simplify asn1_flag

Submitted by: Nils Larsch
Reviewed by: Bodo Moeller

CHANGES

@@ -4,12 +4,20 @@
 
  Changes between 0.9.7 and 0.9.8  [xx XXX 2002]
 
-  *) Add 'nid' and 'asn1_flag' members to EC_GROUP, and functions
-          EC_GROUP_get_nid()
-          EC_GROUP_get_set_asn1_flag()
-          EC_GROUP_get_get_asn1_flag()
-     'nid' is an optional NID for named curves.  'asn1_flag'
-     determines the encoding to be used for ASN1 purposes.
+  *) Add 'asn1_flag' and 'asn1_form' member to EC_GROUP with access
+     functions
+          EC_GROUP_set_asn1_flag()
+          EC_GROUP_get_asn1_flag()
+          EC_GROUP_set_point_conversion_form()
+          EC_GROUP_get_point_conversion_form()
+     These control ASN1 encoding details:
+     - Curve are encoded explicitly unless asn1_flag has been set to
+       OPENSSL_EC_NAMED_CURVE.
+     - Points are encoded in compressed form by default; options for
+       asn1_for are as for point2oct, namely
+          POINT_CONVERSION_COMPRESSED
+          POINT_CONVERSION_UNCOMPRESSED
+          POINT_CONVERSION_HYBRID
      [Nils Larsch <nla@trustcenter.de>]
 
   *) Add 'field_type' member to EC_METHOD, which holds the NID
@@ -69,8 +77,8 @@
      functions
           EC_GROUP_new_by_nid()
           EC_GROUP_new_by_name()
-     Also add a 'nid' field to EC_GROUP objects, which can be accessed
-     via
+     Also add a 'curve_name' member to EC_GROUP objects, which can be
+     accessed via
          EC_GROUP_set_nid()
          EC_GROUP_get_nid()
      [Nils Larsch <nla@trustcenter.de, Bodo Moeller]

apps/ecdsaparam.c

@@ -432,8 +432,7 @@ bad:
 		ecdsa->group = EC_GROUP_new_by_name(curve_type);
 		if (named_curve)
 			EC_GROUP_set_asn1_flag(ecdsa->group, 
-                                OPENSSL_EC_NAMED_CURVE |
-				(EC_GROUP_get_asn1_flag(ecdsa->group) & ~0x3));
+						OPENSSL_EC_NAMED_CURVE);
 	}
 	else if (informat == FORMAT_ASN1)
 		ecdsa = d2i_ECDSAParameters_bio(in,NULL);

crypto/asn1/x_pubkey.c

@@ -145,7 +145,7 @@ int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
 			goto err;
 			}
 
-		if ((EC_GROUP_get_asn1_flag(ecdsa->group) & OPENSSL_EC_NAMED_CURVE) 
+		if (EC_GROUP_get_asn1_flag(ecdsa->group)
                      && (nid = EC_GROUP_get_nid(ecdsa->group)))
 			{
 			/* just set the OID */
@@ -312,8 +312,8 @@ EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key)
 			if ((ecdsa->group = EC_GROUP_new_by_name(
                              OBJ_obj2nid(a->parameter->value.object))) == NULL)
 				goto err;
-			EC_GROUP_set_asn1_flag(ecdsa->group, OPENSSL_EC_NAMED_CURVE |
-                               (EC_GROUP_get_asn1_flag(ecdsa->group) & ~0x03));
+			EC_GROUP_set_asn1_flag(ecdsa->group, 
+						OPENSSL_EC_NAMED_CURVE);
 			}
 			/* the case implicitlyCA is currently not implemented */
 		ret->save_parameters = 1;

crypto/ec/ec.h

@@ -229,11 +229,7 @@ int EC_GROUP_precompute_mult(EC_GROUP *, BN_CTX *);
 
 
 /* ASN1 stuff */
-#define OPENSSL_EC_EXPLICIT	0x001
-#define OPENSSL_EC_NAMED_CURVE	0x002
-#define OPENSSL_EC_COMPRESSED	0x010
-#define OPENSSL_EC_UNCOMPRESSED	0x020
-#define OPENSSL_EC_HYBRID	0x040
+#define OPENSSL_EC_NAMED_CURVE	0x001
 
 typedef struct ec_parameters_st ECPARAMETERS;
 typedef struct ecpk_parameters_st ECPKPARAMETERS;
@@ -249,6 +245,9 @@ ECPKPARAMETERS *EC_ASN1_group2pkparameters(const EC_GROUP *, ECPKPARAMETERS *);
 void EC_GROUP_set_asn1_flag(EC_GROUP *, int flag);
 int EC_GROUP_get_asn1_flag(const EC_GROUP *);
 
+void EC_GROUP_set_point_conversion_form(EC_GROUP *, point_conversion_form_t);
+point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP *);
+
 EC_GROUP *d2i_ECParameters(EC_GROUP **, const unsigned char **in, long len);
 int i2d_ECParameters(const EC_GROUP *, unsigned char **out);
 

crypto/ec/ec_asn1.c

@@ -394,7 +394,7 @@ err :	if (!ok)
 static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
                                               ECPARAMETERS *param)
 	{
-	int	ok=0, i;
+	int	ok=0;
 	size_t  len=0;
 	ECPARAMETERS   *ret=NULL;
 	BIGNUM	       *tmp=NULL;
@@ -455,15 +455,7 @@ static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
 		goto err;
 		}
 
