[PATCH 0/2] quoting bug sending push-options over http

[PATCH 0/2] quoting bug sending push-options over http

[Jeff King]

This series fixes a small quoting problem in 511155db51 (remote-curl:
allow push options, 2017-03-22). The interesting one is the second
patch.

  [1/2]: t5545: factor out http repository setup
  [2/2]: remote-curl: unquote incoming push-options

 remote-curl.c           | 11 ++++++++++-
 t/t5545-push-options.sh | 40 +++++++++++++++++++++++++++++-----------
 2 files changed, 39 insertions(+), 12 deletions(-)

-Peff

[PATCH 1/2] t5545: factor out http repository setup

[Jeff King]

We repeat many lines of setup code in the two http tests,
and further tests would need to repeat it again.  Let's
factor this out into a function.

Incidentally, this also fixes an unlikely bug: if the httpd
root path contains a double-quote, our test_when_finished
would barf due to improper quoting (we escape the embedded
quotes, but not the $, meaning we expand the variable before
the eval).

Signed-off-by: Jeff King <peff@peff.net>
---
Arguably this setup could be done once and then reused by several tests,
which would be a bit more efficient.  But the whole script is written in
this "remake repos fresh" style, so I didn't look into switching it.

 t/t5545-push-options.sh | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/t/t5545-push-options.sh b/t/t5545-push-options.sh
index 463783789c..c64dee2127 100755
--- a/t/t5545-push-options.sh
+++ b/t/t5545-push-options.sh
@@ -220,14 +220,20 @@ test_expect_success 'invalid push option in config' '
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
-test_expect_success 'push option denied properly by http server' '
+# set up http repository for fetching/pushing, with push options config
+# bool set to $1
+mk_http_pair () {
 	test_when_finished "rm -rf test_http_clone" &&
-	test_when_finished "rm -rf \"$HTTPD_DOCUMENT_ROOT_PATH\"/upstream.git" &&
+	test_when_finished 'rm -rf "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git' &&
 	mk_repo_pair &&
-	git -C upstream config receive.advertisePushOptions false &&
+	git -C upstream config receive.advertisePushOptions "$1" &&
 	git -C upstream config http.receivepack true &&
 	cp -R upstream/.git "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git &&
-	git clone "$HTTPD_URL"/smart/upstream test_http_clone &&
+	git clone "$HTTPD_URL"/smart/upstream test_http_clone
+}
+
+test_expect_success 'push option denied properly by http server' '
+	mk_http_pair false &&
 	test_commit -C test_http_clone one &&
 	test_must_fail git -C test_http_clone push --push-option=asdf origin master 2>actual &&
 	test_i18ngrep "the receiving end does not support push options" actual &&
@@ -235,13 +241,7 @@ test_expect_success 'push option denied properly by http server' '
 '
 
 test_expect_success 'push options work properly across http' '
-	test_when_finished "rm -rf test_http_clone" &&
-	test_when_finished "rm -rf \"$HTTPD_DOCUMENT_ROOT_PATH\"/upstream.git" &&
-	mk_repo_pair &&
-	git -C upstream config receive.advertisePushOptions true &&
-	git -C upstream config http.receivepack true &&
-	cp -R upstream/.git "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git &&
-	git clone "$HTTPD_URL"/smart/upstream test_http_clone &&
+	mk_http_pair true &&
 
 	test_commit -C test_http_clone one &&
 	git -C test_http_clone push origin master &&
-- 
2.16.2.552.gea2a3cf654

[PATCH 2/2] remote-curl: unquote incoming push-options

[Jeff King]

The transport-helper protocol c-style quotes the value of
any options passed to the helper via the "option <key> <value>"
directive. However, remote-curl doesn't actually unquote the
push-option values, meaning that we will send the quoted
version to the other side (whereas git-over-ssh would send
the raw value).

The pack-protocol.txt documentation defines the push-options
as a series of VCHARs, which excludes most characters that
would need quoting. But:

  1. You can still see the bug with a valid push-option that
     starts with a double-quote (since that triggers
     quoting).

  2. We do currently handle any non-NUL characters correctly
     in git-over-ssh. So even though the spec does not say
     that we need to handle most quoted characters, it's
     nice if our behavior is consistent between protocols.

There are two new tests: the "direct" one shows that this
already works in the non-http case, and the http one covers
this bugfix.

Reported-by: Jon Simons <jon@jonsimons.org>
Signed-off-by: Jeff King <peff@peff.net>
---
 remote-curl.c           | 11 ++++++++++-
 t/t5545-push-options.sh | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/remote-curl.c b/remote-curl.c
index 6ec5352435..f5b3d22e26 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -13,6 +13,7 @@
 #include "credential.h"
 #include "sha1-array.h"
 #include "send-pack.h"
+#include "quote.h"
 
 static struct remote *remote;
 /* always ends with a trailing slash */
@@ -145,7 +146,15 @@ static int set_option(const char *name, const char *value)
 			return -1;
 		return 0;
 	} else if (!strcmp(name, "push-option")) {
-		string_list_append(&options.push_options, value);
+		if (*value != '"')
+			string_list_append(&options.push_options, value);
+		else {
+			struct strbuf unquoted = STRBUF_INIT;
+			if (unquote_c_style(&unquoted, value, NULL) < 0)
+				die("invalid quoting in push-option value");
+			string_list_append_nodup(&options.push_options,
+						 strbuf_detach(&unquoted, NULL));
+		}
 		return 0;
 
