Visual FoxPro

P7S - Access Signature Information (date/time, certificate used, etc.)

See more Digital Signatures Examples

Examine a PKCS7 signature (.p7s) and get information about it. Visual FoxPro

LOCAL lnSuccess
LOCAL loBd
LOCAL loCrypt
LOCAL loJson
LOCAL i
LOCAL lnCount_i
LOCAL lcStrVal
LOCAL lcCertSerialNumber
LOCAL lcCertIssuerCN
LOCAL lcCertIssuerDN
LOCAL lcCertDigestAlgOid
LOCAL lcCertDigestAlgName
LOCAL lcContentType
LOCAL lcSigningTime
LOCAL lcMessageDigest
LOCAL lcSigningAlgOid
LOCAL lcSignerDigest
LOCAL loDt

lnSuccess = 0

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

* First load the .p7s file into a BinData object..
loBd = CreateObject('Chilkat.BinData')
lnSuccess = loBd.LoadFile("qa_data/p7s/sample.p7s")
IF (lnSuccess <> 1) THEN
    ? "Failed to load .p7s file."
    RELEASE loBd
    CANCEL
ENDIF

loCrypt = CreateObject('Chilkat.Crypt2')

* Assuming this is a signature that contains the original data that was signed..
lnSuccess = loCrypt.OpaqueVerifyBd(loBd)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loBd
    RELEASE loCrypt
    CANCEL
ENDIF

* Examine the last JSON data after signature verification..
loJson = CreateObject('Chilkat.JsonObject')
loCrypt.GetLastJsonData(loJson)

loJson.EmitCompact = 0
? loJson.Emit()

* Sample output...
* Go to http://tools.chilkat.io/jsonParse.cshtml
* and paste the JSON into the online form to generate JSON parsing code.

* {
*   "pkcs7": {
*     "verify": {
*       "digestAlgorithms": [
*         "sha256"
*       ],
*       "signerInfo": [
*         {
*           "cert": {
*             "serialNumber": "AAC5FC48C0FD8FBB",
*             "issuerCN": "AC ABCDEF RFB v5",
*             "issuerDN": "",
*             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
*             "digestAlgName": "SHA-256"
*           },
*           "contentType": "1.2.840.113549.1.7.1",
*           "signingTime": "180607195054Z",
*           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
*           "signingAlgOid": "1.2.840.113549.1.1.11",
*           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
*         },
*         {
*           "cert": {
*             "serialNumber": "324FB38ABD59723F",
*             "issuerCN": "AC ABCDEF RFB v5",
*             "issuerDN": "",
*             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
*             "digestAlgName": "SHA-256"
*           },
*           "contentType": "1.2.840.113549.1.7.1",
*           "signingTime": "180608182517Z",
*           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
*           "signingAlgOid": "1.2.840.113549.1.1.11",
*           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
*         }
*       ]
*     }
*   }
* }
* 

loDt = CreateObject('Chilkat.CkDateTime')

i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.digestAlgorithms")
DO WHILE i < lnCount_i
    loJson.I = i
    lcStrVal = loJson.StringOf("pkcs7.verify.digestAlgorithms[i]")
    i = i + 1
ENDDO
i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.signerInfo")
DO WHILE i < lnCount_i
    loJson.I = i
    lcCertSerialNumber = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
    lcCertIssuerCN = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
    lcCertIssuerDN = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.issuerDN")
    lcCertDigestAlgOid = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
    lcCertDigestAlgName = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
    lcContentType = loJson.StringOf("pkcs7.verify.signerInfo[i].contentType")
    lcSigningTime = loJson.StringOf("pkcs7.verify.signerInfo[i].signingTime")

    * The signingTime isin UTCTime format.
    * UTCTime values take the form of either "YYMMDDhhmm[ss]Z" or "YYMMDDhhmm[ss](+|-)hhmm"
    * Starting in Chilkat v9.5.0.77, the SetFromTimestamp method auto-recognizes the UTCTime format and parses it correctly.
    lnSuccess = loDt.SetFromTimestamp(lcSigningTime)
    * To get the signingTime in other date/time formats, look at the online reference documentation for CkDateTime.
    * There are numerous methods such as GetAsDateTime, GetAsIso8601, GetAsUnixTime, GetAsRfc822, etc.

    lcMessageDigest = loJson.StringOf("pkcs7.verify.signerInfo[i].messageDigest")
    lcSigningAlgOid = loJson.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    lcSignerDigest = loJson.StringOf("pkcs7.verify.signerInfo[i].signerDigest")
    i = i + 1
ENDDO

* println crypt.LastErrorText;
? "Success."

RELEASE loBd
RELEASE loCrypt
RELEASE loJson
RELEASE loDt