Re: Building Git with HTTPS support: avoiding libcurl?

[Dave Borowitz <dborowitz@google.com>]

On Tue, Dec 22, 2015 at 7:39 AM, Paul Smith <paul@mad-scientist.net> wrote:
> I'm trying to build Git (2.6.4) on GNU/Linux, but without any
> requirements (other than basic libc etc.) on the local system.  This
> works fine except for one thing: git-remote-https.
>
> In order to build this I need to have libcurl, but libcurl is a MONSTER
> library with an enormous number of prerequisites (see below).

Well, IIUC one of the reasons for Git's fork-everything strategy is to
avoid having to dynamically link the core git binary against large
libraries like libcurl, so the dependency size has been taken into
account at least in that sense.

> Just wondering if anyone has considered an alternative to libcurl; maybe
> I'm wrong but it seems to me that HTTPS support for Git would require
> only a tiny fraction of the libcurl features and maybe there's an
> alternative available which would be more targeted?
>
> I realize this is not a short-term thing in that there won't be an API
> compatible library that can just be dropped in.  This is more a forward
> -looking question.  For now I'm looking to see if I can rebuild libcurl
> myself without most of these dependencies such as Kerberos, LDAP, etc.
>
>
> $ ldd /usr/lib/x86_64-linux-gnu/libcurl.so.4
>         linux-vdso.so.1 =>  (0x00007fff37d81000)
>         libidn.so.11 => /usr/lib/x86_64-linux-gnu/libidn.so.11 (0x00007f682b921000)
>         librtmp.so.1 => /usr/lib/x86_64-linux-gnu/librtmp.so.1 (0x00007f682b704000)
>         libssl.so.1.0.0 => /lib/x86_64-linux-gnu/libssl.so.1.0.0 (0x00007f682b49a000)
>         libcrypto.so.1.0.0 => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0 (0x00007f682b058000)
>         libgssapi_krb5.so.2 => /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f682ae0e000)
>         liblber-2.4.so.2 => /usr/lib/x86_64-linux-gnu/liblber-2.4.so.2 (0x00007f682abfe000)
>         libldap_r-2.4.so.2 => /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 (0x00007f682a9ac000)
>         libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f682a792000)
>         libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f682a573000)
>         libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f682a1a9000)
>         libgnutls-deb0.so.28 => /usr/lib/x86_64-linux-gnu/libgnutls-deb0.so.28 (0x00007f6829e8d000)
>         libhogweed.so.4 => /usr/lib/x86_64-linux-gnu/libhogweed.so.4 (0x00007f6829c59000)
>         libnettle.so.6 => /usr/lib/x86_64-linux-gnu/libnettle.so.6 (0x00007f6829a23000)
>         libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f68297a3000)
>         libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f682959e000)
>         libkrb5.so.3 => /usr/lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f68292cc000)
>         libk5crypto.so.3 => /usr/lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f682909d000)
>         libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f6828e98000)
>         libkrb5support.so.0 => /usr/lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f6828c8d000)
>         libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f6828a71000)
>         libsasl2.so.2 => /usr/lib/x86_64-linux-gnu/libsasl2.so.2 (0x00007f6828855000)
>         libgssapi.so.3 => /usr/lib/x86_64-linux-gnu/libgssapi.so.3 (0x00007f6828615000)
>         /lib64/ld-linux-x86-64.so.2 (0x0000559b03259000)
>         libp11-kit.so.0 => /usr/lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f68283b0000)
>         libtasn1.so.6 => /usr/lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f682819c000)
>         libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f6827f98000)
>         libheimntlm.so.0 => /usr/lib/x86_64-linux-gnu/libheimntlm.so.0 (0x00007f6827d8e000)
>         libkrb5.so.26 => /usr/lib/x86_64-linux-gnu/libkrb5.so.26 (0x00007f6827b04000)
>         libasn1.so.8 => /usr/lib/x86_64-linux-gnu/libasn1.so.8 (0x00007f6827861000)
>         libhcrypto.so.4 => /usr/lib/x86_64-linux-gnu/libhcrypto.so.4 (0x00007f682762d000)
>         libroken.so.18 => /usr/lib/x86_64-linux-gnu/libroken.so.18 (0x00007f6827418000)
>         libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f6827210000)
>         libwind.so.0 => /usr/lib/x86_64-linux-gnu/libwind.so.0 (0x00007f6826fe6000)
>         libheimbase.so.1 => /usr/lib/x86_64-linux-gnu/libheimbase.so.1 (0x00007f6826dd7000)
>         libhx509.so.5 => /usr/lib/x86_64-linux-gnu/libhx509.so.5 (0x00007f6826b8c000)
>         libsqlite3.so.0 => /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f68268be000)
>         libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f6826686000)

Maybe half of those dependencies are crypto libraries, so even if you
managed to eliminate libcurl, you'd have a hard time supporting HTTPS
without them. Or maybe use something like boringssl instead?