Unicode C

Check if a MIME Entity is Signed (S/MIME)

Demonstrates the Chilkat Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper, including detached multipart/signed and opaque forms. It takes no arguments.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: Before verifying a signature you need to know one is present, and this is the check. A signed S/MIME message comes in two shapes — detached (multipart/signed, signature alongside the content) and opaque (application/pkcs7-mime, content wrapped inside the signature) — and this recognizes both. Follow a true result with Verify.

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Unicode C

#include <C_CkMimeW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMimeW mime;

    success = FALSE;

    //  Demonstrates the Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper.  It takes no arguments.

    mime = CkMimeW_Create();
    success = CkMimeW_LoadMimeFile(mime,L"qa_data/signed.eml");
    if (success == FALSE) {
        wprintf(L"%s\n",CkMimeW_lastErrorText(mime));
        CkMimeW_Dispose(mime);
        return;
    }

    if (CkMimeW_IsSigned(mime)) {
        wprintf(L"This is a signed S/MIME message.\n");
    }
    else {
        wprintf(L"This is not a signed S/MIME message.\n");
    }



    CkMimeW_Dispose(mime);

    }