mbedtls_ecp_write_key_ext(): new function
Same as mbedtls_ecp_write_key(), but doesn't require the caller to figure out
the length of the output and possibly distinguish between Weierstrass and
Montgomery curves.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 9cf0ce1..c061275 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1296,6 +1296,42 @@
}
/* END_CASE */
+/* BEGIN_CASE */
+void ecp_write_key_ext(int grp_id, data_t *in_key,
+ int exported_size, int expected_ret)
+{
+ mbedtls_ecp_keypair key;
+ mbedtls_ecp_keypair_init(&key);
+ unsigned char *exported = NULL;
+
+ if (in_key->len != 0) {
+ TEST_EQUAL(mbedtls_ecp_read_key(grp_id, &key, in_key->x, in_key->len), 0);
+ } else if (grp_id != MBEDTLS_ECP_DP_NONE) {
+ TEST_EQUAL(mbedtls_ecp_group_load(&key.grp, grp_id), 0);
+ }
+
+ TEST_CALLOC(exported, exported_size);
+ size_t olen = 0xdeadbeef;
+ TEST_EQUAL(mbedtls_ecp_write_key_ext(&key, &olen, exported, exported_size),
+ expected_ret);
+
+ if (expected_ret == 0) {
+ TEST_EQUAL(olen, (key.grp.nbits + 7) / 8);
+ TEST_LE_U(olen, MBEDTLS_ECP_MAX_BYTES);
+ TEST_MEMORY_COMPARE(in_key->x, in_key->len,
+ exported, olen);
+ } else {
+ /* Robustness check: even in the error case, insist that olen is less
+ * than the buffer size. */
+ TEST_LE_U(olen, exported_size);
+ }
+
+exit:
+ mbedtls_ecp_keypair_free(&key);
+ mbedtls_free(exported);
+}
+/* END_CASE */
+
/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_MONTGOMERY_ENABLED:MBEDTLS_ECP_LIGHT */
void genkey_mx_known_answer(int bits, data_t *seed, data_t *expected)
{