[openssl-dev] [openssl.org #3676] [PATCH] Export ASN1 templates for DH and ECDH groups

Dr. Matthias St. Pierre via RT rt at openssl.org
Wed Jan 28 09:42:02 UTC 2015


Add missing forward declarations and export declarations for DHparams
and EC[PK]PARAMETERS.

Add public functions to convert between EC_GROUP objects and EC[PK]PARAMETERS
objects: EC_GROUP_new_from_ec[pk]parameters(), EC_GROUP_get_ec[pk]parameters().

Signed-off-by: Dr. Matthias St. Pierre <msp at ncp-e.com>
---
 crypto/ec/ec.h      | 38 ++++++++++++++++++++++++++++++++++++++
 crypto/ec/ec_asn1.c | 30 ++++++++++++++++++++++++++----
 util/libeay.num     | 10 ++++++++++
 3 files changed, 74 insertions(+), 4 deletions(-)

This patch makes the ASN1 templates used internally by OpenSSL for
serializing DH and ECDH group parameters publicly available for reuse.

For example, if one wants to save a set of [EC]DH Groups together with
application defined data (like, group-name, group-id) to a file, it is
much easier to define a small set of ASN1 rules extending the existing
ones and let OpenSSL do the serialization, than having to fiddle around
with i2d_DHparams(), i2d_ECParameters(), etc., to embed the curve data
as a blob into an opaque ASN1 octet string.

diff --git a/crypto/ec/ec.h b/crypto/ec/ec.h
index 98edfdf..97ccee8 100644
--- a/crypto/ec/ec.h
+++ b/crypto/ec/ec.h
@@ -128,6 +128,9 @@ typedef struct ec_group_st
 
 typedef struct ec_point_st EC_POINT;
 
+typedef struct ecpk_parameters_st ECPKPARAMETERS;
+typedef struct ec_parameters_st ECPARAMETERS;
+
 /********************************************************************/
 /*               EC_METHODs for curves over GF(p)                   */
 /********************************************************************/
@@ -393,6 +396,38 @@ EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a,
  */
 EC_GROUP *EC_GROUP_new_by_curve_name(int nid);
 
+/** Creates a new EC_GROUP object from an ECPARAMETERS object
+ *  \param  params  pointer to the ECPARAMETERS object
+ *  \return newly created EC_GROUP object with specified curve or NULL
+ *          if an error occurred
+ */
+EC_GROUP *EC_GROUP_new_from_ecparameters(const ECPARAMETERS *params);
+
+/** Creates an ECPARAMETERS object for the the given EC_GROUP object.
+ *  \param  group   pointer to the EC_GROUP object
+ *  \param  params  pointer to an existing ECPARAMETERS object or NULL
+ *  \return pointer to the new ECPARAMETERS object or NULL
+ *          if an error occurred.
+ */
+ECPARAMETERS *EC_GROUP_get_ecparameters(const EC_GROUP *group,
+                                        ECPARAMETERS *params);
+
+/** Creates a new EC_GROUP object from an ECPKPARAMETERS object
+ *  \param  params  pointer to an existing ECPKPARAMETERS object, or NULL
+ *  \return newly created EC_GROUP object with specified curve, or NULL
+ *          if an error occurred
+ */
+EC_GROUP *EC_GROUP_new_from_ecpkparameters(const ECPKPARAMETERS *params);
+
+/** Creates an ECPKPARAMETERS object for the the given EC_GROUP object.
+ *  \param  group   pointer to the EC_GROUP object
+ *  \param  params  pointer to an existing ECPKPARAMETERS object or NULL
+ *  \return pointer to the new ECPKPARAMETERS object or NULL
+ *          if an error occurred.
+ */
+ECPKPARAMETERS *EC_GROUP_get_ecpkparameters(const EC_GROUP *group,
+                                            ECPKPARAMETERS *params);
+
 /********************************************************************/
 /*               handling of internal curves                        */
 /********************************************************************/
@@ -702,6 +737,9 @@ int EC_GROUP_have_precompute_mult(const EC_GROUP *group);
 /*                       ASN1 stuff                                 */
 /********************************************************************/
 
