Subject: Re: libssh2: Ported to UC Linux ?

Re: libssh2: Ported to UC Linux ?

From: Peter Stuge <peter_at_stuge.se>
Date: Thu, 1 Jul 2010 21:31:36 +0200

Hi Paul,

Paul Romero wrote:
> libssh2
..
> Has it previously been ported to the UC Linux OS ?

No porting is required. You may know that uClinux provides the exact
same API as the regular Linux kernel.

> Note that UC Linux is a diskless embedded system OS,

Um, no, uClinux is a kernel variant..

> and typically runs on processors without an MMU. Also, the .o file
> format is ELF 32-bit MSB relocatable 68020, not stripped.

That will obviously depend on which binary file formats you enable in
the uClinux configuration, and which architecture you are running on.

> My target system is M5249C3 dev. board with UC Linux version 2.4.27
> and version 2.4.X or the kernel.

Maybe this is what you got delivered to you but I highly doubt that
this would be the only configuration that you could use with that
board. I would suggest that you create a fresh set of binaries for
your target, from the latest versions of what makes up a typical
embedded Linux system.

> It must be compiled with version 2.95.3 of the GNU ELF Toolchain

I also doubt this very strongly. The 2.4 codebase might indeed have
some requirements on compiler version, but I don't think that 2.95.3
is the only thing you can use. Note also that 2.95.3 is the version
of GCC only. "Toolchain" is a term commonly used to describe C
compiler (GCC) along with linker and other binary utilities (GNU
binutils). binutils has it's own versioning scheme.

> which does not have modern automake capabilities.

Again I doubt this. You could most likely use the very latest
autotools also with the older toolchain that you got.

> I use the SASL library
..
> I wonder if the libssh2 SH-2 library duplicates a significant part
> of functionality.

No. libssh2 implements SSH, not SASL. libssh2 specifically does not
implement cryptography, for that it uses libgcrypt or OpenSSL. I
don't think the SASL library implements cryptography either.

> The size of the current SASL authentication/encryption library I am
> using is about 605.4 K, and it provides GNU TLS functionality.

If there's a libgcrypt API then libssh2 can use it.

> The other functionality it provides is as follows: DES, MD5, ARC4,
> DSA, BLOWFISH, TWOFISH, CAST5, MD2, MD4, RSA, SHA1, SHA265, SHA512,
> RIJNDAEL, SERPENT, TIGER, X.509, ANS1, HMAC-MD5, DIGEST-MD5. The
> largest components are DEs, RSA and ASN1 whose sizes are about 18.3,
> 9.1, and 67 K respectively.

The minimum you need for libssh2 is AES, RSA, DSA and SHA1.

//Peter
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Received on 2010-07-01