Add Explicit EC parameter support to providers.

This was added for backward compatability.
Added EC_GROUP_new_from_params() that supports explicit curve parameters.

This fixes the 15-test_genec.t TODO.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12604)

3 files changed, 488 insertions, 22 deletions

diff --git a/test/ectest.c b/test/ectest.c
index 3678c42f71..9088fd166a 100644
--- a/test/ectest.c
+++ b/test/ectest.c
@@ -2340,6 +2340,225 @@ static int ec_point_hex2point_test(int id)
     return ret;
 }
 
+static int do_test_custom_explicit_fromdata(EC_GROUP *group, BN_CTX *ctx,
+                                            unsigned char *gen, int gen_size)
+{
+    int ret = 0, i_out;
+    EVP_PKEY_CTX *pctx = NULL;
+    EVP_PKEY *pkeyparam = NULL;
+    OSSL_PARAM_BLD *bld = NULL;
+    const char *field_name;
+    OSSL_PARAM *params = NULL;
+    const OSSL_PARAM *gettable;
+    BIGNUM *p, *a, *b;
+    BIGNUM *p_out = NULL, *a_out = NULL, *b_out = NULL;
+    BIGNUM *order_out = NULL, *cofactor_out = NULL;
+    char name[80];
+    unsigned char buf[1024];
+    size_t buf_len, name_len;
+#ifndef OPENSSL_NO_EC2M
+    unsigned int k1 = 0, k2 = 0, k3 = 0;
+    const char *basis_name = NULL;
+#endif
+
+    p = BN_CTX_get(ctx);
+    a = BN_CTX_get(ctx);
+    b = BN_CTX_get(ctx);
+
+    if (!TEST_ptr(b)
+        || !TEST_ptr(bld = OSSL_PARAM_BLD_new()))
+        goto err;
+
+    if (EC_GROUP_get_field_type(group) == NID_X9_62_prime_field) {
+        field_name = SN_X9_62_prime_field;
+    } else {
+        field_name = SN_X9_62_characteristic_two_field;
+#ifndef OPENSSL_NO_EC2M
+        if (EC_GROUP_get_basis_type(group) == NID_X9_62_tpBasis) {
+            basis_name = SN_X9_62_tpBasis;
+            if (!TEST_true(EC_GROUP_get_trinomial_basis(group, &k1)))
+                goto err;
+        } else {
+            basis_name = SN_X9_62_ppBasis;
+            if (!TEST_true(EC_GROUP_get_pentanomial_basis(group, &k1, &k2, &k3)))
+                goto err;
+        }
+#endif /* OPENSSL_NO_EC2M */
+    }
+    if (!TEST_true(EC_GROUP_get_curve(group, p, a, b, ctx))
+        || !TEST_true(OSSL_PARAM_BLD_push_utf8_string(bld,
+                          OSSL_PKEY_PARAM_EC_FIELD_TYPE, field_name, 0))
+        || !TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_P, p))
+        || !TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_A, a))
+        || !TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_B, b)))
+        goto err;
+
+    if (EC_GROUP_get0_seed(group) != NULL) {
+        if (!TEST_true(OSSL_PARAM_BLD_push_octet_string(bld,
+                           OSSL_PKEY_PARAM_EC_SEED, EC_GROUP_get0_seed(group),
+                           EC_GROUP_get_seed_len(group))))
+            goto err;
+    }
+    if (EC_GROUP_get0_cofactor(group) != NULL) {
+        if (!TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_COFACTOR,
+                                              EC_GROUP_get0_cofactor(group))))
+            goto err;
+    }
+
+    if (!TEST_true(OSSL_PARAM_BLD_push_octet_string(bld,
+                       OSSL_PKEY_PARAM_EC_GENERATOR, gen, gen_size))
+        || !TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_ORDER,
+                                             EC_GROUP_get0_order(group))))
+        goto err;
+
+    if (!TEST_ptr(params = OSSL_PARAM_BLD_to_param(bld))
+        || !TEST_ptr(pctx = EVP_PKEY_CTX_new_from_name(NULL, "EC", NULL))
+        || !TEST_int_gt(EVP_PKEY_param_fromdata_init(pctx), 0)
+        || !TEST_int_gt(EVP_PKEY_fromdata(pctx, &pkeyparam, params), 0))
+        goto err;
+
+    /*- Check that all the set values are retrievable -*/
+
+    /* There should be no match to a group name since the generator changed */
+    if (!TEST_false(EVP_PKEY_get_utf8_string_param(pkeyparam,
+                        OSSL_PKEY_PARAM_GROUP_NAME, name, sizeof(name),
+                        &name_len)))
+        goto err;
+
+    /* The encoding should be explicit as it has no group */
+    if (!TEST_true(EVP_PKEY_get_utf8_string_param(pkeyparam,
+                       OSSL_PKEY_PARAM_EC_ENCODING,
+                       name, sizeof(name), &name_len))
+        || !TEST_str_eq(name, OSSL_PKEY_EC_ENCODING_EXPLICIT))
+        goto err;
+
+    if (!TEST_true(EVP_PKEY_get_utf8_string_param(pkeyparam,
+                       OSSL_PKEY_PARAM_EC_FIELD_TYPE, name, sizeof(name),
+                       &name_len))
+        || !TEST_str_eq(name, field_name))
+        goto err;
+
+    if (!TEST_true(EVP_PKEY_get_octet_string_param(pkeyparam,
+                       OSSL_PKEY_PARAM_EC_GENERATOR, buf, sizeof(buf), &buf_len))
+        || !TEST_mem_eq(buf, (int)buf_len, gen, gen_size))
+        goto err;
+
+    if (!TEST_true(EVP_PKEY_get_bn_param(pkeyparam, OSSL_PKEY_PARAM_EC_P, &p_out))
+        || !TEST_BN_eq(p_out, p)
+        || !TEST_true(EVP_PKEY_get_bn_param(pkeyparam, OSSL_PKEY_PARAM_EC_A,
+                                            &a_out))
+        || !TEST_BN_eq(a_out, a)
+        || !TEST_true(EVP_PKEY_get_bn_param(pkeyparam, OSSL_PKEY_PARAM_EC_B,
+                                            &b_out))
+        || !TEST_BN_eq(b_out, b)
+        || !TEST_true(EVP_PKEY_get_bn_param(pkeyparam, OSSL_PKEY_PARAM_EC_ORDER,
