From 208e5687ff2e48622e28d8888ce5444a54353bbd Mon Sep 17 00:00:00 2001
From: Jouni Malinen <jouni@codeaurora.org>
Date: Tue, 27 Aug 2019 16:33:15 +0300
Subject: [PATCH 1/4] crypto: Add more bignum/EC helper functions

These are needed for implementing SAE hash-to-element.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
---
 src/crypto/crypto.h         | 45 ++++++++++++++++++++++
 src/crypto/crypto_openssl.c | 94 +++++++++++++++++++++++++++++++++++++++++++++
 src/crypto/crypto_wolfssl.c | 66 +++++++++++++++++++++++++++++++
 3 files changed, 205 insertions(+)

diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h
index bdc3ba6..0bc9df4 100644
--- a/src/crypto/crypto.h
+++ b/src/crypto/crypto.h
@@ -508,6 +508,13 @@ struct crypto_bignum * crypto_bignum_init(void);
 struct crypto_bignum * crypto_bignum_init_set(const u8 *buf, size_t len);
 
 /**
+ * crypto_bignum_init_set - Allocate memory for bignum and set the value (uint)
+ * @val: Value to set
+ * Returns: Pointer to allocated bignum or %NULL on failure
+ */
+struct crypto_bignum * crypto_bignum_init_uint(unsigned int val);
+
+/**
  * crypto_bignum_deinit - Free bignum
  * @n: Bignum from crypto_bignum_init() or crypto_bignum_init_set()
  * @clear: Whether to clear the value from memory
@@ -594,6 +601,19 @@ int crypto_bignum_div(const struct crypto_bignum *a,
 		      struct crypto_bignum *c);
 
 /**
+ * crypto_bignum_addmod - d = a + b (mod c)
+ * @a: Bignum
+ * @b: Bignum
+ * @c: Bignum
+ * @d: Bignum; used to store the result of (a + b) % c
+ * Returns: 0 on success, -1 on failure
+ */
+int crypto_bignum_addmod(const struct crypto_bignum *a,
+			 const struct crypto_bignum *b,
+			 const struct crypto_bignum *c,
+			 struct crypto_bignum *d);
+
+/**
  * crypto_bignum_mulmod - d = a * b (mod c)
  * @a: Bignum
  * @b: Bignum
@@ -607,6 +627,28 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 			 struct crypto_bignum *d);
 
 /**
+ * crypto_bignum_sqrmod - c = a^2 (mod b)
+ * @a: Bignum
+ * @b: Bignum
+ * @c: Bignum; used to store the result of a^2 % b
+ * Returns: 0 on success, -1 on failure
+ */
+int crypto_bignum_sqrmod(const struct crypto_bignum *a,
+			 const struct crypto_bignum *b,
+			 struct crypto_bignum *c);
+
+/**
+ * crypto_bignum_sqrtmod - returns sqrt(a) (mod b)
+ * @a: Bignum
+ * @b: Bignum
+ * @c: Bignum; used to store the result
+ * Returns: 0 on success, -1 on failure
+ */
+int crypto_bignum_sqrtmod(const struct crypto_bignum *a,
+			  const struct crypto_bignum *b,
+			  struct crypto_bignum *c);
+
+/**
  * crypto_bignum_cmp - Compare two bignums
  * @a: Bignum
  * @b: Bignum
@@ -695,6 +737,9 @@ const struct crypto_bignum * crypto_ec_get_prime(struct crypto_ec *e);
  */
 const struct crypto_bignum * crypto_ec_get_order(struct crypto_ec *e);
 
+const struct crypto_bignum * crypto_ec_get_a(struct crypto_ec *e);
+const struct crypto_bignum * crypto_ec_get_b(struct crypto_ec *e);
+
 /**
  * struct crypto_ec_point - Elliptic curve point
  *
diff --git a/src/crypto/crypto_openssl.c b/src/crypto/crypto_openssl.c
index 00b61b9..80867b6 100644
--- a/src/crypto/crypto_openssl.c
+++ b/src/crypto/crypto_openssl.c
@@ -1117,6 +1117,24 @@ struct crypto_bignum * crypto_bignum_init_set(const u8 *buf, size_t len)
 }
 
 
+struct crypto_bignum * crypto_bignum_init_uint(unsigned int val)
+{
+	BIGNUM *bn;
+
+	if (TEST_FAIL())
+		return NULL;
+
+	bn = BN_new();
+	if (!bn)
+		return NULL;
+	if (BN_set_word(bn, val) != 1) {
+		BN_free(bn);
+		return NULL;
+	}
+	return (struct crypto_bignum *) bn;
+}
+
+
 void crypto_bignum_deinit(struct crypto_bignum *n, int clear)
 {
 	if (clear)
@@ -1278,6 +1296,28 @@ int crypto_bignum_div(const struct crypto_bignum *a,
 }
 
 
+int crypto_bignum_addmod(const struct crypto_bignum *a,
+			 const struct crypto_bignum *b,
+			 const struct crypto_bignum *c,
+			 struct crypto_bignum *d)
+{
+	int res;
+	BN_CTX *bnctx;
+
+	if (TEST_FAIL())
+		return -1;
+
+	bnctx = BN_CTX_new();
+	if (!bnctx)
+		return -1;
+	res = BN_mod_add((BIGNUM *) d, (const BIGNUM *) a, (const BIGNUM *) b,
+			 (const BIGNUM *) c, bnctx);
+	BN_CTX_free(bnctx);
+
+	return res ? 0 : -1;
+}
+
+
 int crypto_bignum_mulmod(const struct crypto_bignum *a,
 			 const struct crypto_bignum *b,
 			 const struct crypto_bignum *c,
@@ -1301,6 +1341,48 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 }
 
