private void ParseAuthorizationHeader()
{
string logMessage = "";
if (String.IsNullOrEmpty(Authorization))
{
return;
}
string exceptionMsg = "Invalid authorization header format: " + Authorization;
try
{
#region Retrieve-Outer-Values
// [encryption] [values]
string[] valsOuter = Authorization.Split(new[] { ' ' }, 2);
if (valsOuter == null || valsOuter.Length < 2)
{
throw new ArgumentException(exceptionMsg);
}
logMessage += _Header + "Authorization header : " + Authorization + Environment.NewLine;
logMessage += _Header + "Outer header values :" + Environment.NewLine;
for (int i = 0; i < valsOuter.Length; i++)
{
logMessage += " " + i + ": " + valsOuter[i].Trim() + Environment.NewLine;
}
#endregion
if (valsOuter[0].Equals("AWS"))
{
#region Signature-V2
// see https://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheAuthenticationHeader
// Authorization: AWS AWSAccessKeyId:Signature
string[] valsInner = valsOuter[1].Split(':');
logMessage += _Header + "Inner header values" + Environment.NewLine;
for (int i = 0; i < valsInner.Length; i++)
{
logMessage += " " + i + ": " + valsInner[i].Trim() + Environment.NewLine;
}
if (valsInner.Length != 2)
{
throw new ArgumentException(exceptionMsg);
}
SignatureVersion = S3SignatureVersion.Version2;
AccessKey = valsInner[0].Trim();
Signature = valsInner[1].Trim();
logMessage +=
_Header + "Signature version : " + SignatureVersion.ToString() + Environment.NewLine +
_Header + "Access key : " + AccessKey + Environment.NewLine +
_Header + "Signature : " + Signature;
return;
#endregion
}
else if (valsOuter[0].Equals("AWS4-HMAC-SHA256"))
{
#region Signature-V4
// see https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-auth-using-authorization-header.html
//
// AWS4-HMAC-SHA256 Credential=access/20190418/us-east-1/s3/aws4_request, SignedHeaders=content-length;content-type;host;user-agent;x-amz-content-sha256;x-amz-date;x-amz-decoded-content-length, Signature=66946e06895806f4e32d32217c1a02313b9d9235b759f3a690742c8f9971daa0
//
// valsOuter[0] AWS4-HMAC-SHA256
// valsOuter[1] everything else...
SignatureVersion = S3SignatureVersion.Version4;
string[] keyValuePairs = valsOuter[1].Split(',');
List <string> keyValuePairsTrimmed = new List <string>();
logMessage += _Header + "Inner header values" + Environment.NewLine;
for (int i = 0; i < keyValuePairs.Length; i++)
{
string currKey = keyValuePairs[i];
if (String.IsNullOrEmpty(currKey))
{
continue;
}
currKey = currKey.Trim();
keyValuePairsTrimmed.Add(currKey);
logMessage += i + ": " + keyValuePairs[i].Trim() + Environment.NewLine;
}
foreach (string currKey in keyValuePairsTrimmed)
{
if (currKey.StartsWith("Credential="))
{
#region Credentials
string credentialString = currKey.Replace("Credential=", "").Trim();
string[] credentialVals = credentialString.Split('/');
if (credentialVals.Length < 5)
{
throw new ArgumentException(exceptionMsg);
}
AccessKey = credentialVals[0].Trim();
Region = credentialVals[2].Trim();
#endregion
}
else if (currKey.StartsWith("SignedHeaders="))
{
#region Signed-Headers
string signedHeadersString = currKey.Replace("SignedHeaders=", "").Trim();
string[] signedHeaderVals = signedHeadersString.Split(';');
if (signedHeaderVals != null && signedHeaderVals.Length > 0)
{
foreach (string currSignedHeader in signedHeaderVals)
{
SignedHeaders.Add(currSignedHeader.Trim());
}
SignedHeaders.Sort();
}
#endregion
}
else if (currKey.StartsWith("Signature="))
{
#region Signature
Signature = currKey.Replace("Signature=", "").Trim();
#endregion
}
else if (currKey.StartsWith("Expires="))
{
#region Expires
Expires = currKey.Replace("Expires=", "").Trim();
#endregion
}
}
logMessage +=
_Header + "Signature version : " + SignatureVersion.ToString() + Environment.NewLine +
_Header + "Access key : " + AccessKey + Environment.NewLine +
_Header + "Region : " + Region + Environment.NewLine +
_Header + "Signature : " + Signature;
return;
#endregion
}
else
{
throw new ArgumentException(exceptionMsg + Authorization);
}
}
finally
{
_Logger?.Invoke(logMessage);
}
}
private void FormExternalSignature_Load(object sender, EventArgs e)
{
txtSignature.Text = Signature;
txtSignatureVersion.Text = SignatureVersion.ToString();
txtSoftwareCertNumber.Text = SoftwareCertificateNumber.ToString();
}