Digital Signature Formats

[Former Member]

Hi Experts,

I am having some basic doubts in Signature Formats. We have 3 types of signature formats namely, SsfDataPKCS7, SsfDataSMIME and SsfDataXML using Java. What is the difference between these 3 signature formats? At what situation, we will use these formats? I have searched in SDN, no clue.

Please help me in this regard.

Regards,

Venkatesh. K

[Former Member]

Hi,

Check the links:

/people/varadharajan.krishnasamy/blog/2007/05/11/how-to-use-digital-certificates-for-signing-encrypting-messages-in-xi

https://www.sdn.sap.com/irj/sdn/advancedsearch?cat=sdn_weblog&query=creatingaDigitalsignature+&adv=false&sortby=cm_rnd_rankvalue

Thanks

Soumya

[former_member193376]

Hi

ISsfData

There is a central interface IssfData that contains all basic methods such as sign, verify, encrypt, and decrypt. This interface is implemented for the different classes (SsfDataPKCS7, SsfDataSMIME, SsfDataXML) that provide specific methods for each format.

This interface is the central interface used for the cryptographic functions. Its underlying classes specify the data format used, for example, SsfDataPKCS7, SsfDataSMIME and SsfDataXML.

Available methods: sign, verify, encrypt, decrypt, writeTo

SsfDataPKCS7

This class is derived from the interface ISsfData. It provides specific methods for using the PKCS#7 data format

SsfDataSMIME

This class is also derived from the interface ISsfData. It provides specific methods for using S/MIME.

SsfDataXML

This class is also derived from the interface ISsfData. It provides the specific methods for using XML

Thanks

Saiyog

[Former Member]

Hi Venkatesh,

If the SsfSMIME sign method returns false, it means that for some reason it was unable to sign the (MIME) data, and because of that is plenty normal that the verify method throws the exception SsfInvalidDataException: No signed MIME data provided.

Check the trace logs (in Visual Administrator or SAP Netweaver Administrator) if you see any error.

Regards,

Alexandre

[Former Member]

Hi Venkatesh,

The classes SsfDataPKCS7, SsfDataSMIME anda SffDataXML represent different data formats to be digitally signed, verified, encrypted or decrypted. Consequentelly each one use different security formats to do so, namelly PKCS#7, S/MIME and XMLSignature/Encryption respectively.

You should use SsfDataXML class to digital sign a XML message using the standard XMLSignature and the SsfDataSMIME class to sign for instance a e-mail message using the S/MIME security format for instance.

The PKCS#7 is the basis for the S/MIME specification.

Follow the [link|http://www.rsa.com/rsalabs/node.asp?id=2129] for more info about PKCS#7.

Regards,

Alexandre

[Former Member]

Hi Experts,

I have a problem with Digital Signature based on SsfDataSMIME class. When I pass the InputStream as argument to the SsfDataSMIME, While signing it returns false and in verifying it showing the Exception as:

com.sap.security.core.server.ssf.SsfInvalidDataException: No signed MIME data provided. What Could be the problem?

Do I need to convert the inputstream as mimemessage? If so, guide me how to convert the inputstream to mimemessage?

Any help would be appreciated.

Regards,

Venkatesh. K

[Former Member]

Hi Venkatesh,

I can provide you some information which may usefull for you.

http://help.sap.com/saphelp_nw04s/helpdata/en/18/6197044da2a745a4d588da33e0facf/frameset.htm

https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/7f52fd28-0b01-0010-afb0-cc7...

Thanks,

Bala

[Former Member]

Hi,

You can find a short description and usage types of those 3 classes here :

http://help.sap.com/saphelp_nw04/helpdata/en/18/6197044da2a745a4d588da33e0facf/content.htm

Hope this helps

Chris