Chilkat2-Python

Verify an XML Signature with Multiple References

See more XML Digital Signatures Examples

Demonstrates how to verify an XML digital signature that contains multiple references. Chilkat2-Python

import sys
import chilkat2

success = False

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# An example of an enveloping XML signature with mulitple references is available at
# https://www.chilkatsoft.com/exampleData/envelopedMultipleRefs.xml

# This example will show how to verify the signature and all references, and also how
# to verify each reference individually.  This is useful to distinguish which part
# of the XML signature validation failed.  It could be that one or more of the references
# failed because of a hash computation mismatch.  Or it could be that the signature over
# the SignedInfo failed.  

# First, let's grab the sample XML signature.
http = chilkat2.Http()
sbXml = chilkat2.StringBuilder()
success = http.QuickGetSb("https://www.chilkatsoft.com/exampleData/envelopedMultipleRefs.xml",sbXml)
if (success != True):
    print(http.LastErrorText)
    sys.exit()

# Load the XML containing the signature to be verified.
verifier = chilkat2.XmlDSig()
success = verifier.LoadSignatureSb(sbXml)
if (success != True):
    print(verifier.LastErrorText)
    sys.exit()

verifyReferenceDigests = True

# The quick way to validate all references and the signature over the SignedInfo
# is to call VerifySignature with verifyReferenceDigests equal to True.
verified = verifier.VerifySignature(verifyReferenceDigests)
print("Signature and all reference digests verified = " + str(verified))

# Let's pretend the call to VerifySignature returned False.  Something did not validate.
# Was it one or more of the References that did not hash to the correct value?
# Or was it the signature over the SignedInfo that failed?
# We can check just the signature over the SignedInfo by passing False to VerifySignature.
# This allows us to skip the hashing and checking each Reference.  
verifyReferenceDigests = False
signedInfoVerified = verifier.VerifySignature(verifyReferenceDigests)
print("Neglecting the reference hashes, the SignedInfo validation result = " + str(signedInfoVerified))

# We can also verify each reference digest separately
numRefs = verifier.NumReferences
i = 0
while i < numRefs :
    refDigestVerified = verifier.VerifyReferenceDigest(i)
    print("Reference " + str(i) + " digest verified = " + str(refDigestVerified))
    i = i + 1

# For this sample XML signature with 3 References, we get the following output:

# Signature and all reference digests verified = True
# Neglecting the reference hashes, the SignedInfo validation result = True
# Reference 0 digest verified = True
# Reference 1 digest verified = True
# Reference 2 digest verified = Tru