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Xbase++ Requires Chilkat v11.0.0+

Validate JWS with Multiple Signatures using the General JSON Serialization Format

See more JSON Web Signatures (JWS) Examples

Validates and recovers data and headers from a JSON Web Signature (JWS) containing 3 signatures.

Note: Chilkat supports all of the following JWS algorithms:

   +--------------+-------------------------------+--------------------+
   | "alg" Param  | Digital Signature or MAC      | Implementation     |
   | Value        | Algorithm                     | Requirements       |
   +--------------+-------------------------------+--------------------+
   | HS256        | HMAC using SHA-256            | Required           |
   | HS384        | HMAC using SHA-384            | Optional           |
   | HS512        | HMAC using SHA-512            | Optional           |
   | RS256        | RSASSA-PKCS1-v1_5 using       | Recommended        |
   |              | SHA-256                       |                    |
   | RS384        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-384                       |                    |
   | RS512        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-512                       |                    |
   | ES256        | ECDSA using P-256 and SHA-256 | Recommended+       |
   | ES384        | ECDSA using P-384 and SHA-384 | Optional           |
   | ES512        | ECDSA using P-521 and SHA-512 | Optional           |
   | PS256        | RSASSA-PSS using SHA-256 and  | Optional           |
   |              | MGF1 with SHA-256             |                    |
   | PS384        | RSASSA-PSS using SHA-384 and  | Optional           |
   |              | MGF1 with SHA-384             |                    |
   | PS512        | RSASSA-PSS using SHA-512 and  | Optional           |
   |              | MGF1 with SHA-512             |                    |
   +--------------+-------------------------------+--------------------+

Chilkat Xbase++ Downloads

Xbase++
LOCAL nSuccess
LOCAL oSbRsaJwk
LOCAL oRsaKey
LOCAL oSbEccJwk
LOCAL oEccKey
LOCAL cHmacKey
LOCAL oSbJws
LOCAL oJws
LOCAL oSbKeyId
LOCAL nBCaseSensitive
LOCAL oProtHeader
LOCAL nNumSignatures
LOCAL i
LOCAL v

nSuccess := 0

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

//  First, prepare the public keys that will be needed for each signature.

//  ---------------------------------------------------
//  Use the following RSA key loaded from JWK format.
oSbRsaJwk := CreateObject("Chilkat.StringBuilder")
oSbRsaJwk:Append('{"kty":"RSA",')
oSbRsaJwk:Append('"n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx')
oSbRsaJwk:Append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs")
oSbRsaJwk:Append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH")
oSbRsaJwk:Append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV")
oSbRsaJwk:Append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8")
oSbRsaJwk:Append('NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ",')
oSbRsaJwk:Append('"e":"AQAB"')
oSbRsaJwk:Append("}")

oRsaKey := CreateObject("Chilkat.PublicKey")
nSuccess := oRsaKey:LoadFromString(oSbRsaJwk:GetAsString())
IF (nSuccess == 0)
    ? oRsaKey:LastErrorText
    oSbRsaJwk:destroy()
    oRsaKey:destroy()
    RETURN
ENDIF

//  ---------------------------------------------------
//  Use the following ECC public key loaded from JWK format.
oSbEccJwk := CreateObject("Chilkat.StringBuilder")
oSbEccJwk:Append('{"kty":"EC",')
oSbEccJwk:Append('"crv":"P-256",')
oSbEccJwk:Append('"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",')
oSbEccJwk:Append('"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"')
oSbEccJwk:Append("}")

oEccKey := CreateObject("Chilkat.PublicKey")
nSuccess := oEccKey:LoadFromString(oSbEccJwk:GetAsString())
IF (nSuccess == 0)
    ? oEccKey:LastErrorText
    oSbRsaJwk:destroy()
    oRsaKey:destroy()
    oSbEccJwk:destroy()
    oEccKey:destroy()
    RETURN
ENDIF

//  ---------------------------------------------------
//  The HMAC key (in base64url format)
cHmacKey := "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"

//  The code below will verify each of the signatures in this JWS:

