(Tcl) Get Certificate Authority Information Access

Demonstrates how to get a certificate's Authority Information Access extension data (if it exists).

Note: This example requires Chilkat v9.5.0.76 or greater.

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load ./chilkat.dll

set cert [new_CkCert]

set success [CkCert_LoadFromFile $cert "qa_data/certs/test_haswdt.cer"]
if {$success != 1} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

# Get the Authority Information Access extension, which is at OID 1.3.6.1.5.5.7.1.1
set extensionXmlStr [CkCert_getExtensionAsXml $cert "1.3.6.1.5.5.7.1.1"]
if {[CkCert_get_LastMethodSuccess $cert] == 0} then {
    puts "Certificate does not have the AuthInfoAccess extension."
    delete_CkCert $cert
    exit
}

set xml [new_CkXml]

CkXml_LoadXml $xml $extensionXmlStr

# See what we have..
puts [CkXml_getXml $xml]

# We should get XML like this:

# <?xml version="1.0" encoding="utf-8" ?>
# <sequence>
#     <sequence>
#         <oid>1.3.6.1.5.5.7.48.2</oid>
#         <contextSpecific tag="6" constructed="0">aHR0cDovL2NydC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
# cmVFbWFpbENBLmNydA==</contextSpecific>
#     </sequence>
#     <sequence>
#         <oid>1.3.6.1.5.5.7.48.1</oid>
#         <contextSpecific tag="6" constructed="0">aHR0cDovL29jc3AuY29tb2RvY2EuY29t</contextSpecific>
#     </sequence>
# </sequence>

# Typically, a certificate AIA(Authority Information access) contains 2 parts:
# 
#     On-line Certificate Status Protocol (1.3.6.1.5.5.7.48.1)
#     Certification Authority Issuer (1.3.6.1.5.5.7.48.2)
# 
# The base64 content for each OID (in this case) is just a string.  
# The data can be accessed and decoded like this:

set sbOcsp [new_CkStringBuilder]

set success [CkXml_GetChildContentSb $xml "/C/oid,1.3.6.1.5.5.7.48.1|++" $sbOcsp]
if {$success == 1} then {
    CkStringBuilder_Decode $sbOcsp "base64" "utf-8"
    puts "1.3.6.1.5.5.7.48.1:  [CkStringBuilder_getAsString $sbOcsp]"
}

set sbIssuer [new_CkStringBuilder]

set success [CkXml_GetChildContentSb $xml "/C/oid,1.3.6.1.5.5.7.48.2|++" $sbIssuer]
if {$success == 1} then {
    CkStringBuilder_Decode $sbIssuer "base64" "utf-8"
    puts "1.3.6.1.5.5.7.48.2:  [CkStringBuilder_getAsString $sbIssuer]"
}

# The output looks like this:

# 1.3.6.1.5.5.7.48.1:  http://ocsp.comodoca.com
# 1.3.6.1.5.5.7.48.2:  http://crt.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crt

# -------------------------------------------------------------------------------
# Note: The Chilkat path passed to GetChildContentSb is composed of two commands:
# The first command is "/C/oid,1.3.6.1.5.5.7.48.1".   It says "traverse the XML tree from the caller
# node and stop at the 1st node having tag = "oid" and content = "1.3.6.1.5.5.7.48.1".
# The "|" char separates the 1st command from the 2nd.
# The 2nd command is "++" and says "move to the next sibling".

delete_CkCert $cert
delete_CkXml $xml
delete_CkStringBuilder $sbOcsp
delete_CkStringBuilder $sbIssuer