Use application/pem-certificate-chain for PEMs (#13927)

* Use application/pem-certificate-chain for PEMs As mentioned in #10948, it appears we're incorrectly using the `application/pkix-cert` media type for PEM blobs, when `application/x-pem-file` is more appropriate. Per RFC 5280 Section 4.2.1.13, `application/pkix-crl` is only appropriate when the CRL is in DER form. Likewise, Section 4.2.2.1 states that `application/pkix-cert` is only applicable when a single DER certificate is used. Per recommendation in RFC 8555 ("ACME"), Section 7.4.2 and 9.1, we use the newer `application/pem-certificate-chain` media type for certificates. However, this is not applicable for CRLs, so we use fall back to `application/x-pem-file` for these. Notably, no official IETF source is present for the latter. On the OpenSSL PKI tutorial (https://pki-tutorial.readthedocs.io/en/latest/mime.html), this type is cited as coming from S/MIME's predecessor, PEM, but neither of the main PEM RFCs (RFC 934, 1421, 1422, 1423, or 1424) mention this type. Signed-off-by: Alexander Scheel <[email protected]> * Add changelog entry Signed-off-by: Alexander Scheel <[email protected]>
hashicorp · Feb 8, 2022 · f267c3a · f267c3a
1 parent 82e8bc1
commit f267c3a
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Showing 4 changed files with 8 additions and 2 deletions.
diff --git a/builtin/logical/pki/backend_test.go b/builtin/logical/pki/backend_test.go
@@ -1768,7 +1768,7 @@ func TestBackend_PathFetchValidRaw(t *testing.T) {
 	if bytes.Compare(resp.Data[logical.HTTPRawBody].([]byte), pemCert) != 0 {
 		t.Fatalf("failed to get pem cert")
 	}
-	if resp.Data[logical.HTTPContentType] != "application/pkix-cert" {
+	if resp.Data[logical.HTTPContentType] != "application/pem-certificate-chain" {
 		t.Fatalf("failed to get raw cert content-type")
 	}
 }

diff --git a/builtin/logical/pki/ca_test.go b/builtin/logical/pki/ca_test.go
@@ -320,7 +320,7 @@ func runSteps(t *testing.T, rootB, intB *backend, client *api.Client, rootName,
 			if diff := deep.Equal(resp.Data["http_raw_body"].([]byte), []byte(caCert)); diff != nil {
 				t.Fatal(diff)
 			}
-			if resp.Data["http_content_type"].(string) != "application/pkix-cert" {
+			if resp.Data["http_content_type"].(string) != "application/pem-certificate-chain" {
 				t.Fatal("wrong content type")
 			}
 		}

diff --git a/builtin/logical/pki/path_fetch.go b/builtin/logical/pki/path_fetch.go
@@ -157,6 +157,7 @@ func (b *backend) pathFetchRead(ctx context.Context, req *logical.Request, data
 		contentType = "application/pkix-cert"
 		if req.Path == "ca/pem" {
 			pemType = "CERTIFICATE"
+			contentType = "application/pem-certificate-chain"
 		}
 	case req.Path == "ca_chain" || req.Path == "cert/ca_chain":
 		serial = "ca_chain"
@@ -168,6 +169,7 @@ func (b *backend) pathFetchRead(ctx context.Context, req *logical.Request, data
 		contentType = "application/pkix-crl"
 		if req.Path == "crl/pem" {
 			pemType = "X509 CRL"
+			contentType = "application/x-pem-file"
 		}
 	case req.Path == "cert/crl":
 		serial = "crl"
@@ -177,6 +179,7 @@ func (b *backend) pathFetchRead(ctx context.Context, req *logical.Request, data
 		contentType = "application/pkix-cert"
 		if strings.HasSuffix(req.Path, "/pem") {
 			pemType = "CERTIFICATE"
+			contentType = "application/pem-certificate-chain"
 		}
 	default:
 		serial = data.Get("serial").(string)

diff --git a/changelog/13927.txt b/changelog/13927.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+secrets/pki: Use application/pem-certificate-chain for PEM certificates, application/x-pem-file for PEM CRLs
+```