feat: add utility functions and helpers

- Add JWT token generation and validation utilities
- Add password hashing with bcrypt for secure authentication
- Add pagination helper for API responses
- Add random string generation for tokens and IDs
- Add session management utilities
- Add admin user initialization functionality

utils/session.go

@@ -0,0 +1,94 @@
+package utils
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strings"
+
+	"git.secnex.io/secnex/idp-api/api"
+	"github.com/gofiber/fiber/v2"
+)
+
+type AuthType string
+
+const (
+	AuthTypeSession AuthType = "scn"
+)
+
+func ExtractBasicAuthFromHeader(header string, c *fiber.Ctx) (string, string, error) {
+	if header == "" {
+		return "", "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Authorization header is required",
+		})
+	}
+
+	// Decode base64
+	basicDecoded, err := base64.StdEncoding.DecodeString(header)
+	if err != nil {
+		return "", "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Invalid authorization header",
+		})
+	}
+
+	basicSplit := strings.Split(string(basicDecoded), ":")
+
+	return basicSplit[0], basicSplit[1], nil
+}
+
+func ExtractSessionFromHeader(header string, c *fiber.Ctx) (string, error) {
+	if header == "" {
+		return "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Authorization header is required",
+		})
+	}
+
+	sessionSplit := strings.Split(header, ":")
+
+	if len(sessionSplit) != 2 {
+		return "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Invalid authorization header",
+		})
+	}
+
+	authType := AuthType(sessionSplit[0])
+	if authType != AuthTypeSession {
+		return "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Invalid authorization header",
+		})
+	}
+
+	sessionId, err := base64.StdEncoding.DecodeString(sessionSplit[1])
+	if err != nil {
+		return "", api.Error(c, "Unauthorized", fiber.StatusUnauthorized, fiber.Map{
+			"message": "Invalid authorization header",
+		})
+	}
+
+	return string(sessionId), nil
+}
+
+// ExtractSessionFromToken extracts session ID from a session token without Fiber context
+// This is used for gRPC services where we don't have a Fiber context
+func ExtractSessionFromToken(token string) (string, error) {
+	if token == "" {
+		return "", fmt.Errorf("session token is required")
+	}
+
+	sessionSplit := strings.Split(token, ":")
+
+	if len(sessionSplit) != 2 {
+		return "", fmt.Errorf("invalid session token format")
+	}
+
+	authType := AuthType(sessionSplit[0])
+	if authType != AuthTypeSession {
+		return "", fmt.Errorf("invalid auth type")
+	}
+
+	sessionId, err := base64.StdEncoding.DecodeString(sessionSplit[1])
+	if err != nil {
+		return "", fmt.Errorf("invalid session token encoding")
+	}
+
+	return string(sessionId), nil
+}