Add unit tests for weak key and key parity checks

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/16953)

(cherry picked from commit cc350c882218b1053a636d01eb36573b3e7b20c2)

1 files changed, 69 insertions, 0 deletions

diff --git a/test/destest.c b/test/destest.c
index ee5a70db27..e0c4b30f90 100644
--- a/test/destest.c
+++ b/test/destest.c
@@ -771,6 +771,73 @@ static int test_des_key_wrap(int idx)
     EVP_CIPHER_CTX_free(ctx);
     return res;
 }
+
+/*-
+ * Weak and semi weak keys as taken from
+ * %A D.W. Davies
+ * %A W.L. Price
+ * %T Security for Computer Networks
+ * %I John Wiley & Sons
+ * %D 1984
+ */
+static struct {
+    const DES_cblock key;
+    int expect;
+} weak_keys[] = {
+    /* weak keys */
+    {{0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01}, 1 },
+    {{0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE}, 1 },
+    {{0x1F, 0x1F, 0x1F, 0x1F, 0x0E, 0x0E, 0x0E, 0x0E}, 1 },
+    {{0xE0, 0xE0, 0xE0, 0xE0, 0xF1, 0xF1, 0xF1, 0xF1}, 1 },
+    /* semi-weak keys */
+    {{0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE}, 1 },
+    {{0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01}, 1 },
+    {{0x1F, 0xE0, 0x1F, 0xE0, 0x0E, 0xF1, 0x0E, 0xF1}, 1 },
+    {{0xE0, 0x1F, 0xE0, 0x1F, 0xF1, 0x0E, 0xF1, 0x0E}, 1 },
+    {{0x01, 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1}, 1 },
+    {{0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1, 0x01}, 1 },
+    {{0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E, 0xFE}, 1 },
+    {{0xFE, 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E}, 1 },
+    {{0x01, 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E}, 1 },
+    {{0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E, 0x01}, 1 },
+    {{0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE}, 1 },
+    {{0xFE, 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1}, 1 },
+    /* good key */
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF}, 0 }
+};
+
+static int test_des_weak_keys(int n)
+{
+    const_DES_cblock *key = (unsigned char (*)[8])weak_keys[n].key;
+
+    return TEST_int_eq(DES_is_weak_key(key), weak_keys[n].expect);
+}
+
+static struct {
+    const DES_cblock key;
+    int expect;
+} bad_parity_keys[] = {
+    {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, 0 },
+    {{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 0 },
+    /* Perturb each byte in turn to create even parity */
+    {{0x48, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE8, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5C, 0x6D, 0x4C, 0xA2, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5D, 0x7D, 0x4C, 0xA2, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x5C, 0xA2, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA3, 0x29, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x39, 0xBF}, 0 },
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBE}, 0 },
+    /* Odd parity version of above */
+    {{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF}, 1 }
+};
+
+static int test_des_check_bad_parity(int n)
+{
+    const_DES_cblock *key = (unsigned char (*)[8])bad_parity_keys[n].key;
+
+    return TEST_int_eq(DES_check_key_parity(key), bad_parity_keys[n].expect);
+}
 #endif
 
 int setup_tests(void)
@@ -797,6 +864,8 @@ int setup_tests(void)
     ADD_ALL_TESTS(test_input_align, 4);
     ADD_ALL_TESTS(test_output_align, 4);
     ADD_ALL_TESTS(test_des_key_wrap, OSSL_NELEM(test_des_key_wrap_sizes));
+    ADD_ALL_TESTS(test_des_weak_keys, OSSL_NELEM(weak_keys));
+    ADD_ALL_TESTS(test_des_check_bad_parity, OSSL_NELEM(bad_parity_keys));
 #endif
     return 1;
 }