From b717bfc043ecaa27f65dfebae65177590e2102a6 Mon Sep 17 00:00:00 2001 From: Sam Hartman Date: Wed, 21 Nov 2001 21:28:14 +0000 Subject: [PATCH] On fork, perturb the PRNG stream in the child git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@14016 dc483132-0cff-0310-8789-dd5450dbe970 --- src/lib/crypto/yarrow/ChangeLog | 4 ++++ src/lib/crypto/yarrow/yarrow.c | 16 +++++++++++++--- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/src/lib/crypto/yarrow/ChangeLog b/src/lib/crypto/yarrow/ChangeLog index 22413ecfd..d5f52f577 100644 --- a/src/lib/crypto/yarrow/ChangeLog +++ b/src/lib/crypto/yarrow/ChangeLog @@ -1,3 +1,7 @@ +2001-11-21 Sam Hartman + + * yarrow.c (Yarrow_detect_fork): Reseed the number generator including the fork rather than throwing away state. + 2001-11-19 Sam Hartman * yhash.h: Work around sha1 implementation using host byte order diff --git a/src/lib/crypto/yarrow/yarrow.c b/src/lib/crypto/yarrow/yarrow.c index e3e26f1cb..b4e5a218e 100644 --- a/src/lib/crypto/yarrow/yarrow.c +++ b/src/lib/crypto/yarrow/yarrow.c @@ -121,14 +121,24 @@ static void krb5int_yarrow_init_Limits(Yarrow_CTX* y) static int Yarrow_detect_fork(Yarrow_CTX *y) { + pid_t newpid; EXCEP_DECL; /* this does not work for multi-threaded apps if threads have different * pids */ - if ( y->pid != getpid() ) + newpid = getpid(); + if ( y->pid != newpid ) { - TRY( krb5int_yarrow_init( y, y->entropyfile ) ); - } + /* we input the pid twice, so it will get into the fast pool at least once + * Then we reseed. This doesn't really increase entropy, but does make the + * streams distinct assuming we already have good entropy*/ + y->pid = newpid; + TRY (krb5int_yarrow_input (y, 0, &newpid, + sizeof (newpid), 0)); + TRY (krb5int_yarrow_input (y, 0, &newpid, + sizeof (newpid), 0)); + TRY (krb5int_yarrow_reseed (y, YARROW_FAST_POOL)); + } CATCH: EXCEP_RET; -- 2.26.2