Hacking NSS

Using NSS from Pluto

use lsw_nss_error*() to report errors

It includes both the error symbol name and the error message (the former is really useful when reading the code^D^D^D^D documentation when tracking down why the error was returned).

Debugging NSS

NSS_ENABLE_PKIX_VERIFY=1 LD_LIBRARY_PATH=$(cd ../dist/Debug/lib && pwd) gdb --args $(cd ../dist/Debug/bin && pwd)/certutil -V -n PasswordCert -u S -d ../tests_results/security/build.1/dbpass
(gdb) break PKIX_Shutdown
(gdb) break cert_VerifyCertChainPkix

Using custom NSS RPMs

Building NSS RPMs ...

... using fedpkg local and a KVM

Here, we use the build machine (it has lots of memory and network access) and the 9p mounted directory /pool (aka $(KVM_POOLDIR), but /testing and /root should also work). Just remember that any changes to build aren't permanent, we'll get to that later.

First lets set things up:

$ ./kvm sh build
build# cd /pool
build# dnf install -y fedpkg
build# cat /etc/fedora-release
Fedora release 32 (Thirty Two)
build# fedpkg clone --branch f32 --anonymous nss
build# cd nss
build# dnf builddep nss

Hack xmlto so that it doesn't try to preserve permissions when copying files within the 9p file system (remember, ./kvm uninstall install will wipe this):

build# sed -i -e 's/ -p / /' \
   /usr/share/xmlto/format/docbook/man \
   /usr/share/xmlto/format/docbook/html

hack nss.specso that it has a unique suffix:

build# sed -i -e '/Release:/ s/\([0-9]*\)%/\1_lsw%/' nss.spec
build# fedpkg verrel
nss-3.63.0-1_lsw.fc32

hobble running tests during the build (optional):

build# sed -i -e 's/bcond_without tests/bcond_with tests/' nss.spec

finally build:

build# fedpkg local --without tests:

or:

build# fedpkg prep --without tests
build# fedpkg compile --short-circuit --without tests

the RPMs are under x86_64.

... using fedpkg mock and the Fedora host

Hmm, something goes here!

fedpkg mock-config
fedpkg mockbuild

Installing the NSS RPMs (and making them stick)

The NSS RPMs can either be installed manually on build (which means they only stick around until ./kvm uninstall), or they can be made more permenant by installing them into the base domain.

To install the RPMs on the base domain, add the following lines to Makefile.inc.local:

# Prepend the directory containing the RPMs, include /
KVM_NSS_RPMDIR = /pool/nss/x86_64/
# Append the actual RPM version
KVM_NSS_VERSION = -3.63.0-1_lsw.fc32.x86_64.rpm

and then upgrade the base domain:

$ ./kvm upgrade
...
 Upgrading        : nss-util-3.63.0-1_lsw.fc32.x86_64                     1/20 
...

finally, confirm:

$ ./kvm install
$ ./kvm sh east
east# rpm -q nss
nss-3.63.0-1_lsw.fc32.x86_64

If needed, the the customized domains can be reverted. In Makefile.inc.local, comment out the lines added above, and then run:

$ ./kvm downgrade
$ ./kvm upgrade
...
 Installing       : nss-util-3.63.0-1.fc32.x86_64                       13/330 

Distributing Custom NSS RPMs

Tar up both the .rpm and .srpm files into a single archive and make that available. That way, who ever downloads the archive always gets the source code.

Using a scratch NSS+NSPR build

Scratch building NSS+NSPR

Setup:

$ ./kvm sh build
build# mkdir -p /pool/nss+nspr
build# cd !$
cd /pool/nss+nspr
build# dnf builddep nss
build# dnf install hg python gyp ninja-build

Hack xmlto so that it doesn't try to preserve permissions when copying files within the 9p file system (remember, ./kvm uninstall install will wipe this):

build# sed -i -e 's/ -p / /' \
   /usr/share/xmlto/format/docbook/man \
   /usr/share/xmlto/format/docbook/html

Using Building NSS as a guide:

build# hg clone https://hg.mozilla.org/projects/nspr
build# hg clone https://hg.mozilla.org/projects/nss
build# ./nss/build.sh --enable-libpkix

testing (for comparison, NSS build farm):

build# HOST=localhost DOMSUF=localdomain USE_64=1 nss/tests/all.sh

however, of most interest is PKIX:

( cd nss/tests/cert/ ; USE_64=1 NSS_ENABLE_PKIX_VERIFY=1 DOMSUF=localdomain ./cert.sh )

Linking with libreswan

finally, to link nss against the build, add the following to Makefile.inc.local (how correct is this?):

NSSDIR = /pool/nss+nspr
NSS_LIBDIR = $(NSSDIR)/dist/Debug/lib/
NSS_CFLAGS = -I$(NSSDIR)/nspr/Debug/dist/include/nspr -I$(NSSDIR)/dist/public/nss
NSS_LDFLAGS = -L$(NSS_LIBDIR) -Wl,-rpath,$(NSS_LIBDIR) -lnss3

and then build as per normal:

$ ./kvm install check

and confirm it worked:

$ ./kvm sh east
cat /proc/$(pgrep pluto)/maps | grep nss