test HKDF with empty IKM

Add an extra EVP test that provides empty input key material.  It
currently fails, since we lose the information about "key present but
zero length" as we deserialize parameters in the provider.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11920)

diff --git a/test/evp_extra_test.c b/test/evp_extra_test.c
index 2ab4be89a36eaa00bc535e39d66a2de4cd5c6d62..e6a76a1fa61a69d115d9877e35a565f0c4c84ede 100644 (file)
--- a/test/evp_extra_test.c
+++ b/test/evp_extra_test.c
@@ -1246,6 +1246,47 @@ static int test_HKDF(void)
     return ret;
 }
 
+static int test_emptyikm_HKDF(void)
+{
+    EVP_PKEY_CTX *pctx;
+    unsigned char out[20];
+    size_t outlen;
+    int ret = 0;
+    unsigned char salt[] = "9876543210";
+    unsigned char key[] = "";
+    unsigned char info[] = "stringinfo";
+    const unsigned char expected[] = {
+        0x68, 0x81, 0xa5, 0x3e, 0x5b, 0x9c, 0x7b, 0x6f, 0x2e, 0xec, 0xc8, 0x47,
+        0x7c, 0xfa, 0x47, 0x35, 0x66, 0x82, 0x15, 0x30
+    };
+    size_t expectedlen = sizeof(expected);
+
+    if (!TEST_ptr(pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL)))
+        goto done;
+
+    outlen = sizeof(out);
+    memset(out, 0, outlen);
+
+    if (!TEST_int_gt(EVP_PKEY_derive_init(pctx), 0)
+            || !TEST_int_gt(EVP_PKEY_CTX_set_hkdf_md(pctx, EVP_sha256()), 0)
+            || !TEST_int_gt(EVP_PKEY_CTX_set1_hkdf_salt(pctx, salt,
+                                                        sizeof(salt) - 1), 0)
+            || !TEST_int_gt(EVP_PKEY_CTX_set1_hkdf_key(pctx, key,
+                                                       sizeof(key) - 1), 0)
+            || !TEST_int_gt(EVP_PKEY_CTX_add1_hkdf_info(pctx, info,
+                                                        sizeof(info) - 1), 0)
+            || !TEST_int_gt(EVP_PKEY_derive(pctx, out, &outlen), 0)
+            || !TEST_mem_eq(out, outlen, expected, expectedlen))
+        goto done;
+
+    ret = 1;
+
+ done:
+    EVP_PKEY_CTX_free(pctx);
+
+    return ret;
+}
+
 #ifndef OPENSSL_NO_EC
 static int test_X509_PUBKEY_inplace(void)
 {
@@ -1698,6 +1739,7 @@ int setup_tests(void)
     ADD_TEST(test_CMAC_keygen);
 #endif
     ADD_TEST(test_HKDF);
+    ADD_TEST(test_emptyikm_HKDF);
 #ifndef OPENSSL_NO_EC
     ADD_TEST(test_X509_PUBKEY_inplace);
     ADD_ALL_TESTS(test_invalide_ec_char2_pub_range_decode,