Revamp ec_key_new()

1 files changed, 158 insertions, 132 deletions

diff --git a/lib/crypto/c_src/ec.c b/lib/crypto/c_src/ec.c
index 6d831ec9d2..98d3007f13 100644
--- a/lib/crypto/c_src/ec.c
+++ b/lib/crypto/c_src/ec.c
@@ -50,157 +50,183 @@ static EC_KEY* ec_key_new(ErlNifEnv* env, ERL_NIF_TERM curve_arg)
     BIGNUM *cofactor = NULL;
     EC_GROUP *group = NULL;
     EC_POINT *point = NULL;
+    int f_arity = -1;
+    const ERL_NIF_TERM *field;
+    int p_arity = -1;
+    const ERL_NIF_TERM *prime;
+    long field_bits;
 
     /* {Field, Prime, Point, Order, CoFactor} = Curve */
-    if (enif_get_tuple(env,curve_arg,&c_arity,&curve)
-	&& c_arity == 5
-	&& get_bn_from_bin(env, curve[3], &bn_order)
-	&& (curve[4] != atom_none && get_bn_from_bin(env, curve[4], &cofactor))) {
-
-	int f_arity = -1;
-	const ERL_NIF_TERM* field;
-	int p_arity = -1;
-	const ERL_NIF_TERM* prime;
-
-	long field_bits;
-
-	/* {A, B, Seed} = Prime */
-	if (!enif_get_tuple(env,curve[1],&p_arity,&prime)
-	    || !get_bn_from_bin(env, prime[0], &a)
-	    || !get_bn_from_bin(env, prime[1], &b))
-	    goto out_err;
-
-	if (!enif_get_tuple(env,curve[0],&f_arity,&field))
-	    goto out_err;
-
-	if (f_arity == 2 && field[0] == atom_prime_field) {
-	    /* {prime_field, Prime} */
-
-	    if (!get_bn_from_bin(env, field[1], &p))
-		goto out_err;
-
-	    if (BN_is_negative(p) || BN_is_zero(p))
-		goto out_err;
-
-	    field_bits = BN_num_bits(p);
-	    if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS)
-		goto out_err;
-
-	    /* create the EC_GROUP structure */
-	    group = EC_GROUP_new_curve_GFp(p, a, b, NULL);
+    if (!enif_get_tuple(env, curve_arg, &c_arity, &curve))
+        goto err;
+    if (c_arity != 5)
+        goto err;
+    if (!get_bn_from_bin(env, curve[3], &bn_order))
+        goto err;
+    if (curve[4] != atom_none) {
+        if (!get_bn_from_bin(env, curve[4], &cofactor))
+            goto err;
+    }
 
