这个问题与TOTP有关,其在RFC6238中进行了规定,链接如下:https://www.rfc-editor.org/rfc/rfc6238#section-1.2。
我需要实现RFC6238以生成一个10位的TOTP密码,该密码将在稍后的POST请求中使用。 TOTP的示例输入和输出应该如下所示:
示例输入:
- 共享密钥:“ninja@example.comHDECHALLENGE003”(不含双引号) - 使用的哈希函数:HMAC-SHA-512 - T0 = 0,时间步长= 30秒(根据RFC6238规定) - 预期的10位TOTP
示例输出:
成功生成TOTP: 1773133250,时间为Mon, 17 Mar 2014 15:20:51 GMT
base64编码的POST授权用户名/密码请求:bmluamFAZXhhbXBsZS5jb206MTc3MzEzMzI1MA==
(我已解码样本POST授权为“ninja@example.com:1773133250”,因此我可以说样本TOTP输出为1773133250)
尝试根据rfc6238规范编写自己的脚本后,我无法获得与上面示例输入相同的输出。 我尝试使用其他可用的在线TOTP模块(大多数是Python),发现它们生成与我创建的脚本相同的输出。 最后,我尝试了RFC6238示例中给出的Java代码,并得到了与我的脚本相同的结果,即:
尝试的输入:
- HMAC512的十六进制编码种子:“6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033”+“6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033”; - 输入时间为1395069651L,表示样本输出接收到的时间。
尝试结果(自定义脚本、其他Python模块和RFC6238文档中给出的Java实现的输出相同):
生成的TOTP:0490867067
以下是我最初尝试在Python中生成TOTP的代码:
请注意,对于修改后的RFC Java代码,输出将是测试时间[]数组中列出的几个日期/时间,但目标GMT也包含在其中。在我的Ubuntu上进行测试显示与我的Python脚本相同的结果。
我相信我已经按照任务给出的说明进行了操作。我使用了实际的RFC给定Java代码,发现它没有生成与任务中给出的代码相同的输出。我联系了任务提供者询问是否存在错误,但他们说这是正确的。
也许我在这里漏掉了什么,例如任务提供者实际加密共享密钥的方式?
我需要实现RFC6238以生成一个10位的TOTP密码,该密码将在稍后的POST请求中使用。 TOTP的示例输入和输出应该如下所示:
示例输入:
- 共享密钥:“ninja@example.comHDECHALLENGE003”(不含双引号) - 使用的哈希函数:HMAC-SHA-512 - T0 = 0,时间步长= 30秒(根据RFC6238规定) - 预期的10位TOTP
示例输出:
成功生成TOTP: 1773133250,时间为Mon, 17 Mar 2014 15:20:51 GMT
base64编码的POST授权用户名/密码请求:bmluamFAZXhhbXBsZS5jb206MTc3MzEzMzI1MA==
(我已解码样本POST授权为“ninja@example.com:1773133250”,因此我可以说样本TOTP输出为1773133250)
尝试根据rfc6238规范编写自己的脚本后,我无法获得与上面示例输入相同的输出。 我尝试使用其他可用的在线TOTP模块(大多数是Python),发现它们生成与我创建的脚本相同的输出。 最后,我尝试了RFC6238示例中给出的Java代码,并得到了与我的脚本相同的结果,即:
尝试的输入:
- HMAC512的十六进制编码种子:“6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033”+“6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033”; - 输入时间为1395069651L,表示样本输出接收到的时间。
尝试结果(自定义脚本、其他Python模块和RFC6238文档中给出的Java实现的输出相同):
生成的TOTP:0490867067
以下是我最初尝试在Python中生成TOTP的代码:
# Mission/Task Description:
# * For the "password", provide an 10-digit time-based one time password conforming to RFC6238 TOTP.
#
# ** You have to read RFC6238 (and the errata too!) and get a correct one time password by yourself.
# ** TOTP's "Time Step X" is 30 seconds. "T0" is 0.
# ** Use HMAC-SHA-512 for the hash function, instead of the default HMAC-SHA-1.
# ** Token shared secret is the userid followed by ASCII string value "HDECHALLENGE003" (not including double quotations).
