Files
Cyrene_v2/internal/auth/auth.go
T

94 lines
3.2 KiB
Go

// Package auth provides authentication and authorization primitives for the
// Cyrene v2 gateway: JWT signing/verification (HS256), an RBAC middleware built
// on an owner>admin>viewer role hierarchy, in-memory API keys, and salted
// password hashing. All APIs are self-contained and use only the standard
// library, so the package compiles without adding dependencies to the module.
//
// Identity is carried as strong-typed actor metadata and decided by policy (see
// DevDocs/design/11): it is never inferred by an LLM. This package supplies the
// credential layer that such policies rely on.
package auth
import (
"errors"
"fmt"
)
// Role is an authorization role in the owner>admin>viewer hierarchy.
type Role string
const (
// RoleOwner has full authority, including security/key/system settings.
RoleOwner Role = "owner"
// RoleAdmin manages modules but no sensitive security items.
RoleAdmin Role = "admin"
// RoleViewer is read-only (dashboard/logs/monitoring).
RoleViewer Role = "viewer"
)
// Sentinel errors returned by the auth package.
var (
// ErrInvalidSecret reports a JWTSecret shorter than the required minimum.
ErrInvalidSecret = errors.New("auth: JWTSecret must be at least 32 characters")
// ErrInvalidRole reports an unknown or unparseable role name.
ErrInvalidRole = errors.New("auth: invalid role")
// ErrMalformedToken reports a token that is not well-formed.
ErrMalformedToken = errors.New("auth: malformed token")
// ErrInvalidSignature reports a token whose HMAC signature does not verify.
ErrInvalidSignature = errors.New("auth: invalid signature")
// ErrTokenExpired reports a token whose exp is in the past.
ErrTokenExpired = errors.New("auth: token expired")
// ErrUnsupportedAlg reports a token declaring an algorithm other than HS256.
ErrUnsupportedAlg = errors.New("auth: unsupported algorithm")
// ErrUnauthorized reports a missing/invalid/unexpired-failed credential.
ErrUnauthorized = errors.New("auth: unauthorized")
// ErrForbidden reports a valid credential with insufficient privilege.
ErrForbidden = errors.New("auth: forbidden")
)
// Package-wide constants. `source` is the log provenance tag used by every
// logger.WithSource call in this package (no bare logs are emitted).
const (
source = "auth"
minSecretLen = 32
keyLength = 32
passwordScheme = "sha256"
saltLength = 16
passwordIterations = 100000
)
// ParseRole converts a string into a Role, erroring on unknown values.
func ParseRole(s string) (Role, error) {
r := Role(s)
if !r.Valid() {
return "", fmt.Errorf("%w: %q", ErrInvalidRole, s)
}
return r, nil
}
// Valid reports whether r is one of owner, admin, or viewer.
func (r Role) Valid() bool {
return r.rank() > 0
}
// rank returns the privilege rank of r. Invalid roles rank below viewer.
func (r Role) rank() int {
switch r {
case RoleOwner:
return 3
case RoleAdmin:
return 2
case RoleViewer:
return 1
default:
return 0
}
}
// HasRole reports whether role holds at least the privilege of required, where
// owner>admin>viewer. Owner satisfies admin and viewer, admin satisfies viewer,
// and viewer satisfies only viewer.
func HasRole(role, required Role) bool {
return role.rank() >= required.rank()
}