diff options
Diffstat (limited to 'doc/api/crypto.markdown')
| -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 |