#
# *** For example, if the userid is "ninja@example.com", the token shared secret is "ninja@example.comHDECHALLENGE003".
# *** For example, if the userid is "ninjasamuraisumotorishogun@example.com", the token shared secret is "ninjasamuraisumotorishogun@example.comHDECHALLENGE003"
#
import hmac
import hashlib
import time
import sys
import struct
userid = "ninja@example.com"
secret_suffix = "HDECHALLENGE003"
shared_secret = userid+secret_suffix
timestep = 30
T0 = 0
def HOTP(K, C, digits=10):
"""HTOP:
K is the shared key
C is the counter value
digits control the response length
"""
K_bytes = K.encode()
C_bytes = struct.pack(">Q", C)
hmac_sha512 = hmac.new(key = K_bytes, msg=C_bytes, digestmod=hashlib.sha512).hexdigest()
return Truncate(hmac_sha512)[-digits:]
def Truncate(hmac_sha512):
"""truncate sha512 value"""
offset = int(hmac_sha512[-1], 16)
binary = int(hmac_sha512[(offset *2):((offset*2)+8)], 16) & 0x7FFFFFFF
return str(binary)
def TOTP(K, digits=10, timeref = 0, timestep = 30):
"""TOTP, time-based variant of HOTP
digits control the response length
the C in HOTP is replaced by ( (currentTime - timeref) / timestep )
"""
C = int ( 1395069651 - timeref ) // timestep
return HOTP(K, C, digits = digits)
passwd = TOTP("ninja@example.comHDECHALLENGE003ninja@example.comHDECHALLENGE003", 10, T0, timestep).zfill(10)
print passwd
这里是Java中的第二个代码,基本上是RFC6238中找到的Java实现的修改版本:
/**
Copyright (c) 2011 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license
terms contained in, the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
*/
import java.lang.reflect.UndeclaredThrowableException;
import java.security.GeneralSecurityException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.util.TimeZone;
import java.util.Calendar;
/**
* This is an example implementation of the OATH
* TOTP algorithm.
* Visit www.openauthentication.org for more information.
*
* @author Johan Rydell, PortWise, Inc.
*/
public class TOTP {
private TOTP() {}
/**
* This method uses the JCE to provide the crypto algorithm.
* HMAC computes a Hashed Message Authentication Code with the
* crypto hash algorithm as a parameter.
*
* @param crypto: the crypto algorithm (HmacSHA1, HmacSHA256,
* HmacSHA512)
* @param keyBytes: the bytes to use for the HMAC key
* @param text: the message or text to be authenticated
*/
private static byte[] hmac_sha(String crypto, byte[] keyBytes,
byte[] text){
try {
Mac hmac;
hmac = Mac.getInstance(crypto);
SecretKeySpec macKey =
new SecretKeySpec(keyBytes, "RAW");
hmac.init(macKey);
return hmac.doFinal(text);
} catch (GeneralSecurityException gse) {
throw new UndeclaredThrowableException(gse);
}
}
/**
* This method converts a HEX string to Byte[]
*
* @param hex: the HEX string
*
* @return: a byte array
*/
private static byte[] hexStr2Bytes(String hex){
// Adding one byte to get the right conversion
// Values starting with "0" can be converted
byte[] bArray = new BigInteger("10" + hex,16).toByteArray();
// Copy all the REAL bytes, not the "first"
byte[] ret = new byte[bArray.length - 1];
for (int i = 0; i < ret.length; i++)
ret[i] = bArray[i+1];
return ret;
}
private static final long[] DIGITS_POWER
// 0 1 2 3 4 5 6 7 8 9 10
= {1,10,100,1000,10000,100000,1000000,10000000,100000000,1000000000,10000000000L};
/**
* This method generates a TOTP value for the given
* set of parameters.
*
* @param key: the shared secret, HEX encoded
* @param time: a value that reflects a time
* @param returnDigits: number of digits to return
*
* @return: a numeric String in base 10 that includes
* {@link truncationDigits} digits
*/
public static String generateTOTP(String key,
String time,
String returnDigits){
return generateTOTP(key, time, returnDigits, "HmacSHA1");
}
/**
* This method generates a TOTP value for the given
* set of parameters.
*
* @param key: the shared secret, HEX encoded
* @param time: a value that reflects a time
* @param returnDigits: number of digits to return
*
* @return: a numeric String in base 10 that includes
* {@link truncationDigits} digits
*/
public static String generateTOTP256(String key,
String time,
String returnDigits){
return generateTOTP(key, time, returnDigits, "HmacSHA256");
}
/**
* This method generates a TOTP value for the given
* set of parameters.
*
* @param key: the shared secret, HEX encoded
* @param time: a value that reflects a time
* @param returnDigits: number of digits to return
*
* @return: a numeric String in base 10 that includes
* {@link truncationDigits} digits
*/
public static String generateTOTP512(String key,
String time,
String returnDigits){
return generateTOTP(key, time, returnDigits, "HmacSHA512");
}
/**
* This method generates a TOTP value for the given
* set of parameters.
