i have some parsed data in two files. i need to send these to a webserver of a website. i also need to be logged into the webserver first. i am new to this web interaction thing. i just need to know how might i go about doing this. i am learning the libcurl library so i guess it can send standard HTTP POST messages. i will make a simple webserver to test it myself. can anyone tell me what kind of interaction is needed. by that i mean how do i send the username and password information, know that i am logged in and then be send the files. may be some examples of Form Posts which i believe is what i shud be doing right now.
Depending on the type of authentication being performed, the libcurl library may have functionality already built into it to support what you are trying to do. Check out the curl_easy_setopt function--specifically the section dealing with authentication.
For basic authentication, you can do the following.
curl_easy_setopt( curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC );
curl_easy_setopt( curl, CURLOPT_USERPWD, "username:password" );
You can use for example an old Wininet.dll (http://msdn.microsoft.com/en-us/library/aa385473%28VS.85%29.aspx) or more recent Winhttp.dll on the client side. The last one (WinHTTP) has two C/C++ API and COM Interface. Moreover, in WinHTTP you have more Authentication options (http://msdn.microsoft.com/en-us/library/aa383144%28VS.85%29.aspx).
On the other side old Wininet.dll has function like InternetWriteFile. In InternetConnect (Wininet.dll) you can give lpszUsername and lpszPassword.
In WinHTTP you should use WinHttpSetOption and WinHttpSetCredentials to give Username and password.
Search for both Wininet and WinHTTP and you will find enough Information to decide which one is better for your requirements.
Related
Does LibCurl provide some functionality to produce tokens or hash/salt a string and shared secret? My c++ program will upload files to the server and my server script will authenticate that the HTTP post is coming from my c++ application and not someone else. So I'll send a auth token or hash in the query string that the server script can compare with its own to authenticate the request.
I've seen that you can authenticate using curl --user name:password http://www.example.com but can't a user just read the binary executable and see the username and password?
Although, maybe I am reinventing the wheel with my auth approach. Does LibCurl or another c++ provide the ability to perform shared-secret authentication?
I haven't tried this, but since the command line supports a netrc file as described here https://stackoverflow.com/a/27894407/1542667. This is more secure when using the command line as you don't make your password visible to everyone on the same host via the ps command.
It looks like you could use the same approach for libcurl
https://curl.haxx.se/libcurl/c/CURLOPT_NETRC_FILE.html
Contemplating building an Angular 2 front-end to my website. My question is not necessarily related to Angular but I want to provide full context.
Application logic that displays content to user would shift to the client. So on the server side, I would need to expose data via a RESTful JSON feed. What worries me, is that someone can completely bypass my front-end and execute requests to the service with various parameters, effectively scraping my database. I realize some of this is possible by scraping HTML but exposing a service with nicely formatted data is just a no-brainer.
Is there a way to protect the RESTful service from this? In other words, is there a way to ensure such service would only respond to my Angular 2 application call? Authentication certainly isn't a solution here - I don't want to force visitors to authenticate and the scraper could very well authenticate and get access, anyway.
I would recommend JWT Authorization. One such implementation is OAuth. Basically you get a json web token ( JWT ) that has been signed by an authority you trust that tells about the user and what resources they can access on your api.
If the request doesn't include an Authorization token - your API rejects it.
If the token has been tampered with by someone trying to grant themselves privledges after the token is signed by the authorization authority - your API rejects it.
It is a pretty cool piece of kit.
This site has information about OAuth implementations in different languages, hopefully your favorite is listed.
Some light bed time reading.
There is no obvious way to do it that I know of, but a lot of people seem to be looking at Amazon S3 as a model. If you put credentials in your client code, then anyone getting the client code can see them. I might suggest that you could write the server to pass a time limited token back to the browser with the client code. The client code would be required to pass it back to the server for access. This would prevent anyone from writing their own client code, as only client code sent by the server would work, though only for some period of time. The user might occasionally get timeouts, but that depends on how strict you want to make the token timeouts. Of course, even this kind of thing could be hacked by someone making a client request to get a copy of the token to use with their own client API, but at that point you should be proud that someone is trying so hard to use your API! I have not tried to write such a thing, so I don't have any practical experience with the issue. I myself have wondered about it, but also don't have enough experience with this architecture to see what, if anything, others have been doing. What do angularJS forums suggest?
