Timeline for Is transporting a salt, IV, ciphertext and HMAC in an encrypted token an acceptable practice?
Current License: CC BY-SA 4.0
12 events
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| Jun 2, 2018 at 21:48 | history | edited | Ilmari Karonen | CC BY-SA 4.0 |
copyedit, make clear that the question can stand on its own even without the code, add authenticated-encryption tag
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| Jun 1, 2018 at 2:43 | comment | added | Future Security | You can use the same key as long as you change the IV | |
| May 31, 2018 at 19:29 | comment | added | Robert | @FutureSecurity Are you suggesting that I rely on the master key rather than the derived key for the AES encryption? Is the point there simply that using a derived key is unnecessary? The 32-bit is a typo and should read 32-bytes (256 bit) for the key size. | |
| May 31, 2018 at 2:28 | comment | added | Future Security | If you look into your actual requirements then you'll find that the former employee didn't implement the best construction regardless of how the algorithms are implemented or what libraries are used. | |
| May 31, 2018 at 2:26 | comment | added | Future Security | The crypto part of this code looks really hack-y. Normally you use one key to encrypt many messages and use a different IV for each message. It is unnecessary (but acceptable) to derive a new key for each one for typical algorithms. What's extra sketchy is the KDF use. 1st you shouldn't use a 32 bit key even if you stretch it. 2nd you shouldn't re-derive a key (new or not) from a password. If your time cost is T and you derive 2 keys, you use 2T time and each key has T brute-force resistance. Instead derive one key in 2T time and use the master key to derive new keys (without more stretching) | |
| May 31, 2018 at 2:10 | comment | added | Future Security | Code review is considered off topic for this exchange even when the code involves cryptography. If you want to know if some construct is secure then you can ask a question about that. Then you should replace code with a precise statement of what algorithms are being used and the specifics of how they're used. | |
| May 31, 2018 at 1:33 | comment | added | Maarten Bodewes♦ | MarkDown has specific formatting to create (un-) numbered lists (also available as button). I've definitely seen worse code, great that you're moving away from mcrypt. | |
| May 31, 2018 at 1:32 | history | edited | Maarten Bodewes♦ | CC BY-SA 4.0 |
formatting
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| May 31, 2018 at 1:30 | answer | added | Maarten Bodewes♦ | timeline score: 4 | |
| May 31, 2018 at 1:22 | review | Close votes | |||
| Jun 5, 2018 at 21:58 | |||||
| May 30, 2018 at 21:50 | review | First posts | |||
| May 31, 2018 at 20:04 | |||||
| May 30, 2018 at 21:48 | history | asked | Robert | CC BY-SA 4.0 |