AWS4签名密钥 - 本教程错了吗？

Question

根据此页面：Examples of How to Derive a Signing Key for Signature Version 4

此代码的结果：

$kSecret = "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY";

$kDate = hash_hmac('sha256', "20120215", "AWS4" . $kSecret);
echo "date: " . $kDate . "<br>";

$kRegion = hash_hmac('sha256', "us-east-1", $kDate);
echo "region: " . $kRegion . "<br>";

$kService = hash_hmac('sha256', "iam", $kRegion);
echo "service: " . $kService . "<br>";

$kSigning = hash_hmac('sha256', "aws4_request", $kService);
echo "signing: " . $kSigning . "<br>";

应打印：

kDate    = '969fbb94feb542b71ede6f87fe4d5fa29c789342b0f407474670f0c2489e0a0d'

kRegion  = '69daa0209cd9c5ff5c8ced464a696fd4252e981430b10e3d3fd8e2f197d7a70c'

kService = 'f72cfd46f26bc4643f06a11eabb6c0ba18780c19a8da0c31ace671265e3c87fa'

kSigning = 'f4780e2d9f65fa895f9c67b32ce1baf0b0d8a43505a000a1a9e090d414db404d'

所以，我得到的kDate是正确的。 kRegion不正确，因为我得到了值：

a59e30f9d899c47b3dd68ea1c0ab3bb529e03a8f4ed2f54cb64af547330a22a0

我已尝试使用此网站计算HMAC（hmac generator），我得到的结果相同。

我真的很想知道页面是否错误。任何人都可以解释这是我的错还是AWS错误？

谢谢

Answer 1

1. 您应该了解这些值是二进制的并以十六进制格式打印
2. 您以十六进制传递日期。您应该将其转换为二进制并在调用hash_hmac之前传递它。或者将其存储为二进制文件并以十六进制格式打印
3. 您从未提及您使用的语言。我不得不谷歌找出你正在使用的语言。在PHP中，您可以传递： $ raw_output = true 以获取二进制字符串
4. 将字符串存储为二进制文件并在打印前将其转换为hex。

由于我不熟悉PHP，我在Python中尝试了相同的操作，输出与预期输出相匹配。看看我如何将其转换为十六进制并打印。

import hmac
import hashlib
from base64 import b16encode as b16

def sign(key, msg):
    return hmac.new(key, msg.encode("utf-8"), hashlib.sha256).digest()

def getSignatureKey(key, dateStamp, regionName, serviceName):
    kDate = sign(("AWS4" + key).encode("utf-8"), dateStamp)
    print b16(kDate)
    kRegion = sign(kDate, regionName)
    print b16(kRegion)
    kService = sign(kRegion, serviceName)
    print b16(kService)
    kSigning = sign(kService, "aws4_request")
    print b16(kSigning)
    return kSigning

key = 'wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY'
dateStamp = '20120215'
regionName = 'us-east-1'
serviceName = 'iam'

getSignatureKey(key, dateStamp, regionName, serviceName)

<强>输出

969FBB94FEB542B71EDE6F87FE4D5FA29C789342B0F407474670F0C2489E0A0D
69DAA0209CD9C5FF5C8CED464A696FD4252E981430B10E3D3FD8E2F197D7A70C
F72CFD46F26BC4643F06A11EABB6C0BA18780C19A8DA0C31ACE671265E3C87FA
F4780E2D9F65FA895F9C67B32CE1BAF0B0D8A43505A000A1A9E090D414DB404D

<强> PHP

string hash_hmac ( string $algo , string $data , string $key [, bool $raw_output = false ] )