On 10 December 2017 at 18:23, Sven Van Caekenberghe <sven@stfx.eu> wrote:

> On 10 Dec 2017, at 10:01, Ben Coman <btc@openinworld.com> wrote:
>
> Can anyone recommend libraries (native Smalltalk or via FFI)
> to do generate a HMAC-SHA512 ?
>
> cheers -ben

Well Pharo itself of course !��

(HMAC on: SHA256)
�� key: (ByteArray new: 32);
�� digestMessage: #[1 2 3].

SHA256 new hmac
�� key: (ByteArray new: 32);
�� digestMessage: #[1 2 3].

Thanks Sven. Its interesting to trace that through to put other stuff I've read about HMAC into perspective.

However SHA256 != SHA512 which is a defined requirement of the site I'm accessing.

What I understand from the trace is that the HMAC is generic regardless of size of SHA function

and could remain in-Image while the SHA512 part could be supplied from outside the image.��

I could perhaps use the one from the OpenSSL library already included with Pharo.

$ readelf -a ./pharo-vm/lib/pharo/5.0-201707201942/libssl.so.1.0.0 | grep 512

�� EVP_sha512

�� SHA512_Init

�� SHA512_Update

�� SHA512_Transform

�� SHA512_Final

where the "EVP function provide a high level interface to OpenSSL cryptographic functions."

and I guess could be used similar to...�� ftp://188.44.46.157/Augustus/blatSrc/lib/hmac.c

except I'm not sure how I'd use proceed without it taking any parameters...��

�� const EVP_MD *EVP_sha512(void);�� // include/openssl/evp.h

The lower level functions could be used like...

�� http://www.askyb.com/cpp/openssl-sha512-hashing-example-in-cpp/

�� https://github.com/openssl/openssl/blob/OpenSSL_1_1_0-stable/crypto/sha/sha512.c#L264

unsigned char *SHA512(const unsigned char *d, size_t n, unsigned char *md);

int SHA512_Init(SHA512_CTX *c);�� // include/openssl/sha.h

int SHA512_Update(SHA512_CTX *c, const void *data, size_t len);

int SHA512_Final(unsigned char *md, SHA512_CTX *c);

void SHA512_Transform(SHA512_CTX *c, const unsigned char *data);

Actually the lower level functions look easier from an FFI perspective.

Other options I found...��

* http://forum.world.st/How-to-encrypt-a-password-td3933585.html#a3933778

�� but it seems to be NativeBoost rather than UFFI, and also is Linux only (which might not be an issue)��

* https://github.com/mygityf/cipher/blob/master/cipher/sha512.h
�� https://github.com/mygityf/cipher/blob/master/cipher/sha512.c

�� to compile into a (hopefully) cross platform shared library

cheers -ben

P.S. I learnt today that "SHA-512 is faster than SHA-256 on 64 bit machines (as they use 64 bit arithmetic internally)"
https://stackoverflow.com/a/18083633