token-generator/TokenGenerator.kt at master · fcsapi/token-generator · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
/**
 * FCS API - Token Generator (Kotlin)
 *
 * Generate secure tokens for frontend JavaScript authentication
 *
 * Usage:
 * 1. Set your accessKey and publicKey
 * 2. Call generateToken()
 * 3. Pass the token data to your frontend JavaScript
 *
 * @package FcsApi
 * @author FCS API <support@fcsapi.com>
 * @link https://fcsapi.com
 */

package com.fcsapi

import javax.crypto.Mac
import javax.crypto.spec.SecretKeySpec
import com.google.gson.Gson
import com.google.gson.annotations.SerializedName

/**
 * Token data class
 */
data class TokenData(
    @SerializedName("_token") val token: String,
    @SerializedName("_expiry") val expiry: Long,
    @SerializedName("_public_key") val publicKey: String
)

/**
 * Token generator for FCS API
 * Token expiry options (in seconds): 300 (5min), 900 (15min), 1800 (30min), 3600 (1hr), 86400 (24hr)
 *
 * @param accessKey Your API access key (get from https://fcsapi.com/dashboard)
 * @param publicKey Your public key (get from https://fcsapi.com/dashboard)
 * @param tokenExpiry Token expiry in seconds (default: 3600 = 1 hour)
 */
class FcsTokenGenerator(
    private val accessKey: String = "YOUR_ACCESS_KEY_HERE",
    private val publicKey: String = "YOUR_PUBLIC_KEY_HERE",
    private val tokenExpiry: Long = 3600
) {
    /**
     * Generate token for frontend authentication
     * @return TokenData with token, expiry, and public_key
     */
    fun generateToken(): TokenData {
        val expiry = System.currentTimeMillis() / 1000 + tokenExpiry
        val message = "$publicKey$expiry"

        val mac = Mac.getInstance("HmacSHA256")
        val secretKey = SecretKeySpec(accessKey.toByteArray(), "HmacSHA256")
        mac.init(secretKey)
        val hash = mac.doFinal(message.toByteArray())
        val token = hash.joinToString("") { "%02x".format(it) }

        return TokenData(token, expiry, publicKey)
    }

    /**
     * Generate token and return as JSON string
     * @return JSON string of token data
     */
    fun toJson(): String {
        return Gson().toJson(generateToken())
    }

    /**
     * Generate HTML meta tags for token
     * @return HTML meta tags string
     */
    fun getMetaTags(): String {
        val tokenData = generateToken()
        return """
            <meta name="fcs-public-key" content="${tokenData.publicKey}">
            <meta name="fcs-token" content="${tokenData.token}">
            <meta name="fcs-token-expiry" content="${tokenData.expiry}">
        """.trimIndent()
    }
}

// ============================================
// USAGE EXAMPLES
// ============================================

fun main() {
    // Example 1: Generate token
    val generator = FcsTokenGenerator("your_access_key", "your_public_key")
    val tokenData = generator.generateToken()
    println("Token Data: $tokenData")

    // Example 2: Get as JSON
    println("\nJSON: ${generator.toJson()}")

    // Example 3: Get meta tags
    println("\nMeta Tags:\n${generator.getMetaTags()}")
}

// Spring Boot example:
// @RestController
// class FcsTokenController {
//     @GetMapping("/fcs-token")
//     fun getToken(): TokenData {
//         val generator = FcsTokenGenerator(
//             System.getenv("FCS_ACCESS_KEY"),
//             System.getenv("FCS_PUBLIC_KEY")
//         )
//         return generator.generateToken()
//     }
// }

// Ktor example:
// routing {
//     get("/fcs-token") {
//         val generator = FcsTokenGenerator(
//             System.getenv("FCS_ACCESS_KEY"),
//             System.getenv("FCS_PUBLIC_KEY")
//         )
//         call.respond(generator.generateToken())
//     }
// }