-	i = EC_GROUP_get_asn1_flag(group);
-	if (i | OPENSSL_EC_COMPRESSED)
-		form = POINT_CONVERSION_COMPRESSED;
-	else if (i | OPENSSL_EC_UNCOMPRESSED)
-		form = POINT_CONVERSION_UNCOMPRESSED;
-	else if (i | OPENSSL_EC_HYBRID)
-		form = POINT_CONVERSION_HYBRID;
-	else 
-		goto err;
+	form = EC_GROUP_get_point_conversion_form(group);
 
 	len = EC_POINT_point2oct(group, point, form, NULL, len, NULL);
 	if (len == 0)
@@ -556,9 +548,7 @@ ECPKPARAMETERS *EC_ASN1_group2pkparameters(const EC_GROUP *group,
 			ECPARAMETERS_free(ret->value.parameters);
 		}
 
-	tmp = EC_GROUP_get_asn1_flag(group);
-
-	if (tmp & OPENSSL_EC_NAMED_CURVE)
+	if (EC_GROUP_get_asn1_flag(group))
 		{
 		/* use the asn1 OID to describe the
 		 * the elliptic curve parameters
@@ -581,7 +571,7 @@ ECPKPARAMETERS *EC_ASN1_group2pkparameters(const EC_GROUP *group,
 				ok = 0;
 			}
 		}
-	else if (tmp & OPENSSL_EC_EXPLICIT)
+	else
 		{	
 		/* use the ECPARAMETERS structure */
 		ret->type = 1;
@@ -589,8 +579,6 @@ ECPKPARAMETERS *EC_ASN1_group2pkparameters(const EC_GROUP *group,
 		     group, NULL)) == NULL)
 			ok = 0;
 		}
-	else
-		ok = 0;
 
 	if (!ok)
 		{
@@ -759,9 +747,7 @@ EC_GROUP *EC_ASN1_pkparameters2group(const ECPKPARAMETERS *params)
 			      EC_R_EC_GROUP_NEW_BY_NAME_FAILURE);
 			return NULL;
 			}
-		tmp = EC_GROUP_get_asn1_flag(ret);
-		tmp = (tmp & ~0x03) | OPENSSL_EC_NAMED_CURVE;
-		EC_GROUP_set_asn1_flag(ret, tmp);
+		EC_GROUP_set_asn1_flag(ret, OPENSSL_EC_NAMED_CURVE);
 		}
 	else if (params->type == 1)
 		{ /* the parameters are given by a ECPARAMETERS
@@ -772,9 +758,7 @@ EC_GROUP *EC_ASN1_pkparameters2group(const ECPKPARAMETERS *params)
 			ECerr(EC_F_EC_ASN1_PKPARAMETERS2GROUP, ERR_R_EC_LIB);
 			return NULL;
 			}
-		tmp = EC_GROUP_get_asn1_flag(ret);
-		tmp = (tmp & ~0x03) | OPENSSL_EC_EXPLICIT;
-		EC_GROUP_set_asn1_flag(ret, tmp);
+		EC_GROUP_set_asn1_flag(ret, 0x0);
 		}
 	else if (params->type == 2)
 		{ /* implicitlyCA */

crypto/ec/ec_lcl.h

@@ -144,8 +144,9 @@ struct ec_group_st {
 	EC_POINT *generator; /* optional */
 	BIGNUM order, cofactor;
 
-	int nid;       /* optional NID for named curve */
+	int curve_name;/* optional NID for named curve */
 	int asn1_flag; /* flag to control the asn1 encoding */
+	point_conversion_form_t asn1_form;
 
 	void *extra_data;
 	void *(*extra_data_dup_func)(void *);

crypto/ec/ec_lib.c

@@ -98,8 +98,9 @@ EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
 	BN_init(&ret->order);
 	BN_init(&ret->cofactor);
 
-	ret->nid = 0;	
-	ret->asn1_flag = OPENSSL_EC_EXPLICIT | OPENSSL_EC_COMPRESSED;
+	ret->curve_name = 0;	
+	ret->asn1_flag  = 0;
+	ret->asn1_form  = POINT_CONVERSION_COMPRESSED;
 
 	ret->seed = NULL;
 	ret->seed_len = 0;
@@ -214,8 +215,9 @@ int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 	if (!BN_copy(&dest->order, &src->order)) return 0;
 	if (!BN_copy(&dest->cofactor, &src->cofactor)) return 0;
 
-	dest->nid = src->nid;
-	dest->asn1_flag = src->asn1_flag;
+	dest->curve_name = src->curve_name;
+	dest->asn1_flag  = src->asn1_flag;
+	dest->asn1_form  = src->asn1_form;
 
 	if (src->seed)
 		{
@@ -308,13 +310,13 @@ int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx)
 
 void EC_GROUP_set_nid(EC_GROUP *group, int nid)
 	{
-	group->nid = nid;
+	group->curve_name = nid;
 	}
 
 
 int EC_GROUP_get_nid(const EC_GROUP *group)
 	{
-	return group->nid;
+	return group->curve_name;
 	}
 
 
@@ -330,6 +332,19 @@ int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
 	}
 
 
+void EC_GROUP_set_point_conversion_form(EC_GROUP *group, 
+                                        point_conversion_form_t form)
+	{
+	group->asn1_form = form;
+	}
+
+
+point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP *group)
+	{
+	return group->asn1_form;
+	}
+
+
 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 	{
 	if (group->meth->group_set_curve_GFp == 0)