 #if LIBCURL_VERSION_NUM >= 0x070a08
diff --git a/t/t5545-push-options.sh b/t/t5545-push-options.sh
index c64dee2127..b47a95871c 100755
--- a/t/t5545-push-options.sh
+++ b/t/t5545-push-options.sh
@@ -217,6 +217,15 @@ test_expect_success 'invalid push option in config' '
 	test_refs master HEAD@{1}
 '
 
+test_expect_success 'push options keep quoted characters intact (direct)' '
+	mk_repo_pair &&
+	git -C upstream config receive.advertisePushOptions true &&
+	test_commit -C workbench one &&
+	git -C workbench push --push-option="\"embedded quotes\"" up master &&
+	echo "\"embedded quotes\"" >expect &&
+	test_cmp expect upstream/.git/hooks/pre-receive.push_options
+'
+
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
@@ -260,6 +269,15 @@ test_expect_success 'push options work properly across http' '
 	test_cmp expect actual
 '
 
+test_expect_success 'push options keep quoted characters intact (http)' '
+	mk_http_pair true &&
+
+	test_commit -C test_http_clone one &&
+	git -C test_http_clone push --push-option="\"embedded quotes\"" origin master &&
+	echo "\"embedded quotes\"" >expect &&
+	test_cmp expect "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git/hooks/pre-receive.push_options
+'
+
 stop_httpd
 
 test_done
-- 
2.16.2.552.gea2a3cf654

Re: [PATCH 2/2] remote-curl: unquote incoming push-options

[Brandon Williams]

On 02/19, Jeff King wrote:
> The transport-helper protocol c-style quotes the value of
> any options passed to the helper via the "option <key> <value>"
> directive. However, remote-curl doesn't actually unquote the
> push-option values, meaning that we will send the quoted
> version to the other side (whereas git-over-ssh would send
> the raw value).
> 
> The pack-protocol.txt documentation defines the push-options
> as a series of VCHARs, which excludes most characters that
> would need quoting. But:
> 
>   1. You can still see the bug with a valid push-option that
>      starts with a double-quote (since that triggers
>      quoting).
> 
>   2. We do currently handle any non-NUL characters correctly
>      in git-over-ssh. So even though the spec does not say
>      that we need to handle most quoted characters, it's
>      nice if our behavior is consistent between protocols.
> 
> There are two new tests: the "direct" one shows that this
> already works in the non-http case, and the http one covers
> this bugfix.

This seems like a fairly obvious fix.  If the value is quoted, unquote
it and send the unquoted value as a push-option, otherwise just send the
already unquoted value as a push-option.

Thanks for finding and fixing this :)

> 
> Reported-by: Jon Simons <jon@jonsimons.org>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
>  remote-curl.c           | 11 ++++++++++-
>  t/t5545-push-options.sh | 18 ++++++++++++++++++
>  2 files changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/remote-curl.c b/remote-curl.c
> index 6ec5352435..f5b3d22e26 100644
> --- a/remote-curl.c
> +++ b/remote-curl.c
> @@ -13,6 +13,7 @@
>  #include "credential.h"
>  #include "sha1-array.h"
>  #include "send-pack.h"
> +#include "quote.h"
>  
>  static struct remote *remote;
>  /* always ends with a trailing slash */
> @@ -145,7 +146,15 @@ static int set_option(const char *name, const char *value)
>  			return -1;
>  		return 0;
>  	} else if (!strcmp(name, "push-option")) {
> -		string_list_append(&options.push_options, value);
> +		if (*value != '"')
> +			string_list_append(&options.push_options, value);
> +		else {
> +			struct strbuf unquoted = STRBUF_INIT;
> +			if (unquote_c_style(&unquoted, value, NULL) < 0)
> +				die("invalid quoting in push-option value");
> +			string_list_append_nodup(&options.push_options,
> +						 strbuf_detach(&unquoted, NULL));
> +		}
>  		return 0;
>  
>  #if LIBCURL_VERSION_NUM >= 0x070a08
> diff --git a/t/t5545-push-options.sh b/t/t5545-push-options.sh
> index c64dee2127..b47a95871c 100755
> --- a/t/t5545-push-options.sh
> +++ b/t/t5545-push-options.sh
> @@ -217,6 +217,15 @@ test_expect_success 'invalid push option in config' '
>  	test_refs master HEAD@{1}
>  '
>  
> +test_expect_success 'push options keep quoted characters intact (direct)' '
> +	mk_repo_pair &&
> +	git -C upstream config receive.advertisePushOptions true &&
> +	test_commit -C workbench one &&
> +	git -C workbench push --push-option="\"embedded quotes\"" up master &&
> +	echo "\"embedded quotes\"" >expect &&
> +	test_cmp expect upstream/.git/hooks/pre-receive.push_options
> +'
> +
>  . "$TEST_DIRECTORY"/lib-httpd.sh
>  start_httpd
>  
> @@ -260,6 +269,15 @@ test_expect_success 'push options work properly across http' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'push options keep quoted characters intact (http)' '
> +	mk_http_pair true &&
> +
> +	test_commit -C test_http_clone one &&
> +	git -C test_http_clone push --push-option="\"embedded quotes\"" origin master &&
> +	echo "\"embedded quotes\"" >expect &&
> +	test_cmp expect "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git/hooks/pre-receive.push_options
> +'
> +
>  stop_httpd
>  
>  test_done
> -- 
> 2.16.2.552.gea2a3cf654

-- 
Brandon Williams