fastpbkdf2
This is a fast PBKDF2-HMAC-{SHA1,SHA256,SHA512} implementation in C.
It uses OpenSSL's hash functions, but out-performs OpenSSL's own PBKDF2 thanks to various optimisations in the inner loop.
Interface
void fastpbkdf2_hmac_sha1(const uint8_t *pw, size_t npw,
const uint8_t *salt, size_t nsalt,
uint32_t iterations,
uint8_t *out, size_t nout);
void fastpbkdf2_hmac_sha256(const uint8_t *pw, size_t npw,
const uint8_t *salt, size_t nsalt,
uint32_t iterations,
uint8_t *out, size_t nout);
void fastpbkdf2_hmac_sha512(const uint8_t *pw, size_t npw,
const uint8_t *salt, size_t nsalt,
uint32_t iterations,
uint8_t *out, size_t nout);
Please see the header file for details and constraints.
Performance
These values are wall time, output from the bench
tool.
AMD64
Hash | OpenSSL | fastpbkdf2 | (comparison) |
---|---|---|---|
SHA1 | 11.84s | 3.07s | x3.86 |
SHA256 | 16.54s | 7.45s | x2.22 |
SHA512 | 21.90s | 9.33s | x2.34 |
222 iterations, 1.86GHz Intel Atom N2800, amd64.
ARM
Hash | OpenSSL | fastpbkdf2 | (comparison) |
---|---|---|---|
SHA1 | 30.4s | 4.43s | x6.86 |
SHA256 | 36.52s | 7.04s | x5.19 |
SHA512 | 77.44s | 28.1s | x2.76 |
220 iterations, Raspberry Pi - 700MHz ARM11.
Requirements
- OpenSSL's libcrypto.
- C compiler supporting C99.
Building and testing
Run 'make test' to build and run tests.
The program bench
provides a very basic performance comparison between OpenSSL and fastpbkdf2.
The implementation has one header and one translation unit. This is intended for easy integration into your project.
Optional parallelisation of outer loop
PBKDF2 is misdesigned and you should avoid asking for more than your hash function's output length.
In other words, nout should be <= 20 for fastpbkdf2_hmac_sha1
, <= 32 for fastpbkdf2_hmac_sha256
and <= 64 for fastpbkdf2_hmac_sha512
.
If you can't avoid this (for compatibility reasons, say) compile everything with -fopenmp
and -DWITH_OPENMP
to have this computation done in parallel. Note that this has non-zero
overhead.
The program multibench
provides a basic performance comparison for using this option.
Windows
Details on building for Windows.
License
CC0.
Language bindings
- python-fastpbkdf2 by Ayrx.
- go-fastpbkdf2 by me.
- rust-fastpbkdf2 by me.
- node-fastpbkdf2 by S-YOU.
- ruby-fastpbkdf2 by S-YOU.
- fastpbkdf2-hs by adinapoli.
- perl-fastpbkdf2 by duanehutchins.
Author
Joseph Birr-Pixton [email protected]