Call Create File on Azure File Service REST Api - azure

Question

I am trying to create a file in Azure File Service:
https://learn.microsoft.com/en-us/rest/api/storageservices/create-file
I've seen and read multiple threads about this issue, but I can't figure out what might be the problem in my case... Most likely I am missing some small thing in the request which I cannot find.
The error I am getting: The MAC signature found in the HTTP request (...) is not the same as any computed signature.
The signature string I've used:
PUT
\n
\n
\n
\n
text/plain // Content-Type
\n
\n
\n
\n
\n
\n
x-ms-content-length:1000
x-ms-date:Tue, 20 Apr 2021 19:23:30 GMT
x-ms-type:file
x-ms-version:2015-02-21
/account/share/test
Authorization header:
SharedKey account:XXXXXXXXXX
I've used the HMACSHA256 for hashing the authorization header and signature string, it all works when I use other endpoint (List Shares: https://learn.microsoft.com/en-us/rest/api/storageservices/list-shares), but I can't make it work for the file. I've seen this topic AZURE File Service - Upload PDF through REST API and I believe I am using very similar request, but with no success...
I appreciate any help : )
Edit:
I am not sure if I correctly set the content headers. For example, does the x-ms-content-length should be placed in the CanonicalizedHeaders string?
Edit2:
With regard to what Ivan Yang wrote, I made the code to work, but only when my CanonicalizedHeaders are built like that:
CanonicalizedHeaders := 'x-ms-content-length:1200'
+ LF + 'x-ms-date:' + UTCDateTimeText
+ LF + 'x-ms-file-attributes:Archive' + LF + 'x-ms-file-creation-time:Now' + LF + 'x-ms-file-last-write-time:Now' + LF + 'x-ms-file-permission:Inherit'
+ LF + 'x-ms-type:file' + LF + 'x-ms-version:2019-02-02';
If I have them in different order, then it crashes:
CanonicalizedHeaders := 'x-ms-date:' + UTCDateTimeText + LF +
'x-ms-content-length:1200' + LF +
'x-ms-version:2019-02-02' + LF +
'x-ms-file-attributes:Archive' + LF +
'x-ms-file-creation-time:Now' + LF +
'x-ms-file-last-write-time:Now' + LF +
'x-ms-file-permission:Inherit' + LF +
'x-ms-type:file';
How come does this make a difference?

Answer 1

Your signature string is incorrect(you're missing some "\n"). I'm using the x-ms-version:2019-02-02 instead of the older one x-ms-version:2015-02-21, and the correct signature string should look like this one:
"PUT\n"
+ "\n" // content encoding
+ "\n" // content language
+ "\n" // content length
+ "\n" // content md5
+ content_type + "\n" // content type
+ "\n" // date
+ "\n" // if modified since
+ "\n" // if match
+ "\n" // if none match
+ "\n" // if unmodified since
+ "\n" // range
+ "x-ms-content-length:" + content_length
+ "\nx-ms-date:" + dt.ToString("R")
+ "\nx-ms-file-attributes:Archive" + "\nx-ms-file-creation-time:Now" + "\nx-ms-file-last-write-time:Now" + "\nx-ms-file-permission:Inherit"
+ "\nx-ms-type:file" + "\nx-ms-version:" + apiversion + "\n" // headers
+ "/{0}/{1}/{2}", Account, FileShare, FileName);
Here is the c# code using create file api:
using System;
using System.Globalization;
using System.Net;
using System.Security.Cryptography;
namespace ConsoleApp25
{
class Program
{
static void Main(string[] args)
{
string Account = "storage_account_name";
string Key = "storage_account_key";
string FileShare = "file_share_name";
string FileName = "test555.txt";
string apiversion = "2019-02-02";
int content_length = 1200;
string content_type = "text/plain";
DateTime dt = DateTime.UtcNow;
string StringToSign = String.Format("PUT\n"
+ "\n" // content encoding
+ "\n" // content language
+ "\n" // content length
+ "\n" // content md5
+ content_type + "\n" // content type
+ "\n" // date
+ "\n" // if modified since
+ "\n" // if match
+ "\n" // if none match
+ "\n" // if unmodified since
+ "\n" // range
+ "x-ms-content-length:" + content_length
+ "\nx-ms-date:" + dt.ToString("R")
+ "\nx-ms-file-attributes:Archive" + "\nx-ms-file-creation-time:Now" + "\nx-ms-file-last-write-time:Now" + "\nx-ms-file-permission:Inherit"
+ "\nx-ms-type:file" + "\nx-ms-version:" + apiversion + "\n" // headers
+ "/{0}/{1}/{2}", Account, FileShare, FileName);
string auth = SignThis(StringToSign, Key, Account);
string method = "PUT";
string urlPath = string.Format("https://{0}.file.core.windows.net/{1}/{2}", Account, FileShare, FileName);
Uri uri = new Uri(urlPath);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = method;
request.ContentLength = 0;
request.Headers.Add("x-ms-content-length", $"{content_length}");
request.Headers.Add("Content-Type", content_type);
request.Headers.Add("x-ms-type", "file");
request.Headers.Add("x-ms-date", dt.ToString("R"));
request.Headers.Add("x-ms-version", apiversion);
request.Headers.Add("x-ms-file-attributes", "Archive"); //note it is case-sensitive.
request.Headers.Add("x-ms-file-permission", "Inherit");
request.Headers.Add("x-ms-file-creation-time", "Now");
request.Headers.Add("x-ms-file-last-write-time", "Now");
request.Headers.Add("Authorization", auth);
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
//read the response code
Console.WriteLine("the response is:" + response.StatusCode);
}
Console.WriteLine("**completed**");
Console.ReadLine();
}
private static String SignThis(String StringToSign, string Key, string Account)
{
String signature = string.Empty;
byte[] unicodeKey = Convert.FromBase64String(Key);
using (HMACSHA256 hmacSha256 = new HMACSHA256(unicodeKey))
{
Byte[] dataToHmac = System.Text.Encoding.UTF8.GetBytes(StringToSign);
signature = Convert.ToBase64String(hmacSha256.ComputeHash(dataToHmac));
}
String authorizationHeader = String.Format(
CultureInfo.InvariantCulture,
"{0} {1}:{2}",
"SharedKey",
Account,
signature);
return authorizationHeader;
}
}
}