+DECLARE_ASN1_ITEM(ECPKPARAMETERS)
+DECLARE_ASN1_ITEM(ECPARAMETERS)
+
 /*
  * EC_GROUP_get_basis_type() returns the NID of the basis type used to
  * represent the field elements
diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c
index 2924374..d84c6d2 100644
--- a/crypto/ec/ec_asn1.c
+++ b/crypto/ec/ec_asn1.c
@@ -306,6 +306,28 @@ static EC_GROUP *ec_asn1_pkparameters2group(const ECPKPARAMETERS *);
 static ECPKPARAMETERS *ec_asn1_group2pkparameters(const EC_GROUP *,
                                                   ECPKPARAMETERS *);
 
+EC_GROUP *EC_GROUP_new_from_ecparameters(const ECPARAMETERS *params)
+{
+    return ec_asn1_parameters2group(params);
+}
+
+ECPARAMETERS *EC_GROUP_get_ecparameters(const EC_GROUP *group,
+                                        ECPARAMETERS *params)
+{
+    return ec_asn1_group2parameters(group, params);
+}
+
+EC_GROUP *EC_GROUP_new_from_ecpkparameters(const ECPKPARAMETERS *params)
+{
+    return ec_asn1_pkparameters2group(params);
+}
+
+ECPKPARAMETERS *EC_GROUP_get_ecpkparameters(const EC_GROUP *group,
+                                            ECPKPARAMETERS *params)
+{
+    return ec_asn1_group2pkparameters(group, params);
+}
+
 /* the function definitions */
 
 static int ec_asn1_group2fieldid(const EC_GROUP *group, X9_62_FIELDID *field)
@@ -540,7 +562,7 @@ static int ec_asn1_group2curve(const EC_GROUP *group, X9_62_CURVE *curve)
 }
 
 static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
-                                              ECPARAMETERS *param)
+                                              ECPARAMETERS *params)
 {
     int ok = 0;
     size_t len = 0;
@@ -555,13 +577,13 @@ static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
         goto err;
     }
 
-    if (param == NULL) {
+    if (params == NULL) {
         if ((ret = ECPARAMETERS_new()) == NULL) {
             ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_MALLOC_FAILURE);
             goto err;
         }
     } else
-        ret = param;
+        ret = params;
 
     /* set the version (always one) */
     ret->version = (long)0x1;
@@ -631,7 +653,7 @@ static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
     ok = 1;
 
  err:if (!ok) {
-        if (ret && !param)
+        if (ret && !params)
             ECPARAMETERS_free(ret);
         ret = NULL;
     }
diff --git a/util/libeay.num b/util/libeay.num
index 4a11d78..bf0adc5 100755
--- a/util/libeay.num
+++ b/util/libeay.num
@@ -4412,3 +4412,13 @@ ECDSA_METHOD_get_app_data               4770	EXIST::FUNCTION:ECDSA
 X509_VERIFY_PARAM_add1_host             4771	EXIST::FUNCTION:
 EC_GROUP_get_mont_data                  4772	EXIST::FUNCTION:EC
 i2d_re_X509_tbs                         4773	EXIST::FUNCTION:
+DHparams_it                             4774	EXIST:!EXPORT_VAR_AS_FUNCTION:VARIABLE:DH
+DHparams_it                             4774	EXIST:EXPORT_VAR_AS_FUNCTION:FUNCTION:DH
+ECPARAMETERS_it                         4775	EXIST:!EXPORT_VAR_AS_FUNCTION:VARIABLE:EC
+ECPARAMETERS_it                         4775	EXIST:EXPORT_VAR_AS_FUNCTION:FUNCTION:EC
+ECPKPARAMETERS_it                       4776	EXIST:!EXPORT_VAR_AS_FUNCTION:VARIABLE:EC
+ECPKPARAMETERS_it                       4776	EXIST:EXPORT_VAR_AS_FUNCTION:FUNCTION:EC
+EC_GROUP_new_from_ecparameters          4777	EXIST::FUNCTION:EC
+EC_GROUP_get_ecparameters               4778	EXIST::FUNCTION:EC
+EC_GROUP_new_from_ecpkparameters        4779	EXIST::FUNCTION:EC
+EC_GROUP_get_ecpkparameters             4780	EXIST::FUNCTION:EC
-- 
2.0.5




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