VAULT-8518 Increase HMAC limit to 4096, and limit approle names to the same limit (#17768)

* VAULT-8518 Increase HMAC limit to 4096, and limit approle names to the same limit

* VAULT-8518 Changelog

* VAULT-8518 Sprintf the byte limit

builtin/credential/approle/path_role.go

@@ -113,7 +113,7 @@ func rolePaths(b *backend) []*framework.Path {
 		Fields: map[string]*framework.FieldSchema{
 			"role_name": {
 				Type:        framework.TypeString,
-				Description: "Name of the role.",
+				Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 			},
 			"bind_secret_id": {
 				Type:        framework.TypeBool,
@@ -196,7 +196,7 @@ can only be set during role creation and once set, it can't be reset later.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 			},
 			Callbacks: map[logical.Operation]framework.OperationFunc{
@@ -210,7 +210,7 @@ can only be set during role creation and once set, it can't be reset later.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"policies": {
 					Type:        framework.TypeCommaStringSlice,
@@ -235,7 +235,7 @@ can only be set during role creation and once set, it can't be reset later.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"bound_cidr_list": {
 					Type: framework.TypeCommaStringSlice,
@@ -256,7 +256,7 @@ of CIDR blocks. If set, specifies the blocks of IP addresses which can perform t
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id_bound_cidrs": {
 					Type: framework.TypeCommaStringSlice,
@@ -277,7 +277,7 @@ IP addresses which can perform the login operation.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"token_bound_cidrs": {
 					Type:        framework.TypeCommaStringSlice,
@@ -297,7 +297,7 @@ IP addresses which can perform the login operation.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"bind_secret_id": {
 					Type:        framework.TypeBool,
@@ -318,7 +318,7 @@ IP addresses which can perform the login operation.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id_num_uses": {
 					Type:        framework.TypeInt,
@@ -338,7 +338,7 @@ IP addresses which can perform the login operation.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id_ttl": {
 					Type: framework.TypeDurationSecond,
@@ -359,7 +359,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"period": {
 					Type:        framework.TypeDurationSecond,
@@ -384,7 +384,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"token_num_uses": {
 					Type:        framework.TypeInt,
@@ -404,7 +404,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"token_ttl": {
 					Type:        framework.TypeDurationSecond,
@@ -424,7 +424,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"token_max_ttl": {
 					Type:        framework.TypeDurationSecond,
@@ -444,7 +444,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"role_id": {
 					Type:        framework.TypeString,
@@ -463,7 +463,7 @@ to 0, meaning no expiration.`,
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"metadata": {
 					Type: framework.TypeString,
@@ -504,7 +504,7 @@ Overrides secret_id_ttl role option when supplied. May not be longer than role's
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id": {
 					Type:        framework.TypeString,
@@ -522,7 +522,7 @@ Overrides secret_id_ttl role option when supplied. May not be longer than role's
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id": {
 					Type:        framework.TypeString,
@@ -541,7 +541,7 @@ Overrides secret_id_ttl role option when supplied. May not be longer than role's
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id_accessor": {
 					Type:        framework.TypeString,
@@ -559,7 +559,7 @@ Overrides secret_id_ttl role option when supplied. May not be longer than role's
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id_accessor": {
 					Type:        framework.TypeString,
@@ -578,7 +578,7 @@ Overrides secret_id_ttl role option when supplied. May not be longer than role's
 			Fields: map[string]*framework.FieldSchema{
 				"role_name": {
 					Type:        framework.TypeString,
-					Description: "Name of the role.",
+					Description: fmt.Sprintf("Name of the role. Must be less than %d bytes.", maxHmacInputLength),
 				},
 				"secret_id": {
 					Type:        framework.TypeString,
@@ -880,6 +880,10 @@ func (b *backend) pathRoleCreateUpdate(ctx context.Context, req *logical.Request
 		return logical.ErrorResponse("missing role_name"), nil
 	}
 
+	if len(roleName) > maxHmacInputLength {
+		return logical.ErrorResponse(fmt.Sprintf("role_name is longer than maximum of %d bytes", maxHmacInputLength)), nil
+	}
+
 	lock := b.roleLock(roleName)
 	lock.Lock()
 	defer lock.Unlock()

builtin/credential/approle/validation.go

@@ -92,7 +92,7 @@ func verifyCIDRRoleSecretIDSubset(secretIDCIDRs []string, roleBoundCIDRList []st
 	return nil
 }
 
-const maxHmacInputLength = 1024
+const maxHmacInputLength = 4096
 
 // Creates a SHA256 HMAC of the given 'value' using the given 'key' and returns
 // a hex encoded string.

