(Tcl) How to Parse a X.509 Certificate and Extract its Public Key

Demonstrates how to load an X.509 certificate and extract the public key. Chilkat supports many certificate encodings:

• DER (binary) encoded certificates (.crt/.cer)
• PEM (BASE64) encoded certificates (.pem)
• Load Certificates Directly from Windows Certificate Stores
• PFX/PKCS12 (.pfx/.p12)
• Java KeyStore (.jks)
• Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)

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load ./chilkat.dll

set cert [new_CkCert]

# Load a DER (binary) encoded certificate.
# To load from a .pem or .p7b, or any other file format that contains
# just one certificate, call LoadFromFile in exactly the same way.
# The LoadFromFile method automatically detects the format and loads the certificate.
set success [CkCert_LoadFromFile $cert "qa_data/certs/testCert.cer"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

# Get the public key:
# pubKey is a CkPublicKey
set pubKey [CkCert_ExportPublicKey $cert]
if {[CkCert_get_LastMethodSuccess $cert] != 1} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

# Examine the key type.
# A PublicKey object can contain an RSA, ECC, or DSA public key.
# The KeyType property will contain "rsa", "ecc", or "dsa".
puts "key type = [CkPublicKey_keyType $pubKey]"

delete_CkPublicKey $pubKey


delete_CkCert $cert