SharePoint linked service input is not a valid Base-64

Question

Hello Team,

We are trying to connect to a sharePoint list, when testing connection we are getting the below error message:

The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.

Some details:

Site URL
Service principal credential type: Service principal certificate (Recommended) / Azure Key Vault

Using secret name, secret version.

Please let us know how to resolve.

Or propose a method to connect with sharePoint List.

Thanks

Answer 1

I think that the certificate or secret you are using is not correctly encoded in Base-64. You can use online tools or PowerShell to verify the encoding.

$certPath = "path\to\your\certificate.pfx"

$certBytes = [System.IO.File]::ReadAllBytes($certPath)

$base64Cert = [System.Convert]::ToBase64String($certBytes)

$base64Cert

If you are using Azure Key Vault to store the certificate or secret, verify that the secret is correctly stored and retrieved.

$secret = Get-AzKeyVaultSecret -VaultName "YourKeyVaultName" -Name "YourSecretName"

$secretValue = $secret.SecretValueText

$secretValue

Or, instead of using a certificate, you can use a client secret for authentication. Ensure that the client secret is correctly configured in Azure Active Directory and Azure Key Vault.

You can also use OAuth 2.0 authentication to connect to SharePoint. This method involves registering an application in Azure AD and obtaining an access token.