(Visual FoxPro) URL Signing for Google Maps API

Demonstrates how to sign a URL for the Google Maps API.

Download Chilkat Crypt ActiveX

LOCAL loCrypt
LOCAL lnSuccess
LOCAL lcSig

loCrypt = CreateObject('Chilkat.Crypt2')

*  Any string argument automatically begins the 30-day trial.

lnSuccess = loCrypt.UnlockComponent("Anything for 30-day trial.")
IF (lnSuccess <> 1) THEN
    ? loCrypt.LastErrorText
    QUIT
ENDIF

*  The output will be modified Base64.
*  Modified Base64 for URLs replaces the '+' and '/' characters
*  of standard Base64 with '-' and '_' respectively, so that these
*  Base64 signatures no longer need to be URL-encoded.
loCrypt.EncodingMode = "modBase64"

*  NOTE: At the time of this writing, the "modBase64" encoding mode is
*  available in the pre-release build only.  Send email to
*  support@chilkatsoft.com if you need a pre-release.  This feature will be
*  included in the next official release.

*  Set the hash algorithm to sha-1
loCrypt.HashAlgorithm = "sha-1"

*  Set the HMAC key (this is the private key provided by Google)
loCrypt.SetHmacKeyEncoded("vNIXE0xscrmjlyV-12Nj_BvUPaw=","modBase64")

*  Compute the URL signature
lcSig = loCrypt.HmacStringENC("/maps/api/geocode/json?address=New+York&sensor=false&client=clientID")

*  The result should be KrU1TzVQM7Ur0i8i7K3huiw3MsA=
? lcSig