Subject: Re: [PATCH] http: check CURLE_SSL_PINNEDPUBKEYNOTMATCH when emitting errors

From: SZEDER Gábor <[email-masked]>
Date: Sun, 10 Oct 2021 23:42:09 +0200

On Fri, Sep 24, 2021 at 12:08:20PM +0200, Ævar Arnfjörð Bjarmason wrote:
> Change the error shown when a http.pinnedPubKey doesn't match to point
> the http.pinnedPubKey variable 

I'm not sure what this means.  Between the repeated
'http.pinnedPubKey' config variable name and the "doesn't match to
point the ..." part I can't decipher it.

> added in aeff8a61216 (http: implement
> public key pinning, 2016-02-15), e.g.:
> 
>     git -c http.pinnedPubKey=sha256/someNonMatchingKey ls-remote https://github.com/git/git.git
>     fatal: unable to access 'https://github.com/git/git.git/' with http.pinnedPubkey configuration: SSL: public key does not match pinned public key!
> 
> Before this we'd emit the exact same thing without the " with
> http.pinnedPubkey configuration". The advantage of doing this is that
> we're going to get a translated message (everything after the ":" is
> hardcoded in English in libcurl), and we've got a reference to the
> git-specific configuration variable that's causing the error.
> 
> Unfortunately we can't test this easily, as there are no tests that
> require https:// in the test suite, and t/lib-httpd.sh doesn't know
> how to set up such tests. See [1] for the start of a discussion about
> what it would take to have divergent "t/lib-httpd/apache.conf" test
> setups. #leftoverbits
> 
> 1. https://lore.kernel.org/git/[email-masked]/
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
> ---
> 
> I had this waiting on the now-landed ab/http-drop-old-curl-plus due to
> adding a new entry to git-curl-compat.h.
> 
>  git-curl-compat.h | 3 ++-
>  http.c            | 4 ++++
>  http.h            | 1 +
>  remote-curl.c     | 4 ++++
>  4 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/git-curl-compat.h b/git-curl-compat.h
> index a308bdb3b9b..56a83b6bbd8 100644
> --- a/git-curl-compat.h
> +++ b/git-curl-compat.h
> @@ -64,16 +64,17 @@
>  #if LIBCURL_VERSION_NUM >= 0x072200
>  #define GIT_CURL_HAVE_CURL_SSLVERSION_TLSv1_0
>  #endif
>  
>  /**
>   * CURLOPT_PINNEDPUBLICKEY was added in 7.39.0, released in November
> - * 2014.
> + * 2014. CURLE_SSL_PINNEDPUBKEYNOTMATCH was added in that same version.
>   */
>  #if LIBCURL_VERSION_NUM >= 0x072c00
>  #define GIT_CURL_HAVE_CURLOPT_PINNEDPUBLICKEY 1
> +#define GIT_CURL_HAVE_CURLE_SSL_PINNEDPUBKEYNOTMATCH 1
>  #endif
>  
>  /**
>   * CURL_HTTP_VERSION_2 was added in 7.43.0, released in June 2015.
>   *
>   * The CURL_HTTP_VERSION_2 alias (but not CURL_HTTP_VERSION_2_0) has
> diff --git a/http.c b/http.c
> index d7c20493d7f..b6735b51c31 100644
> --- a/http.c
> +++ b/http.c
> @@ -1486,12 +1486,16 @@ static int handle_curl_result(struct slot_results *results)
>  		 * certificate, bad password, or something else wrong
>  		 * with the certificate.  So we reject the credential to
>  		 * avoid caching or saving a bad password.
>  		 */
>  		credential_reject(&cert_auth);
>  		return HTTP_NOAUTH;
> +#ifdef GIT_CURL_HAVE_CURLE_SSL_PINNEDPUBKEYNOTMATCH
> +	} else if (results->curl_result == CURLE_SSL_PINNEDPUBKEYNOTMATCH) {
> +		return HTTP_NOMATCHPUBLICKEY;
> +#endif
>  	} else if (missing_target(results))
>  		return HTTP_MISSING_TARGET;
>  	else if (results->http_code == 401) {
>  		if (http_auth.username && http_auth.password) {
>  			credential_reject(&http_auth);
>  			return HTTP_NOAUTH;
> diff --git a/http.h b/http.h
> index 3db5a0cf320..df1590e53a4 100644
> --- a/http.h
> +++ b/http.h
> @@ -151,12 +151,13 @@ struct http_get_options {
>  #define HTTP_OK			0
>  #define HTTP_MISSING_TARGET	1
>  #define HTTP_ERROR		2
>  #define HTTP_START_FAILED	3
>  #define HTTP_REAUTH	4
>  #define HTTP_NOAUTH	5
> +#define HTTP_NOMATCHPUBLICKEY	6
>  
>  /*
>   * Requests a URL and stores the result in a strbuf.
>   *
>   * If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
>   */
> diff --git a/remote-curl.c b/remote-curl.c
> index 598cff7cde6..8700dbdc0ac 100644
> --- a/remote-curl.c
> +++ b/remote-curl.c
> @@ -496,12 +496,16 @@ static struct discovery *discover_refs(const char *service, int for_push)
>  		die(_("repository '%s' not found"),
>  		    transport_anonymize_url(url.buf));
>  	case HTTP_NOAUTH:
>  		show_http_message(&type, &charset, &buffer);
>  		die(_("Authentication failed for '%s'"),
>  		    transport_anonymize_url(url.buf));
> +	case HTTP_NOMATCHPUBLICKEY:
> +		show_http_message(&type, &charset, &buffer);
> +		die(_("unable to access '%s' with http.pinnedPubkey configuration: %s"),
> +		    transport_anonymize_url(url.buf), curl_errorstr);
>  	default:
>  		show_http_message(&type, &charset, &buffer);
>  		die(_("unable to access '%s': %s"),
>  		    transport_anonymize_url(url.buf), curl_errorstr);
>  	}
>  
> -- 
> 2.33.0.1231.g24d802460a8
>