From 9b25b05d7aa4a816cfa06f4750cb600cb94e27b7 Mon Sep 17 00:00:00 2001
From: Stef Walter <stef@memberwebs.com>
Date: Wed, 18 Nov 2009 17:30:31 +0000
Subject: Add support for checking AES keys and DH derive

---
 src/dh.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)

(limited to 'src/dh.c')

diff --git a/src/dh.c b/src/dh.c
index 3325caa..7016498 100644
--- a/src/dh.c
+++ b/src/dh.c
@@ -7,6 +7,137 @@
 
 #include <openssl/dh.h>
 
+static int
+compare_secret_values (void *one, size_t n_one, void *two, size_t n_two)
+{
+	if (n_one > n_two)
+		return memcmp (one + (n_one - n_two), two, n_two);
+	else
+		return memcmp (one, two + (n_two - n_one), n_one);
+}
+
+static DH*
+generate_peer_dh (CK_SESSION_HANDLE session, CK_OBJECT_HANDLE key)
+{
+	CK_ATTRIBUTE attrs[2];
+	CK_BYTE prime[16384];
+	CK_BYTE base[1024];
+	DH *dh;
+
+	attrs[0].type = CKA_PRIME;
+	attrs[0].ulValueLen = sizeof (prime);
+	attrs[0].pValue = prime;
+
+	attrs[1].type = CKA_BASE;
+	attrs[1].ulValueLen = sizeof (base);
+	attrs[1].pValue = base;
+
+	if (!p11t_object_get (session, key, attrs, 2))
+		return NULL;
+
+	if(attrs[0].ulValueLen == CK_INVALID ||
+	   attrs[1].ulValueLen == CK_INVALID)
+		return NULL;
+
+	dh = DH_new ();
+	dh->p = BN_bin2bn (prime, attrs[0].ulValueLen, NULL);
+	dh->g = BN_bin2bn (base, attrs[1].ulValueLen, NULL);
+	assert(dh && dh->p && dh->g);
+
+	if (!DH_generate_key (dh)) {
+		DH_free (dh);
+		return NULL;
+	}
+
+	return dh;
+}
+
+int
+test_dh_private_derive (CK_SESSION_HANDLE session, CK_OBJECT_HANDLE pub, CK_OBJECT_HANDLE prv)
+{
+	CK_ATTRIBUTE attrs[3];
+	CK_KEY_TYPE key_type = CKK_AES;
+	CK_OBJECT_CLASS klass = CKO_SECRET_KEY;
+	CK_BYTE buffer[16384];
+	CK_BYTE value[16384];
+	CK_OBJECT_HANDLE derived;
+	CK_MECHANISM mech;
+	BIGNUM *our_pub;
+	CK_RV rv;
+	DH *dh;
+
+	P11T_SECTION("C_DeriveKey");
+
+	/* Setup peer's DH */
+	dh = generate_peer_dh (session, pub);
+	if (dh == NULL)
+		p11t_check_warn ("Couldn't retrieve DH parameters from DH pub key");
+
+	/* Dig out our public key */
+	attrs[0].type = CKA_VALUE;
+	attrs[0].pValue = value;
+	attrs[0].ulValueLen = sizeof (value);
+	if (p11t_object_get (session, pub, attrs, 1)) {
+		our_pub = BN_bin2bn (value, attrs[0].ulValueLen, NULL);
+	} else {
+		p11t_check_warn ("Couldn't retrieve DH public value from DH pub key");
+		our_pub = NULL;
+	}
+
+	mech.mechanism = CKM_DH_PKCS_DERIVE;
+	mech.pParameter = buffer;
+	mech.ulParameterLen = BN_num_bytes (dh->pub_key);
+	BN_bn2bin (dh->pub_key, buffer);
+
+	/* TODO: How can we know this key type is supported? */
+	attrs[0].type = CKA_KEY_TYPE;
+	attrs[0].pValue = &key_type;
+	attrs[0].ulValueLen = sizeof (key_type);
+
+	attrs[1].type = CKA_CLASS;
+	attrs[1].pValue = &klass;
+	attrs[1].ulValueLen = sizeof (klass);
+
+	rv = (p11t_module_funcs->C_DeriveKey) (session, &mech, prv, attrs, 2, &derived);
+	P11T_CHECK_RV ("CKM_DH_PKCS_DERIVE", rv, CKR_OK);
+
+	/* Compare to our generated key */
+	attrs[0].type = CKA_VALUE;
+	attrs[0].pValue = value;
+	attrs[0].ulValueLen = sizeof (value);
+	if (p11t_object_get (session, derived, attrs, 1) && attrs[0].ulValueLen != (CK_ULONG)-1 &&
+	    dh != NULL && our_pub != NULL) {
+		if (!DH_compute_key (buffer, our_pub, dh))
+			assert (0);
+		if (compare_secret_values (value, attrs[0].ulValueLen, buffer, DH_size (dh)) != 0)
+			P11T_CHECK_FAIL_MSG ("CKM_DH_PKCS_DERIVE", "Derived key has wrong secret value");
+	}
+
+	BN_free (our_pub);
+	DH_free (dh);
+
+	return p11t_key_test (session, derived, CKO_SECRET_KEY);
+}
+
+int
+p11t_dh_test_key_pair (CK_SESSION_HANDLE session, CK_OBJECT_HANDLE pub, CK_OBJECT_HANDLE prv)
+{
+	CK_ULONG mechanisms[128];
+	CK_ATTRIBUTE attr = { CKA_ALLOWED_MECHANISMS, mechanisms, sizeof (mechanisms) };
+	CK_ULONG i;
+
+	/* Let's see if it support derivation */
+	if (!p11t_object_get (session, prv, &attr, 1))
+		return STOP;
+
+	for (i = 0; i < attr.ulValueLen / sizeof (CK_ULONG); ++i) {
+		if (mechanisms[i] == CKM_DH_PKCS_DERIVE)
+			test_dh_private_derive (session, pub, prv);
+	}
+
+	return CONTINUE;
+}
+
 static void
 test_dh_key_pair_gen (CK_SLOT_ID slot, CK_MECHANISM_TYPE mech, CK_MECHANISM_INFO_PTR info)
 {
-- 
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