Petri-X reports an issue where uploading to Azure Storage works in the browser but fails via Set-AzStorageBlobContent in PowerShell, highlighting a permissions mismatch.

Troubleshooting Authorization Errors with Set-AzStorageBlobContent in PowerShell

Author: Petri-X

Problem Overview

When uploading a file to an Azure Storage Account via the browser, the operation is successful. However, running the equivalent upload using the PowerShell command Set-AzStorageBlobContent on the same workstation fails with:

ErrorCode: AuthorizationPermissionMismatch
HTTP Status Code: 403
ErrorMessage: This request is not authorized to perform this operation using this permission.

Example PowerShell Code

$sa = Get-AzStorageAccount -ResourceGroupName RG01 -Name storage01
$strCTX = New-AzStorageContext -StorageAccountName $sa.StorageAccountName
Set-AzStorageBlobContent -Context $strCTX -File C:\temp\test.txt -Container delate -Blob test.txt -Verbose

Observations

Browser upload succeeds: File can be uploaded to the Azure Storage account using the browser interface with the same user account.
PowerShell upload fails: The same user fails to upload via PowerShell with an AuthorizationPermissionMismatch error.
Role assignments seem identical: Both interfaces have seemingly equal role/data access assigned.

Analysis and Possible Causes

1. Different Authentication Paths

Browser/Portal: Likely uses Azure AD authentication or shared access signature (SAS) tokens with delegated permissions set via the portal.
PowerShell CLI: May utilize a different authentication flow or cached credentials that do not have equivalent permissions. The context object (New-AzStorageContext) may create a context with insufficient access.

2. Role Assignment Caveats

Azure roles (e.g., Storage Blob Data Contributor) may be scoped differently (user, group, or service principal) or only grant permissions in portal sessions.
RBAC changes may not propagate instantly or may be context-specific depending on how authentication is performed in each environment.

3. Command-Specific Permissions

Some storage operations (especially via SDKs/CLI) require explicit Storage Blob Data Contributor or higher at the storage account, resource group, or subscription scope.
Portal operations may temporarily elevate permissions or work around missing assignments (e.g., by issuing a SAS token or delegated access).

4. Active Directory Token Issues

Cached or stale access tokens in PowerShell session may not have the right claims.

5. Container-Level Policies

The target blob container may have specific policy or ACL settings restricting direct upload.

Troubleshooting Steps

Check Effective Role Assignments:
- In the Azure Portal, go to the Storage Account > Access Control (IAM) > Check if your user explicitly has Storage Blob Data Contributor or higher.
- Confirm if the assignment is at the storage account, resource group, or subscription scope.
Refresh Authentication:
- Re-authenticate PowerShell with Connect-AzAccount.
- Try running Get-AzContext to confirm that you are using the correct user/context.
Use Current Azure Context:
- Try omitting the manual New-AzStorageContext and allow the module to use the current Azure CLI login context (if possible).
Compare Authentication Methods:
- Review how the browser session authenticates versus the PowerShell session.
Check Container and Access Policies:
- Review the access policies at the container level in case restrictions are enforced there.
Test with Azure CLI:
- Attempt upload using az storage blob upload to further isolate if the issue is with PowerShell or role assignments.

References

Summary

A 403 AuthorizationPermissionMismatch in PowerShell but not the browser usually results from differences in Azure AD authentication or role assignment propagation. Verify the user’s assigned role scope, refresh credentials in PowerShell, and confirm the correct authentication context is in use.

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