Adding transit logical backend

builtin/logical/transit/backend.go

@@ -0,0 +1,35 @@
+package transit
+
+import (
+	"github.com/hashicorp/vault/logical"
+	"github.com/hashicorp/vault/logical/framework"
+)
+
+func Factory(map[string]string) (logical.Backend, error) {
+	return Backend(), nil
+}
+
+func Backend() *framework.Backend {
+	var b backend
+	b.Backend = &framework.Backend{
+		PathsSpecial: &logical.Paths{
+			Root: []string{
+				"policy/*",
+			},
+		},
+
+		Paths: []*framework.Path{
+			pathPolicy(),
+			pathEncrypt(),
+			pathDecrypt(),
+		},
+
+		Secrets: []*framework.Secret{},
+	}
+
+	return b.Backend
+}
+
+type backend struct {
+	*framework.Backend
+}

builtin/logical/transit/backend_test.go

@@ -0,0 +1,132 @@
+package transit
+
+import (
+	"encoding/base64"
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/vault/logical"
+	logicaltest "github.com/hashicorp/vault/logical/testing"
+	"github.com/mitchellh/mapstructure"
+)
+
+const (
+	testPlaintext = "the quick brown fox"
+)
+
+func TestBackend_basic(t *testing.T) {
+	decryptData := make(map[string]interface{})
+	logicaltest.Test(t, logicaltest.TestCase{
+		Backend: Backend(),
+		Steps: []logicaltest.TestStep{
+			testAccStepWritePolicy(t, "test"),
+			testAccStepReadPolicy(t, "test", false),
+			testAccStepEncrypt(t, "test", testPlaintext, decryptData),
+			testAccStepDecrypt(t, "test", testPlaintext, decryptData),
+			testAccStepDeletePolicy(t, "test"),
+			testAccStepReadPolicy(t, "test", true),
+		},
+	})
+}
+
+func testAccStepWritePolicy(t *testing.T, name string) logicaltest.TestStep {
+	return logicaltest.TestStep{
+		Operation: logical.WriteOperation,
+		Path:      "policy/" + name,
+	}
+}
+
+func testAccStepDeletePolicy(t *testing.T, name string) logicaltest.TestStep {
+	return logicaltest.TestStep{
+		Operation: logical.DeleteOperation,
+		Path:      "policy/" + name,
+	}
+}
+
+func testAccStepReadPolicy(t *testing.T, name string, expectNone bool) logicaltest.TestStep {
+	return logicaltest.TestStep{
+		Operation: logical.ReadOperation,
+		Path:      "policy/" + name,
+		Check: func(resp *logical.Response) error {
+			if resp == nil && !expectNone {
+				return fmt.Errorf("missing response")
+			} else if expectNone {
+				if resp != nil {
+					return fmt.Errorf("response when expecting none")
+				}
+				return nil
+			}
+			var d struct {
+				Name       string `mapstructure:"name"`
+				Key        []byte `mapstructure:"key"`
+				CipherMode string `mapstructure:"cipher_mode"`
+			}
+			if err := mapstructure.Decode(resp.Data, &d); err != nil {
+				return err
+			}
+
+			if d.Name != name {
+				return fmt.Errorf("bad: %#v", d)
+			}
+			if d.CipherMode != "aes-gcm" {
+				return fmt.Errorf("bad: %#v", d)
+			}
+			if len(d.Key) != 32 {
+				return fmt.Errorf("bad: %#v", d)
+			}
+			return nil
+		},
+	}
+}
+
+func testAccStepEncrypt(
+	t *testing.T, name, plaintext string, decryptData map[string]interface{}) logicaltest.TestStep {
+	return logicaltest.TestStep{
+		Operation: logical.WriteOperation,
+		Path:      "encrypt/" + name,
+		Data: map[string]interface{}{
+			"plaintext": base64.StdEncoding.EncodeToString([]byte(plaintext)),
+		},
+		Check: func(resp *logical.Response) error {
+			var d struct {
+				Ciphertext string `mapstructure:"ciphertext"`
+			}
+			if err := mapstructure.Decode(resp.Data, &d); err != nil {
+				return err
+			}
+			if d.Ciphertext == "" {
+				return fmt.Errorf("missing ciphertext")
+			}
+			decryptData["ciphertext"] = d.Ciphertext
+			return nil
+		},
+	}
+}
+
+func testAccStepDecrypt(
+	t *testing.T, name, plaintext string, decryptData map[string]interface{}) logicaltest.TestStep {
+	return logicaltest.TestStep{
+		Operation: logical.WriteOperation,
+		Path:      "decrypt/" + name,
+		Data:      decryptData,
+		Check: func(resp *logical.Response) error {
+			var d struct {
+				Plaintext string `mapstructure:"plaintext"`
+			}
+			if err := mapstructure.Decode(resp.Data, &d); err != nil {
+				return err
+			}
+
+			// Decode the base64
+			plainRaw, err := base64.StdEncoding.DecodeString(d.Plaintext)
+			if err != nil {
+				return err
+			}
+
+			if string(plainRaw) != plaintext {
+				return fmt.Errorf("plaintext mismatch: %s expect: %s", plainRaw, plaintext)
+			}
+			return nil
+		},
+	}
+}

