idk

tokens.go

@@ -1,23 +1,101 @@
 package main
 
 import (
-	_ "context"
+	"context"
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/hex"
-	_ "fmt"
-	_ "time"
+	"fmt"
+	"time"
+
+	"github.com/redis/go-redis/v9"
 )
 
-func hashToken(token string) string {
-	var hash = sha256.Sum256([]byte(token))
-	return hex.EncodeToString(hash[:])
+var rdb *redis.Client
+
+func init() {
+	rdb = redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "",
+		DB:       0,
+	})
 }
 
-func generateToken() string {
-	var bytes = make([]byte, 32)
+func getAndSaveTokenFor(ctx context.Context, userID string, timeToDie time.Duration) string {
+	bytes := make([]byte, 32)
 	if _, err := rand.Read(bytes); err != nil {
-		panic(err)
+		panic(fmt.Sprintf("failed to generate random bytes: %v", err))
 	}
-	return hex.EncodeToString(bytes)
+	token := hex.EncodeToString(bytes)
+	tokenHash := hashToken(token)
+	tokenKey := fmt.Sprintf("token:%s", tokenHash)
+	userKey := fmt.Sprintf("user_tokens:%s", userID)
+
+	now := time.Now()
+	expiresAt := now.Add(timeToDie)
+
+	pipe := rdb.Pipeline()
+	pipe.Set(ctx, tokenKey, userID, timeToDie)
+	// score = expiration unix timestamp
+	pipe.ZAdd(ctx, userKey, redis.Z{Score: float64(expiresAt.Unix()), Member: tokenHash})
+	// remove already-expired members
+	pipe.ZRemRangeByScore(ctx, userKey, "-inf", fmt.Sprintf("%d", now.Unix()))
+	// set key expiry to latest possible token death
+	pipe.ExpireAt(ctx, userKey, expiresAt)
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		panic(fmt.Sprintf("failed to execute redis pipeline: %v", err))
+	}
+
+	return token
+}
+
+func hashToken(plaintext string) string {
+	h := sha256.Sum256([]byte(plaintext))
+	return hex.EncodeToString(h[:])
+}
+
+// GetUserID resolves a plaintext token to its owning userID.
+// Returns an error if the token is missing or expired.
+func GetUserID(ctx context.Context, plaintext string) (string, error) {
+	key := fmt.Sprintf("token:%s", hashToken(plaintext))
+
+	userID, err := rdb.Get(ctx, key).Result()
+	if err == redis.Nil {
+		return "", fmt.Errorf("token not found or expired")
+	}
+	return userID, err
+}
+
+// RevokeToken deletes a single token by its plaintext value.
+func RevokeToken(ctx context.Context, plaintext, userID string) error {
+	hashed := hashToken(plaintext)
+	tokenKey := fmt.Sprintf("token:%s", hashed)
+	userKey := fmt.Sprintf("user_tokens:%s", userID)
+
+	pipe := rdb.Pipeline()
+	pipe.Del(ctx, tokenKey)
+	pipe.SRem(ctx, userKey, hashed)
+
+	_, err := pipe.Exec(ctx)
+	return err
+}
+
+// RevokeAllUserTokens deletes every token belonging to a userID.
+func RevokeAllUserTokens(ctx context.Context, userID string) error {
+	userKey := fmt.Sprintf("user_tokens:%s", userID)
+
+	hashedTokens, err := rdb.SMembers(ctx, userKey).Result()
+	if err != nil {
+		return err
+	}
+
+	pipe := rdb.Pipeline()
+	for _, hashed := range hashedTokens {
+		pipe.Del(ctx, fmt.Sprintf("token:%s", hashed))
+	}
+	pipe.Del(ctx, userKey)
+
+	_, err = pipe.Exec(ctx)
+	return err
 }