Initial commit: Luminary AI Gateway

OpenAI-compatible AI gateway with Vue admin UI, multi-provider egress,
ingress key governance, monitoring, and security controls.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/auth/crypto.go

@@ -0,0 +1,74 @@
+package auth
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+)
+
+func deriveKey(secret string) []byte {
+	h := sha256.Sum256([]byte(secret))
+	return h[:]
+}
+
+func Encrypt(plaintext, secret string) (string, error) {
+	key := deriveKey(secret)
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+	ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+func Decrypt(encoded, secret string) (string, error) {
+	data, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return "", err
+	}
+	key := deriveKey(secret)
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonceSize := gcm.NonceSize()
+	if len(data) < nonceSize {
+		return "", errors.New("ciphertext too short")
+	}
+	nonce, ciphertext := data[:nonceSize], data[nonceSize:]
+	plain, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return "", err
+	}
+	return string(plain), nil
+}
+
+func HashToken(token string) string {
+	h := sha256.Sum256([]byte(token))
+	return fmt.Sprintf("%x", h)
+}
+
+func GenerateToken(n int) (string, error) {
+	b := make([]byte, n)
+	if _, err := rand.Read(b); err != nil {
+		return "", err
+	}
+	return base64.URLEncoding.EncodeToString(b)[:n], nil
+}