ASN1 for binary curves

Submitted by: Nils Larsch

crypto/asn1/t_pkey.c

@@ -412,13 +412,32 @@ int ECPKParameters_print(BIO *bp, const EC_GROUP *x, int off)
 			if (BIO_write(bp, str, off) <= 0)
 				goto err;
 			}
-
+		/* print the 'short name' of the field type */
 		if (BIO_printf(bp, "Field Type: %s\n", OBJ_nid2sn(tmp_nid))
 			<= 0)
 			goto err;  
 
 		if (is_char_two)
 			{
+			/* print the 'short name' of the base type OID */
+			int basis_type = EC_GROUP_get_basis_type(x, NULL,
+				NULL, NULL);
+			if (basis_type == 0)
+				goto err;
+
+			if (off)
+				{
+				if (off > 128) off=128;
+				memset(str,' ',off);
+				if (BIO_write(bp, str, off) <= 0)
+					goto err;
+				}
+
+			if (BIO_printf(bp, "Basis Type: %s\n", 
+				OBJ_nid2sn(basis_type)) <= 0)
+				goto err;
+
+			/* print the polynomial */
 			if ((p != NULL) && !print(bp, "Polynomial:", p, buffer,
 				off))
 				goto err;
@@ -565,6 +584,13 @@ static int print(BIO *bp, const char *number, BIGNUM *num, unsigned char *buf,
 		if (BIO_write(bp,str,off) <= 0) return(0);
 		}
 
+	if (BN_is_zero(num))
+		{
+		if (BIO_printf(bp, "%s 0\n", number) <= 0)
+			return 0;
+		return 1;
+		}
+
 	if (BN_num_bytes(num) <= BN_BYTES)
 		{
 		if (BIO_printf(bp,"%s %s%lu (%s0x%lx)\n",number,neg,

crypto/ec/ec.h

@@ -191,6 +191,14 @@ const char *EC_GROUP_get0_comment(int nid);
  * with the given index i from the internal curve list */
 int ec_group_index2nid(int i);
 
+/* EC_GROUP_get_basis_type() returns the NID of the basis type
+ * used to represent the field elements (in case of a pentanomial or trinomial
+ * basis the coefficient are returned in the k? arguments) */
+int EC_GROUP_get_basis_type(const EC_GROUP *, unsigned int *k1,
+	unsigned int *k2, unsigned int *k3);
+
+
+/* EC_POINT functions */
 
 EC_POINT *EC_POINT_new(const EC_GROUP *);
 void EC_POINT_free(EC_POINT *);

crypto/ec/ec_lib.c

@@ -537,6 +537,45 @@ void EC_GROUP_clear_free_extra_data(EC_GROUP *group)
 	}
 
 
+int EC_GROUP_get_basis_type(const EC_GROUP *group, unsigned int *k1, 
+	unsigned int *k2, unsigned int *k3)
+	{
+	int i = 0;
+
+	if (group == NULL)
+		return 0;
+
+	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
+		NID_X9_62_characteristic_two_field)
+		/* everything else is currently not supported */
+		return 0;
+
+	while (group->poly[i] != 0)
+		i++;
+
+	if (i == 4)
+		{
+		if (k1)
+			*k1 = group->poly[3];
+		if (k2)
+			*k2 = group->poly[2];
+		if (k3)
+			*k3 = group->poly[1];
+
+		return NID_X9_62_ppBasis;
+		}
+	else if (i == 2)
+		{
+		if (k1)
+			*k1 = group->poly[1];
+
+		return NID_X9_62_tpBasis;
+		}
+	else
+		/* everything else is currently not supported */
+		return 0;
+	}
+
 /* functions for EC_POINT objects */
 
 EC_POINT *EC_POINT_new(const EC_GROUP *group)

util/libeay.num

@@ -3005,3 +3005,5 @@ ENGINE_set_default_ECDH                 3438	EXIST::FUNCTION:
 ENGINE_register_ECDH                    3439	EXIST::FUNCTION:
 EC_GROUP_get0_comment                   3440	EXIST::FUNCTION:EC
 ec_group_index2nid                      3441	EXIST::FUNCTION:EC
+EC_GROUP_get_basis_type                 3442	EXIST::FUNCTION:EC
+X509_REQ_print_ex                       3443	EXIST::FUNCTION:BIO