Merge branch '17810-s3-escape-non-unreserved-chars'

fixes #17810

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>

diff --git a/services/keep-web/s3.go b/services/keep-web/s3.go
index f03ff01b8127d6ee1d1056ee72bee5bd6507d26b..6ea9bf9f7a8383cc10ed82e108b76bb3ca97585b 100644 (file)
--- a/services/keep-web/s3.go
+++ b/services/keep-web/s3.go
@@ -136,15 +136,39 @@ func s3stringToSign(alg, scope, signedHeaders string, r *http.Request) (string,
                }
        }
 
-       normalizedURL := *r.URL
-       normalizedURL.RawPath = ""
-       normalizedURL.Path = reMultipleSlashChars.ReplaceAllString(normalizedURL.Path, "/")
-       ctxlog.FromContext(r.Context()).Infof("escapedPath %s", normalizedURL.EscapedPath())
-       canonicalRequest := fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s", r.Method, normalizedURL.EscapedPath(), s3querystring(r.URL), canonicalHeaders, signedHeaders, r.Header.Get("X-Amz-Content-Sha256"))
+       normalizedPath := normalizePath(r.URL.Path)
+       ctxlog.FromContext(r.Context()).Debugf("normalizedPath %q", normalizedPath)
+       canonicalRequest := fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s", r.Method, normalizedPath, s3querystring(r.URL), canonicalHeaders, signedHeaders, r.Header.Get("X-Amz-Content-Sha256"))
        ctxlog.FromContext(r.Context()).Debugf("s3stringToSign: canonicalRequest %s", canonicalRequest)
        return fmt.Sprintf("%s\n%s\n%s\n%s", alg, r.Header.Get("X-Amz-Date"), scope, hashdigest(sha256.New(), canonicalRequest)), nil
 }
 
+func normalizePath(s string) string {
+       // (url.URL).EscapedPath() would be incorrect here. AWS
+       // documentation specifies the URL path should be normalized
+       // according to RFC 3986, i.e., unescaping ALPHA / DIGIT / "-"
+       // / "." / "_" / "~". The implication is that everything other
+       // than those chars (and "/") _must_ be percent-encoded --
+       // even chars like ";" and "," that are not normally
+       // percent-encoded in paths.
+       out := ""
+       for _, c := range []byte(reMultipleSlashChars.ReplaceAllString(s, "/")) {
+               if (c >= 'a' && c <= 'z') ||
+                       (c >= 'A' && c <= 'Z') ||
+                       (c >= '0' && c <= '9') ||
+                       c == '-' ||
+                       c == '.' ||
+                       c == '_' ||
+                       c == '~' ||
+                       c == '/' {
+                       out += string(c)
+               } else {
+                       out += fmt.Sprintf("%%%02X", c)
+               }
+       }
+       return out
+}
+
 func s3signature(secretKey, scope, signedHeaders, stringToSign string) (string, error) {
        // scope is {datestamp}/{region}/{service}/aws4_request
        drs := strings.Split(scope, "/")

diff --git a/services/keep-web/s3_test.go b/services/keep-web/s3_test.go
index 4f70168b5629ecfbdb06193d75344cb4e27673eb..f411fde871cdba0cc9bbb2584be9a9bb878c6c1e 100644 (file)
--- a/services/keep-web/s3_test.go
+++ b/services/keep-web/s3_test.go
@@ -558,12 +558,15 @@ func (s *IntegrationSuite) TestS3NormalizeURIForSignature(c *check.C) {
                rawPath        string
                normalizedPath string
        }{
-               {"/foo", "/foo"},             // boring case
-               {"/foo%5fbar", "/foo_bar"},   // _ must not be escaped
-               {"/foo%2fbar", "/foo/bar"},   // / must not be escaped
-               {"/(foo)", "/%28foo%29"},     // () must be escaped
-               {"/foo%5bbar", "/foo%5Bbar"}, // %XX must be uppercase
+               {"/foo", "/foo"},                           // boring case
+               {"/foo%5fbar", "/foo_bar"},                 // _ must not be escaped
+               {"/foo%2fbar", "/foo/bar"},                 // / must not be escaped
+               {"/(foo)/[];,", "/%28foo%29/%5B%5D%3B%2C"}, // ()[];, must be escaped
+               {"/foo%5bbar", "/foo%5Bbar"},               // %XX must be uppercase
+               {"//foo///.bar", "/foo/.bar"},              // "//" and "///" must be squashed to "/"
        } {
+               c.Logf("trial %q", trial)
+
                date := time.Now().UTC().Format("20060102T150405Z")
                scope := "20200202/zzzzz/S3/aws4_request"
                canonicalRequest := fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s", "GET", trial.normalizedPath, "", "host:host.example.com\n", "host", "")
@@ -1098,6 +1101,15 @@ func (s *IntegrationSuite) TestS3cmd(c *check.C) {
        buf, err := cmd.CombinedOutput()
        c.Check(err, check.IsNil)
        c.Check(string(buf), check.Matches, `.* 3 +s3://`+arvadostest.FooCollection+`/foo\n`)
+
+       // This tests whether s3cmd's path normalization agrees with
+       // keep-web's signature verification wrt chars like "|"
+       // (neither reserved nor unreserved) and "," (not normally
+       // percent-encoded in a path).
+       cmd = exec.Command("s3cmd", "--no-ssl", "--host="+s.testServer.Addr, "--host-bucket="+s.testServer.Addr, "--access_key="+arvadostest.ActiveTokenUUID, "--secret_key="+arvadostest.ActiveToken, "get", "s3://"+arvadostest.FooCollection+"/foo,;$[|]bar")
+       buf, err = cmd.CombinedOutput()
+       c.Check(err, check.NotNil)
+       c.Check(string(buf), check.Matches, `(?ms).*NoSuchKey.*\n`)
 }
 
 func (s *IntegrationSuite) TestS3BucketInHost(c *check.C) {