResultType resultType;
OSStatus statusTrustEval =  SecTrustEvaluate(trust, &resultType);
SecKeyRef publicKey = SecTrustCopyPublicKey(trust);

NSString* licensingPolicyString = @"ZKL3YXtqtFcIeWRqSekNuCmtu/nvy3ApsbJ+8xad6cO/E8smLHGfDrTQ3h/38d0IMJcUThsVMyX8qtqILmPeTnBpZgJetBjb8kAfuPznzxOrIcYd27/50ThWv6guLqZL7j1apnfRZHAdMiozvEYH62sma1Q9qTl+W7qxEAxWs2AXDTQcF7nGciEM6MEohs8u879VNIE1VcPW8ahMoe25wf8pvBvrzE0z0MR4UFE3ZSWIeeQsiaUPYFwHbfQAOifaw/qIisjL5Su6WURoaSupWTMdQh3ZNyqZuYJaT70u8S7NgF3BzG8uBiYOUYsf6UayvkABmF0UuMdcvhPQefyhuXsiYWxsb3dFeGNoYW5nZSI6dHJ1ZSwiYWxsb3dTaGFmZXIiOnRydWUsInBvbGljeSBuYW1lIjp0cnVlfQ==";

size_t signedHashBytesSize  = SecKeyGetBlockSize(publicKey);

NSData* messageData = [[NSData alloc] initWithBase64EncodedData:[licensingPolicyString dataUsingEncoding: NSUTF8StringEncoding] options:0];

NSData* signatureData = [messageData subdataWithRange:NSMakeRange(0, signedHashBytesSize)];
NSData* rawMessageData = [messageData subdataWithRange: NSMakeRange(signedHashBytesSize, messageData.length - signedHashBytesSize)];


uint8_t sha1HashDigest[CC_SHA1_DIGEST_LENGTH];
CC_SHA1([rawMessageData bytes], (CC_LONG)[rawMessageData length], sha1HashDigest);

OSStatus verficationResult = SecKeyRawVerify(publicKey,  kSecPaddingPKCS1SHA1, sha1HashDigest, CC_SHA1_DIGEST_LENGTH, [signatureData bytes], [signatureData length]);
CFRelease(publicKey);
CFRelease(trust);
CFRelease(secPolicy);
CFRelease(certificateFromFile);
if (verficationResult == errSecSuccess) NSLog(@"Verified");

Is there some difference in digital signature verification for Mac and iOS? I didn't manage to find anything about it in Apple's documentation.

回答1:

Well after some experimenting with sign/verify, I've found out that changing padding agreement to SecKeyRawVerify/SecKeyRawSign from kSecPaddingPKCS1SHA1 to kSecPaddingPKCS1, solves my problem. Don't know why it doesn't work with kSecPaddingPKCS1SHA1, there is not deprecations described in Apple's documentation. Also I didn't try this code on iOS different from 8.3 so maybe it is iOs8.3 issue.