Upload checksums for installation artifacts (#4191)

The checksums are SHA-512 hashes, which users can use to verify file
integrity and authenticity.

build_projects/dotnet-cli-build/CheckIfAllBuildsHavePublished.cs

@@ -0,0 +1,86 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public class CheckIfAllBuildsHavePublished : Task
+    {
+        private AzurePublisher _azurePublisher;
+
+        [Required]
+        public string AccountName { get; set; }
+
+        [Required]
+        public string AccountKey { get; set; }
+
+        [Required]
+        public string ContainerName { get; set; }
+
+        [Required]
+        public string NugetVersion { get; set; }
+
+        [Output]
+        public string HaveAllBuildsPublished { get; set; }
+
+        private AzurePublisher AzurePublisherTool
+        {
+            get
+            {
+                if (_azurePublisher == null)
+                {
+                    _azurePublisher = new AzurePublisher(AccountName, AccountKey, ContainerName);
+                }
+
+                return _azurePublisher;
+            }
+        }
+
+        public override bool Execute()
+        {
+            var badges = new Dictionary<string, bool>()
+            {
+                { "Windows_x86", false },
+                { "Windows_x64", false },
+                { "Ubuntu_x64", false },
+                { "Ubuntu_16_04_x64", false },
+                { "RHEL_x64", false },
+                { "OSX_x64", false },
+                { "Debian_x64", false },
+                { "CentOS_x64", false },
+                { "Fedora_23_x64", false },
+                { "openSUSE_13_2_x64", false }
+            };
+
+            var versionBadgeName = $"{Monikers.GetBadgeMoniker()}";
+            if (!badges.ContainsKey(versionBadgeName))
+            {
+                throw new ArgumentException($"A new OS build '{versionBadgeName}' was added without adding the moniker to the {nameof(badges)} lookup");
+            }
+
+            IEnumerable<string> blobs = AzurePublisherTool.ListBlobs(AzurePublisher.Product.Sdk, NugetVersion);
+            foreach (string file in blobs)
+            {
+                string name = Path.GetFileName(file);
+                foreach (string img in badges.Keys)
+                {
+                    if ((name.StartsWith($"{img}")) && (name.EndsWith(".svg")))
+                    {
+                        badges[img] = true;
+                        break;
+                    }
+                }
+            }
+
+            HaveAllBuildsPublished = badges.Values.All(v => v).ToString();
+
+            return true;
+        }
+    }
+}