From 76754353988703719623717de9d1252434b69507 Mon Sep 17 00:00:00 2001
From: Huaxin Lu <luhuaxin1@huawei.com>
Date: Sun, 2 Oct 2022 19:05:00 +0800
Subject: [PATCH 3/4] nss add implement of SM2 signature algorithm

Co-authored-by: godcansee <liu332084460@foxmail.com>
Signed-off-by: Huaxin Lu <luhuaxin1@huawei.com>
---
 lib/freebl/sm2.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++
 lib/freebl/sm2.h |  16 ++++++
 2 files changed, 150 insertions(+)
 create mode 100644 lib/freebl/sm2.c
 create mode 100644 lib/freebl/sm2.h

diff --git a/lib/freebl/sm2.c b/lib/freebl/sm2.c
new file mode 100644
index 0000000..f80b8ca
--- /dev/null
+++ b/lib/freebl/sm2.c
@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifdef FREEBL_NO_DEPEND
+#include "stubs.h"
+#endif
+
+#include "blapi.h"
+#include "blapii.h"
+#include "prerr.h"
+#include "secerr.h"
+#include "secmpi.h"
+#include "secitem.h"
+#include "ecl.h"
+
+SECStatus
+SM2_SignDigestWithSeed(ECPrivateKey *key, SECItem *signature,
+                       const SECItem *digest, const unsigned char *kb, const int kblen)
+{
+    SECStatus rv = SECFailure;
+    mp_int e, k, x1, y1, r, n, dA, tmp, s;
+    mp_err err = MP_OKAY;
+    ECParams *ecParams;
+    ECGroup *group;
+    SECItem kGpoint = { siBuffer, NULL, 0 };
+    mp_size olen;
+
+    if (!key || !signature || !signature->data || !digest || !kb || (kblen < 0)) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return SECFailure;
+    }
+
+    ecParams = &(key->ecParams);
+    olen = ecParams->order.len;
+    if (signature->len < 2 * olen) {
+        PORT_SetError(SEC_ERROR_OUTPUT_LEN);
+        return SECFailure;
+    }
+
+    CHECK_MPI_OK(mp_init(&e));
+    CHECK_MPI_OK(mp_init(&k));
+    CHECK_MPI_OK(mp_init(&x1));
+    CHECK_MPI_OK(mp_init(&y1));
+    CHECK_MPI_OK(mp_init(&r));
+    CHECK_MPI_OK(mp_init(&n));
+    CHECK_MPI_OK(mp_init(&dA));
+    CHECK_MPI_OK(mp_init(&tmp));
+    CHECK_MPI_OK(mp_init(&s));
+    CHECK_MPI_OK(mp_init(&tmp));
+    CHECK_MPI_OK(mp_init(&s));
+
+    SECITEM_TO_MPINT(key->privateValue, &dA);
+    SECITEM_TO_MPINT(*digest, &e);
+    SECITEM_TO_MPINT(ecParams->order, &n);
+
+    CHECK_MPI_OK(mp_read_unsigned_octets(&k, kb, kblen));
+
+    /* Make sure k is in the interval [1, n-1] */
+    if ((mp_cmp_z(&k) <= 0) || (mp_cmp(&k, &n) >= 0)) {
+        PORT_SetError(SEC_ERROR_NEED_RANDOM);
+        goto cleanup;
+    }
+
+    /* (x1, y1) = [k]G */
+    group = ECGroup_fromName(ecParams->name);
+    if (!group)
+        goto cleanup;
+
+    kGpoint.len = EC_GetPointSize(ecParams);
+    kGpoint.data = PORT_Alloc(kGpoint.len);
+    if (kGpoint.data == NULL)
+        goto cleanup;
+
+    CHECK_MPI_OK(ECPoints_mul(group, &k, NULL, NULL, NULL, &x1, &y1));
+
+    /* r = (e + x1) mod n */
+    CHECK_MPI_OK(mp_addmod(&e, &x1, &n, &r));
+
+    /* r != 0 */
+    if (mp_cmp_z(&r) == 0) {
+        PORT_SetError(SEC_ERROR_NEED_RANDOM);
+        goto cleanup;
+    }
+
+    /* r + k != n */
+    CHECK_MPI_OK(mp_add(&r, &k, &tmp));
+    if (mp_cmp(&tmp, &n) == 0) {
+        PORT_SetError(SEC_ERROR_NEED_RANDOM);
+        goto cleanup;
+    }
+
+    /* s = ((d + 1)^-1 * (k - r * dA)) mod n */
+    CHECK_MPI_OK(mp_add_d(&dA, 1, &tmp));
+    CHECK_MPI_OK(mp_mod (&tmp, &n, &s));
+    CHECK_MPI_OK(mp_invmod (&s, &n, &s));
+    CHECK_MPI_OK(mp_mulmod (&r, &dA, &n, &tmp));
+    CHECK_MPI_OK(mp_submod (&k, &tmp, &n, &tmp));
+    CHECK_MPI_OK(mp_mulmod (&s, &tmp, &n, &s));
+
+    /* s != 0 */
+    if (mp_cmp_z(&s) == 0) {
+        PORT_SetError(SEC_ERROR_NEED_RANDOM);
+        goto cleanup;
+    }
+
+    CHECK_MPI_OK(mp_to_fixlen_octets(&r, signature->data, olen));
+    CHECK_MPI_OK(mp_to_fixlen_octets(&s, signature->data + olen, olen));
+
+    signature->len = 2 * olen;
+    rv = SECSuccess;
+    err = MP_OKAY;
+
+cleanup:
+    mp_clear(&e);
+    mp_clear(&k);
+    mp_clear(&x1);
+    mp_clear(&y1);
+    mp_clear(&r);
+    mp_clear(&n);
+    mp_clear(&dA);
+    mp_clear(&tmp);
+    mp_clear(&s);
+
+    if (kGpoint.data)
+        PORT_ZFree(kGpoint.data, kGpoint.len);
+
+    if (err) {
+        MP_TO_SEC_ERROR(err);
+        rv = SECFailure;
+    }
+
+    return rv;
+}
diff --git a/lib/freebl/sm2.h b/lib/freebl/sm2.h
new file mode 100644
index 0000000..0e2072c
--- /dev/null
+++ b/lib/freebl/sm2.h
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef _SM2_H_
+#define _SM2_H_
+
+
+#include <blapit.h>
+
+SECStatus
+SM2_SignDigestWithSeed(ECPrivateKey *key, SECItem *signature,
+                       const SECItem *digest, const unsigned char *kb, const int kblen);
+
+#endif
+
-- 
2.33.0