 
+int crypto_bignum_sqrmod(const struct crypto_bignum *a,
+                        const struct crypto_bignum *b,
+                        struct crypto_bignum *c)
+{
+       int res;
+       BN_CTX *bnctx;
+
+       if (TEST_FAIL())
+               return -1;
+
+       bnctx = BN_CTX_new();
+       if (!bnctx)
+               return -1;
+       res = BN_mod_sqr((BIGNUM *) c, (const BIGNUM *) a, (const BIGNUM *) b,
+                        bnctx);
+       BN_CTX_free(bnctx);
+
+       return res ? 0 : -1;
+}
+
+
+int crypto_bignum_sqrtmod(const struct crypto_bignum *a,
+                         const struct crypto_bignum *b,
+                         struct crypto_bignum *c)
+{
+       BN_CTX *bnctx;
+       BIGNUM *res;
+
+       if (TEST_FAIL())
+               return -1;
+
+       bnctx = BN_CTX_new();
+       if (!bnctx)
+               return -1;
+       res = BN_mod_sqrt((BIGNUM *) c, (const BIGNUM *) a, (const BIGNUM *) b,
+                         bnctx);
+       BN_CTX_free(bnctx);
+
+       return res ? 0 : -1;
+}
+
+
 int crypto_bignum_cmp(const struct crypto_bignum *a,
 		      const struct crypto_bignum *b)
 {
@@ -1494,6 +1576,18 @@ const struct crypto_bignum * crypto_ec_get_order(struct crypto_ec *e)
 }
 
 
+const struct crypto_bignum * crypto_ec_get_a(struct crypto_ec *e)
+{
+	return (const struct crypto_bignum *) e->a;
+}
+
+
+const struct crypto_bignum * crypto_ec_get_b(struct crypto_ec *e)
+{
+	return (const struct crypto_bignum *) e->b;
+}
+
+
 void crypto_ec_point_deinit(struct crypto_ec_point *p, int clear)
 {
 	if (clear)
diff --git a/src/crypto/crypto_wolfssl.c b/src/crypto/crypto_wolfssl.c
index 90163c4..683c553 100644
--- a/src/crypto/crypto_wolfssl.c
+++ b/src/crypto/crypto_wolfssl.c
@@ -1043,6 +1043,26 @@ struct crypto_bignum * crypto_bignum_init_set(const u8 *buf, size_t len)
 }
 
 
+struct crypto_bignum * crypto_bignum_init_uint(unsigned int val)
+{
+	mp_int *a;
+
+	if (TEST_FAIL())
+		return NULL;
+
+	a = (mp_int *) crypto_bignum_init();
+	if (!a)
+		return NULL;
+
+	if (mp_set_int(a, val) != MP_OKAY) {
+		os_free(a);
+		a = NULL;
+	}
+
+	return (struct crypto_bignum *) a;
+}
+
+
 void crypto_bignum_deinit(struct crypto_bignum *n, int clear)
 {
 	if (!n)
@@ -1167,6 +1187,19 @@ int crypto_bignum_div(const struct crypto_bignum *a,
 }
 
 
+int crypto_bignum_addmod(const struct crypto_bignum *a,
+			 const struct crypto_bignum *b,
+			 const struct crypto_bignum *c,
+			 struct crypto_bignum *d)
+{
+	if (TEST_FAIL())
+		return -1;
+
+	return mp_addmod((mp_int *) a, (mp_int *) b, (mp_int *) c,
+			 (mp_int *) d) == MP_OKAY ?  0 : -1;
+}
+
+
 int crypto_bignum_mulmod(const struct crypto_bignum *a,
 			 const struct crypto_bignum *b,
 			 const struct crypto_bignum *m,
@@ -1180,6 +1213,27 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 }
 
 
+int crypto_bignum_sqrmod(const struct crypto_bignum *a,
+			 const struct crypto_bignum *b,
+			 struct crypto_bignum *c)
+{
+	if (TEST_FAIL())
+		return -1;
+
+	return mp_sqrmod((mp_int *) a, (mp_int *) b,
+			 (mp_int *) c) == MP_OKAY ?  0 : -1;
+}
+
+
+int crypto_bignum_sqrtmod(const struct crypto_bignum *a,
+			  const struct crypto_bignum *b,
+			  struct crypto_bignum *c)
+{
+	/* TODO */
+	return -1;
+}
+
+
 int crypto_bignum_rshift(const struct crypto_bignum *a, int n,
 			 struct crypto_bignum *r)
 {
@@ -1401,6 +1455,18 @@ const struct crypto_bignum * crypto_ec_get_order(struct crypto_ec *e)
 }
 
 
+const struct crypto_bignum * crypto_ec_get_a(struct crypto_ec *e)
+{
+	return (const struct crypto_bignum *) &e->a;
+}
+
+
+const struct crypto_bignum * crypto_ec_get_b(struct crypto_ec *e)
+{
+	return (const struct crypto_bignum *) &e->b;
+}
+
+
 void crypto_ec_point_deinit(struct crypto_ec_point *p, int clear)
 {
 	ecc_point *point = (ecc_point *) p;
-- 
1.8.3.1

