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| author | Calvin Metcalf <calvin.metcalf@state.ma.us> | 2014-10-19 10:31:22 -0400 |
|---|---|---|
| committer | Bert Belder <bertbelder@gmail.com> | 2015-01-10 22:15:48 +0100 |
| commit | 43226dd40e36d96a6a1abd12fffde59519dd6aef (patch) | |
| tree | 8345b2ecd2527fa4c394d35b7594e59e46dd8c56 /doc | |
| parent | 90f07a7b3ebb779832ab01204d994e4feab850d1 (diff) | |
| download | node-new-43226dd40e36d96a6a1abd12fffde59519dd6aef.tar.gz | |
doc: add note about key derivation
adds a note to the crypto docs passing along
the advice that openssl gives about what
key derivation function they recommend.
PR-URL: https://github.com/joyent/node/pull/8580
Reviewed-by: Fedor Indutny <fedor@indutny.com>
Cherry-picked-from: https://github.com/joyent/node/commit/7dbc024c8573670170d4f561c01ae892d06399db
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/api/crypto.markdown | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/doc/api/crypto.markdown b/doc/api/crypto.markdown index b6dcf46124..25c2f75216 100644 --- a/doc/api/crypto.markdown +++ b/doc/api/crypto.markdown @@ -191,6 +191,16 @@ written data is used to compute the hash. Once the writable side of the stream is ended, use the `read()` method to get the enciphered contents. The legacy `update` and `final` methods are also supported. +Note: `createCipher` derives keys with the OpenSSL function [EVP_BytesToKey][] +with the digest algorithm set to MD5, one iteration, and no salt. The lack of +salt allows dictionary attacks as the same password always creates the same key. +The low iteration count and non-cryptographically secure hash algorithm allow +passwords to be tested very rapidly. + +In line with OpenSSL's recommendation to use pbkdf2 instead of EVP_BytesToKey it +is recommended you derive a key and iv yourself with [crypto.pbkdf2][] and to +then use [createCipheriv()][] to create the cipher stream. + ## crypto.createCipheriv(algorithm, key, iv) Creates and returns a cipher object, with the given algorithm, key and @@ -756,3 +766,5 @@ temporary measure. [diffieHellman.setPublicKey()]: #crypto_diffiehellman_setpublickey_public_key_encoding [RFC 2412]: http://www.rfc-editor.org/rfc/rfc2412.txt [RFC 3526]: http://www.rfc-editor.org/rfc/rfc3526.txt +[crypto.pbkdf2]: #crypto_crypto_pbkdf2_password_salt_iterations_keylen_callback +[EVP_BytesToKey]: https://www.openssl.org/docs/crypto/EVP_BytesToKey.html |