Using the connection String to Authenticate into Azure

Question

I have given an Connection String. I need to use this to authenticate into Azure Blob Storage. The connection String, as it appears, contains: Key, AccountName, protocol, Suffix.

Connection String Example:

DefaultEndpointsProtocol=https;AccountName=$$$$$*****;AccountKey=kjdjkfhdjskhfsdfhlksdhfkldshfishishfldslflkjfklsVvJDynYEkiEqWCZkdfkhdkjshfdshfs==;EndpointSuffix=core.windows.net

Now when I look up the authorization article there are multiple methods mentioned and there are no article or method described to use this connection string to Authorize.

It would be really helpful if someone can guide on how to use the connection string to connect to the azure storage so that we can list the containers.

Is there any reason why you would want to consume REST API directly instead of using SDK? Storage SDK is available for most of the commonly used programming languages like .net, java, node, php etc. — Gaurav Mantri
@GauravMantri: I need to use this in salesforce. From what I found there are no packages available for Salesforce — Sam

Jayendran Jayendran · Accepted Answer · 2018-08-18T08:42:13

You can do this using without any Azure SDK, Simply follow the reference here

Clone the Source code from GitHub and start using this,

git clone https://github.com/Azure-Samples/storage-dotnet-rest-api-with-auth.git

You only need the StorageAccountName and StorageAccount Key

string StorageAccountName = "myaccount";
string StorageAccountKey = "WoZ0ZnpXzvdAKoCPRrsa7RniqsdsdfedDFddasds+msk4ViI38WUUMS+qZmd7aoxw==";

All the things were easy, you only need the Authorization logic

internal static AuthenticationHeaderValue GetAuthorizationHeader(
           string storageAccountName, string storageAccountKey, DateTime now,
           HttpRequestMessage httpRequestMessage, string ifMatch = "", string md5 = "")
        {
            // This is the raw representation of the message signature.
            HttpMethod method = httpRequestMessage.Method;
            String MessageSignature = String.Format("{0}\n\n\n{1}\n{5}\n\n\n\n{2}\n\n\n\n{3}{4}",
                      method.ToString(),
                      (method == HttpMethod.Get || method == HttpMethod.Head) ? String.Empty
                        : httpRequestMessage.Content.Headers.ContentLength.ToString(),
                      ifMatch,
                      GetCanonicalizedHeaders(httpRequestMessage),
                      GetCanonicalizedResource(httpRequestMessage.RequestUri, storageAccountName),
                      md5);

            // Now turn it into a byte array.
            byte[] SignatureBytes = Encoding.UTF8.GetBytes(MessageSignature);

            // Create the HMACSHA256 version of the storage key.
            HMACSHA256 SHA256 = new HMACSHA256(Convert.FromBase64String(storageAccountKey));

            // Compute the hash of the SignatureBytes and convert it to a base64 string.
            string signature = Convert.ToBase64String(SHA256.ComputeHash(SignatureBytes));

            // This is the actual header that will be added to the list of request headers.
            // You can stop the code here and look at the value of 'authHV' before it is returned.
            AuthenticationHeaderValue authHV = new AuthenticationHeaderValue("SharedKey",
                storageAccountName + ":" + Convert.ToBase64String(SHA256.ComputeHash(SignatureBytes)));
            return authHV;
        }

This is the key part which produces the Hashed Authorization header like

Authorization: SharedKey myaccount:38Uh5PAe29Kk8dKZ/km90u2sIyEfKiG5RWCb77VoPpE=

Finally you can list your container

Using the connection String to Authenticate into Azure

1 Answers