+                                            &order_out))
+        || !TEST_BN_eq(order_out, EC_GROUP_get0_order(group)))
+        goto err;
+
+    if (EC_GROUP_get0_cofactor(group) != NULL) {
+        if (!TEST_true(EVP_PKEY_get_bn_param(pkeyparam,
+                           OSSL_PKEY_PARAM_EC_COFACTOR, &cofactor_out))
+            || !TEST_BN_eq(cofactor_out, EC_GROUP_get0_cofactor(group)))
+            goto err;
+    }
+    if (EC_GROUP_get0_seed(group) != NULL) {
+        if (!TEST_true(EVP_PKEY_get_octet_string_param(pkeyparam,
+                           OSSL_PKEY_PARAM_EC_SEED, buf, sizeof(buf), &buf_len))
+            || !TEST_mem_eq(buf, buf_len, EC_GROUP_get0_seed(group),
+                            EC_GROUP_get_seed_len(group)))
+            goto err;
+    }
+
+    if (EC_GROUP_get_field_type(group) == NID_X9_62_prime_field) {
+        /* No extra fields should be set for a prime field */
+        if (!TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                            OSSL_PKEY_PARAM_EC_CHAR2_M, &i_out))
+            || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS, &i_out))
+            || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_PP_K1, &i_out))
+            || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_PP_K2, &i_out))
+            || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_PP_K3, &i_out))
+            || !TEST_false(EVP_PKEY_get_utf8_string_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_TYPE, name, sizeof(name),
+                               &name_len)))
+            goto err;
+    } else {
+#ifndef OPENSSL_NO_EC2M
+        if (!TEST_true(EVP_PKEY_get_int_param(pkeyparam,
+                           OSSL_PKEY_PARAM_EC_CHAR2_M, &i_out))
+            || !TEST_int_eq(EC_GROUP_get_degree(group), i_out)
+            || !TEST_true(EVP_PKEY_get_utf8_string_param(pkeyparam,
+                              OSSL_PKEY_PARAM_EC_CHAR2_TYPE, name, sizeof(name),
+                              &name_len))
+            || !TEST_str_eq(name, basis_name))
+            goto err;
+
+        if (EC_GROUP_get_basis_type(group) == NID_X9_62_tpBasis) {
+            if (!TEST_true(EVP_PKEY_get_int_param(pkeyparam,
+                               OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS, &i_out))
+                || !TEST_int_eq(k1, i_out)
+                || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                                   OSSL_PKEY_PARAM_EC_CHAR2_PP_K1, &i_out))
+                || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                                   OSSL_PKEY_PARAM_EC_CHAR2_PP_K2, &i_out))
+                || !TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                                   OSSL_PKEY_PARAM_EC_CHAR2_PP_K3, &i_out)))
+                goto err;
+        } else {
+            if (!TEST_false(EVP_PKEY_get_int_param(pkeyparam,
+                                OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS, &i_out))
+                || !TEST_true(EVP_PKEY_get_int_param(pkeyparam,
+                                  OSSL_PKEY_PARAM_EC_CHAR2_PP_K1, &i_out))
+                || !TEST_int_eq(k1, i_out)
+                || !TEST_true(EVP_PKEY_get_int_param(pkeyparam,
+                                  OSSL_PKEY_PARAM_EC_CHAR2_PP_K2, &i_out))
+                || !TEST_int_eq(k2, i_out)
+                || !TEST_true(EVP_PKEY_get_int_param(pkeyparam,
+                                  OSSL_PKEY_PARAM_EC_CHAR2_PP_K3, &i_out))
+                || !TEST_int_eq(k3, i_out))
+                goto err;
+        }
+#endif /* OPENSSL_NO_EC2M */
+    }
+    if (!TEST_ptr(gettable = EVP_PKEY_gettable_params(pkeyparam))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_GROUP_NAME))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_ENCODING))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_FIELD_TYPE))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_P))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_A))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_B))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_GENERATOR))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_ORDER))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_COFACTOR))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_SEED))
+#ifndef OPENSSL_NO_EC2M
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_M))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_TYPE))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_PP_K1))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_PP_K2))
+        || !TEST_ptr(OSSL_PARAM_locate_const(gettable, OSSL_PKEY_PARAM_EC_CHAR2_PP_K3))
+#endif
+        )
+        goto err;
+    ret = 1;
+err:
+    BN_free(order_out);
+    BN_free(cofactor_out);
+    BN_free(a_out);
+    BN_free(b_out);
+    BN_free(p_out);
+    OSSL_PARAM_BLD_free_params(params);
+    OSSL_PARAM_BLD_free(bld);
+    EVP_PKEY_free(pkeyparam);
+    EVP_PKEY_CTX_free(pctx);
+    return ret;
+}
+
 /*
  * check the EC_METHOD respects the supplied EC_GROUP_set_generator G
  */
@@ -2406,14 +2625,17 @@ static int custom_generator_test(int id)
         || !TEST_mem_eq(b1, bsize, b2, bsize))
         goto err;
 
