sys-apps/shadow: fix SHA hash behavior with USE=-pam

Closes: https://bugs.gentoo.org/808195
Signed-off-by: Mike Gilbert <floppym@gentoo.org>

2 files changed, 58 insertions, 0 deletions

diff --git a/sys-apps/shadow/files/shadow-4.9-SHA-rounds.patch b/sys-apps/shadow/files/shadow-4.9-SHA-rounds.patch
new file mode 100644
index 000000000000..05be7adc1b19
--- /dev/null
+++ b/sys-apps/shadow/files/shadow-4.9-SHA-rounds.patch
@@ -0,0 +1,57 @@
+From 234e8fa7b134d1ebabfdad980a3ae5b63c046c62 Mon Sep 17 00:00:00 2001
+From: Mike Gilbert <floppym@gentoo.org>
+Date: Sat, 14 Aug 2021 13:24:34 -0400
+Subject: [PATCH] libmisc: fix default value in SHA_get_salt_rounds()
+
+If SHA_CRYPT_MIN_ROUNDS and SHA_CRYPT_MAX_ROUNDS are both unspecified,
+use SHA_ROUNDS_DEFAULT.
+
+Previously, the code fell through, calling shadow_random(-1, -1). This
+ultimately set rounds = (unsigned long) -1, which ends up being a very
+large number! This then got capped to SHA_ROUNDS_MAX later in the
+function.
+
+The new behavior matches BCRYPT_get_salt_rounds().
+
+Bug: https://bugs.gentoo.org/808195
+Fixes: https://github.com/shadow-maint/shadow/issues/393
+---
+ libmisc/salt.c | 21 +++++++++++----------
+ 1 file changed, 11 insertions(+), 10 deletions(-)
+
+diff --git a/libmisc/salt.c b/libmisc/salt.c
+index 91d528fd..30eefb9c 100644
+--- a/libmisc/salt.c
++++ b/libmisc/salt.c
+@@ -223,20 +223,21 @@ static /*@observer@*/const unsigned long SHA_get_salt_rounds (/*@null@*/int *pre
+ 		if ((-1 == min_rounds) && (-1 == max_rounds)) {
+ 			rounds = SHA_ROUNDS_DEFAULT;
+ 		}
++		else {
++			if (-1 == min_rounds) {
++				min_rounds = max_rounds;
++			}
+ 
+-		if (-1 == min_rounds) {
+-			min_rounds = max_rounds;
+-		}
++			if (-1 == max_rounds) {
++				max_rounds = min_rounds;
++			}
+ 
+-		if (-1 == max_rounds) {
+-			max_rounds = min_rounds;
+-		}
++			if (min_rounds > max_rounds) {
++				max_rounds = min_rounds;
++			}
+ 
+-		if (min_rounds > max_rounds) {
+-			max_rounds = min_rounds;
++			rounds = (unsigned long) shadow_random (min_rounds, max_rounds);
+ 		}
+-
+-		rounds = (unsigned long) shadow_random (min_rounds, max_rounds);
+ 	} else if (0 == *prefered_rounds) {
+ 		rounds = SHA_ROUNDS_DEFAULT;
+ 	} else {
diff --git a/sys-apps/shadow/shadow-4.9-r1.ebuild b/sys-apps/shadow/shadow-4.9-r2.ebuild
index 545c8cb652b1..8ce94660aad6 100644
--- a/sys-apps/shadow/shadow-4.9-r1.ebuild
+++ b/sys-apps/shadow/shadow-4.9-r2.ebuild
@@ -57,6 +57,7 @@ PATCHES=(
 	"${FILESDIR}/${P}-libsubid_pam_linking.patch"
 	"${FILESDIR}/${P}-libsubid_oot_build.patch"
 	"${FILESDIR}/shadow-4.9-libcrack.patch"
+	"${FILESDIR}/shadow-4.9-SHA-rounds.patch"
 )
 
 src_prepare() {