Adding support for configuration from yaml file

pkg/config/config.go

@@ -34,6 +34,7 @@ import (
 	fulciogrpc "github.com/sigstore/fulcio/pkg/generated/protobuf"
 	"github.com/sigstore/fulcio/pkg/log"
 	"github.com/spiffe/go-spiffe/v2/spiffeid"
+	"gopkg.in/yaml.v3"
 )
 
 const defaultOIDCDiscoveryTimeout = 10 * time.Second
@@ -48,7 +49,7 @@ type verifierWithConfig struct {
 }
 
 type FulcioConfig struct {
-	OIDCIssuers map[string]OIDCIssuer `json:"OIDCIssuers,omitempty"`
+	OIDCIssuers map[string]OIDCIssuer `json:"OIDCIssuers,omitempty" yaml:"oidc-issuers,omitempty"`
 
 	// A meta issuer has a templated URL of the form:
 	//   https://oidc.eks.*.amazonaws.com/id/*
@@ -57,7 +58,7 @@ type FulcioConfig struct {
 	// other special characters)  Some examples we want to match:
 	// * https://oidc.eks.us-west-2.amazonaws.com/id/B02C93B6A2D30341AD01E1B6D48164CB
 	// * https://container.googleapis.com/v1/projects/mattmoor-credit/locations/us-west1-b/clusters/tenant-cluster
-	MetaIssuers map[string]OIDCIssuer `json:"MetaIssuers,omitempty"`
+	MetaIssuers map[string]OIDCIssuer `json:"MetaIssuers,omitempty" yaml:"meta-issuers,omitempty"`
 
 	// verifiers is a fixed mapping from our OIDCIssuers to their OIDC verifiers.
 	verifiers map[string][]*verifierWithConfig
@@ -67,24 +68,24 @@ type FulcioConfig struct {
 
 type OIDCIssuer struct {
 	// The expected issuer of an OIDC token
-	IssuerURL string `json:"IssuerURL,omitempty"`
+	IssuerURL string `json:"IssuerURL,omitempty" yaml:"issuer-url,omitempty"`
 	// The expected client ID of the OIDC token
-	ClientID string `json:"ClientID"`
+	ClientID string `json:"ClientID" yaml:"client-id,omitempty"`
 	// Used to determine the subject of the certificate and if additional
 	// certificate values are needed
-	Type IssuerType `json:"Type"`
+	Type IssuerType `json:"Type" yaml:"type,omitempty"`
 	// Optional, if the issuer is in a different claim in the OIDC token
-	IssuerClaim string `json:"IssuerClaim,omitempty"`
+	IssuerClaim string `json:"IssuerClaim,omitempty" yaml:"issuer-claim,omitempty"`
 	// The domain that must be present in the subject for 'uri' issuer types
 	// Also used to create an email for 'username' issuer types
-	SubjectDomain string `json:"SubjectDomain,omitempty"`
+	SubjectDomain string `json:"SubjectDomain,omitempty" yaml:"subject-domain,omitempty"`
 	// SPIFFETrustDomain specifies the trust domain that 'spiffe' issuer types
 	// issue ID tokens for. Tokens with a different trust domain will be
 	// rejected.
-	SPIFFETrustDomain string `json:"SPIFFETrustDomain,omitempty"`
+	SPIFFETrustDomain string `json:"SPIFFETrustDomain,omitempty" yaml:"spiffe-trust-domain,omitempty"`
 	// Optional, the challenge claim expected for the issuer
 	// Set if using a custom issuer
-	ChallengeClaim string `json:"ChallengeClaim,omitempty"`
+	ChallengeClaim string `json:"ChallengeClaim,omitempty" yaml:"challenge-claim,omitempty"`
 }
 
 func metaRegex(issuer string) (*regexp.Regexp, error) {
@@ -287,7 +288,9 @@ const (
 func parseConfig(b []byte) (cfg *FulcioConfig, err error) {
 	cfg = &FulcioConfig{}
 	if err := json.Unmarshal(b, cfg); err != nil {
-		return nil, fmt.Errorf("unmarshal: %w", err)
+		if err = yaml.Unmarshal(b, cfg); err != nil {
+			return nil, fmt.Errorf("unmarshal: %w", err)
+		}
 	}
 