changelog/17768.txt

@@ -0,0 +1,3 @@
+```release-note:change
+auth/approle: Add maximum length of 4096 for approle role_names, as this value results in HMAC calculation
+```

command/agent/approle_end_to_end_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -400,6 +401,52 @@ func testAppRoleEndToEnd(t *testing.T, removeSecretIDFile bool, bindSecretID boo
 	}
 }
 
+// TestAppRoleLongRoleName tests that the creation of an approle is a maximum of 4096 bytes
+// Prior to VAULT-8518 being fixed, you were unable to delete an approle value longer than 1024 bytes
+// due to a restriction put into place by PR #14746, to prevent unbounded HMAC creation.
+func TestAppRoleLongRoleName(t *testing.T) {
+	approleName := strings.Repeat("a", 5000)
+
+	coreConfig := &vault.CoreConfig{
+		DisableMlock: true,
+		DisableCache: true,
+		Logger:       log.NewNullLogger(),
+		CredentialBackends: map[string]logical.Factory{
+			"approle": credAppRole.Factory,
+		},
+	}
+
+	cluster := vault.NewTestCluster(t, coreConfig, &vault.TestClusterOptions{
+		HandlerFunc: vaulthttp.Handler,
+	})
+
+	cluster.Start()
+	defer cluster.Cleanup()
+
+	cores := cluster.Cores
+
+	vault.TestWaitActive(t, cores[0].Core)
+
+	client := cores[0].Client
+
+	err := client.Sys().EnableAuthWithOptions("approle", &api.EnableAuthOptions{
+		Type: "approle",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = client.Logical().Write(fmt.Sprintf("auth/approle/role/%s", approleName), map[string]interface{}{
+		"token_ttl":     "6s",
+		"token_max_ttl": "10s",
+	})
+	if err != nil {
+		if !strings.Contains(err.Error(), "role_name is longer than maximum") {
+			t.Fatal(err)
+		}
+	}
+}
+
 func TestAppRoleWithWrapping(t *testing.T) {
 	testCases := []struct {
 		bindSecretID bool

website/content/api-docs/auth/approle.mdx

@@ -60,7 +60,7 @@ enabled while creating or updating a role.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `bind_secret_id` `(bool: true)` - Require `secret_id` to be presented when
   logging in using this AppRole.
 - `secret_id_bound_cidrs` `(array: [])` - Comma-separated string or list of CIDR
@@ -112,7 +112,7 @@ Reads the properties of an existing AppRole.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 
 ### Sample Request
 
@@ -155,7 +155,7 @@ Deletes an existing AppRole from the method.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 
 ### Sample Request
 
@@ -176,7 +176,7 @@ Reads the RoleID of an existing AppRole.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 
 ### Sample Request
 
@@ -212,7 +212,7 @@ Updates the RoleID of an existing AppRole to a custom value.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `role_id` `(string: <required>)` - Value to be set as RoleID.
 
 ### Sample Payload
@@ -262,7 +262,7 @@ itself, and also to delete the SecretID from the AppRole.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `metadata` `(string: "")` - Metadata to be tied to the SecretID. This should be
   a JSON-formatted string containing the metadata in key-value pairs. This
   metadata will be set on tokens issued with this SecretID, and is logged in
@@ -333,7 +333,7 @@ This includes the accessors for "custom" SecretIDs as well.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 
 ### Sample Request
 
@@ -376,7 +376,7 @@ Reads out the properties of a SecretID.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `secret_id` `(string: <required>)` - Secret ID attached to the role.
 
 ### Sample Payload
@@ -407,7 +407,7 @@ Destroy an AppRole secret ID.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `secret_id` `(string: <required>)` - Secret ID attached to the role.
 
 ### Sample Payload
@@ -438,7 +438,7 @@ Reads out the properties of a SecretID.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `secret_id_accessor` `(string: <required>)` - Secret ID accessor attached to the role.
 
 ### Sample Payload
@@ -469,7 +469,7 @@ Destroy an AppRole secret ID by its accessor.
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `secret_id_accessor` `(string: <required>)` - Secret ID accessor attached to the role.
 
 ### Sample Payload
@@ -501,7 +501,7 @@ Assigns a "custom" SecretID against an existing AppRole. This is used in the
 
 ### Parameters
 
-- `role_name` `(string: <required>)` - Name of the AppRole.
+- `role_name` `(string: <required>)` - Name of the AppRole. Must be less than 4096 bytes.
 - `secret_id` `(string: <required>)` - SecretID to be attached to the Role.
 - `metadata` `(string: "")` - Metadata to be tied to the SecretID. This should be
   a JSON-formatted string containing the metadata in key-value pairs. This