(Tcl) Verify and Unwrap S/MIME, and get Information about CMS Signature

Demonstrates calling the Verify method to verify and unwrap S/MIME. The MIME is restored to the original structure that it would have originally had prior to signing. The Verify method works with both detached signatures, as well as opaque/attached signatures.

Calls LastJsonData to get information about the signature(s) that were verified.

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load ./chilkat.dll

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

set mime [new_CkMime]

# Load the signed MIME from a file...
set success [CkMime_LoadMimeFile $mime "qa_data/mime/detached_sig.eml"]
if {$success == 0} then {
    puts [CkMime_lastErrorText $mime]
    delete_CkMime $mime
    exit
}

# Verify the S/MIME and restore the MIME
# to the structure/content it had prior to signing.
set verified [CkMime_Verify $mime]
if {$verified == 0} then {
    puts [CkMime_lastErrorText $mime]
    delete_CkMime $mime
    exit
}

# Examine the details of what was verified.
# json is a CkJsonObject
set json [CkMime_LastJsonData $mime]
CkJsonObject_put_EmitCompact $json 0
puts [CkJsonObject_emit $json]

# The code to parse the following JSON (i.e. extract desired information) is shown below..

# {
#   "pkcs7": {
#     "verify": {
#       "certs": [
#         {
#           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
#           "serial": "0702A21A85B84B659E180A6EE6F5A365"
#         },
#         {
#           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
#           "serial": "008B5B75568454850B00CFAF3848CEB1A4"
#         },
#         {
#           "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
#           "serial": "619C55C32FF6BD1A7B7E0330D21C8F3C"
#         }
#       ],
#       "digestAlgorithms": [
#         "sha1"
#       ],
#       "signerInfo": [
#         {
#           "cert": {
#             "serialNumber": "619C55C32FF6BD1A7B7E0330D21C8F3C",
#             "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
#             "digestAlgOid": "1.3.14.3.2.26",
#             "digestAlgName": "SHA1"
#           },
#           "contentType": "1.2.840.113549.1.7.1",
#           "signingTime": "160428055000Z",
#           "messageDigest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY=",
#           "signingAlgOid": "1.2.840.113549.1.1.1",
#           "signingAlgName": "RSA-PKCSV-1_5",
#           "authAttr": {
#             "1.2.840.113549.1.9.3": {
#               "name": "contentType",
#               "oid": "1.2.840.113549.1.7.1"
#             },
#             "1.2.840.113549.1.9.5": {
#               "name": "signingTime",
#               "utctime": "160428055000Z"
#             },
#             "1.2.840.113549.1.9.4": {
#               "name": "messageDigest",
#               "digest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY="
#             },
#             "1.2.840.113549.1.9.15": {
#               "der": "MFAwCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIAgDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKA=="
#             },
#             "1.3.6.1.4.1.311.16.4": {
#               "der": "MIG7MIG...7fgMw0hyPPA=="
#             }
#           }
#         }
#       ]
#     }
#   }
# }

# Use this online tool to generate parsing code from sample JSON: 
# Generate Parsing Code from JSON

set signingTime [new_CkDtObj]

set authAttrSigningTimeUtctime [new_CkDtObj]

set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.certs"]
while {$i < $count_i} {
    CkJsonObject_put_I $json $i
    set issuerCN [CkJsonObject_stringOf $json "pkcs7.verify.certs[i].issuerCN"]
    set serial [CkJsonObject_stringOf $json "pkcs7.verify.certs[i].serial"]
    set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.digestAlgorithms"]
while {$i < $count_i} {
    CkJsonObject_put_I $json $i
    set strVal [CkJsonObject_stringOf $json "pkcs7.verify.digestAlgorithms[i]"]
    set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.signerInfo"]
while {$i < $count_i} {
    CkJsonObject_put_I $json $i
    set certSerialNumber [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.serialNumber"]
    set certIssuerCN [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.issuerCN"]
    set certDigestAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.digestAlgOid"]
    set certDigestAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.digestAlgName"]
    set contentType [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].contentType"]
    CkJsonObject_DtOf $json "pkcs7.verify.signerInfo[i].signingTime" 0 $signingTime
    set messageDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].messageDigest"]
    set signingAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].signingAlgOid"]
    set signingAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].signingAlgName"]
    set authAttrContentTypeName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".name"]
    set authAttrContentTypeOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".oid"]
    set authAttrSigningTimeName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".name"]
    CkJsonObject_DtOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".utctime" 0 $authAttrSigningTimeUtctime
    set authAttrMessageDigestName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".name"]
    set authAttrMessageDigestDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".digest"]
    set authAttr1_2_840_113549_1_9_15Der [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.15\".der"]
    set authAttr1_3_6_1_4_1_311_16_4Der [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.3.6.1.4.1.311.16.4\".der"]
    set i [expr $i + 1]
}

delete_CkJsonObject $json


delete_CkMime $mime
delete_CkDtObj $signingTime
delete_CkDtObj $authAttrSigningTimeUtctime