builtin/logical/transit/path_decrypt.go

@@ -0,0 +1,100 @@
+package transit
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"encoding/base64"
+	"strings"
+
+	"github.com/hashicorp/vault/logical"
+	"github.com/hashicorp/vault/logical/framework"
+)
+
+func pathDecrypt() *framework.Path {
+	return &framework.Path{
+		Pattern: `decrypt/(?P<name>\w+)`,
+		Fields: map[string]*framework.FieldSchema{
+			"name": &framework.FieldSchema{
+				Type:        framework.TypeString,
+				Description: "Name of the policy",
+			},
+
+			"ciphertext": &framework.FieldSchema{
+				Type:        framework.TypeString,
+				Description: "Ciphertext value to decrypt",
+			},
+		},
+
+		Callbacks: map[logical.Operation]framework.OperationFunc{
+			logical.WriteOperation: pathDecryptWrite,
+		},
+	}
+}
+
+func pathDecryptWrite(
+	req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
+	name := d.Get("name").(string)
+	value := d.Get("ciphertext").(string)
+	if len(value) == 0 {
+		return logical.ErrorResponse("missing ciphertext to decrypt"), logical.ErrInvalidRequest
+	}
+
+	// Get the policy
+	p, err := getPolicy(req, name)
+	if err != nil {
+		return nil, err
+	}
+
+	// Error if invalid policy
+	if p == nil {
+		return logical.ErrorResponse("policy not found"), logical.ErrInvalidRequest
+	}
+
+	// Guard against a potentially invalid cipher-mode
+	switch p.CipherMode {
+	case "aes-gcm":
+	default:
+		return logical.ErrorResponse("unsupported cipher mode"), logical.ErrInvalidRequest
+	}
+
+	// Verify the prefix
+	if !strings.HasPrefix(value, "vault:v0:") {
+		return logical.ErrorResponse("invalid ciphertext"), logical.ErrInvalidRequest
+	}
+
+	// Decode the base64
+	decoded, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(value, "vault:v0:"))
+	if err != nil {
+		return logical.ErrorResponse("invalid ciphertext"), logical.ErrInvalidRequest
+	}
+
+	// Setup the cipher
+	aesCipher, err := aes.NewCipher(p.Key)
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup the GCM AEAD
+	gcm, err := cipher.NewGCM(aesCipher)
+	if err != nil {
+		return nil, err
+	}
+
+	// Extract the nonce and ciphertext
+	nonce := decoded[:gcm.NonceSize()]
+	ciphertext := decoded[gcm.NonceSize():]
+
+	// Verify and Decrypt
+	plain, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return logical.ErrorResponse("invalid ciphertext"), logical.ErrInvalidRequest
+	}
+
+	// Generate the response
+	resp := &logical.Response{
+		Data: map[string]interface{}{
+			"plaintext": base64.StdEncoding.EncodeToString(plain),
+		},
+	}
+	return resp, nil
+}

builtin/logical/transit/path_encrypt.go

@@ -0,0 +1,104 @@
+package transit
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+
+	"github.com/hashicorp/vault/logical"
+	"github.com/hashicorp/vault/logical/framework"
+)
+
+func pathEncrypt() *framework.Path {
+	return &framework.Path{
+		Pattern: `encrypt/(?P<name>\w+)`,
+		Fields: map[string]*framework.FieldSchema{
+			"name": &framework.FieldSchema{
+				Type:        framework.TypeString,
+				Description: "Name of the policy",
+			},
+
+			"plaintext": &framework.FieldSchema{
+				Type:        framework.TypeString,
+				Description: "Plaintext value to encrypt",
+			},
+		},
+
+		Callbacks: map[logical.Operation]framework.OperationFunc{
+			logical.WriteOperation: pathEncryptWrite,
+		},
+	}
+}
+
+func pathEncryptWrite(
+	req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
+	name := d.Get("name").(string)
+	value := d.Get("plaintext").(string)
+	if len(value) == 0 {
+		return logical.ErrorResponse("missing plaintext to encrypt"), logical.ErrInvalidRequest
+	}
+
+	// Decode the plaintext value
+	plaintext, err := base64.StdEncoding.DecodeString(value)
+	if err != nil {
+		return logical.ErrorResponse("failed to decode plaintext as base64"), logical.ErrInvalidRequest
+	}
+
+	// Get the policy
+	p, err := getPolicy(req, name)
+	if err != nil {
+		return nil, err
+	}
+
+	// Error if invalid policy
+	if p == nil {
+		return logical.ErrorResponse("policy not found"), logical.ErrInvalidRequest
+	}
+
+	// Guard against a potentially invalid cipher-mode
+	switch p.CipherMode {
+	case "aes-gcm":
+	default:
+		return logical.ErrorResponse("unsupported cipher mode"), logical.ErrInvalidRequest
+	}
+
+	// Setup the cipher
+	aesCipher, err := aes.NewCipher(p.Key)
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup the GCM AEAD
+	gcm, err := cipher.NewGCM(aesCipher)
+	if err != nil {
+		return nil, err
+	}
+
+	// Compute random nonce
+	nonce := make([]byte, gcm.NonceSize())
+	_, err = rand.Read(nonce)
+	if err != nil {
+		return nil, err
+	}
+
+	// Encrypt and tag with GCM
+	out := gcm.Seal(nil, nonce, plaintext, nil)
+
+	// Place the encrypted data after the nonce
+	full := append(nonce, out...)
+
+	// Convert to base64
+	encoded := base64.StdEncoding.EncodeToString(full)
+
+	// Prepend some information
+	encoded = "vault:v0:" + encoded
+
+	// Generate the response
+	resp := &logical.Response{
+		Data: map[string]interface{}{
+			"ciphertext": encoded,
+		},
+	}
+	return resp, nil
+}