static void Main(string[] args)
{
// This is standard code to interact with Blob Storage
StorageCredentials creds = new StorageCredentials(
ConfigurationManager.AppSettings["accountName"],
ConfigurationManager.AppSettings["accountKey"]);
CloudStorageAccount account = new CloudStorageAccount(creds, useHttps: true);
CloudBlobClient client = account.CreateCloudBlobClient();
CloudBlobContainer contain = client.GetContainerReference(ConfigurationManager.AppSettings["container"]);
contain.CreateIfNotExists();
// The Resolver object is used to interact with Key Vault for Azure Storage
// This is where the GetToken method from above is used
KeyVaultKeyResolver cloudResolver = new KeyVaultKeyResolver(GetToken);
// Retrieve the key that you created previously
// The IKey that is returned here is an RsaKey
// Remember that we used the names contosokeyvault and testrsakey1
var rsa = cloudResolver.ResolveKeyAsync("https://contosokeyvault.vault.azure.net/keys/TestRSAKey1", CancellationToken.None).GetAwaiter().GetResult();
// Now you simply use the RSA key to encrypt by setting it in the BlobEncryptionPolicy.
BlobEncryptionPolicy policy = new BlobEncryptionPolicy(rsa, null);
BlobRequestOptions options = new BlobRequestOptions() { EncryptionPolicy = policy };
// Reference a block blob
CloudBlockBlob blob = contain.GetBlockBlobReference("MyFile.txt");
// Upload using the UploadFromStream method
using (var stream = System.IO.File.OpenRead(@"C:\data\MyFile.txt"))
blob.UploadFromStream(stream, stream.Length, null, options, null);
// In this case we will not pass a key and only pass the resolver because
// this policy will only be used for downloading / decrypting
policy = new BlobEncryptionPolicy(null, cloudResolver);
options = new BlobRequestOptions() { EncryptionPolicy = policy };
using (var np = File.Open(@"C:\data\MyFileDecrypted.txt", FileMode.Create))
blob.DownloadToStream(np, null, options, null);
}
static void Main(string[] args)
{
Console.WriteLine("Blob encryption with Key Vault integration demonstrating key rotation from Key 1 to Key 2");
Console.WriteLine();
// Create two secrets and obtain their IDs. This is normally a one-time setup step.
// Although it is possible to use keys (rather than secrets) stored in Key Vault, this prevents caching.
// Therefore it is recommended to use secrets along with a caching resolver (see below).
string keyID1 = EncryptionShared.KeyVaultUtility.SetUpKeyVaultSecret("KeyRotationSampleSecret1");
string keyID2 = EncryptionShared.KeyVaultUtility.SetUpKeyVaultSecret("KeyRotationSampleSecret2");
// Retrieve storage account information from connection string
// How to create a storage connection string - https://azure.microsoft.com/en-us/documentation/articles/storage-configure-connection-string/
CloudStorageAccount storageAccount = EncryptionShared.Utility.CreateStorageAccountFromConnectionString();
CloudBlobClient client = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = client.GetContainerReference(DemoContainer + Guid.NewGuid().ToString("N"));
// Construct a resolver capable of looking up keys and secrets stored in Key Vault.
KeyVaultKeyResolver cloudResolver = new KeyVaultKeyResolver(EncryptionShared.KeyVaultUtility.GetAccessToken);
// Set up a caching resolver so the secrets can be cached on the client. This is the recommended usage
// pattern since the throttling targets for Storage and Key Vault services are orders of magnitude
// different.
CachingKeyResolver cachingResolver = new CachingKeyResolver(2, cloudResolver);
// Create key instances corresponding to the key IDs. This will cache the secrets.
IKey cloudKey1 = cachingResolver.ResolveKeyAsync(keyID1, CancellationToken.None).GetAwaiter().GetResult();
IKey cloudKey2 = cachingResolver.ResolveKeyAsync(keyID2, CancellationToken.None).GetAwaiter().GetResult();
// We begin with cloudKey1, and a resolver capable of resolving and caching Key Vault secrets.
