Summary

Upgading from an Older Version of FLEXlm, SIGN and SIGN2

Synopsis

The existence of SIGN and SIGN2 keywords has caused some confusion in the past. This article attempts to explain why they exist and how they should be used.

Discussion

In older versions of FLEXlm, licenses were authenticated by a 12 character license key. The key used to generate this signature was derived from 2 ENCRYPTION_SEED definitions made in the customer's lm_code.h file. In an effort to offer improved security, Macrovision added a public key signature system to FLEXlm. Customers who wished to take advantage of this system did so by adding 2 extra ENCRYPTION_SEED definitions to their lm_code.h files, which were then used to seed a random number generator used by the key pair generating algorithm. Customers then added a SIGN= statement to a license file feature line to cause lc_crypstr() to generate a public key signature for the line.

In a later version of the product, Flexera Software made some improvements to their public key signature system, however, in order to allow backward compatibility with applications linked with previous versions of the library, the older system was retained as well. In order to seed the random number generator used by the key pair generator for the new system, 3 LM_SEED definitions were introduced into the lm_code.h file and since there were now 2 possible signatures an extra keyword for license files was introduced: SIGN2 .

When the FLEXlm toolkit is being built, 4 ENCRYPTION_SEED definitions as well as the LM_SEED definitions cause the kit to be built so that SIGN= is seen as the original public key signature system and SIGN2= the new improved system. Note that this is the case even if ENCRYPTION_SEEDs 3 and 4 and defined as 0.

When the FLEXlm toolkit is being built with either 2 ENCRPTION_SEED definitions or no ENCRYPTION_SEED definitions? Which indicate that the old public key signature system is not being used - SIGN= is seen as the new improved system. SIGN2= is not needed.