+    if (!do_test_custom_explicit_fromdata(group, ctx, b1, bsize))
+        goto err;
+
     ret = 1;
 
  err:
-    BN_CTX_end(ctx);
     EC_POINT_free(Q1);
     EC_POINT_free(Q2);
     EC_POINT_free(G2);
     EC_GROUP_free(group);
+    BN_CTX_end(ctx);
     BN_CTX_free(ctx);
     OPENSSL_free(b1);
     OPENSSL_free(b2);
diff --git a/test/endecode_test.c b/test/endecode_test.c
index 5f3fa3d220..0a2f5d0b40 100644
--- a/test/endecode_test.c
+++ b/test/endecode_test.c
@@ -12,7 +12,9 @@
 #include <openssl/pem.h>
 #include <openssl/rsa.h>
 #include <openssl/x509.h>
+#include <openssl/core_names.h>
 #include <openssl/params.h>
+#include <openssl/param_build.h>
 #include <openssl/encoder.h>
 #include <openssl/decoder.h>
 
@@ -21,6 +23,21 @@
 
 #include "testutil.h"
 
+#ifndef OPENSSL_NO_EC
+static BN_CTX *bnctx = NULL;
+static OSSL_PARAM_BLD *bld_prime_nc = NULL;
+static OSSL_PARAM_BLD *bld_prime = NULL;
+static OSSL_PARAM *ec_explicit_prime_params_nc = NULL;
+static OSSL_PARAM *ec_explicit_prime_params_explicit = NULL;
+
+# ifndef OPENSSL_NO_EC2M
+static OSSL_PARAM_BLD *bld_tri_nc = NULL;
+static OSSL_PARAM_BLD *bld_tri = NULL;
+static OSSL_PARAM *ec_explicit_tri_params_nc = NULL;
+static OSSL_PARAM *ec_explicit_tri_params_explicit = NULL;
+# endif
+#endif
+
 /*
  * TODO(3.0) Modify PEM_write_bio_PrivateKey_traditional() to handle
  * provider side EVP_PKEYs (which don't necessarily have an ameth)
@@ -75,7 +92,6 @@ static EVP_PKEY *make_key(const char *type, EVP_PKEY *template,
     return pkey;
 }
 
