test/recipes/test_genrsa.t : don't fail because of size limit changes

There is a test to check that 'genrsa' doesn't accept absurdly low
number of bits.  Apart from that, this test is designed to check the
working functionality of 'openssl genrsa', so instead of having a hard
coded lower limit on the size key, let's figure out what it is.

Partially fixes #5751

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/5754)

diff --git a/test/recipes/15-test_genrsa.t b/test/recipes/15-test_genrsa.t
index cc74e303f115a36d44a356cdb7b9543f832604d8..270c2ccb5bfb646c8a5cf149fc424243da8c0a3d 100644 (file)
--- a/test/recipes/15-test_genrsa.t
+++ b/test/recipes/15-test_genrsa.t
@@ -18,9 +18,38 @@ setup("test_genrsa");
 
 plan tests => 5;
 
+# We want to know that an absurdly small number of bits isn't support
 is(run(app([ 'openssl', 'genrsa', '-3', '-out', 'genrsatest.pem', '8'])), 0, "genrsa -3 8");
-ok(run(app([ 'openssl', 'genrsa', '-3', '-out', 'genrsatest.pem', '16'])), "genrsa -3 16");
-ok(run(app([ 'openssl', 'rsa', '-check', '-in', 'genrsatest.pem', '-noout'])), "rsa -check");
-ok(run(app([ 'openssl', 'genrsa', '-f4', '-out', 'genrsatest.pem', '16'])), "genrsa -f4 16");
-ok(run(app([ 'openssl', 'rsa', '-check', '-in', 'genrsatest.pem', '-noout'])), "rsa -check");
+
+# Depending on the shared library, we might have different lower limits.
+# Let's find it!  This is a simple binary search
+# ------------------------------------------------------------
+# NOTE: $good may need an update in the future
+# ------------------------------------------------------------
+note "Looking for lowest amount of bits";
+my $bad = 3;                    # Log2 of number of bits (2 << 3  == 8)
+my $good = 11;                  # Log2 of number of bits (2 << 11 == 2048)
+while ($good > $bad + 1) {
+    my $checked = int(($good + $bad + 1) / 2);
+    if (run(app([ 'openssl', 'genrsa', '-3', '-out', 'genrsatest.pem',
+                  2 ** $checked ], stderr => undef))) {
+        note 2 ** $checked, " bits is good";
+        $good = $checked;
+    } else {
+        note 2 ** $checked, " bits is bad";
+        $bad = $checked;
+    }
+}
+$good++ if $good == $bad;
+$good = 2 ** $good;
+note "Found lowest allowed amount of bits to be $good";
+
+ok(run(app([ 'openssl', 'genrsa', '-3', '-out', 'genrsatest.pem', $good ])),
+   "genrsa -3 $good");
+ok(run(app([ 'openssl', 'rsa', '-check', '-in', 'genrsatest.pem', '-noout' ])),
+   "rsa -check");
+ok(run(app([ 'openssl', 'genrsa', '-f4', '-out', 'genrsatest.pem', $good ])),
+   "genrsa -f4 $good");
+ok(run(app([ 'openssl', 'rsa', '-check', '-in', 'genrsatest.pem', '-noout' ])),
+   "rsa -check");
 unlink 'genrsatest.pem';