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

@@ -518,6 +518,13 @@ 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()
@@ -612,6 +619,19 @@ int crypto_bignum_div(const struct crypto_bignum *a,
 		      const struct crypto_bignum *b,
 		      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
@@ -625,6 +645,28 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 			 const struct crypto_bignum *c,
 			 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_rshift - r = a >> n
  * @a: Bignum
@@ -731,6 +773,9 @@ 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
  *

src/crypto/crypto_openssl.c

@@ -1283,6 +1283,24 @@ 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)
@@ -1449,6 +1467,28 @@ 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,
@@ -1472,6 +1512,48 @@ 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_rshift(const struct crypto_bignum *a, int n,
 			 struct crypto_bignum *r)
 {
@@ -1682,6 +1764,18 @@ 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)

src/crypto/crypto_wolfssl.c

@@ -1042,6 +1042,26 @@ 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)
@@ -1168,6 +1188,19 @@ 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,
@@ -1181,6 +1214,27 @@ 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)
 {
@@ -1386,6 +1440,18 @@ 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;