Encode artifact path to fix wrongly generated URLs

2 files changed, 26 insertions, 1 deletions

diff --git a/internal/artifact/artifact.go b/internal/artifact/artifact.go
index 28a595bb..91ecbcf8 100644
--- a/internal/artifact/artifact.go
+++ b/internal/artifact/artifact.go
@@ -130,6 +130,22 @@ func addCacheHeader(w http.ResponseWriter, resp *http.Response) {
 	}
 }
 
+// encodePathSegments separately encodes each segment of the path, as
+// segments can have special characters in them, if the path is not valid
+// and gets re-encoded by URL.Parse, %2f will get replaced with '/',
+// breaking the namespace that we pass for group%2fproject.
+//
+// See https://github.com/golang/go/issues/6658 for more context
+func encodePathSegments(path string) string {
+	parsed := strings.Split(path, "/")
+
+	var encoded []string
+	for _, str := range parsed {
+		encoded = append(encoded, url.PathEscape(str))
+	}
+	return strings.Join(encoded, "/")
+}
+
 // BuildURL returns a pointer to a url.URL for where the request should be
 // proxied to. The returned bool will indicate if there is some sort of issue
 // with the url while it is being generated.
@@ -156,7 +172,7 @@ func (a *Artifact) BuildURL(host, requestPath string) (*url.URL, bool) {
 	}
 
 	jobID := parts[0][2]
-	artifactPath := parts[0][3]
+	artifactPath := encodePathSegments(parts[0][3])
 
 	projectID := url.PathEscape(path.Join(topGroup, restOfPath))
 	generated := fmt.Sprintf(apiURLTemplate, a.server, projectID, jobID, artifactPath)
diff --git a/internal/artifact/artifact_test.go b/internal/artifact/artifact_test.go
index 689effb5..930e1438 100644
--- a/internal/artifact/artifact_test.go
+++ b/internal/artifact/artifact_test.go
@@ -143,6 +143,15 @@ func TestBuildURL(t *testing.T) {
 		{
 			"https://gitlab.com/api/v4/",
 			"GROUP.GITLAB.IO",
+			"/-/SUBGROUP/PROJECT/-/JOBS/1/ARTIFACTS/PATH/TO/FILE {!#1.txt",
+			"https://gitlab.com/api/v4/projects/GROUP%2FSUBGROUP%2FPROJECT/jobs/1/artifacts/PATH/TO/FILE%20%7B%21%231.txt",
+			"gitlab.io",
+			true,
+			"Special characters in name",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"GROUP.GITLAB.IO",
 			"/-/SUBGROUP/PROJECT/-/JOBS/1/ARTIFACTS/PATH/TO/FILE.txt",
 			"https://gitlab.com/api/v4/projects/GROUP%2FSUBGROUP%2FPROJECT/jobs/1/artifacts/PATH/TO/FILE.txt",
 			"gitlab.io",