SAE: Use more generic random bignum generation

Move the bignum comparison part into the bignum library to allow a
single implementation of rand generation for both ECC and FCC based
groups.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/crypto/crypto.h

@@ -589,6 +589,22 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 			 const struct crypto_bignum *c,
 			 struct crypto_bignum *d);
 
+/**
+ * crypto_bignum_cmp - Compare two bignums
+ * @a: Bignum
+ * @b: Bignum
+ * Returns: -1 if a < b, 0 if a == b, or 1 if a > b
+ */
+int crypto_bignum_cmp(const struct crypto_bignum *a,
+		      const struct crypto_bignum *b);
+
+/**
+ * crypto_bignum_bits - Get size of a bignum in bits
+ * @a: Bignum
+ * Returns: Number of bits in the bignum
+ */
+int crypto_bignum_bits(const struct crypto_bignum *a);
+
 /**
  * struct crypto_ec - Elliptic curve context
  *

src/crypto/crypto_openssl.c

@@ -987,6 +987,19 @@ int crypto_bignum_mulmod(const struct crypto_bignum *a,
 }
 
 
+int crypto_bignum_cmp(const struct crypto_bignum *a,
+		      const struct crypto_bignum *b)
+{
+	return BN_cmp((const BIGNUM *) a, (const BIGNUM *) b);
+}
+
+
+int crypto_bignum_bits(const struct crypto_bignum *a)
+{
+	return BN_num_bits((const BIGNUM *) a);
+}
+
+
 #ifdef CONFIG_ECC
 
 struct crypto_ec {