This section describes how to set up ODBC connectivity and configure DSNs on several Linux distributions: Debian-based systems, like Ubuntu, and Red Hat Linux platforms, like Red Hat Enterprise Linux (RHEL), CentOS, and Fedora.

Minimum Linux Versions

Here are the minimum supported versions for Red Hat-based and Debian-based systems:

OS	Min. Version
Ubuntu	11.04
Debian	7
RHEL	6.9
CentOS	6.9
Fedora	13
SUSE	12.1

Installing the Driver Dependencies

Run the following commands as root or with sudo to install the necessary dependencies:

• Debian/Ubuntu:
  

  apt-get install libc6 libstdc++6 zlib1g libgcc1

• RHEL/CentOS/Fedora:
  

  yum install glibc libstdc++ zlib libgcc

Here are the corresponding libraries required by the driver:

Debian/Ubuntu Package	RHEL/CentOS/Fedora Package	File
libc6	glibc	linux-vdso.1
libc6	glibc	libm.so.6
libc6	glibc	librt.so.1
libc6	glibc	libdl.so.2
libc6	glibc	libpthread.so.0
libc6	glibc	libc.so.6
libc6	glibc	ld-linux-x86-64.so.2
libstdc++6	libstdc++	libstdc++.so.6
zlib1g	zlib	libz.so.1
libgcc1	libgcc	libgcc_s.so.1

Installing the Driver

You can use standard package management systems to install the driver.

On Debian-based systems, like Ubuntu, run the following command with root or sudo:

dpkg -i /path/to/driver/setup/SquareODBCDriverforUnix.deb 

On systems that support the RPM package format, run the following command with root or sudo:

rpm -ivh /path/to/driver/SquareODBCDriverforUnix.rpm 

Licensing the Driver

Run the following commands to license the driver. To activate a trial, omit the <key> input.

cd /opt/cdata/cdata-odbc-driver-for-square/bin/
sudo ./install-license.sh <key>

Connecting through the Driver Manager

The driver manager loads the driver and passes function calls from the application to the driver. You need to register the driver with the driver manager and you define DSNs in the driver manager's configuration files.

The driver installation registers the driver with the unixODBC driver manager and creates a system DSN. The unixODBC driver manager can be used from Python and from many other applications. Your application may embed another driver manager.

Creating the DSN

See Using unixODBC to install unixODBC and configure DSNs. See Using the DataDirect Driver Manager to create a DSN to connect to OBIEE, Informatica, and SAS.

Connecting to Square

Square provides two different ways to connect:

• Via personal acess token -- to connect to your own data or test data through the sandbox.
• Via OAuth -- to connect to shared Square data over a browser.

Both of the above methods make use of OAuth functionality that is embedded in the CData Square driver.

Before You Connect

• Set the OAuthAccessToken connection property as described below, for the way you want to access data.
• Set the LocationId property to specify a default business location.

Personal Access Token

To connect to personal data, obtain your personal access token, then set the OAuthAccessToken connection property to that token:

1. Navigate to the Square Developer Dashboard at "https://developer.squareup.com/apps".
2. After the app is created, open the Credentials tab to find the personal token.

Square Sandbox

Version 2 of the Connect API permits you to test in a sandbox environment. Transactions created in the sandbox are not sent through to card networks, and cards are never charged.

To connect to the sandbox, obtain the sandbox access token, then set the OAuthAccessToken connection property to that token:

1. Navigate to the Square Developer Dashboard at "https://developer.squareup.com/apps".
2. After the app is created, open the Credentials tab to find the sandbox token.

OAuth

service; supports OAuth authentication only. To enable this authentication from all OAuth flows, you must set AuthScheme to OAuth.

The following subsections describe how to authenticate to Square from three common authentication flows:

• Desktop: a connection to a server on the user's local machine, frequently used for testing and prototyping. Authenticated via either embedded OAuth or custom OAuth.
• Web: access to data via a shared website. Authenticated via custom OAuth only.
• Headless Server: a dedicated computer that provides services to other computers and their users, which is configured to operate without a monitor and keyboard. Authenticated via embedded OAuth or custom OAuth.

For information about how to create a custom OAuth application, and why you might want to create one even for auth flows that have embedded OAuth credentials, see Creating a Custom OAuth Application.

For a complete list of connection string properties available in Square, see Connection.

Desktop Applications

CData provides an embedded OAuth application that simplifies authentication at the desktop; that is, in situations where the user is using a local server not connected to the internet.

You can also authenticate from the desktop via a custom OAuth application, which you configure and register at the Square console. For further information, see Creating a Custom OAuth Application.

Before you connect, set the following variables:

• InitiateOAuth = GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
• Custom OAuth applications only:
  • OAuthClientId = the client Id assigned when you registered your custom OAuth application.
  • OAuthClientSecret = the client secret assigned when you registered your custom OAuth application.
  • CallbackURL = the redirect URI defined when you registered your custom OAuth application.

When you connect, the driver opens Square's OAuth endpoint in your default browser. Log in and grant permissions to the application.

When the access token expires, the driver refreshes it automatically.

Automatic refresh of the OAuth access token:

To have the driver automatically refresh the OAuth access token, do the following:

1. The first time you connect to data, set the following connection parameters:
   • InitiateOAuth = REFRESH.
   • OAuthClientId = the client Id in your application settings.
   • OAuthClientSecret = the client secret in your application settings.
   • OAuthAccessToken = the access token returned by GetOAuthAccessToken.
   • OAuthSettingsLocation = the path where you want the driver to save the OAuth values, which persist across connections.
2. On subsequent data connections, set the following:
   • InitiateOAuth
   • OAuthSettingsLocation

Manual refresh of the OAuth Access Token:

The only value needed to manually refresh the OAUth access token is the OAuth refresh token.

