Merge pull request #829 from vijayjt/new-azure-token-authz-options

Add subscription and object ID validation options to Azure provisioner

authority/provisioner/azure.go

@@ -89,6 +89,8 @@ type Azure struct {
 	Name                   string   `json:"name"`
 	TenantID               string   `json:"tenantID"`
 	ResourceGroups         []string `json:"resourceGroups"`
+	SubscriptionIDs        []string `json:"subscriptionIDs"`
+	ObjectIDs              []string `json:"ObjectIDs"`
 	Audience               string   `json:"audience,omitempty"`
 	DisableCustomSANs      bool     `json:"disableCustomSANs"`
 	DisableTrustOnFirstUse bool     `json:"disableTrustOnFirstUse"`
@@ -224,14 +226,14 @@ func (p *Azure) Init(config Config) (err error) {
 	return nil
 }
 
-// authorizeToken returns the claims, name, group, error.
-func (p *Azure) authorizeToken(token string) (*azurePayload, string, string, error) {
+// authorizeToken returns the claims, name, group, subscription, identityObjectID, error.
+func (p *Azure) authorizeToken(token string) (*azurePayload, string, string, string, string, error) {
 	jwt, err := jose.ParseSigned(token)
 	if err != nil {
-		return nil, "", "", errs.Wrap(http.StatusUnauthorized, err, "azure.authorizeToken; error parsing azure token")
+		return nil, "", "", "", "", errs.Wrap(http.StatusUnauthorized, err, "azure.authorizeToken; error parsing azure token")
 	}
 	if len(jwt.Headers) == 0 {
-		return nil, "", "", errs.Unauthorized("azure.authorizeToken; azure token missing header")
+		return nil, "", "", "", "", errs.Unauthorized("azure.authorizeToken; azure token missing header")
 	}
 
 	var found bool
@@ -244,34 +246,35 @@ func (p *Azure) authorizeToken(token string) (*azurePayload, string, string, err
 		}
 	}
 	if !found {
-		return nil, "", "", errs.Unauthorized("azure.authorizeToken; cannot validate azure token")
+		return nil, "", "", "", "", errs.Unauthorized("azure.authorizeToken; cannot validate azure token")
 	}
 
 	if err := claims.ValidateWithLeeway(jose.Expected{
 		Audience: []string{p.Audience},
 		Issuer:   p.oidcConfig.Issuer,
 		Time:     time.Now(),
 	}, 1*time.Minute); err != nil {
-		return nil, "", "", errs.Wrap(http.StatusUnauthorized, err, "azure.authorizeToken; failed to validate azure token payload")
+		return nil, "", "", "", "", errs.Wrap(http.StatusUnauthorized, err, "azure.authorizeToken; failed to validate azure token payload")
 	}
 
 	// Validate TenantID
 	if claims.TenantID != p.TenantID {
-		return nil, "", "", errs.Unauthorized("azure.authorizeToken; azure token validation failed - invalid tenant id claim (tid)")
+		return nil, "", "", "", "", errs.Unauthorized("azure.authorizeToken; azure token validation failed - invalid tenant id claim (tid)")
 	}
 
 	re := azureXMSMirIDRegExp.FindStringSubmatch(claims.XMSMirID)
 	if len(re) != 4 {
-		return nil, "", "", errs.Unauthorized("azure.authorizeToken; error parsing xms_mirid claim - %s", claims.XMSMirID)
+		return nil, "", "", "", "", errs.Unauthorized("azure.authorizeToken; error parsing xms_mirid claim - %s", claims.XMSMirID)
 	}
-	group, name := re[2], re[3]
-	return &claims, name, group, nil
+	identityObjectID := claims.ObjectID
+	subscription, group, name := re[1], re[2], re[3]
+	return &claims, name, group, subscription, identityObjectID, nil
 }
 
 // AuthorizeSign validates the given token and returns the sign options that
 // will be used on certificate creation.
 func (p *Azure) AuthorizeSign(ctx context.Context, token string) ([]SignOption, error) {
-	_, name, group, err := p.authorizeToken(token)
+	_, name, group, subscription, identityObjectID, err := p.authorizeToken(token)
 	if err != nil {
 		return nil, errs.Wrap(http.StatusInternalServerError, err, "azure.AuthorizeSign")
 	}
@@ -290,6 +293,34 @@ func (p *Azure) AuthorizeSign(ctx context.Context, token string) ([]SignOption,
 		}
 	}
 
