Commit 4849a54
doc: Adding best practises for crypto.pbkdf2
Added some information around usages of how to use iterations, how to
choose decent salts and updating the example to have a significant
work factor and to use sha512.
PR-URL: #3290
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>1 parent 77251d9 commit 4849a54
1 file changed
Lines changed: 9 additions & 1 deletion
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -620,9 +620,16 @@ Asynchronous PBKDF2 function. Applies the selected HMAC digest function | |||
| 620 | 620 | salt and number of iterations. The callback gets two arguments: | |
| 621 | 621 | `(err, derivedKey)`. | |
| 622 | 622 | ||
| 623 | + The number of iterations passed to pbkdf2 should be as high as possible, the | ||
| 624 | + higher the number, the more secure it will be, but will take a longer amount of | ||
| 625 | + time to complete. | ||
| 626 | + | ||
| 627 | + Chosen salts should also be unique. It is recommended that the salts are random | ||
| 628 | + and their length is greater than 16 bytes. See [NIST SP 800-132] for details. | ||
| 629 | + | ||
| 623 | 630 | Example: | |
| 624 | 631 | ||
| 625 | - crypto.pbkdf2('secret', 'salt', 4096, 64, 'sha256', function(err, key) { | ||
| 632 | + crypto.pbkdf2('secret', 'salt', 100000, 512, 'sha512', function(err, key) { | ||
| 626 | 633 | if (err) | |
| 627 | 634 | throw err; | |
| 628 | 635 | console.log(key.toString('hex')); // 'c5e478d...1469e50' | |
@@ -789,6 +796,7 @@ See the reference for other recommendations and details. | |||
| 789 | 796 | [RFC 3526]: http://www.rfc-editor.org/rfc/rfc3526.txt | |
| 790 | 797 | [crypto.pbkdf2]: #crypto_crypto_pbkdf2_password_salt_iterations_keylen_digest_callback | |
| 791 | 798 | [EVP_BytesToKey]: https://www.openssl.org/docs/crypto/EVP_BytesToKey.html | |
| 799 | + [NIST SP 800-132]: http://csrc.nist.gov/publications/nistpubs/800-132/nist-sp800-132.pdf | ||
| 792 | 800 | [NIST SP 800-131A]: http://csrc.nist.gov/publications/nistpubs/800-131A/sp800-131A.pdf | |
| 793 | 801 | [initialization vector]: http://en.wikipedia.org/wiki/Initialization_vector | |
| 794 | 802 | [Caveats]: #crypto_caveats | |
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