Additional References: Best Practices for securing a REST API / web service
I believe the answer is "No".
You could do some security by obscurity type stuff. Your rest API could expose garbled data and you could have some function that was "hidden" in your code un-garble it. Though obviously this isn't fool proof, but if you expose data on a public site it's out there regardless of server or client rendering.
I've read quite a few SO threads about authentication and authorization with REST and Angular, but I'm still not feeling like I have a great solution for what I'm hoping to do. For some background, I'm planning to building an app in AngularJS where I want to support:
Limited guest access
Role-based access to the application once authenticated
Authentication via APIs
All of the calls to the REST API will be required to occur over SSL. I'd like to do build the app without breaking RESTful principles, namely not keeping session state stored on the server. Of course, whatever is done vis-a-vis authorization on the client-side has to be reinforced on the server side. Since we need to pass the entire state with each request, I know I need to pass some sort of token so that the backend server receiving the REST request can both authenticate and authorize the call.
With that said, my main question is around authentication - what are the best practices here? It seems there are lots of different approaches discussed, here's just a few that I've found:
http://broadcast.oreilly.com/2009/12/principles-for-standardized-rest-authentication.html
http://frederiknakstad.com/2013/01/21/authentication-in-single-page-applications-with-angular-js/
http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html
There was a similar question asked (AngularJS best practice application authentication), but unless I'm misunderstanding the answer, it seems to imply that a server session should be used, which is breaking RESTful principles.
My main concern with the Amazon AWS and the George Reese article is it seems to assume that the consumer is a program, rather than an end user. A shared secret can be issued to a programmer in advance, who can then use it to encode calls here. This isn't the case here - I need to call the REST API from the app on behalf of the user.
Would this approach be enough? Let's say I have a session resource:
POST /api/session
Create a new session for a user
To create a session, you need to POST a JSON object containing the "username" and "password".
{
"email" : "austen#example.com",
"password" : "password"
}
Curl Example
curl -v -X POST --data '{"username":"austen#example.com","password":"password"}' "https://app.example.com/api/session" --header "Content-Type:application/json"
Response
HTTP/1.1 201 Created {
"session": {
"id":"520138ccfa4634be08000000",
"expires":"2014-03-20T17:56:28+0000"
}
}
Status Codes
201 - Created, new session established
400 - Bad Request, the JSON object is not valid or required information is missing
401 - Unauthorized, Check email/password combo
403 - Access Denied, disabled account or license invalid
I'm leaving out the HATEOAS details for clarity. On the backend, there would be a new, limited duration session key created and associated with the user. On subsequent requests, I could pass this as part of the HTTP headers:
Authorization: MyScheme 520138ccfa4634be08000000
Then the backend servers would be responsible for digesting this out of the request, finding the associated user and enforcing authorization rules for the request. It should probably update the expiration for the session as well.
If all this is happening over SSL, am I leaving the door open to any kind of attacks that I should be protecting against? You could try to guess session keys and place them in the header, so I suppose I could additionally append a user GUID to the session key to further prevent brute force attacks.
It's been a few years since I've actively programmed and I'm just getting back into the swing here. Apologies if I'm being obtuse or unnecessarily reinventing the wheel, just hoping to run my ideas by the community here based on my reading thus far and see if they pass the litmus test.
When someone asks about REST authentication, I defer to the Amazon Web Services and basically suggest "do that". Why? Because, from a "wisdom of the crowds" point of view, AWS solves the problem, is heavily used, heavily analyzed, and vetted by people that know and care far more than most about what makes a secure request than most. And security is a good place to "not reinvent the wheel". In terms of "shoulders to stand on", you can do worse than AWS.
Now, AWS does not use a token technique, rather it uses a secure hash based on shared secrets and the payload. It is arguably a more complicated implementation (with all of its normalization processes, etc.).
But it works.
The downside is that it requires your application to retain the persons shared secret (i.e. the password), and it also requires the server to have access to that a plain text version of the password. That typically means that the password is stored encrypted, and it then decrypted as appropriate. And that invite yet more complexity of key management and other things on the server side vs secure hashing technique.
The biggest issue, of course, with any token passing technique is Man in the Middle attacks, and replay attacks. SSL mitigates these mostly, naturally.
