vault/helper/pluginutil/runner.go
2017-04-12 17:35:53 -07:00

109 lines
2.9 KiB
Go

package pluginutil
import (
"crypto/sha256"
"fmt"
"os"
"os/exec"
"time"
plugin "github.com/hashicorp/go-plugin"
"github.com/hashicorp/vault/helper/mlock"
)
var (
// PluginUnwrapTokenEnv is the ENV name used to pass unwrap tokens to the
// plugin.
PluginMlockEnabled = "VAULT_PLUGIN_MLOCK_ENABLED"
)
// Looker defines the plugin Lookup function that looks into the plugin catalog
// for availible plugins and returns a PluginRunner
type Looker interface {
LookupPlugin(string) (*PluginRunner, error)
}
// Wrapper interface defines the functions needed by the runner to wrap the
// metadata needed to run a plugin process. This includes looking up Mlock
// configuration and wrapping data in a respose wrapped token.
type Wrapper interface {
ResponseWrapData(data map[string]interface{}, ttl time.Duration, jwt bool) (string, error)
MlockDisabled() bool
}
// LookWrapper defines the functions for both Looker and Wrapper
type LookWrapper interface {
Looker
Wrapper
}
// PluginRunner defines the metadata needed to run a plugin securely with
// go-plugin.
type PluginRunner struct {
Name string `json:"name"`
Command string `json:"command"`
Args []string `json:"args"`
Sha256 []byte `json:"sha256"`
Builtin bool `json:"builtin"`
}
// Run takes a wrapper instance, and the go-plugin paramaters and executes a
// plugin.
func (r *PluginRunner) Run(wrapper Wrapper, pluginMap map[string]plugin.Plugin, hs plugin.HandshakeConfig, env []string) (*plugin.Client, error) {
// Get a CA TLS Certificate
CACertBytes, CACert, CAKey, err := GenerateCACert()
if err != nil {
return nil, err
}
// Use CA to sign a client cert and return a configured TLS config
clientTLSConfig, err := CreateClientTLSConfig(CACert, CAKey)
if err != nil {
return nil, err
}
// Use CA to sign a server cert and wrap the values in a response wrapped
// token.
wrapToken, err := WrapServerConfig(wrapper, CACertBytes, CACert, CAKey)
if err != nil {
return nil, err
}
mlock := "true"
if wrapper.MlockDisabled() {
mlock = "false"
}
cmd := exec.Command(r.Command, r.Args...)
cmd.Env = append(cmd.Env, env...)
// Add the response wrap token to the ENV of the plugin
cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", PluginUnwrapTokenEnv, wrapToken))
// Add the mlock setting to the ENV of the plugin
cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", PluginMlockEnabled, mlock))
secureConfig := &plugin.SecureConfig{
Checksum: r.Sha256,
Hash: sha256.New(),
}
client := plugin.NewClient(&plugin.ClientConfig{
HandshakeConfig: hs,
Plugins: pluginMap,
Cmd: cmd,
TLSConfig: clientTLSConfig,
SecureConfig: secureConfig,
})
return client, nil
}
// OptionallyEnableMlock determines if mlock should be called, and if so enables
// mlock.
func OptionallyEnableMlock() error {
if os.Getenv(PluginMlockEnabled) == "true" {
return mlock.LockMemory()
}
return nil
}