view tests/test-convert-cvsnt-mergepoints.t @ 30766:d7bf7d2bd5ab

hgweb: support Content Security Policy

Content-Security-Policy (CSP) is a web security feature that allows
servers to declare what loaded content is allowed to do. For example,
a policy can prevent loading of images, JavaScript, CSS, etc unless
the source of that content is whitelisted (by hostname, URI scheme,
hashes of content, etc). It's a nifty security feature that provides
extra mitigation against some attacks, notably XSS.

Mitigation against these attacks is important for Mercurial because
hgweb renders repository data, which is commonly untrusted. While we
make attempts to escape things, etc, there's the possibility that
malicious data could be injected into the site content. If this happens
today, the full power of the web browser is available to that
malicious content. A restrictive CSP policy (defined by the server
operator and sent in an HTTP header which is outside the control of
malicious content), could restrict browser capabilities and mitigate
security problems posed by malicious data.

CSP works by emitting an HTTP header declaring the policy that browsers
should apply. Ideally, this header would be emitted by a layer above
Mercurial (likely the HTTP server doing the WSGI "proxying"). This
works for some CSP policies, but not all.

For example, policies to allow inline JavaScript may require setting
a "nonce" attribute on <script>. This attribute value must be unique
and non-guessable. And, the value must be present in the HTTP header
and the HTML body. This means that coordinating the value between
Mercurial and another HTTP server could be difficult: it is much
easier to generate and emit the nonce in a central location.

This commit introduces support for emitting a
Content-Security-Policy header from hgweb. A config option defines
the header value. If present, the header is emitted. A special
"%nonce%" syntax in the value triggers generation of a nonce and
inclusion in <script> elements in templates. The inclusion of a
nonce does not occur unless "%nonce%" is present. This makes this
commit completely backwards compatible and the feature opt-in.

The nonce is a type 4 UUID, which is the flavor that is randomly
generated. It has 122 random bits, which should be plenty to satisfy
the guarantees of a nonce.

#require cvs

  $ filterpath()
  > {
  >     eval "$@" | sed "s:$CVSROOT:*REPO*:g"
  > }
  $ cvscall()
  > {
  >     cvs -f "$@"
  > }

output of 'cvs ci' varies unpredictably, so discard most of it
-- just keep the part that matters

  $ cvsci()
  > {
  >     cvs -f ci -f "$@" > /dev/null
  > }
  $ hgcat()
  > {
  >     hg --cwd src-hg cat -r tip "$1"
  > }
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert = " >> $HGRCPATH

create cvs repository

  $ mkdir cvsmaster
  $ cd cvsmaster
  $ CVSROOT=`pwd`
  $ export CVSROOT
  $ CVS_OPTIONS=-f
  $ export CVS_OPTIONS
  $ cd ..
  $ rmdir cvsmaster
  $ filterpath cvscall -Q -d "$CVSROOT" init

checkout #1: add foo.txt

  $ cvscall -Q checkout -d cvsworktmp .
  $ cd cvsworktmp
  $ mkdir foo
  $ cvscall -Q add foo
  $ cd foo
  $ echo foo > foo.txt
  $ cvscall -Q add foo.txt
  $ cvsci -m "add foo.txt" foo.txt
  $ cd ../..
  $ rm -rf cvsworktmp

checkout #2: create MYBRANCH1 and modify foo.txt on it

  $ cvscall -Q checkout -d cvswork foo
  $ cd cvswork
  $ cvscall -q rtag -b -R MYBRANCH1 foo
  $ cvscall -Q update -P -r MYBRANCH1
  $ echo bar > foo.txt
  $ cvsci -m "bar" foo.txt
  $ echo baz > foo.txt
  $ cvsci -m "baz" foo.txt

create MYBRANCH1_2 and modify foo.txt some more

  $ cvscall -q rtag -b -R -r MYBRANCH1 MYBRANCH1_2 foo
  $ cvscall -Q update -P -r MYBRANCH1_2
  $ echo bazzie > foo.txt
  $ cvsci -m "bazzie" foo.txt