*
* @param key: the shared secret, HEX encoded
* @param time: a value that reflects a time
* @param returnDigits: number of digits to return
* @param crypto: the crypto function to use
*
* @return: a numeric String in base 10 that includes
* {@link truncationDigits} digits
*/
public static String generateTOTP(String key,
String time,
String returnDigits,
String crypto){
int codeDigits = Integer.decode(returnDigits).intValue();
String result = null;
// Using the counter
// First 8 bytes are for the movingFactor
// Compliant with base RFC 4226 (HOTP)
while (time.length() < 16 )
time = "0" + time;
// Get the HEX in a Byte[]
byte[] msg = hexStr2Bytes(time);
byte[] k = hexStr2Bytes(key);
byte[] hash = hmac_sha(crypto, k, msg);
// put selected bytes into result int
int offset = hash[hash.length - 1] & 0xf;
int binary =
((hash[offset] & 0x7f) << 24) |
((hash[offset + 1] & 0xff) << 16) |
((hash[offset + 2] & 0xff) << 8) |
(hash[offset + 3] & 0xff);
long otp = binary % DIGITS_POWER[codeDigits];
result = Long.toString(otp);
while (result.length() < codeDigits) {
result = "0" + result;
}
return result;
}
public static void main(String[] args) {
// Seed for HMAC-SHA1 - 20 bytes
String seed = "3132333435363738393031323334353637383930";
// Seed for HMAC-SHA256 - 32 bytes
String seed32 = "3132333435363738393031323334353637383930" +
"313233343536373839303132";
// Seed for HMAC-SHA512 - 64 bytes
String seed64 = "6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033";
//NOTE: this is the 16-bit/hex encoded representation of "ninja@example.comHDECHALLENGE003"
String seednew = "6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033" +
"6E696E6A61406578616D706C652E636F6D4844454348414C4C454E4745303033";
long T0 = 0;
long X = 30;
long current = System.currentTimeMillis()/1000;
System.out.println(current);
long testTime[] = {59L, 1234567890L,1395069651L};
String steps = "0";
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
df.setTimeZone(TimeZone.getTimeZone("UTC"));
try {
System.out.println(
"+---------------+-----------------------+" +
"------------------+--------+--------+");
System.out.println(
"| Time(sec) | Time (UTC format) " +
"| Value of T(Hex) | TOTP | Mode |");
System.out.println(
"+---------------+-----------------------+" +
"------------------+--------+--------+");
for (int i=0; i<testTime.length; i++) {
long T = (testTime[i] - T0)/X;
steps = Long.toHexString(T).toUpperCase();
while (steps.length() < 16) steps = "0" + steps;
String fmtTime = String.format("%1$-11s", testTime[i]);
String utcTime = df.format(new Date(testTime[i]*1000));
System.out.print("| " + fmtTime + " | " + utcTime +
" | " + steps + " |");
System.out.println(generateTOTP(seed, steps, "8",
"HmacSHA1") + "| SHA1 |");
System.out.print("| " + fmtTime + " | " + utcTime +
" | " + steps + " |");
System.out.println(generateTOTP(seed32, steps, "8",
"HmacSHA256") + "| SHA256 |");
System.out.print("| " + fmtTime + " | " + utcTime +
" | " + steps + " |");
System.out.println(generateTOTP(seed64, steps, "10",
"HmacSHA256") + "| SHA256 |");
System.out.print("| " + fmtTime + " | " + utcTime +
" | " + steps + " |");
System.out.println(generateTOTP(seednew, steps, "10",
"HmacSHA512") + "| SHA512 |");
System.out.println(
"+---------------+-----------------------+" +
"------------------+--------+--------+");
}
}catch (final Exception e){
System.out.println("Error : " + e);
}
}
}
请注意,对于修改后的RFC Java代码,输出将是测试时间[]数组中列出的几个日期/时间,但目标GMT也包含在其中。在我的Ubuntu上进行测试显示与我的Python脚本相同的结果。
我相信我已经按照任务给出的说明进行了操作。我使用了实际的RFC给定Java代码,发现它没有生成与任务中给出的代码相同的输出。我联系了任务提供者询问是否存在错误,但他们说这是正确的。
也许我在这里漏掉了什么,例如任务提供者实际加密共享密钥的方式?
1234567890
,并检查在给定时刻将生成什么值。然后将其与样本代码为给定时间生成的值进行比较。这将突出显示 RFC6238 中描述的算法和您尝试使用的实际实现之间是否存在差异。 - zloster