Merge pull request #5642 from mprse/ecp_export
Add ECP keypair export function
diff --git a/ChangeLog.d/mbedtls_ecp_export.txt b/ChangeLog.d/mbedtls_ecp_export.txt
new file mode 100644
index 0000000..4b5d7d4
--- /dev/null
+++ b/ChangeLog.d/mbedtls_ecp_export.txt
@@ -0,0 +1,3 @@
+Features
+ * Add mbedtls_ecp_export() function to export ECP
+ keypair parameters. Fixes #4838.
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 9895573..395db14 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -1278,6 +1278,26 @@
const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+/**
+ * \brief This function exports generic key-pair parameters.
+ *
+ * \param key The key pair to export from.
+ * \param grp Slot for exported ECP group.
+ * It must point to an initialized ECP group.
+ * \param d Slot for the exported secret value.
+ * It must point to an initialized mpi.
+ * \param Q Slot for the exported public value.
+ * It must point to an initialized ECP point.
+ *
+ * \return \c 0 on success,
+ * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if key id doesn't
+ * correspond to a known group.
+ * \return Another negative error code on other kinds of failure.
+ */
+int mbedtls_ecp_export(const mbedtls_ecp_keypair *key, mbedtls_ecp_group *grp,
+ mbedtls_mpi *d, mbedtls_ecp_point *Q);
+
#if defined(MBEDTLS_SELF_TEST)
/**
diff --git a/library/ecp.c b/library/ecp.c
index ba76abb..f39cb02 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -3356,6 +3356,26 @@
return( ret );
}
+/*
+ * Export generic key-pair parameters.
+ */
+int mbedtls_ecp_export(const mbedtls_ecp_keypair *key, mbedtls_ecp_group *grp,
+ mbedtls_mpi *d, mbedtls_ecp_point *Q)
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ if( ( ret = mbedtls_ecp_group_copy( grp, &key->grp ) ) != 0 )
+ return ret;
+
+ if( ( ret = mbedtls_mpi_copy( d, &key->d ) ) != 0 )
+ return ret;
+
+ if( ( ret = mbedtls_ecp_copy( Q, &key->Q ) ) != 0 )
+ return ret;
+
+ return 0;
+}
+
#if defined(MBEDTLS_SELF_TEST)
/*
diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index 0c30e4a..2eb8c2d 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -882,3 +882,11 @@
# The first call to fix_negative in the test case of issue #4296.
ECP fix_negative: #4296.1
fix_negative:"8A4DD4C8B42C5EAED15FE4F4579F4CE513EC90A94010BF000000000000000000":-1:256
+
+ECP export key parameters #1 (OK)
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_export:MBEDTLS_ECP_DP_SECP256R1:"37cc56d976091e5a723ec7592dff206eee7cf9069174d0ad14b5f76822596292":"4ee500d82311ffea2fd2345d5d16bd8a88c26b770d55cd8a2a0efa01c8b4edff":"00f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":0:0
+
+ECP export key parameters #2 (invalid group)
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_export:MBEDTLS_ECP_DP_SECP256R1:"37cc56d976091e5a723ec7592dff206eee7cf9069174d0ad14b5f76822596292":"4ee500d82311ffea2fd2345d5d16bd8a88c26b770d55cd8a2a0efa01c8b4edff":"00f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:1
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 2afc355..c3e6b05 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -16,6 +16,44 @@
mbedtls_ecp_point_free( x ); \
mbedtls_ecp_point_init( x );
+/* Auxiliary function to compare two mbedtls_ecp_group objects. */
+inline static int mbedtls_ecp_group_cmp( mbedtls_ecp_group *grp1,
+ mbedtls_ecp_group *grp2 )
+{
+ if( mbedtls_mpi_cmp_mpi( &grp1->P, &grp2->P ) != 0 )
+ return 1;
+ if( mbedtls_mpi_cmp_mpi( &grp1->A, &grp2->A ) != 0 )
+ return 1;
+ if( mbedtls_mpi_cmp_mpi( &grp1->B, &grp2->B ) != 0 )
+ return 1;
+ if( mbedtls_mpi_cmp_mpi( &grp1->N, &grp2->N ) != 0 )
+ return 1;
+ if( mbedtls_ecp_point_cmp( &grp1->G, &grp2->G ) != 0 )
+ return 1;
+ if( grp1->id != grp2->id )
+ return 1;
+ if( grp1->pbits != grp2->pbits )
+ return 1;
+ if( grp1->nbits != grp2->nbits )
+ return 1;
+ if( grp1->h != grp2->h )
+ return 1;
+ if( grp1->modp != grp2->modp )
+ return 1;
+ if( grp1->t_pre != grp2->t_pre )
+ return 1;
+ if( grp1->t_post != grp2->t_post )
+ return 1;
+ if( grp1->t_data != grp2->t_data )
+ return 1;
+ if( grp1->T_size != grp2->T_size )
+ return 1;
+ if( grp1->T != grp2->T )
+ return 1;
+
+ return 0;
+}
+
/* END_HEADER */
/* BEGIN_DEPENDENCIES
@@ -988,3 +1026,40 @@
TEST_ASSERT( mbedtls_ecp_self_test( 1 ) == 0 );
}
/* END_CASE */
+
+/* BEGIN_CASE */
+void ecp_export( int id, char * Qx, char * Qy,char * d, int expected_ret, int invalid_grp )
+{
+ mbedtls_ecp_keypair key;
+ mbedtls_ecp_group export_grp;
+ mbedtls_mpi export_d;
+ mbedtls_ecp_point export_Q;
+
+ mbedtls_ecp_group_init( &export_grp );
+ mbedtls_ecp_group_init( &key.grp );
+ mbedtls_mpi_init( &export_d );
+ mbedtls_ecp_point_init( &export_Q );
+
+ mbedtls_ecp_keypair_init( &key );
+ if( invalid_grp == 0 )
+ TEST_ASSERT( mbedtls_ecp_group_load( &key.grp, id ) == 0 );
+ TEST_ASSERT( mbedtls_ecp_point_read_string( &key.Q, 16, Qx, Qy ) == 0 );
+ TEST_ASSERT( mbedtls_test_read_mpi( &key.d, 16, d ) == 0 );
+
+ TEST_EQUAL( mbedtls_ecp_export( &key, &export_grp,
+ &export_d, &export_Q ), expected_ret );
+
+ if( expected_ret == 0 )
+ {
+ TEST_EQUAL( mbedtls_ecp_point_cmp( &key.Q, &export_Q ), 0 );
+ TEST_EQUAL( mbedtls_mpi_cmp_mpi( &key.d, &export_d ), 0 );
+ TEST_EQUAL( mbedtls_ecp_group_cmp( &key.grp, &export_grp ), 0 );
+ }
+
+exit:
+ mbedtls_ecp_keypair_free( &key );
+ mbedtls_ecp_group_free( &export_grp );
+ mbedtls_mpi_free( &export_d );
+ mbedtls_ecp_point_free( &export_Q );
+}
+/* END_CASE */