1. To manually refresh the OAuthAccessToken after the ExpiresIn period (returned by GetOAuthAccessToken) has elapsed, call the GetOAuthAccessToken stored procedure.
2. Set the following connection properties:
   • OAuthClientId = the Client Id in your application settings.
   • OAuthClientSecret = the Client Secret in your application settings.

3. Call RefreshOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken.
4. After the new tokens have been retrieved, set the OAuthAccessToken property to the value returned by RefreshOAuthAccessToken. This opens a new connection.

Store the OAuth refresh token so that you can use it to manually refresh the OAuth access token after it has expired.

Headless Machines

If you need to log in to a resource that resides on a headless machine, you must authenticate on another device that has an internet browser. You can do this in either of the following ways:

• Option 1: Obtain the OAuthVerifier value.
• Option 2: Install the driver on a machine with an internet browser and transfer the OAuth authentication values after you authenticate through the usual browser-based flow.

After you execute either Option 1 or Option 2, configure the driver to automatically refresh the access token on the headless machine.

Option 1: Obtaining and Exchanging a Verifier Code

To obtain a verifier code, you must authenticate at the OAuth authorization URL. Do the following:

1. Authenticate from the machine with an internet browser, and obtain the OAuthVerifier connection property.

   If you are using the embedded OAuth application, call the GetOAuthAuthorizationURL stored procedure. Open the URL returned by the stored procedure in a browser.

   If you are using a custom OAuth application, set the following properties:

   • InitiateOAuth = OFF.
   • OAuthClientId = the client Id assigned when you registered your application.
   • OAuthClientSecret = the client secret assigned when you registered your application.

2. Call the GetOAuthAuthorizationURL stored procedure. The stored procedure returns the CallbackURL established when the custom OAuth application was registered. (See Creating a Custom OAuth Application.)

   Copy this URL and paste it into a new browser tab.

3. Log in and grant permissions to the driver. The OAuth application redirects you the redirect URI, with a parameter called code appended. Note the value of this parameter; you will need it later, to configure the OAuthVerifier connection property.

4. Exchange the OAuth verifier code for OAuth refresh and access tokens. On the headless machine, set the following connection properties to obtain the OAuth authentication values:

   • InitiateOAuth = REFRESH.
   • OAuthVerifier = the noted verifier code (the value of the code parameter in the redirect URI).
   • OAuthSettingsLocation = persist the encrypted OAuth authentication values to the specified file.
   • Custom OAuth applications only:
     • OAuthClientId = the client Id in your custom OAuth application settings.
     • OAuthClientSecret = the client secret in the custom OAuth application settings.

5. Test the connection to generate the OAuth settings file.

6. After you re-set the following properties, you are ready to connect:

   • InitiateOAuth = REFRESH.
   • OAuthSettingsLocation = the file containing the encrypted OAuth authentication values. To enable the automatic refreshing of the access token, be sure that this file gives read and write permissions to the driver.
   • Custom OAuth applications only:
     • OAuthClientId = the client Id assigned when you registered your application.
     • OAuthClientSecret = the client secret assigned when you registered your application.

Option 2: Transferring OAuth Settings

Prior to connecting on a headless machine, you must install and create a connection with the driver on a device that supports an internet browser. Set the connection properties as described above in "Desktop Applications".

After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the path specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.

Test the connection to generate the OAuth settings file, then copy the OAuth settings file to your headless machine.

To connect to data via the headless machine, set the following connection properties:

• InitiateOAuth = REFRESH
• OAuthSettingsLocation = the path to the OAuth settings file you copied from the machine with the browser. To enable automatic refreshing of the access token, ensure that this file gives read and write permissions to the driver.
• Custom OAuth applications only:
  • OAuthClientId = the client Id assigned when you registered your custom OAuth application.
  • OAuthClientSecret = the client secret assigned when you registered your custom OAuth application.

Post-Authentication Options

After you authenticate to Square, you can retrieve the Locations table, then set the LocationId to confine your search criteria to a chosen location.

Refreshing OAuth Values

The driver can refresh the temporary OAuth access tokens obtained during the browser-based OAuth authentication exchange. By default, the driver saves the encrypted tokens in the odbc.ini file corresponding to the DSN. Access to this odbc.ini file can be restricted in the case of System DSNs.

To enable the automatic token exchange, you can give the driver write access to the system odbc.ini. Or, you can set the OAuthSettingsLocation connection property to an alternate file path, to which the driver would have read and write access.

    OAuthSettingsLocation=/tmp/oauthsettings.txt
    

Installing Dependencies for OAuth Authentication

The OAuth authentication standard requires the authenticating user to interact with Square, using a web-browser. If the first OAuth interaction is to be done on the same machine the driver is installed on, for example, a desktop application, the driver needs access to the xdg-open program, which opens the default browser.

To satisfy this dependency, install the corresponding package with your package manager:

Debian/Ubuntu Package	RHEL/CentOS/Fedora Package	File
xdg-utils	xdg-utils	xdg-open

Set the Driver Encoding

The ODBC drivers need to specify which encoding to use with the ODBC Driver Manager. By default, the CData ODBC Drivers for Unix are configured to use UTF-16 which is compatible with unixODBC, but other Driver Managers may require alternative encoding.

Alternatively, if you are using the ODBC driver from an application that uses the ANSI ODBC API it may be necessary to set the ANSI code page. For example, to import Japanese characters in an ANSI application, you can specify the code page in the config file '/opt/cdata/cdata-odbc-driver-for-square/lib/cdata.odbc.square.ini':

[Driver]
AnsiCodePage = 932