+	// Filter by subscription id
+	if len(p.SubscriptionIDs) > 0 {
+		var found bool
+		for _, s := range p.SubscriptionIDs {
+			if s == subscription {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return nil, errs.Unauthorized("azure.AuthorizeSign; azure token validation failed - invalid subscription id")
+		}
+	}
+
+	// Filter by Azure AD identity object id
+	if len(p.ObjectIDs) > 0 {
+		var found bool
+		for _, i := range p.ObjectIDs {
+			if i == identityObjectID {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return nil, errs.Unauthorized("azure.AuthorizeSign; azure token validation failed - invalid identity object id")
+		}
+	}
+
 	// Template options
 	data := x509util.NewTemplateData()
 	data.SetCommonName(name)
@@ -348,7 +379,7 @@ func (p *Azure) AuthorizeSSHSign(ctx context.Context, token string) ([]SignOptio
 		return nil, errs.Unauthorized("azure.AuthorizeSSHSign; sshCA is disabled for provisioner '%s'", p.GetName())
 	}
 
-	_, name, _, err := p.authorizeToken(token)
+	_, name, _, _, _, err := p.authorizeToken(token)
 	if err != nil {
 		return nil, errs.Wrap(http.StatusInternalServerError, err, "azure.AuthorizeSSHSign")
 	}

authority/provisioner/azure_test.go

@@ -333,7 +333,7 @@ func TestAzure_authorizeToken(t *testing.T) {
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {
 			tc := tt(t)
-			if claims, name, group, err := tc.p.authorizeToken(tc.token); err != nil {
+			if claims, name, group, subscriptionID, objectID, err := tc.p.authorizeToken(tc.token); err != nil {
 				if assert.NotNil(t, tc.err) {
 					sc, ok := err.(errs.StatusCoder)
 					assert.Fatal(t, ok, "error does not implement StatusCoder interface")
@@ -348,6 +348,8 @@ func TestAzure_authorizeToken(t *testing.T) {
 
 					assert.Equals(t, name, "virtualMachine")
 					assert.Equals(t, group, "resourceGroup")
+					assert.Equals(t, subscriptionID, "subscriptionID")
+					assert.Equals(t, objectID, "the-oid")
 				}
 			}
 		})
@@ -382,6 +384,38 @@ func TestAzure_AuthorizeSign(t *testing.T) {
 	p4.oidcConfig = p1.oidcConfig
 	p4.keyStore = p1.keyStore
 
+	p5, err := generateAzure()
+	assert.FatalError(t, err)
+	p5.TenantID = p1.TenantID
+	p5.SubscriptionIDs = []string{"subscriptionID"}
+	p5.config = p1.config
+	p5.oidcConfig = p1.oidcConfig
+	p5.keyStore = p1.keyStore
+
+	p6, err := generateAzure()
+	assert.FatalError(t, err)
+	p6.TenantID = p1.TenantID
+	p6.SubscriptionIDs = []string{"foobarzar"}
+	p6.config = p1.config
+	p6.oidcConfig = p1.oidcConfig
+	p6.keyStore = p1.keyStore
+
+	p7, err := generateAzure()
+	assert.FatalError(t, err)
+	p7.TenantID = p1.TenantID
+	p7.ObjectIDs = []string{"the-oid"}
+	p7.config = p1.config
+	p7.oidcConfig = p1.oidcConfig
+	p7.keyStore = p1.keyStore
+
+	p8, err := generateAzure()
+	assert.FatalError(t, err)
+	p8.TenantID = p1.TenantID
+	p8.ObjectIDs = []string{"foobarzar"}
+	p8.config = p1.config
+	p8.oidcConfig = p1.oidcConfig
+	p8.keyStore = p1.keyStore
+
 	badKey, err := generateJSONWebKey()
 	assert.FatalError(t, err)
 