create MYBRANCH1_1 and modify foo.txt yet again

  $ cvscall -q rtag -b -R MYBRANCH1_1 foo
  $ cvscall -Q update -P -r MYBRANCH1_1
  $ echo quux > foo.txt
  $ cvsci -m "quux" foo.txt

merge MYBRANCH1 to MYBRANCH1_1

  $ filterpath cvscall -Q update -P -jMYBRANCH1
  rcsmerge: warning: conflicts during merge
  RCS file: *REPO*/foo/foo.txt,v
  retrieving revision 1.1
  retrieving revision 1.1.2.2
  Merging differences between 1.1 and 1.1.2.2 into foo.txt

carefully placed sleep to dodge cvs bug (optimization?) where it
sometimes ignores a "commit" command if it comes too fast (the -f
option in cvsci seems to work for all the other commits in this
script)

  $ sleep 1
  $ echo xyzzy > foo.txt
  $ cvsci -m "merge1+clobber" foo.txt

#if unix-permissions

return to trunk and merge MYBRANCH1_2

  $ cvscall -Q update -P -A
  $ filterpath cvscall -Q update -P -jMYBRANCH1_2
  RCS file: *REPO*/foo/foo.txt,v
  retrieving revision 1.1
  retrieving revision 1.1.2.2.2.1
  Merging differences between 1.1 and 1.1.2.2.2.1 into foo.txt
  $ cvsci -m "merge2" foo.txt
  $ REALCVS=`which cvs`
  $ echo "for x in \$*; do if [ \"\$x\" = \"rlog\" ]; then echo \"RCS file: $CVSROOT/foo/foo.txt,v\"; cat \"$TESTDIR/test-convert-cvsnt-mergepoints.rlog\"; exit 0; fi; done; $REALCVS \$*" > ../cvs
  $ chmod +x ../cvs
  $ PATH=..:${PATH} hg debugcvsps --parents foo
  collecting CVS rlog
  7 log entries
  creating changesets
  7 changeset entries
  ---------------------
  PatchSet 1 
  Date: * (glob)
  Author: user
  Branch: HEAD
  Tag: (none) 
  Branchpoints: MYBRANCH1, MYBRANCH1_1 
  Log:
  foo.txt
  
  Members: 
  	foo.txt:INITIAL->1.1 
  
  ---------------------
  PatchSet 2 
  Date: * (glob)
  Author: user
  Branch: MYBRANCH1
  Tag: (none) 
  Parent: 1
  Log:
  bar
  
  Members: 
  	foo.txt:1.1->1.1.2.1 
  
  ---------------------
  PatchSet 3 
  Date: * (glob)
  Author: user
  Branch: MYBRANCH1
  Tag: (none) 
  Branchpoints: MYBRANCH1_2 
  Parent: 2
  Log:
  baz
  
  Members: 
  	foo.txt:1.1.2.1->1.1.2.2 
  
  ---------------------
  PatchSet 4 
  Date: * (glob)
  Author: user
  Branch: MYBRANCH1_1
  Tag: (none) 
  Parent: 1
  Log:
  quux
  
  Members: 
  	foo.txt:1.1->1.1.4.1 
  
  ---------------------
  PatchSet 5 
  Date: * (glob)
  Author: user
  Branch: MYBRANCH1_2
  Tag: (none) 
  Parent: 3
  Log:
  bazzie
  
  Members: 
  	foo.txt:1.1.2.2->1.1.2.2.2.1 
  
  ---------------------
  PatchSet 6 
  Date: * (glob)
  Author: user
  Branch: HEAD
  Tag: (none) 
  Parents: 1,5
  Log:
  merge
  
  Members: 
  	foo.txt:1.1->1.2 
  
  ---------------------
  PatchSet 7 
  Date: * (glob)
  Author: user
  Branch: MYBRANCH1_1
  Tag: (none) 
  Parents: 4,3
  Log:
  merge
  
  Members: 
  	foo.txt:1.1.4.1->1.1.4.2 
  
#endif

  $ cd ..