 	return cfg, nil

pkg/server/grpc_server_test.go

@@ -322,6 +322,146 @@ func TestGetConfiguration(t *testing.T) {
 	}
 }
 
+// Tests GetConfigurationFromYaml API
+func TestGetConfigurationFromYaml(t *testing.T) {
+	_, emailIssuer := newOIDCIssuer(t)
+	_, spiffeIssuer := newOIDCIssuer(t)
+	_, uriIssuer := newOIDCIssuer(t)
+	_, usernameIssuer := newOIDCIssuer(t)
+	_, k8sIssuer := newOIDCIssuer(t)
+	_, buildkiteIssuer := newOIDCIssuer(t)
+	_, gitHubIssuer := newOIDCIssuer(t)
+	_, gitLabIssuer := newOIDCIssuer(t)
+	_, codefreshIssuer := newOIDCIssuer(t)
+
+	issuerDomain, err := url.Parse(usernameIssuer)
+	if err != nil {
+		t.Fatal("issuer URL could not be parsed", err)
+	}
+
+	yamlBytes := []byte(fmt.Sprintf(`
+    oidc-issuers:
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: spiffe
+        spiffe-trust-domain: example.com
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: uri
+        subject-domain: %q
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: email
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: username
+        subject-domain: %q
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: buildkite-job
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: github-workflow
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: gitlab-pipeline
+      %v:
+        issuer-url: %q
+        client-id: sigstore
+        type: codefresh-workflow
+    meta-issuers:
+      %v:
+        client-id: sigstore
+        type: kubernetes`,
+		spiffeIssuer, spiffeIssuer,
+		uriIssuer, uriIssuer, uriIssuer,
+		emailIssuer, emailIssuer,
+		usernameIssuer, usernameIssuer, issuerDomain.Hostname(),
+		buildkiteIssuer, buildkiteIssuer,
+		gitHubIssuer, gitHubIssuer,
+		gitLabIssuer, gitLabIssuer,
+		codefreshIssuer, codefreshIssuer,
+		k8sIssuer))
+
+	cfg, err := config.Read(yamlBytes)
+	if err != nil {
+		t.Fatalf("config.Read() = %v", err)
+	}
+
+	ctClient, eca := createCA(cfg, t)
+	ctx := context.Background()
+	server, conn := setupGRPCForTest(ctx, t, cfg, ctClient, eca)
+	defer func() {
+		server.Stop()
+		conn.Close()
+	}()
+
+	client := protobuf.NewCAClient(conn)
+
+	config, err := client.GetConfiguration(ctx, &protobuf.GetConfigurationRequest{})
+	if err != nil {
+		t.Fatal("GetConfiguration failed", err)
+	}
+
+	if len(config.Issuers) != 9 {
+		t.Fatalf("expected 9 issuers, got %v", len(config.Issuers))
+	}
+
+	expectedIssuers := map[string]bool{
+		emailIssuer: true, spiffeIssuer: true, uriIssuer: true,
+		usernameIssuer: true, k8sIssuer: true, gitHubIssuer: true,
+		buildkiteIssuer: true, gitLabIssuer: true, codefreshIssuer: true,
+	}
+	for _, iss := range config.Issuers {
+		var issURL string
+		switch {
+		case expectedIssuers[iss.GetIssuerUrl()]:
+			delete(expectedIssuers, iss.GetIssuerUrl())
+			issURL = iss.GetIssuerUrl()
+		case expectedIssuers[iss.GetWildcardIssuerUrl()]:
+			delete(expectedIssuers, iss.GetWildcardIssuerUrl())
+			issURL = iss.GetWildcardIssuerUrl()
+		default:
+			t.Fatal("issuer missing from expected issuers")
+		}
+
+		if iss.Audience != "sigstore" {
+			t.Fatalf("expected audience to be sigstore, got %v", iss.Audience)
+		}
+
+		if issURL == emailIssuer {
+			if iss.ChallengeClaim != "email" {
+				t.Fatalf("expected email claim for email PoP challenge, got %v", iss.ChallengeClaim)
+			}
+		} else {
+			if iss.ChallengeClaim != "sub" {
+				t.Fatalf("expected sub claim for non-email PoP challenge, got %v", iss.ChallengeClaim)
+			}
+		}
+
+		if issURL == spiffeIssuer {
+			if iss.SpiffeTrustDomain != "example.com" {
+				t.Fatalf("expected SPIFFE trust domain example.com, got %v", iss.SpiffeTrustDomain)
+			}
+		} else {
+			if iss.SpiffeTrustDomain != "" {
+				t.Fatalf("expected no SPIFFE trust domain, got %v", iss.SpiffeTrustDomain)
+			}
+		}
+	}
+
+	if len(expectedIssuers) != 0 {
+		t.Fatal("not all issuers were found in configuration")
+	}
+}
+
 // oidcTestContainer holds values needed for each API test invocation
 type oidcTestContainer struct {
 	Signer          jose.Signer