-
 /* Main test driver */
 
 /*
@@ -754,6 +770,16 @@ IMPLEMENT_TEST_SUITE_PVK(DSA, "DSA")
 #ifndef OPENSSL_NO_EC
 DOMAIN_KEYS(EC);
 IMPLEMENT_TEST_SUITE(EC, "EC")
+DOMAIN_KEYS(ECExplicitPrimeNamedCurve);
+IMPLEMENT_TEST_SUITE(ECExplicitPrimeNamedCurve, "EC")
+DOMAIN_KEYS(ECExplicitPrime2G);
+IMPLEMENT_TEST_SUITE(ECExplicitPrime2G, "EC")
+# ifndef OPENSSL_NO_EC2M
+DOMAIN_KEYS(ECExplicitTriNamedCurve);
+IMPLEMENT_TEST_SUITE(ECExplicitTriNamedCurve, "EC")
+DOMAIN_KEYS(ECExplicitTri2G);
+IMPLEMENT_TEST_SUITE(ECExplicitTri2G, "EC")
+# endif
 KEYS(ED25519);
 IMPLEMENT_TEST_SUITE(ED25519, "ED25519")
 KEYS(ED448);
@@ -774,6 +800,189 @@ IMPLEMENT_TEST_SUITE_PVK(RSA, "RSA")
 # endif
 #endif
 