BlobEncryptionPolicy encryptionPolicy = new BlobEncryptionPolicy(cloudKey1, cachingResolver);
client.DefaultRequestOptions.EncryptionPolicy = encryptionPolicy;
client.DefaultRequestOptions.RequireEncryption = true;
try
{
container.Create();
int size = 5 * 1024 * 1024;
byte[] buffer1 = new byte[size];
byte[] buffer2 = new byte[size];
Random rand = new Random();
rand.NextBytes(buffer1);
rand.NextBytes(buffer2);
// Upload the first blob using the secret stored in Azure Key Vault.
CloudBlockBlob blob = container.GetBlockBlobReference("blockblob1");
Console.WriteLine("Uploading Blob 1 using Key 1.");
// Upload the encrypted contents to the first blob.
using (MemoryStream stream = new MemoryStream(buffer1))
{
blob.UploadFromStream(stream, size);
}
Console.WriteLine("Downloading and decrypting Blob 1.");
// Download and decrypt the encrypted contents from the first blob.
using (MemoryStream outputStream = new MemoryStream())
{
blob.DownloadToStream(outputStream);
}
// At this point we will rotate our keys so new encrypted content will use the
// second key. Note that the same resolver is used, as this resolver is capable
// of decrypting blobs encrypted using either key.
Console.WriteLine("Rotating the active encryption key to Key 2.");
client.DefaultRequestOptions.EncryptionPolicy = new BlobEncryptionPolicy(cloudKey2, cachingResolver);
// Upload the second blob using the key stored in Azure Key Vault.
CloudBlockBlob blob2 = container.GetBlockBlobReference("blockblob2");
Console.WriteLine("Uploading Blob 2 using Key 2.");
// Upload the encrypted contents to the second blob.
using (MemoryStream stream = new MemoryStream(buffer2))
{
blob2.UploadFromStream(stream, size);
}
Console.WriteLine("Downloading and decrypting Blob 2.");
// Download and decrypt the encrypted contents from the second blob.
using (MemoryStream outputStream = new MemoryStream())
{
blob2.DownloadToStream(outputStream);
}
// Here we download and re-upload the first blob. This has the effect of updating
// the blob to use the new key.
using (MemoryStream memoryStream = new MemoryStream())
{
Console.WriteLine("Downloading and decrypting Blob 1.");
blob.DownloadToStream(memoryStream);
memoryStream.Seek(0, SeekOrigin.Begin);
Console.WriteLine("Re-uploading Blob 1 using Key 2.");
blob.UploadFromStream(memoryStream);
}
// For the purposes of demonstration, we now override the encryption policy to only recognize key 2.
BlobEncryptionPolicy key2OnlyPolicy = new BlobEncryptionPolicy(cloudKey2, null);
BlobRequestOptions key2OnlyOptions = new BlobRequestOptions()
{
EncryptionPolicy = key2OnlyPolicy
};
Console.WriteLine("Downloading and decrypting Blob 1.");
// The first blob can still be decrypted because it is using the second key.
using (MemoryStream outputStream = new MemoryStream())
{
blob.DownloadToStream(outputStream, options: key2OnlyOptions);
}
Console.WriteLine("Press enter key to exit");
Console.ReadLine();
}
finally
{
container.DeleteIfExists();
}
}
static void Main(string[] args)
{
Console.WriteLine("Blob encryption with Key Vault integration");
Console.WriteLine();
// Get the key ID from App.config if it exists.
string keyID = CloudConfigurationManager.GetSetting("KeyID");
// If no key ID was specified, we will create a new secret in Key Vault.
// To create a new secret, this client needs full permission to Key Vault secrets.
// Once the secret is created, its ID can be added to App.config. Once this is done,
// this client only needs read access to secrets.
if (string.IsNullOrEmpty(keyID))
{
Console.WriteLine("No secret specified in App.config.");
Console.WriteLine("Please enter the name of a new secret to create in Key Vault.");
Console.WriteLine("WARNING: This will delete any existing secret with the same name.");
Console.Write("Name of the new secret to create [{0}]: ", DefaultSecretName);
string newSecretName = Console.ReadLine().Trim();
if (string.IsNullOrEmpty(newSecretName))
{
newSecretName = DefaultSecretName;
}
// Although it is possible to use keys (rather than secrets) stored in Key Vault, this prevents caching.
