open-vault/builtin/logical/transit/path_datakey.go
2016-01-29 14:33:51 -05:00

151 lines
3.9 KiB
Go

package transit
import (
"crypto/rand"
"encoding/base64"
"fmt"
"github.com/hashicorp/vault/helper/certutil"
"github.com/hashicorp/vault/logical"
"github.com/hashicorp/vault/logical/framework"
)
func (b *backend) pathDatakey() *framework.Path {
return &framework.Path{
Pattern: "datakey/" + framework.GenericNameRegex("plaintext") + "/" + framework.GenericNameRegex("name"),
Fields: map[string]*framework.FieldSchema{
"name": &framework.FieldSchema{
Type: framework.TypeString,
Description: "The backend key used for encrypting the data key",
},
"plaintext": &framework.FieldSchema{
Type: framework.TypeString,
Description: `"plaintext" will return the key in both plaintext and
ciphertext; "wrapped" will return the ciphertext only.`,
},
"context": &framework.FieldSchema{
Type: framework.TypeString,
Description: "Context for key derivation. Required for derived keys.",
},
"bits": &framework.FieldSchema{
Type: framework.TypeInt,
Description: `Number of bits for the key; currently 128, 256,
and 512 bits are supported. Defaults to 256.`,
Default: 256,
},
},
Callbacks: map[logical.Operation]framework.OperationFunc{
logical.UpdateOperation: b.pathDatakeyWrite,
},
HelpSynopsis: pathDatakeyHelpSyn,
HelpDescription: pathDatakeyHelpDesc,
}
}
func (b *backend) pathDatakeyWrite(
req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
name := d.Get("name").(string)
plaintext := d.Get("plaintext").(string)
plaintextAllowed := false
switch plaintext {
case "plaintext":
plaintextAllowed = true
case "wrapped":
default:
return logical.ErrorResponse("Invalid path, must be 'plaintext' or 'wrapped'"), logical.ErrInvalidRequest
}
// Decode the context if any
contextRaw := d.Get("context").(string)
var context []byte
if len(contextRaw) != 0 {
var err error
context, err = base64.StdEncoding.DecodeString(contextRaw)
if err != nil {
return logical.ErrorResponse("failed to decode context as base64"), logical.ErrInvalidRequest
}
}
// Get the policy
lp, err := b.policies.getPolicy(req, name)
if err != nil {
return nil, err
}
// Error if invalid policy
if lp == nil {
return logical.ErrorResponse("policy not found"), logical.ErrInvalidRequest
}
lp.RLock()
defer lp.RUnlock()
// Verify if wasn't deleted before we grabbed the lock
if lp.policy == nil {
return nil, fmt.Errorf("no existing policy named %s could be found", name)
}
newKey := make([]byte, 32)
bits := d.Get("bits").(int)
switch bits {
case 512:
newKey = make([]byte, 64)
case 256:
case 128:
newKey = make([]byte, 16)
default:
return logical.ErrorResponse("invalid bit length"), logical.ErrInvalidRequest
}
_, err = rand.Read(newKey)
if err != nil {
return nil, err
}
ciphertext, err := lp.policy.Encrypt(context, base64.StdEncoding.EncodeToString(newKey))
if err != nil {
switch err.(type) {
case certutil.UserError:
return logical.ErrorResponse(err.Error()), logical.ErrInvalidRequest
case certutil.InternalError:
return nil, err
default:
return nil, err
}
}
if ciphertext == "" {
return nil, fmt.Errorf("empty ciphertext returned")
}
// Generate the response
resp := &logical.Response{
Data: map[string]interface{}{
"ciphertext": ciphertext,
},
}
if plaintextAllowed {
resp.Data["plaintext"] = base64.StdEncoding.EncodeToString(newKey)
}
return resp, nil
}
const pathDatakeyHelpSyn = `Generate a data key`
const pathDatakeyHelpDesc = `
This path can be used to generate a data key: a random
key of a certain length that can be used for encryption
and decryption, protected by the named backend key. 128, 256,
or 512 bits can be specified; if not specified, the default
is 256 bits. Call with the the "wrapped" path to prevent the
(base64-encoded) plaintext key from being returned along with
the encrypted key, the "plaintext" path returns both.
`