private/Get-OAuthParameters.ps1
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function Get-OAuthParameters { [OutputType('System.Management.Automation.PSCustomObject')] Param($ApiKey, $ApiSecret, $AccessToken, $AccessTokenSecret, $Method, $ResourceUrl, $Parameters, $Body) Process{ Try { ## Generate a random 32-byte string. I'm using the current time (in seconds) and appending 5 chars to the end to get to 32 bytes ## Base64 allows for an '=' but Twitter does not. If this is found, replace it with some alphanumeric character $OAuthNonce = [System.Convert]::ToBase64String(([System.Text.Encoding]::ASCII.GetBytes("$([System.DateTime]::Now.Ticks.ToString())12345"))).Replace('=', 'g') ## Find the total seconds since 1/1/1970 (epoch time) $OAuthTimestamp = [System.Convert]::ToInt64((Get-Eposh).TotalSeconds).ToString(); ## EscapeDataString the parameters $EscapedParameters = @{} foreach($Param in $($Parameters.Keys)){ $EscapedParameters[$Param] = "$([System.Uri]::EscapeDataString($Parameters[$Param]))".Replace("!","%21").Replace("'","%27").Replace("(","%28").Replace(")","%29").Replace("*","%2A") } ## Build the enpoint url $EndPointUrl = "${ResourceUrl}?" $EscapedParameters.GetEnumerator() | Where-Object { $_.Value -is [string] } | Sort-Object Name | ForEach-Object { $EndPointUrl += "$($_.Key)=$($_.Value)&" } $EndPointUrl = $EndPointUrl.TrimEnd('&') ## Build the signature $SignatureBase = "$([System.Uri]::EscapeDataString("${ResourceUrl}"))&" $SignatureParams = @{ 'oauth_consumer_key' = $ApiKey; 'oauth_nonce' = $OAuthNonce; 'oauth_signature_method' = 'HMAC-SHA1'; 'oauth_timestamp' = $OAuthTimestamp; 'oauth_token' = $AccessToken; 'oauth_version' = "1.0"; } $EscapedParameters.Keys | ForEach-Object { $SignatureParams.Add($_ , $EscapedParameters.Item($_)) } ## Create a string called $SignatureBase that joins all URL encoded 'Key=Value' elements with a & ## Remove the URL encoded & at the end and prepend the necessary 'POST&' verb to the front $SignatureParams.GetEnumerator() | Sort-Object Name | ForEach-Object { $SignatureBase += [System.Uri]::EscapeDataString("$($_.Key)=$($_.Value)&") } $SignatureBase = $SignatureBase.Substring(0,$SignatureBase.Length-3) $SignatureBase = $Method+'&' + $SignatureBase ## Create the hashed string from the base signature $SignatureKey = [System.Uri]::EscapeDataString($ApiSecret) + "&" + [System.Uri]::EscapeDataString($AccessTokenSecret); $hmacsha1 = New-Object System.Security.Cryptography.HMACSHA1; $hmacsha1.Key = [System.Text.Encoding]::ASCII.GetBytes($SignatureKey); $OAuthSignature = [System.Convert]::ToBase64String($hmacsha1.ComputeHash([System.Text.Encoding]::ASCII.GetBytes($SignatureBase))); ## Build the authorization headers using most of the signature headers elements. This is joining all of the 'Key=Value' elements again ## and only URL encoding the Values this time while including non-URL encoded double quotes around each value $OAuthParameters = $SignatureParams $OAuthParameters.Add('oauth_signature', $OAuthSignature) $OAuthString = 'OAuth ' $OAuthParameters.GetEnumerator() | Sort-Object Name | ForEach-Object { $OAuthString += $_.Key + '="' + [System.Uri]::EscapeDataString($_.Value) + '", ' } $OAuthString = $OAuthString.TrimEnd(', ') Write-Verbose "Using authorization string '$OAuthString'" $OAuthParameters.Add('endpoint_url', $EndPointUrl) $OAuthParameters.Add('endpoint_method', $Method) $OAuthParameters.Add('endpoint_authorization', $OAuthString) # If Body is required, change contenttype to json # Example: Send-TwitterDirectMessages_EventsNew If ($Body) { $OAuthParameters.Add('endpoint_contentType', "application/json") $OAuthParameters.Add('endpoint_body', "$($Body | ConvertTo-Json -Depth 99 -Compress)") } Else { $OAuthParameters.Add('endpoint_contentType', "application/x-www-form-urlencoded") } Return $OAuthParameters } Catch { Write-Error $_.Exception.Message } } } |