You can see the code affected by the PURIFY define here:- https://github.com/joyent/node/search?q=PURIFY https://github.com/joyent/node/search?q=PURIFY Specif

You can see the code affected by the PURIFY define here:- https://github.com/joyent/node/search?q=PURIFY https://github.com/joyent/node/search?q=PURIFY Specifically it is these two files:- https://github.com/joyent/node/blob/5fcd6e40385f45bc9091689337a7ab531861ba19/deps/openssl/openssl/crypto/rand/randfile.c https://github.com/joyent/node/blob/5fcd6e40385f45bc90916893... https://github.com/joyent/node/blob/c20b209dbb7e2f3ac8a75a8750bc4205d43952c8/deps/openssl/openssl/crypto/rand/md_rand.c https://github.com/joyent/node/blob/c20b209dbb7e2f3ac8a75a87... In the first it just does a memset of the buffer so that the values are not unset. In the second it doesn't use a (possibly only partially filled) buffer as a source of entropy.