(Ruby) Create JWK Set Containing Certificates

Demonstrates how to create a JWK Set containing N certificates.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example creates the following JWK Set from two certificates:

# {
#   "keys": [
#     {
#       "kty": "RSA",
#       "use": "sig",
#       "kid": "BB8CeFVqyaGrGNuehJIiL4dfjzw",
#       "x5t": "BB8CeFVqyaGrGNuehJIiL4dfjzw",
#       "n": "nYf1jpn7cFdQ...9Iw",
#       "e": "AQAB",
#       "x5c": [
#         "MIIDBTCCAe2...Z+NTZo"
#       ]
#     },
#     {
#       "kty": "RSA",
#       "use": "sig",
#       "kid": "M6pX7RHoraLsprfJeRCjSxuURhc",
#       "x5t": "M6pX7RHoraLsprfJeRCjSxuURhc",
#       "n": "xHScZMPo8F...EO4QQ",
#       "e": "AQAB",
#       "x5c": [
#         "MIIC8TCCAdmgA...Vt5432GA=="
#       ]
#     }
#   ]
# }

# First get two certificates from files.
cert1 = Chilkat::CkCert.new()
success = cert1.LoadFromFile("qa_data/certs/brasil_cert.pem")
if (success != true)
    print cert1.lastErrorText() + "\n";
    exit
end

cert2 = Chilkat::CkCert.new()
success = cert2.LoadFromFile("qa_data/certs/testCert.cer")
if (success != true)
    print cert2.lastErrorText() + "\n";
    exit
end

# We'll need this crypt object re-encode the SHA1 thumbprint from hex to base64.
crypt = Chilkat::CkCrypt2.new()

json = Chilkat::CkJsonObject.new()

# Let's begin with the 1st cert:
json.put_I(0)
json.UpdateString("keys[i].kty","RSA")
json.UpdateString("keys[i].use","sig")

hexThumbprint = cert1.sha1Thumbprint()
base64Thumbprint = crypt.reEncode(hexThumbprint,"hex","base64")
json.UpdateString("keys[i].kid",base64Thumbprint)
json.UpdateString("keys[i].x5t",base64Thumbprint)

# (We're assuming these are RSA certificates)
# To get the modulus (n) and exponent (e), we need to get the cert's public key and then get its JWK.
# pubKey is a CkPublicKey
pubKey = cert1.ExportPublicKey()
pubKeyJwk = Chilkat::CkJsonObject.new()
pubKeyJwk.Load(pubKey.getJwk())

json.UpdateString("keys[i].n",pubKeyJwk.stringOf("n"))
json.UpdateString("keys[i].e",pubKeyJwk.stringOf("e"))

# Now add the entire X.509 certificate 
json.UpdateString("keys[i].x5c[0]",cert1.getEncoded())

# Now do the same for cert2..
json.put_I(1)

json.UpdateString("keys[i].kty","RSA")
json.UpdateString("keys[i].use","sig")

hexThumbprint = cert2.sha1Thumbprint()
base64Thumbprint = crypt.reEncode(hexThumbprint,"hex","base64")
json.UpdateString("keys[i].kid",base64Thumbprint)
json.UpdateString("keys[i].x5t",base64Thumbprint)

# pubKey is a CkPublicKey
pubKey = cert2.ExportPublicKey()
pubKeyJwk.Load(pubKey.getJwk())

json.UpdateString("keys[i].n",pubKeyJwk.stringOf("n"))
json.UpdateString("keys[i].e",pubKeyJwk.stringOf("e"))

# Now add the entire X.509 certificate 
json.UpdateString("keys[i].x5c[0]",cert2.getEncoded())

# Emit the JSON..
json.put_EmitCompact(false)
print json.emit() + "\n";