Hello,
In my MAC application, need to overcome the dependency of Open ssl and use apple APIS to acheive the same.
I have a similar issue where I need to get away from OpenSSL in my app, as it is not encouraged by apple to use them. I do not want to statically link the openssl to my project. I want to achieve the same using crypto APIS. In one of the apple link, it says
OpenSSL
Although OpenSSL is commonly used in the open source community, OpenSSL does not provide a stable API from version to version. For this reason, although OS X provides OpenSSL libraries, the OpenSSL libraries in OS X are deprecated, and OpenSSL has never been provided as part of iOS. Use of the OS X OpenSSL libraries by apps is strongly discouraged.
If your app depends on OpenSSL, you should compile OpenSSL yourself and statically link a known version of OpenSSL into your app. This use of OpenSSL is possible on both OS X and iOS. However, unless you are trying to maintain source compatibility with an existing open source project, you should generally use a different API.
Common Crypto and Security Transforms are the recommended alternatives for general encryption. CFNetwork and Secure Transport are the recommended alternatives for secure communications.
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But if we use the crypto APIs similar to how it works in IOS, the APIs are not generating the expected values. One of the stack overflow discussion link says that the frameworks of IOS and MAC are similar, but not identical
https:/
Can you please guide us on what needs to be used achieve the operations of open SSL through apple APIs in MAC ?
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I have tried using SecKeyGeneratePair to generate the public private key pair. The API is giving just the instance with no values in it.
{
NSString *strTag = nil;
NSString *privateTagString = nil;
NSString *publicTagString = nil;
if( privateTag == nil && publicTag == nil && symmetricTag == nil )
{
strTag = [[HelpMethods UUIDString] lowercaseString]; // This generated a random UUID to have it as a private and a public reference
privateTagString = [NSString stringWithFormat:@"%@.private",strTag];
publicTagString = [NSString stringWithFormat:@"%@.public",strTag];
privateTag = [[NSData alloc] initWithData:[privateTagString dataUsingEncoding:NSUTF16StringEncoding]];
publicTag = [[NSData alloc] initWithData:[publicTagString dataUsingEncoding:NSUTF16StringEncoding]] ;
symmetricTag = [[NSData alloc] initWithBytes:symmetricKeyIdentifier length:sizeof(symmetricKeyIdentifier)];
}
NSMutableDictionary * privateKeyAttr = nil;
NSMutableDictionary * publicKeyAttr = nil;
NSMutableDictionary * keyPairAttr = nil;
OSStatus sanityCheck = noErr;
privateKeyAttr = [[NSMutableDictionary alloc] init];
publicKeyAttr = [[NSMutableDictionary alloc] init];
keyPairAttr = [[NSMutableDictionary alloc] init];
/*************/
// Set the private key dictionary.
[privateKeyAttr setObject:[NSNumber numberWithBool:FALSE] forKey:(id)kSecAttrIsPermanent];
[privateKeyAttr setObject:privateTag forKey:(id)kSecAttrApplicationTag];
/*************/
// Set the public key dictionary.
[publicKeyAttr setObject:[NSNumber numberWithBool:FALSE] forKey:(id)kSecAttrIsPermanent];
[publicKeyAttr setObject:publicTag forKey:(id)kSecAttrApplicationTag];
/************/
[keyPairAttr setObject:( id )kSecAttrKeyTypeRSA forKey:(id)kSecAttrKeyType];
[keyPairAttr setObject:[NSString stringWithFormat:@"%lu", (unsigned long)nKeySize] forKey:( id )kSecAttrKeySizeInBits];
[keyPairAttr setObject:privateKeyAttr forKey:(id)kSecPrivateKeyAttrs];
[keyPairAttr setObject:publicKeyAttr forKey:(id)kSecPublicKeyAttrs];
/*************/
// Generate he key pair
sanityCheck = SecKeyGeneratePair( (CFDictionaryRef)keyPairAttr, &publicKeyRef, &privateKeyRef);
privateKeyAttr = nil;
publicKeyAttr = nil;
keyPairAttr = nil;
}
nKeySize used here is 2048
After this, I tried get the mod data of the public key, which is giving me 0 bytes.
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Also SecKeyGeneratePair documentation says
- In macOS, add the key-value pairs to the parameters dictionary directly. The specified attributes are applied to both the public and private keys.
- In iOS, add dictionaries for the keys and to the parameters dictionary, and provide the attributes in those dictionaries. The attributes specified in these dictionaries are added to either the public or private key, respectively, allowing you to apply separate attributes to each key.
Can you please explain on this or point to some sample where understanding gets better ?
Please guide us in what needs to used to overcome the dependency of Openssl. What other ways to convert Open ssl to apple APIs ?
Thanks,
Champa