Of course, you should also consider the OAuth family, which have their own issues, notably with interoperability, but if that's not a primary goal, then the techniques are certainly valid.
For you application, the token lease is not a big deal. Your application will still need to operate within the time frame of the lease, or be able to renew it. In order to do that it will need to either retain the user credential or re-prompt them for it. Just treat the token as a first class resource, like anything else. If practical, try and associate some other information with the request and bundle it in to the token (browser signature, IP address), just to enforce some locality.
You are still open to (potential) replay problems, where the same request can be sent twice. With a typical hash implementation, a timestamp is part of the signature which can bracket the life span of the request. That's solved differently in this case. For example, each request can be sent with a serial ID or a GUID and you can record that the request has already been played to prevent it from happening again. Different techniques for that.
Here is an incredible article about authentication and login services built with angular.
https://medium.com/opinionated-angularjs/7bbf0346acec
This SO question do a good job of summing up my understanding of REST
Do sessions really violate RESTfulness?
If you store a token in a session you are still creating state on the server side (this is an issue since that session is typically only stored on the one server, this can be mitigated with sticky sessions or other solutions).
I'd like to know what your reasoning is for creating a RESTful service though because perhaps this isn't really a large concern.
If you send a token in the body along with every request (since everything is encrypted with SSL this is okay) then you can have any number of servers (load balanced) servicing the request without any previously knowledge of state.
Long story short I think aiming for RESTful implementations is a good goal but being purely stateless certainly creates an extra layer of complexity when it comes to authentication and verifying authorization.
Thus far I've started building my back-ends with REST in mind, making URIs that make sense and using the correct HTTP verbs, but still use a token in a session for the simplicity of authentication (when not using multiple servers).
I read through the links you posted, the AngularJS one seems to focus just on the client and doesn't seem to explicitly address the server in that article, he does link to another one (I'm not a Node user so forgive me if my interpretation is wrong here) but it appears the server is relying on the client to tell it what level of authorization it has which is clearly not a good idea.
I have the oAuth stuff working as expected. No challenges there. I now need to use the access token to do something. Nothing I have tried works. I'm sure it's very simple, but I am not sure how to translate the examples in curl to http post/get requests.
Box.com help says:
curl https://api.box.com/2.0/folders/FOLDER_ID \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN"
How do i write that using http post/get?
As long as the requests are being sent via standard http functionality I don't believe my platform matters. Regardless, I'm using Apex to write this in Salesforce.com.
Note: I know there is an app on the AppExchange to integrate Box.com and Salesforce. For my purposes I don't want to rely on apps that are unique to a specific platform.
Any help is appreciated.
It's simply a GET request with headers and optionally XML / JSON as POST payload, not sure what's your specific problem? Have you actually tried writing some code?
Simple example: http://www.salesforce.com/us/developer/docs/api_asynch/Content/asynch_api_quickstart_login.htm
Bit more advanced: http://developer.force.com/cookbook/recipe/scheduling-an-apex-call-from-the-command-line
CURL is a powerful tool and the list of it's commandline options is not for the faint of heart. Still - use it as a reference, especially "-H" meaning HTTP header. I think the "\" is just indicating that it's a multiline command, you can ignore it.
I was recently exposed to a new authentication method i had no idea of.
After reading a bit and researching to understand it,I understood it has something to do with SPNEGO, or maybe it is just spnego.
Im running windows xp on a large network, when my browser opens it automatically
connects to a web-service in the network, which requires authentication:
HTTP/1.1 401 Unauthorized
WWW-Authenticate: Negotiate
then my browser sends automatically (along with more headers ofcourse):
Authorization: Negotiate (encrypted string).
I concluded this Handshake uses the SPNEGO protocol.
What i need to do, is to create my own client (actually,its a bot that uses this webservice that requires that authentication). I Need to get that encrypted string (exactly like my browser gets it, probably by using some SPNEGO protocol) without any user interaction (again, as my browser).
the thing is, that i don't have enough time to study the spnego protocol and how to implement one.
I'm using c/c++, but if i have no option c# would be okay as well.
Are there any functions / classes / codes or maybe even good tutorials to help me implement it shortly?
curl works with Kerberos/spnego. I'm not sure how well this functionality works on Windows, you should try and see. It works well enough on Linux. You can look at the source to see how it is done.