diff options
| author | Calvin Metcalf <calvin.metcalf@state.ma.us> | 2014-10-19 10:31:22 -0400 |
|---|---|---|
| committer | Fedor Indutny <fedor@indutny.com> | 2014-10-20 13:41:15 +0400 |
| commit | 7dbc024c8573670170d4f561c01ae892d06399db (patch) | |
| tree | 42816b02401a0a0429e4e184c911f5745969391c | |
| parent | 6c8593d4568b59770aeb5b2cfa1fdc23ac422523 (diff) | |
| download | node-new-7dbc024c8573670170d4f561c01ae892d06399db.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>
| -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 9ca6f22cf7..7a1abb6492 100644 --- a/doc/api/crypto.markdown +++ b/doc/api/crypto.markdown @@ -165,6 +165,16 @@ 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 @@ -532,3 +542,5 @@ 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
\ No newline at end of file |