Merge pull request #4937 from hashicorp/b-vault-panic

vault: protect against empty Vault secret response

Fixes #4921

Sadly, we don't have proper mechanism to mock Vault client, so not sure how to best test this.

I inspected the Vault client interactions, specially for cases where returned value is nil even if the error is also nil.  I believe we covered all correctly now:
* [`v.client.Sys().InitStatus()`](f3853f11da/nomad/vault.go (L427)) - the value is non-nil boolean
* [`v.client.Sys().CapabilitiesSelf(path)`](f3853f11da/nomad/vault.go (L812)): Capabilities handles empty bodies in [`hasCapability`](f3853f11da/vendor/github.com/hashicorp/vault/api/sys_capabilities.go (L43-L45)) - also the `nil` array is handled with proper fail-safe default.
* [`v.client.Logical().Read(fmt.Sprintf("auth/token/roles/%s", role))`](f3853f11da/nomad/vault.go (L834-L840)) handles when `rsecret` is nil
This commit is contained in:
Mahmood Ali 2018-11-29 10:35:58 -05:00 committed by GitHub
commit ea6834e86e
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@ -630,24 +630,15 @@ func (v *vaultClient) getWrappingFn() func(operation, path string) string {
// it in the client. If the token is not valid for Nomads purposes an error is
// returned.
func (v *vaultClient) parseSelfToken() error {
// Get the initial lease duration
auth := v.client.Auth().Token()
var self *vapi.Secret
// Try looking up the token using the self endpoint
secret, err := auth.LookupSelf()
secret, err := v.lookupSelf()
if err != nil {
// Try looking up our token directly
self, err = auth.Lookup(v.client.Token())
if err != nil {
return fmt.Errorf("failed to lookup Vault periodic token: %v", err)
}
return err
}
self = secret
// Read and parse the fields
var data tokenData
if err := mapstructure.WeakDecode(self.Data, &data); err != nil {
if err := mapstructure.WeakDecode(secret.Data, &data); err != nil {
return fmt.Errorf("failed to parse Vault token's data block: %v", err)
}
root := false
@ -724,6 +715,29 @@ func (v *vaultClient) parseSelfToken() error {
return mErr.ErrorOrNil()
}
// lookupSelf is a helper function that looks up latest self lease info.
func (v *vaultClient) lookupSelf() (*vapi.Secret, error) {
// Get the initial lease duration
auth := v.client.Auth().Token()
secret, err := auth.LookupSelf()
if err == nil && secret != nil && secret.Data != nil {
return secret, nil
}
// Try looking up our token directly, even when we get an empty response,
// in case of an unexpected event - a true failure would occur in this lookup again
secret, err = auth.Lookup(v.client.Token())
switch {
case err != nil:
return nil, fmt.Errorf("failed to lookup Vault periodic token: %v", err)
case secret == nil || secret.Data == nil:
return nil, fmt.Errorf("failed to lookup Vault periodic token: got empty response")
default:
return secret, nil
}
}
// getRole returns the role name to be used when creating tokens
func (v *vaultClient) getRole() string {
if v.config.Role != "" {