// Therefore it is recommended to use secrets along with a caching resolver (see below).
keyID = EncryptionShared.KeyVaultUtility.SetUpKeyVaultSecret(newSecretName);
Console.WriteLine();
Console.WriteLine("Created a secret with ID: {0}", keyID);
Console.WriteLine("Copy the secret ID to App.config to reuse.");
Console.WriteLine();
}
// Retrieve storage account information from connection string
// How to create a storage connection string - https://azure.microsoft.com/en-us/documentation/articles/storage-configure-connection-string/
CloudStorageAccount storageAccount = EncryptionShared.Utility.CreateStorageAccountFromConnectionString();
CloudBlobClient client = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = client.GetContainerReference(DemoContainer + Guid.NewGuid().ToString("N"));
// Construct a resolver capable of looking up keys and secrets stored in Key Vault.
KeyVaultKeyResolver cloudResolver = new KeyVaultKeyResolver(EncryptionShared.KeyVaultUtility.GetAccessToken);
// To demonstrate how multiple different types of key can be used, we also create a local key and resolver.
// This key is temporary and won't be persisted.
RsaKey rsaKey = new RsaKey("rsakey");
LocalResolver resolver = new LocalResolver();
resolver.Add(rsaKey);
// If there are multiple key sources like Azure Key Vault and local KMS, set up an aggregate resolver as follows.
// This helps users to define a plug-in model for all the different key providers they support.
AggregateKeyResolver aggregateResolver = new AggregateKeyResolver()
.Add(resolver)
.Add(cloudResolver);
// Set up a caching resolver so the secrets can be cached on the client. This is the recommended usage
// pattern since the throttling targets for Storage and Key Vault services are orders of magnitude
// different.
CachingKeyResolver cachingResolver = new CachingKeyResolver(2, aggregateResolver);
// Create a key instance corresponding to the key ID. This will cache the secret.
IKey cloudKey = cachingResolver.ResolveKeyAsync(keyID, CancellationToken.None).GetAwaiter().GetResult();
try
{
container.Create();
int size = 5 * 1024 * 1024;
byte[] buffer = new byte[size];
Random rand = new Random();
rand.NextBytes(buffer);
// The first blob will use the key stored in Azure Key Vault.
CloudBlockBlob blob = container.GetBlockBlobReference("blockblob1");
// Create the encryption policy using the secret stored in Azure Key Vault to be used for upload.
BlobEncryptionPolicy uploadPolicy = new BlobEncryptionPolicy(cloudKey, null);
// Set the encryption policy on the request options.
BlobRequestOptions uploadOptions = new BlobRequestOptions() { EncryptionPolicy = uploadPolicy };
Console.WriteLine("Uploading the 1st encrypted blob.");
// Upload the encrypted contents to the blob.
using (MemoryStream stream = new MemoryStream(buffer))
{
blob.UploadFromStream(stream, size, null, uploadOptions, null);
}
// Download the encrypted blob.
BlobEncryptionPolicy downloadPolicy = new BlobEncryptionPolicy(null, cachingResolver);
// Set the decryption policy on the request options.
BlobRequestOptions downloadOptions = new BlobRequestOptions() { EncryptionPolicy = downloadPolicy };
Console.WriteLine("Downloading the 1st encrypted blob.");
// Download and decrypt the encrypted contents from the blob.
using (MemoryStream outputStream = new MemoryStream())
{
blob.DownloadToStream(outputStream, null, downloadOptions, null);
}
// Upload second blob using the local key.
blob = container.GetBlockBlobReference("blockblob2");
// Create the encryption policy using the local key.
uploadPolicy = new BlobEncryptionPolicy(rsaKey, null);
// Set the encryption policy on the request options.
uploadOptions = new BlobRequestOptions() { EncryptionPolicy = uploadPolicy };
Console.WriteLine("Uploading the 2nd encrypted blob.");
// Upload the encrypted contents to the blob.
using (MemoryStream stream = new MemoryStream(buffer))
{
blob.UploadFromStream(stream, size, null, uploadOptions, null);
}
// Download the encrypted blob. The same policy and options created before can be used because the aggregate resolver contains both
// resolvers and will pick the right one based on the key ID stored in blob metadata on the service.
Console.WriteLine("Downloading the 2nd encrypted blob.");
// Download and decrypt the encrypted contents from the blob.
using (MemoryStream outputStream = new MemoryStream())
{
blob.DownloadToStream(outputStream, null, downloadOptions, null);
}
Console.WriteLine("Press enter key to exit");
Console.ReadLine();
}
finally
{
container.DeleteIfExists();
}
}
