erlang-bcrypt is a wrapper around the OpenBSD Blowfish password hashing algorithm, as described in A Future-Adaptable Password Scheme by Niels Provos and David Mazieres.
This bcrypt repository at erlangpack is in active maintainance and used as the basis of the Hex package.
erlang-bcrypt is compatible with OTP 21.3 to 23.
Use version 1.0.3 on OTP versions before 21.3
In version 1.1.0 support for OTP 21.2 and earlier is removed due to the removal of erl_interface in OTP 23.
erlang-bcrypt is on Hex:
{deps, [
{bcrypt, "1.1.0"}
]}.
To use the master branch:
{deps, [
{bcrypt, {git, ".*", {git, "https://github.com/erlangpack/bcrypt.git", {branch, "master"}}}
]}.
-
Build it (project uses rebar3, a Makefile is included):
make
-
Run it (simple way, starting sasl, crypto and bcrypt):
$ ./rebar3 shell ===> Verifying dependencies... ===> Compiling bcrypt make: Nothing to be done for `all'. Erlang/OTP 23 [erts-11.0] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [hipe] Eshell V11.0 (abort with ^G) 1> application:ensure_all_started(bcrypt). {ok,[bcrypt]} 2>
Hash a password using a salt with the default number of rounds:
1> {ok, Salt} = bcrypt:gen_salt().
{ok,"$2a$12$sSS8Eg.ovVzaHzi1nUHYK."}
2> {ok, Hash} = bcrypt:hashpw("foo", Salt).
{ok,"$2a$12$sSS8Eg.ovVzaHzi1nUHYK.HbUIOdlQI0iS22Q5rd5z.JVVYH6sfm6"}
Verify the password:
3> {ok, Hash} =:= bcrypt:hashpw("foo", Hash).
true
4> {ok, Hash} =:= bcrypt:hashpw("bar", Hash).
false
The bcrypt application is configured by changing values in the application's environment:
default_log_rounds
Sets the default number of rounds which define the complexity of the
hash function. Defaults to 12
.
mechanism
Specifies whether to use the NIF implementation ('nif'
) or a
pool of port programs ('port'
). Defaults to 'nif'
.
Note: the NIF implementation no longer blocks the Erlang VM scheduler threads
pool_size
Specifies the size of the port program pool. Defaults to 4
.
nif_pool_size
Specifies the size of the nif program pool. Defaults to 4
.
nif_pool_max_overflow
Specifies the max workers to overflow of the nif program pool. Defaults to 10
.
To run the eunit tests use:
make tests
Both the port and the NIF version of bcrypt are tested. All tests should pass.
Hunter Morris & Mrinal Wadhwa.