//  { 
//    "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
//    "signatures": [
//      { 
//        "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",
//        "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"
//      },
//      { 
//        "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",
//        "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"
//      },
//      { 
//        "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",
//        "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"
//      }
//    ]
//  }

oSbJws := CreateObject("Chilkat.StringBuilder")
oSbJws:Append("{ ")
oSbJws:Append('  "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",')
oSbJws:Append('  "signatures": [')
oSbJws:Append("    { ")
oSbJws:Append('      "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",')
oSbJws:Append('      "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"')
oSbJws:Append("    },")
oSbJws:Append("    { ")
oSbJws:Append('      "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",')
oSbJws:Append('      "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"')
oSbJws:Append("    },")
oSbJws:Append("    { ")
oSbJws:Append('      "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",')
oSbJws:Append('      "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"')
oSbJws:Append("    }")
oSbJws:Append("  ]")
oSbJws:Append("}")

oJws := CreateObject("Chilkat.Jws")

nSuccess := oJws:LoadJwsSb(oSbJws)
IF (nSuccess == 0)
    ? oJws:LastErrorText
    oSbRsaJwk:destroy()
    oRsaKey:destroy()
    oSbEccJwk:destroy()
    oEccKey:destroy()
    oSbJws:destroy()
    oJws:destroy()
    RETURN
ENDIF

//  The payload is easily accessible:
? "Payload: " + oJws:GetPayload("utf-8")

oSbKeyId := CreateObject("Chilkat.StringBuilder")
nBCaseSensitive := 0

oProtHeader := CreateObject("Chilkat.JsonObject")
nNumSignatures := oJws:NumSignatures
i := 0
DO WHILE i < nNumSignatures
    nSuccess := oJws:GetProtectedH(i, oProtHeader)
    IF (nSuccess == 0)
        ? oJws:LastErrorText
        oSbRsaJwk:destroy()
        oRsaKey:destroy()
        oSbEccJwk:destroy()
        oEccKey:destroy()
        oSbJws:destroy()
        oJws:destroy()
        oSbKeyId:destroy()
        oProtHeader:destroy()
        RETURN
    ENDIF

    ? "--------------------------"
    ? Str(i) + ": "

    //  Get the protected header.
    oProtHeader:EmitCompact := 0
    ? oProtHeader:Emit()

    //  Get the key ID ("kid") member.

    //  Note: In this example, the "kid" values are contained in the protected headers.
    //  They could've just as easily been located in unprotected headers.  In that case,
    //  we would've called GetUnprotectedH instead of GetProtectedH(i).

    oSbKeyId:Clear()
    oSbKeyId:Append(oProtHeader:StringOf("kid"))

    //  Set the key based on key ID.
    IF (oSbKeyId:ContentsEqual("myRsaKey", nBCaseSensitive) == 1)
        oJws:SetPublicKey(i, oRsaKey)
    ENDIF

    IF (oSbKeyId:ContentsEqual("myEcKey", nBCaseSensitive) == 1)
        oJws:SetPublicKey(i, oEccKey)
    ENDIF

    IF (oSbKeyId:ContentsEqual("myMacKey", nBCaseSensitive) == 1)
        oJws:SetMacKey(i, cHmacKey, "base64url")
    ENDIF

    //  Validate this signature.
    v := oJws:Validate(i)
    IF (v < 0)
        //  Perhaps Chilkat was not unlocked or the trial expired..
        ? "Validate failed for some other reason."
        ? oJws:LastErrorText
    ELSE
        IF (v == 0)
            ? "Invalid signature.  The key was incorrect, the JWS was invalid, or both."
        ELSE
            ? "Signature validated."
        ENDIF

    ENDIF

    i := i + 1
ENDDO

//  The output of this program is:

//  	Payload: In our village, folks say God crumbles up the old moon into stars.
//  	--------------------------
//  	0: 
//  	{
//  	  "alg": "RS256",
//  	  "kid": "myRsaKey"
//  	}
//  
//  	Signature validated.
//  	--------------------------
//  	1: 
//  	{
//  	  "alg": "ES256",
//  	  "kid": "myEcKey"
//  	}
//  
//  	Signature validated.
//  	--------------------------
//  	2: 
//  	{
//  	  "alg": "HS256",
//  	  "kid": "myMacKey"
//  	}
//  
//  	Signature validated.

oSbRsaJwk:destroy()
oRsaKey:destroy()
oSbEccJwk:destroy()
oEccKey:destroy()
oSbJws:destroy()
oJws:destroy()
oSbKeyId:destroy()
oProtHeader:destroy()