-	} else if (f_arity == 3 && field[0] == atom_characteristic_two_field) {
+    /* {A, B, Seed} = Prime */
+    if (!enif_get_tuple(env, curve[1], &p_arity, &prime))
+        goto err;
+    if (!get_bn_from_bin(env, prime[0], &a))
+        goto err;
+    if (!get_bn_from_bin(env, prime[1], &b))
+        goto err;
+
+    if (!enif_get_tuple(env, curve[0], &f_arity, &field))
+        goto err;
+
+    if (f_arity == 2 && field[0] == atom_prime_field) {
+        /* {prime_field, Prime} */
+        if (!get_bn_from_bin(env, field[1], &p))
+            goto err;
+        if (BN_is_negative(p))
+            goto err;
+        if (BN_is_zero(p))
+            goto err;
+
+        field_bits = BN_num_bits(p);
+        if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS)
+            goto err;
+
+        /* create the EC_GROUP structure */
+        if ((group = EC_GROUP_new_curve_GFp(p, a, b, NULL)) == NULL)
+            goto err;
+
+    } else if (f_arity == 3 && field[0] == atom_characteristic_two_field) {
 #if defined(OPENSSL_NO_EC2M)
-	    enif_raise_exception(env, atom_notsup);
-	    goto out_err;
+        enif_raise_exception(env, atom_notsup);
+        goto out_err;
 #else
-	    /* {characteristic_two_field, M, Basis} */
-
-	    int b_arity = -1;
-	    const ERL_NIF_TERM* basis;
-	    unsigned int k1, k2, k3;
-
-	    if ((p = BN_new()) == NULL)
-		goto out_err;
-
-	    if (!enif_get_long(env, field[1], &field_bits)
-		|| field_bits > OPENSSL_ECC_MAX_FIELD_BITS)
-		goto out_err;
-
-	    if (enif_get_tuple(env,field[2],&b_arity,&basis)) {
-		if (b_arity == 2
-		    && basis[0] == atom_tpbasis
-		    && enif_get_uint(env, basis[1], &k1)) {
-		    /* {tpbasis, k} = Basis */
-
-		    if (!(field_bits > k1 && k1 > 0))
-			goto out_err;
-
-		    /* create the polynomial */
-		    if (!BN_set_bit(p, (int)field_bits)
-                        || !BN_set_bit(p, (int)k1)
-                        || !BN_set_bit(p, 0))
-                                goto out_err;
-
-		} else if (b_arity == 4
-		    && basis[0] == atom_ppbasis
-		    && enif_get_uint(env, basis[1], &k1)
-		    && enif_get_uint(env, basis[2], &k2)
-		    && enif_get_uint(env, basis[3], &k3)) {
-		    /* {ppbasis, k1, k2, k3} = Basis */
-
-		    if (!(field_bits > k3 && k3 > k2 && k2 > k1 && k1 > 0))
-			goto out_err;
-
-		    /* create the polynomial */
-		    if (!BN_set_bit(p, (int)field_bits)
-			|| !BN_set_bit(p, (int)k1)
-			|| !BN_set_bit(p, (int)k2)
-			|| !BN_set_bit(p, (int)k3)
-			|| !BN_set_bit(p, 0))
-			goto out_err;
-
-		} else
-		    goto out_err;
-	    } else if (field[2] == atom_onbasis) {
-		/* onbasis = Basis */
-		/* no parameters */
-		goto out_err;
-
-	    } else
-		goto out_err;
-
-	    group = EC_GROUP_new_curve_GF2m(p, a, b, NULL);
+        /* {characteristic_two_field, M, Basis} */
+        int b_arity = -1;
+        const ERL_NIF_TERM* basis;
+
+        if ((p = BN_new()) == NULL)
+            goto err;
+        if (!enif_get_long(env, field[1], &field_bits))
+            goto err;
+        if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS || field_bits > INT_MAX)
+            goto err;
+
+        if (enif_get_tuple(env, field[2], &b_arity, &basis)) {
+            if (b_arity == 2) {
+                unsigned int k1;
+
+                if (basis[0] != atom_tpbasis)
+                    goto err;
+                if (!enif_get_uint(env, basis[1], &k1))
+                    goto err;
+
+                /* {tpbasis, k} = Basis */
+                if (field_bits <= k1 || k1 == 0 || k1 > INT_MAX)
+                    goto err;
+
+                /* create the polynomial */
+                if (!BN_set_bit(p, (int)field_bits))
+                    goto err;
+                if (!BN_set_bit(p, (int)k1))
+                    goto err;
+                if (!BN_set_bit(p, 0))
+                    goto err;
+
+            } else if (b_arity == 4) {
+                unsigned int k1, k2, k3;
+
+                if (basis[0] != atom_ppbasis)
+                    goto err;
+                if (!enif_get_uint(env, basis[1], &k1))
+                    goto err;
+                if (!enif_get_uint(env, basis[2], &k2))
+                    goto err;
+                if (!enif_get_uint(env, basis[3], &k3))
+                    goto err;
+
+                /* {ppbasis, k1, k2, k3} = Basis */
+                if (field_bits <= k3 || k3 <= k2 || k2 <= k1 || k1 == 0 || k3 > INT_MAX || k2 > INT_MAX || k1 > INT_MAX)
+                    goto err;
+
+                /* create the polynomial */
+                if (!BN_set_bit(p, (int)field_bits))
+                    goto err;
+                if (!BN_set_bit(p, (int)k1))
+                    goto err;
+                if (!BN_set_bit(p, (int)k2))
+                    goto err;
+                if (!BN_set_bit(p, (int)k3))
+                    goto err;
+                if (!BN_set_bit(p, 0))
+                    goto err;
+
+            } else
+                goto err;
+        } else if (field[2] == atom_onbasis) {
+            /* onbasis = Basis */
+            /* no parameters */
+            goto err;
+
+        } else
+            goto err;
+
+        if ((group = EC_GROUP_new_curve_GF2m(p, a, b, NULL)) == NULL)
+            goto err;
 #endif
-	} else
-	    goto out_err;
-
-        if (!group)
-            goto out_err;
+    } else
+        goto err;
 
-	if (enif_inspect_binary(env, prime[2], &seed)) {
-	    EC_GROUP_set_seed(group, seed.data, seed.size);
-	}
+    if (enif_inspect_binary(env, prime[2], &seed)) {
+        if (!EC_GROUP_set_seed(group, seed.data, seed.size))
+            goto err;
+    }
 
-	if (!term2point(env, curve[2], group, &point))
-	    goto out_err;
+    if (!term2point(env, curve[2], group, &point))
+        goto err;
 
-	if (BN_is_negative(bn_order)
-	    || BN_is_zero(bn_order)
-	    || BN_num_bits(bn_order) > (int)field_bits + 1)
-	    goto out_err;
+    if (BN_is_negative(bn_order))
+        goto err;
+    if (BN_is_zero(bn_order))
+        goto err;
+    if (BN_num_bits(bn_order) > (int)field_bits + 1)
+        goto err;
 
-	if (!EC_GROUP_set_generator(group, point, bn_order, cofactor))
-	    goto out_err;
+    if (!EC_GROUP_set_generator(group, point, bn_order, cofactor))
+        goto err;
 
-	EC_GROUP_set_asn1_flag(group, 0x0);
+    EC_GROUP_set_asn1_flag(group, 0x0);
 
-	key = EC_KEY_new();
-	if (!key)
-	    goto out_err;
-	EC_KEY_set_group(key, group);
-    }
-    else {
-	goto out_err;
-    }
+    if ((key = EC_KEY_new()) == NULL)
+        goto err;
 
+    if (!EC_KEY_set_group(key, group))
+        goto err;
 
-    goto out;
+    goto done;
 
-out_err:
-    if (key) EC_KEY_free(key);
+ err:
+    if (key)
+        EC_KEY_free(key);
     key = NULL;
 
-out:
+ done:
     /* some OpenSSL structures are mem-dup'ed into the key,
        so we have to free our copies here */
-    if (p) BN_free(p);
-    if (a) BN_free(a);
-    if (b) BN_free(b);
-    if (bn_order) BN_free(bn_order);
-    if (cofactor) BN_free(cofactor);
-    if (group) EC_GROUP_free(group);
-    if (point) EC_POINT_free(point);
+    if (bn_order)
+        BN_free(bn_order);
+    if (cofactor)
+        BN_free(cofactor);
+    if (a)
+        BN_free(a);
+    if (b)
+        BN_free(b);
+    if (p)
+        BN_free(p);
+    if (group)
+        EC_GROUP_free(group);
+    if (point)
+        EC_POINT_free(point);
 
     return key;
 }