@@ -393,6 +427,14 @@ func TestAzure_AuthorizeSign(t *testing.T) {
 	assert.FatalError(t, err)
 	t4, err := p4.GetIdentityToken("subject", "caURL")
 	assert.FatalError(t, err)
+	t5, err := p5.GetIdentityToken("subject", "caURL")
+	assert.FatalError(t, err)
+	t6, err := p6.GetIdentityToken("subject", "caURL")
+	assert.FatalError(t, err)
+	t7, err := p6.GetIdentityToken("subject", "caURL")
+	assert.FatalError(t, err)
+	t8, err := p6.GetIdentityToken("subject", "caURL")
+	assert.FatalError(t, err)
 
 	t11, err := generateAzureToken("subject", p1.oidcConfig.Issuer, azureDefaultAudience,
 		p1.TenantID, "subscriptionID", "resourceGroup", "virtualMachine",
@@ -434,8 +476,12 @@ func TestAzure_AuthorizeSign(t *testing.T) {
 		{"ok", p1, args{t1}, 5, http.StatusOK, false},
 		{"ok", p2, args{t2}, 10, http.StatusOK, false},
 		{"ok", p1, args{t11}, 5, http.StatusOK, false},
+		{"ok", p5, args{t5}, 5, http.StatusOK, false},
+		{"ok", p7, args{t7}, 5, http.StatusOK, false},
 		{"fail tenant", p3, args{t3}, 0, http.StatusUnauthorized, true},
 		{"fail resource group", p4, args{t4}, 0, http.StatusUnauthorized, true},
+		{"fail subscription", p6, args{t6}, 0, http.StatusUnauthorized, true},
+		{"fail object id", p8, args{t8}, 0, http.StatusUnauthorized, true},
 		{"fail token", p1, args{"token"}, 0, http.StatusUnauthorized, true},
 		{"fail issuer", p1, args{failIssuer}, 0, http.StatusUnauthorized, true},
 		{"fail audience", p1, args{failAudience}, 0, http.StatusUnauthorized, true},

authority/provisioners.go

@@ -710,6 +710,8 @@ func ProvisionerToCertificates(p *linkedca.Provisioner) (provisioner.Interface,
 			Name:                   p.Name,
 			TenantID:               cfg.TenantId,
 			ResourceGroups:         cfg.ResourceGroups,
+			SubscriptionIDs:        cfg.SubscriptionIds,
+			ObjectIDs:              cfg.ObjectIds,
 			Audience:               cfg.Audience,
 			DisableCustomSANs:      cfg.DisableCustomSans,
 			DisableTrustOnFirstUse: cfg.DisableTrustOnFirstUse,
@@ -869,6 +871,8 @@ func ProvisionerToLinkedca(p provisioner.Interface) (*linkedca.Provisioner, erro
 					Azure: &linkedca.AzureProvisioner{
 						TenantId:               p.TenantID,
 						ResourceGroups:         p.ResourceGroups,
+						SubscriptionIds:        p.SubscriptionIDs,
+						ObjectIds:              p.ObjectIDs,
 						Audience:               p.Audience,
 						DisableCustomSans:      p.DisableCustomSANs,
 						DisableTrustOnFirstUse: p.DisableTrustOnFirstUse,

go.mod

@@ -35,7 +35,7 @@ require (
 	go.mozilla.org/pkcs7 v0.0.0-20210826202110-33d05740a352
 	go.step.sm/cli-utils v0.7.0
 	go.step.sm/crypto v0.15.0
-	go.step.sm/linkedca v0.9.2
+	go.step.sm/linkedca v0.10.0
 	golang.org/x/crypto v0.0.0-20211215153901-e495a2d5b3d3
 	golang.org/x/net v0.0.0-20220114011407-0dd24b26b47d
 	golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 // indirect

go.sum

@@ -687,6 +687,8 @@ go.step.sm/crypto v0.15.0 h1:VioBln+x3+RoejgeBhvxkLGVYdWRy6PFiAaUUN29/E0=
 go.step.sm/crypto v0.15.0/go.mod h1:3G0yQr5lQqfEG0CMYz8apC/qMtjLRQlzflL2AxkcN+g=
 go.step.sm/linkedca v0.9.2 h1:CpAkd174sLXFfrOZrbPEiTzik91QRj3+L0omsiwsiok=
 go.step.sm/linkedca v0.9.2/go.mod h1:5uTRjozEGSPAZal9xJqlaD38cvJcLe3o1VAFVjqcORo=
+go.step.sm/linkedca v0.10.0 h1:+bqymMRulHYkVde4l16FnqFVskoS6HCWJN5Z5cxAqF8=
+go.step.sm/linkedca v0.10.0/go.mod h1:5uTRjozEGSPAZal9xJqlaD38cvJcLe3o1VAFVjqcORo=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=