open-vault/vault/policy.go

102 lines
2.1 KiB
Go

package vault
import (
"fmt"
"strings"
"github.com/hashicorp/hcl"
)
const (
PathPolicyDeny = "deny"
PathPolicyRead = "read"
PathPolicyWrite = "write"
PathPolicySudo = "sudo"
)
// Policy is used to represent the policy specified by
// an ACL configuration.
type Policy struct {
Name string `hcl:"name"`
Paths []*PathPolicy `hcl:"path,expand"`
Raw string
}
// PathPolicy represents a policy for a path in the namespace
type PathPolicy struct {
Prefix string `hcl:",key"`
Policy string
Glob bool
}
// TakesPrecedence is used when multiple policies
// collide on a path to determine which policy takes
// precendence.
func (p *PathPolicy) TakesPrecedence(other *PathPolicy) bool {
// Handle the full merge matrix
switch p.Policy {
case PathPolicyDeny:
// Deny always takes precendence
return true
case PathPolicyRead:
// Read never takes precedence
return false
case PathPolicyWrite:
switch other.Policy {
case PathPolicyRead:
return true
case PathPolicyDeny, PathPolicyWrite, PathPolicySudo:
return false
default:
panic("missing case")
}
case PathPolicySudo:
switch other.Policy {
case PathPolicyRead, PathPolicyWrite:
return true
case PathPolicyDeny, PathPolicySudo:
return false
default:
panic("missing case")
}
default:
panic("missing case")
}
return false
}
// Parse is used to parse the specified ACL rules into an
// intermediary set of policies, before being compiled into
// the ACL
func Parse(rules string) (*Policy, error) {
// Decode the rules
p := &Policy{Raw: rules}
if err := hcl.Decode(p, rules); err != nil {
return nil, fmt.Errorf("Failed to parse ACL rules: %v", err)
}
// Validate the path policy
for _, pp := range p.Paths {
// Strip the glob character if found
if strings.HasSuffix(pp.Prefix, "*") {
pp.Prefix = strings.TrimSuffix(pp.Prefix, "*")
pp.Glob = true
}
// Check the policy is valid
switch pp.Policy {
case PathPolicyDeny:
case PathPolicyRead:
case PathPolicyWrite:
case PathPolicySudo:
default:
return nil, fmt.Errorf("Invalid path policy: %#v", pp)
}
}
return p, nil
}