Questions tagged [hmac]

a method for constructing a message authentication code based on a cryptographic hash function.

22 questions with no upvoted or accepted answers
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What is a AUTH-KEY in the security of the computers?

I'm studying security in computers and in particular the URL Spoofing. I understand that a form of URL spoofing is phishing. Then I read that a countermeasure against phishing is the authentication ...
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0answers
109 views

how to create TPM_AUTHDATA as input in tpm commands ?

I'm writing my first program which use tpm (version 1.2) services in Windows 7 using TBS, in this program I'm trying to execute the TPM_CreateWrapKey command. I noticed that many commands like the ...
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0answers
608 views

HMAC authenticated API calls with multipart/form-data file uploads

We have an existing API where 3rd parties can push data. The API calls are authenticated with HMAC using the same scheme as described in Ruby's ApiAuth library which I use to verify signed requests. ...
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0answers
424 views

Allowing third-party clients to authenticate with an app server

I'm working on an app that is planned to be licensed to OEMs, who would in turn offer it as a service to their users.  We would host the app server and the OEM would optionally host the app's web ...
2
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0answers
391 views

Is hashing the HMAC secret key a good idea?

I'm implementing a REST API and I've generated 128-bit random API keys which are used with HMAC-SHA1 for authorization. Should I hash the secret key on both the client and server before using it, ...
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1answer
69 views

I am signing (HMAC) outgoing webhooks to allow users to verify their source, should I also sign outgoing responses?

To allow api users to verify the authenticity of outgoing webhooks, I am using a similar model to slack: Concatenate timestamp and body, HMAC with pre-shared key, add timestamp and HMAC digest to ...
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0answers
38 views

concatenation vs multiple rounds of HMAC

I was studying the AWS request signature process and found that they derive the signing key from multiple sources (one and two related questions). Specifically this: kSecret = Your AWS Secret Access ...
1
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0answers
110 views

API protection - JWT vs HMAC signing vs OAuth

Lets say you are designing a new API. The consumer of your API is a mobile app that periodically sends requests in the background, but you expect other consumers as well, such as web apps or servers. ...
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0answers
57 views

Can we send a forms auth token back from an HMAC API?

We have an ASP.NET MVC application used by people from other organisations. Some of the features are accessible via a forms login. Other features are accessible as SHA256-HMAC-authenticated API ...
1
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0answers
567 views

SQLCipher and PRAGMA key on iOS

I'm a bit confused as to how SQLCipher handles the PRAGMA key provided for encrypting the SQLite database For background: I'm looking at options for encrypting application data at rest. From the ...
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0answers
58 views

Is my current implementation of message signing on AVR sufficient and correct?

I am currently implementing a fairly simple signing library (for my personal use) to verify the identity of packets sent with the RF24Mesh library (using NRF24L01+) radios. Never made a flowchart but ...
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0answers
576 views

HMAC Token - Check Logic

I have a situation where I need a token that provides authentication. The common HMAC procedure I found is: Get Some key using login credentials Create Message, append key and other message data (...
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0answers
315 views

How can I use session salt for encrypting data using AES in CTR mode?

I have to implement a crypto-plugin in Java. The approach followed is conceptually similar to that used for SRTP. The algorithm used for data confidentiality is AES in CTR mode (I'm following a ...
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0answers
442 views

Login Authentication with SSL and HMAC

My question is pretty similar to : https://stackoverflow.com/questions/5487757/using-hmac-sha1-for-api-authentication-how-to-store-the-client-password-secure. Basically, I want to write an API for my ...
1
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0answers
443 views

Gladman's file encryption library = AES in counter mode with HMAC-SHA1 authentication?

I would like to use Gladman's algorithm to create AES encrypted data in JavaScript. I use the Crypto-JS library, but its performance is horrible. PBKDF2 is terribly slow, so I switched to another ...
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0answers
609 views

Generating API keys within an OAuth2 session for non-web-browser clients

I am using Google's OAuth2 for authentication for a website which also has a RESTful API component. I would like to support connections from clients which are not within a web browser. Also, I'd ...
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0answers
34 views

Does transmitting short, predictable plaintext along with the HMAC signature of that text present a security risk

In order to allow clients to verify responses originating from our server, we are generating an HMAC signature of the body and a timestamp, and attaching it as a header. The timestamp is also attached ...
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0answers
59 views

Is this symmetric key system secure?

I am creating a secure network data transfer system, and would like to know if there are any obvious flaws in this scheme. Secrets The secret is a password that is known to both clients. This ...
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0answers
76 views

Is it safe to share an Azure SAS token with an untrusted client?

We need to host files in Azure Blob Store, and allow access to end users to their generated "statements"(pdf) for a short period of time. We're considering achieving this by generating a short-lived ...
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0answers
273 views

Understanding the application of hashes, HMACs, and KDFs

I think that I understand the right application cases for the following crypto functions, but I'd like to confirm my understanding and also propagate the safe use of crypto throughout the intertubes. ...
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0answers
147 views

Using HMAC when sending data through an untrusted server

I have a set up like this: Payment Server (PS) <> Front End (FE) <> Client JS. I need to get some data from the Client JS to the PS, without the FE being able to modify it and have PS prove ...
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0answers
237 views

Payment Application Integration - Encryption or HMAC

Doing an integration with an online payment provider. Payment provider will be making a web request to my server to provide some information about the basket content. On my end there's no payment ...