libscrypt about scrypt HOT 9 CLOSED

Hi @Smattr, we're moving in this direction, such as commits like 70ada72 (which might simplify your downstream patch as well). Still a few details to work out, though.

from scrypt.

Two reasons:

1. Password hashing is exactly the same thing as key derivation, so the name isn't really wrong. ;-)

2. There's a whole bunch of libscrypt libraries and scrypt() functions out there, so we figured it would be helpful to avoid using the same name.

from scrypt.

Yeah, maybe. I was avoiding this because (a) there isn't really any cross-platform way to do "libraries", and (b) the scrypt code is small enough that I figured people could just import it into their codebase.

from scrypt.

Doesn't autotools take care of (a)?

from scrypt.

Theoretically, yes. I've heard complaints about it not working very well but I don't know if those were due to autotools being inherently broken or merely difficult to use.

from scrypt.

From offline communication: libscrypt should not include scryptenc_*; it should only include crypto_scrypt().

from scrypt.

This would be great! I had assumed the omission of a librarised scrypt was deliberate and patched the build system to add this (inline below for posterity), but if I could stop doing this and lean on an official upstream libscrypt I (and presumably others) certainly would.

Scrypt's build system does not expose a reusable version of crypto_scrypt(). To
work around this, the following patch adds a library that achieves this.

diff --git Makefile.am Makefile.am
index f037aa6..616c01d 100644
--- Makefile.am
+++ Makefile.am
@@ -69,6 +69,22 @@ noinst_LIBRARIES+=	libscrypt_sse2.a
 libscrypt_sse2_a_SOURCES=	lib/crypto/crypto_scrypt_smix_sse2.c
 libscrypt_sse2_a_CFLAGS=`. ./cpusupport-config.h; echo $${CFLAGS_X86_SSE2}`
 
+noinst_LIBRARIES+= libcrypto_scrypt.a
+libcrypto_scrypt_a_SOURCES= \
+			libcperciva/alg/sha256.c			\
+			libcperciva/alg/sha256.h			\
+			libcperciva/cpusupport/cpusupport_x86_sse2.c	\
+			libcperciva/util/insecure_memzero.c		\
+			libcperciva/util/insecure_memzero.h		\
+			libcperciva/util/warnp.c			\
+			libcperciva/util/warnp.h			\
+			lib/crypto/crypto_scrypt.c			\
+			lib/crypto/crypto_scrypt.h			\
+			lib/crypto/crypto_scrypt_smix.c			\
+			lib/crypto/crypto_scrypt_smix.h			\
+			lib/crypto/crypto_scrypt_smix_sse2.c			\
+			lib/crypto/crypto_scrypt_smix_sse2.h
+
 EXTRA_DIST = \
 	COPYRIGHT						\
 	FORMAT							\

from scrypt.

libscrypt-kdf is now in scrypt master.

from scrypt.

Nice work. Naive question but why is it suffixed with "kdf"? Surely I can use (misuse?) scrypt for purposes other than as a key derivation function?

from scrypt.