Ruby Requires Chilkat v11.0.0+

Create a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) that uses ECDSA P-256 SHA-256 Ruby

require 'chilkat'

success = false

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

#  Note: This example requires Chilkat v9.5.0.66 or greater.

#  Use the following ECC key loaded from JWK format.
sbJwk = Chilkat::CkStringBuilder.new()
sbJwk.Append("{\"kty\":\"EC\",")
sbJwk.Append("\"crv\":\"P-256\",")
sbJwk.Append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",")
sbJwk.Append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\",")
sbJwk.Append("\"d\":\"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI\"")
sbJwk.Append("}")

eccKey = Chilkat::CkPrivateKey.new()
#  Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
#  into the private key object. (See the online reference documentation..)
success = eccKey.LoadJwk(sbJwk.getAsString())
if (success == false)
    print eccKey.lastErrorText() + "\n";
    exit
end

#  Create the JWS Protected Header
jwsProtHdr = Chilkat::CkJsonObject.new()
jwsProtHdr.AppendString("alg","ES256")

jws = Chilkat::CkJws.new()

#  Set the protected header:
signatureIndex = 0
jws.SetProtectedHeader(signatureIndex,jwsProtHdr)

#  Set the ECC key:
jws.SetPrivateKey(signatureIndex,eccKey)

#  Set the payload.
bIncludeBom = false
payloadStr = "In our village, folks say God crumbles up the old moon into stars."
jws.SetPayload(payloadStr,"utf-8",bIncludeBom)

#  Create the JWS
#  By default, the compact serialization is used.
jwsCompact = jws.createJws()
if (jws.get_LastMethodSuccess() == false)
    print jws.lastErrorText() + "\n";
    exit
end

print "JWS: " + jwsCompact + "\n";

#  Note: ECC signatures use random values, so the output will be different each time a signature is produced.
#  sample output:
#  JWS: eyJhbGciOiJFUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.J6EGTNkeuEjehHHBu0SOKzifm8r35wbx49A5964pxzB7gannyZZPMkK7vmlaPJ-K8Xmm8cZsQySAPC12Xd8avw

#  Now load the JWS, validate, and recover the original text.
jws2 = Chilkat::CkJws.new()

#  Load the JWS.
success = jws2.LoadJws(jwsCompact)

eccPubKey = Chilkat::CkPublicKey.new()
eccKey.ToPublicKey(eccPubKey)

#  Set the ECC public key used for validation.
signatureIndex = 0
jws2.SetPublicKey(signatureIndex,eccPubKey)

#  Validate the 1st (and only) signature at index 0..
v = jws2.Validate(signatureIndex)
if (v < 0)
    #  Perhaps Chilkat was not unlocked or the trial expired..
    print "Method call failed for some other reason." + "\n";
    print jws2.lastErrorText() + "\n";
    exit
end

if (v == 0)
    print "Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both." + "\n";
    exit
end

#  If we get here, the signature was validated..
print "Signature validated." + "\n";

#  Recover the original content:
print jws2.getPayload("utf-8") + "\n";

#  Examine the protected header:
joseHeader = Chilkat::CkJsonObject.new()
jws2.GetProtectedH(signatureIndex,joseHeader)
joseHeader.put_EmitCompact(false)

print "Protected (JOSE) header:" + "\n";
print joseHeader.emit() + "\n";

#  Output:

#  Signature validated.
#  In our village, folks say God crumbles up the old moon into stars.
#  Protected (JOSE) header:
#  { 
#    "alg": "ES256"
#  }