Re: [RFC PATCH 1/2] http: support cookie redaction when tracing

[Eric Sunshine <sunshine@sunshineco.com>]

On Wed, Jan 17, 2018 at 7:34 PM, Jonathan Tan <jonathantanmy@google.com> wrote:
> When using GIT_TRACE_CURL, Git already redacts the "Authorization:" and
> "Proxy-Authorization:" HTTP headers. Extend this redaction to a
> user-specified list of cookies, specified through the
> "GIT_REDACT_COOKIES" environment variable.
>
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---
>  http.c                      | 55 +++++++++++++++++++++++++++++++++++++++++++++
>  t/t5551-http-fetch-smart.sh | 12 ++++++++++
>  2 files changed, 67 insertions(+)

Please document GIT_REDACT_COOKIES in Documentation/git.txt.

> diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
> @@ -364,5 +364,17 @@ test_expect_success 'custom http headers' '
> +test_expect_success 'GIT_REDACT_COOKIES redacts cookies' '
> +       rm -rf clone &&
> +       echo "Set-Cookie: NotSecret=Foo" >cookies &&
> +       echo "Set-Cookie: Secret=Bar" >>cookies &&
> +       GIT_TRACE_CURL=true GIT_REDACT_COOKIES=Secret,AnotherSecret \
> +               git -c "http.cookieFile=$(pwd)/cookies" clone \
> +               $HTTPD_URL/smart/repo.git clone 2>err &&
> +       grep "Cookie:.*NotSecret=Foo" err &&
> +       grep "Cookie:.*Secret=<redacted>" err &&
> +       ! grep "Cookie:.*Secret=Bar" err
> +'

The looseness of these grep expressions (/Cookie:.*Secret/ also
matches "Cookie: NotSecret", for instance) requires extra
concentration on the part of the reader to see that you do indeed
cover all cases. I wonder, therefore, if it would be better to tighten
them to instead match the exact string.

Also, after reading the implementation, I had expected to see testing
of the "Cookie: foo=bar; cow=moo" case, as well as the handled corner
cases, such as missing missing "=" and missing value after "=".