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Returns information about the organization that issued the server
certificate.
Syntax
object.CertificateIssuer
Remarks
The CertificateIssuer property returns a string that
contains information about the organization that issued the server
certificate. The string value is a comma separated list of tagged
name and value pairs. In the nomenclature of the X.500 standard, each
of these pairs are called a relative distinguished name (RDN), and
when concatenated together, forms the issuer's distinguished name
(DN). For example:
C=US, O="RSA Data Security, Inc.", OU=Secure Server
Certification Authority
To obtain a specific value, such as the name of the issuer or the
issuer's country, the application must parse the string returned by
this property. Some of the common tokens used in the distinguished
name are:
| Name |
Description |
| C |
The ISO standard two character country code |
| S |
The name of the state or province |
| L |
The name of the city or locality |
| O |
The name of the company or organization |
| OU |
The name of the department or organizational unit |
| CN |
The common name; with X.509 certificates, this is the
domain name of the site the certificate was issued for |
This property will return an empty string if a secure connection
has not been established with the server.
Data Type
String
Example
The following example demonstrates how to extract the value of a
relative distinguished name token:
Function GetCertNameValue(ByVal strValue As String, ByVal strFieldName As String) As String
Dim strFieldValue As String
Dim cchValue As Integer, cchFieldName As Integer
Dim nOffset As Integer
GetCertNameValue = ""
cchValue = Len(strValue)
cchFieldName = Len(strFieldName)
If cchValue = 0 Or cchFieldName = 0 Then
Exit Function
End If
nOffset = InStr(strValue, strFieldName & "=")
If nOffset > 0 Then
'
' If the field name was found in the string, then
' remove everything to the left of the token from
' the string
'
strFieldValue = Right(strValue, cchValue - (nOffset + cchFieldName))
'
' If the value is quoted, then strip off the leading
' quote and look for the ending quote in the string;
' otherwise look for the comma that marks the end of
' the field name/value pair
'
If Left(strFieldValue, 1) = Chr(34) Then
strFieldValue = Right(strFieldValue, Len(strFieldValue) - 1)
nOffset = InStr(strFieldValue, Chr(34))
Else
nOffset = InStr(strFieldValue, ",")
End If
'
' If the offset is 0, then the name/value pair is
' the last token in the string; otherwise, remove
' everything to the right of that position
'
If nOffset > 0 Then
strFieldValue = Left(strFieldValue, nOffset - 1)
End If
GetCertNameValue = strFieldValue
End If
End Function
This function could then be used to return the name of the company
who issued the server certificate:
Dim strIssuer As String
Dim strCompanyName As String
strIssuer = FtpClient1.CertificateIssuer
If Len(strIssuer) = 0 Then
MsgBox "A secure connection has not been established"
Else
strCompanyName = GetCertNameValue(strIssuer, "O")
MsgBox "This certificate was issued by " & strCompanyName
End If
See Also
CertificateExpires Property,
CertificateIssued Property,
CertificateStatus Property,
CertificateSubject Property,
Secure Property
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