Version 4 (V4) of the Amazon SDK for .NET has been released\$1
For information about breaking changes and migrating your applications, see the [migration topic](https://docs.amazonaws.cn/sdk-for-net/v4/developer-guide/net-dg-v4.html).
[https://docs.amazonaws.cn/sdk-for-net/v4/developer-guide/net-dg-v4.html](https://docs.amazonaws.cn/sdk-for-net/v4/developer-guide/net-dg-v4.html)
# Using the shared Amazon credentials file
(Be sure to review the [important warnings and guidance for credentials](net-dg-legacy-creds.md#net-dg-config-creds-warnings-and-guidelines).)
One way to provide credentials for your applications is to create profiles in the *shared Amazon credentials file* and then store credentials in those profiles. This file can be used by the other Amazon SDKs. It can also be used by the [Amazon CLI](https://docs.amazonaws.cn/cli/latest/userguide/), the [Amazon Tools for Windows PowerShell](https://docs.amazonaws.cn/powershell/latest/userguide/), and the Amazon toolkits for [Visual Studio](https://docs.amazonaws.cn/toolkit-for-visual-studio/latest/user-guide/), [JetBrains](https://docs.amazonaws.cn/toolkit-for-jetbrains/latest/userguide/), and [VS Code](https://docs.amazonaws.cn/toolkit-for-vscode/latest/userguide/).
**Warning**
To avoid security risks, don't use IAM users for authentication when developing purpose-built software or working with real data. Instead, use federation with an identity provider such as [Amazon IAM Identity Center](https://docs.amazonaws.cn/singlesignon/latest/userguide/what-is.html).
**Note**
The information in this topic is for circumstances where you need to obtain and manage short-term or long-term credentials manually. For additional information about short-term and long-term credentials, see [Other ways to authenticate](https://docs.amazonaws.cn/sdkref/latest/guide/access-users.html) in the *Amazon SDKs and Tools Reference Guide*.
For best security practices, use Amazon IAM Identity Center, as described in [Authenticating with Amazon](creds-idc.md).
## General information
By default, the shared Amazon credentials file is located in the `.aws` directory within your home directory and is named `credentials`; that is, `~/.aws/credentials` (Linux or macOS) or `%USERPROFILE%\.aws\credentials` (Windows). For information about alternative locations, see [Location of the shared files](https://docs.amazonaws.cn/sdkref/latest/guide/file-location.html) in the *[Amazon SDKs and Tools Reference Guide](https://docs.amazonaws.cn/sdkref/latest/guide/overview.html)*. Also see [Accessing credentials and profiles in an application](creds-locate.md).
The shared Amazon credentials file is a plaintext file and follows a certain format. For information about the format of Amazon credentials files, see [Format of the credentials file](https://docs.amazonaws.cn/sdkref/latest/guide/file-format.html#file-format-creds) in the *Amazon SDKs and Tools Reference Guide*.
You can manage the profiles in the shared Amazon credentials file in several ways.
+ Use any text editor to create and update the shared Amazon credentials file.
+ Use the [Amazon.Runtime.CredentialManagement](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/NRuntimeCredentialManagement.html) namespace of the Amazon SDK for .NET API, as shown later in this topic.
+ Use commands and procedures for the [Amazon Tools for PowerShell](https://docs.amazonaws.cn/powershell/latest/userguide/specifying-your-aws-credentials.html) and the Amazon toolkits for [Visual Studio](https://docs.amazonaws.cn/toolkit-for-visual-studio/latest/user-guide/credentials.html), [JetBrains](https://docs.amazonaws.cn/toolkit-for-jetbrains/latest/userguide/setup-credentials.html), and [VS Code.](https://docs.amazonaws.cn/toolkit-for-vscode/latest/userguide/setup-credentials.html)
+ Use [Amazon CLI](https://docs.amazonaws.cn/cli/latest/userguide/cli-configure-files.html) commands; for example, `aws configure set aws_access_key_id` and `aws configure set aws_secret_access_key`.
## Examples of profile management
The following sections show examples of profiles in the shared Amazon credentials file. Some of the examples show the result, which can be obtained through any of the credential-management methods described earlier. Other examples show how to use a particular method.
### The default profile
The shared Amazon credentials file will almost always have a profile named *default*. This is where the Amazon SDK for .NET looks for credentials if no other profiles are defined.
The `[default]` profile typically looks something like the following.
```
[default]
aws_access_key_id = AKIAIOSFODNN7EXAMPLE
aws_secret_access_key = wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
```
### Create a profile programmatically
This example shows you how to create a profile and save it to the shared Amazon credentials file programmatically. It uses the following classes of the [Amazon.Runtime.CredentialManagement](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/NRuntimeCredentialManagement.html) namespace: [CredentialProfileOptions](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/TCredentialProfileOptions.html), [CredentialProfile](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/TCredentialProfile.html), and [SharedCredentialsFile](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/TSharedCredentialsFile.html).
```
using Amazon.Runtime.CredentialManagement;
...
// Do not include credentials in your code.
WriteProfile("my_new_profile", SecurelyStoredKeyID, SecurelyStoredSecretAccessKey);
...
void WriteProfile(string profileName, string keyId, string secret)
{
Console.WriteLine($"Create the [{profileName}] profile...");
var options = new CredentialProfileOptions
{
AccessKey = keyId,
SecretKey = secret
};
var profile = new CredentialProfile(profileName, options);
var sharedFile = new SharedCredentialsFile();
sharedFile.RegisterProfile(profile);
}
```
**Warning**
Code such as this generally shouldn't be in your application. If you include it in your application, take appropriate precautions to ensure that plaintext keys can't possibly be seen in the code, over the network, or even in computer memory.
The following is the profile that's created by this example.
```
[my_new_profile]
aws_access_key_id=AKIAIOSFODNN7EXAMPLE
aws_secret_access_key=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
```
### Update an existing profile programmatically
This example shows you how to programmatically update the profile that was created earlier. It uses the following classes of the [Amazon.Runtime.CredentialManagement](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/NRuntimeCredentialManagement.html) namespace: [CredentialProfile](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/TCredentialProfile.html) and [SharedCredentialsFile](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Runtime/TSharedCredentialsFile.html). It also uses the [RegionEndpoint](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Amazon/TRegionEndpoint.html) class of the [Amazon](https://docs.amazonaws.cn/sdkfornet/v4/apidocs/items/Amazon/N.html) namespace.
```
using Amazon.Runtime.CredentialManagement;
...
AddRegion("my_new_profile", RegionEndpoint.USWest2);
...
void AddRegion(string profileName, RegionEndpoint region)
{
var sharedFile = new SharedCredentialsFile();
CredentialProfile profile;
if (sharedFile.TryGetProfile(profileName, out profile))
{
profile.Region = region;
sharedFile.RegisterProfile(profile);
}
}
```
The following is the updated profile.
```
[my_new_profile]
aws_access_key_id=AKIAIOSFODNN7EXAMPLE
aws_secret_access_key=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
region=us-west-2
```
**Note**
You can also set the Amazon Region in other locations and by using other methods. For more information, see [Setting the Amazon Region for the Amazon SDK for .NETAmazon Region](net-dg-region-selection.md).