Collaborate Disseminate
HMAC signatures are very commonly used for webhook authorization from service to consumer.
Examples:
Stripe
Slack
Twilio
Twitter
GitHub
and hundreds and hundreds more. This seems a near universal design decision.
Yet, the other direction… Continue reading Why are HMAC signatures frequently used for webhook authorization but not other HTTP API requests?
In TLS separate implicit sequence numbers for sent and received packets are used to calculate the HMAC in the record layer. The RFC 5246 says:
Each connection state contains a sequence number, which is maintained
separately for read and w… Continue reading Why does TLS use two separate sequence numbers?
I have been researching various techniques for preventing CSRF attacks, such as SOP, SameSite, Secure, Referer validation, and CSRF Tokens, and their potential bypasses. During my research, I discovered the following vulnerabilities:
In GlobalPlatform specification for smartcards, I came accross this rather strange scheme:
To calculate the Message Authentication Code, we take some original data (a host cryptogram and a padding), then we apply multiple chained DES calcu… Continue reading Why do we encrypt then decrypt then encrypt data with different keys?
The Double Submit Cookie CSRF Token pattern is a stateless technique that doesn’t require storage or a database. However, it’s vulnerable to session hijacking attacks and sub-/sibling domains that are susceptible to XSS or HTML injection. … Continue reading Session based CSRF Tokens – What value do i use with JWT?
I have been trying to recover the password of my old Point of Sale system.
I have the password file that I generated containing all possible combinations of numbers from 0000-0000 to 9999-9999 called combinations.txt. I know that the passw… Continue reading John returns invalid UTF-8 and askes for HMAC-Sha256 and HMAC-sha512 [closed]
If I pipe these 2 commands:
openssl passwd -6 -salt mysecretsalt | openssl dgst -binary -mac hmac -sha512 -macopt key:mysecretkey |base64
Password:
euOMVgfB/biBeqmizIuXBdD3SyKIUGu9jI+uc37yWmqpVoGv13VIvgyupx0Ld0xQBPCZO5Bwmjp0A7leLL8XiQ==
I am writing browser javascript that has a pre-shared key with nonce, and creates a binary websocket connection. How can I apply block encryption-authentication such as AES-GCM to the messages?
Is it possible to tell the browser to skip th… Continue reading javascript: how to apply block cipher to byte stream
I’ve been reading about HMAC protecting from length extension attacks, but if the message already specifies it size, is HMAC adding any advantange to simple hashing after prepending a secret?
As example consider a protocol where the messag… Continue reading I using sha256 after adding a secret enough if the message includes its length?
I don’t have formal CS education but i’ve written one or 2 little websites. I have troubles communicating even in my native language but i hope this is understandable.
With simple i mean something like we have a single server to authentica… Continue reading What would be the most complete procedure to get a simple login system working securely?