+#ifndef OPENSSL_NO_EC
+/* Explicit parameters that match a named curve */
+static int do_create_ec_explicit_prime_params(OSSL_PARAM_BLD *bld,
+                                              const unsigned char *gen,
+                                              size_t gen_len)
+{
+    BIGNUM *a, *b, *prime, *order;
+
+    /* Curve prime256v1 */
+    static const unsigned char prime_data[] = {
+        0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00,
+        0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff
+    };
+    static const unsigned char a_data[] = {
+        0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00,
+        0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xfc
+    };
+    static const unsigned char b_data[] = {
+        0x5a, 0xc6, 0x35, 0xd8, 0xaa, 0x3a, 0x93, 0xe7,
+        0xb3, 0xeb, 0xbd, 0x55, 0x76, 0x98, 0x86, 0xbc,
+        0x65, 0x1d, 0x06, 0xb0, 0xcc, 0x53, 0xb0, 0xf6,
+        0x3b, 0xce, 0x3c, 0x3e, 0x27, 0xd2, 0x60, 0x4b
+    };
+    static const unsigned char seed[] = {
+        0xc4, 0x9d, 0x36, 0x08, 0x86, 0xe7, 0x04, 0x93,
+        0x6a, 0x66, 0x78, 0xe1, 0x13, 0x9d, 0x26, 0xb7,
+        0x81, 0x9f, 0x7e, 0x90
+    };
+    static const unsigned char order_data[] = {
+        0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00,
+        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xbc, 0xe6, 0xfa, 0xad, 0xa7, 0x17, 0x9e,
+        0x84, 0xf3, 0xb9, 0xca, 0xc2, 0xfc, 0x63, 0x25, 0x51
+    };
+    return TEST_ptr(a = BN_CTX_get(bnctx))
+           && TEST_ptr(b = BN_CTX_get(bnctx))
+           && TEST_ptr(prime = BN_CTX_get(bnctx))
+           && TEST_ptr(order = BN_CTX_get(bnctx))
+           && TEST_ptr(BN_bin2bn(prime_data, sizeof(prime_data), prime))
+           && TEST_ptr(BN_bin2bn(a_data, sizeof(a_data), a))
+           && TEST_ptr(BN_bin2bn(b_data, sizeof(b_data), b))
+           && TEST_ptr(BN_bin2bn(order_data, sizeof(order_data), order))
+           && TEST_true(OSSL_PARAM_BLD_push_utf8_string(bld,
+                            OSSL_PKEY_PARAM_EC_FIELD_TYPE, SN_X9_62_prime_field,
+                            0))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_P, prime))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_A, a))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_B, b))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld,
+                            OSSL_PKEY_PARAM_EC_ORDER, order))
+           && TEST_true(OSSL_PARAM_BLD_push_octet_string(bld,
+                            OSSL_PKEY_PARAM_EC_GENERATOR, gen, gen_len))
+           && TEST_true(OSSL_PARAM_BLD_push_octet_string(bld,
+                            OSSL_PKEY_PARAM_EC_SEED, seed, sizeof(seed)))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_COFACTOR,
+                                               BN_value_one()));
+}
+
+static int create_ec_explicit_prime_params_namedcurve(OSSL_PARAM_BLD *bld)
+{
+    static const unsigned char prime256v1_gen[] = {
+        0x04,
+        0x6b, 0x17, 0xd1, 0xf2, 0xe1, 0x2c, 0x42, 0x47,
+        0xf8, 0xbc, 0xe6, 0xe5, 0x63, 0xa4, 0x40, 0xf2,
+        0x77, 0x03, 0x7d, 0x81, 0x2d, 0xeb, 0x33, 0xa0,
+        0xf4, 0xa1, 0x39, 0x45, 0xd8, 0x98, 0xc2, 0x96,
+        0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b,
+        0x8e, 0xe7, 0xeb, 0x4a, 0x7c, 0x0f, 0x9e, 0x16,
+        0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce,
+        0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5
+    };
+    return do_create_ec_explicit_prime_params(bld, prime256v1_gen,
+                                              sizeof(prime256v1_gen));
+}
+
+static int create_ec_explicit_prime_params(OSSL_PARAM_BLD *bld)
+{
+    /* 2G */
+    static const unsigned char prime256v1_gen2[] = {
+        0x04,
+        0xe4, 0x97, 0x08, 0xbe, 0x7d, 0xfa, 0xa2, 0x9a,
+        0xa3, 0x12, 0x6f, 0xe4, 0xe7, 0xd0, 0x25, 0xe3,
+        0x4a, 0xc1, 0x03, 0x15, 0x8c, 0xd9, 0x33, 0xc6,
+        0x97, 0x42, 0xf5, 0xdc, 0x97, 0xb9, 0xd7, 0x31,
+        0xe9, 0x7d, 0x74, 0x3d, 0x67, 0x6a, 0x3b, 0x21,
+        0x08, 0x9c, 0x31, 0x73, 0xf8, 0xc1, 0x27, 0xc9,
+        0xd2, 0xa0, 0xa0, 0x83, 0x66, 0xe0, 0xc9, 0xda,
+        0xa8, 0xc6, 0x56, 0x2b, 0x94, 0xb1, 0xae, 0x55
+    };
+    return do_create_ec_explicit_prime_params(bld, prime256v1_gen2,
+                                              sizeof(prime256v1_gen2));
+}
+
+# ifndef OPENSSL_NO_EC2M
+static int do_create_ec_explicit_trinomial_params(OSSL_PARAM_BLD *bld,
+                                                  const unsigned char *gen,
+                                                  size_t gen_len)
+{
+    BIGNUM *a, *b, *poly, *order, *cofactor;
+    /* sect233k1 characteristic-two-field tpBasis */
+    static const unsigned char poly_data[] = {
+        0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+    };
+    static const unsigned char a_data[] = {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+    };
+    static const unsigned char b_data[] = {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x01
+    };
+    static const unsigned char order_data[] = {
+        0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x06, 0x9D, 0x5B, 0xB9, 0x15, 0xBC, 0xD4, 0x6E, 0xFB,
+        0x1A, 0xD5, 0xF1, 0x73, 0xAB, 0xDF
+    };
+    static const unsigned char cofactor_data[]= {
+        0x4
+    };
+    return TEST_ptr(a = BN_CTX_get(bnctx))
+           && TEST_ptr(b = BN_CTX_get(bnctx))
+           && TEST_ptr(poly = BN_CTX_get(bnctx))
+           && TEST_ptr(order = BN_CTX_get(bnctx))
+           && TEST_ptr(cofactor = BN_CTX_get(bnctx))
+           && TEST_ptr(BN_bin2bn(poly_data, sizeof(poly_data), poly))
+           && TEST_ptr(BN_bin2bn(a_data, sizeof(a_data), a))
+           && TEST_ptr(BN_bin2bn(b_data, sizeof(b_data), b))
+           && TEST_ptr(BN_bin2bn(order_data, sizeof(order_data), order))
+           && TEST_ptr(BN_bin2bn(cofactor_data, sizeof(cofactor_data), cofactor))
+           && TEST_true(OSSL_PARAM_BLD_push_utf8_string(bld,
+                            OSSL_PKEY_PARAM_EC_FIELD_TYPE,
+                            SN_X9_62_characteristic_two_field, 0))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_P, poly))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_A, a))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_B, b))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld,
+                            OSSL_PKEY_PARAM_EC_ORDER, order))
+           && TEST_true(OSSL_PARAM_BLD_push_octet_string(bld,
+                            OSSL_PKEY_PARAM_EC_GENERATOR, gen, gen_len))
+           && TEST_true(OSSL_PARAM_BLD_push_BN(bld, OSSL_PKEY_PARAM_EC_COFACTOR,
+                                               cofactor));
+}
+
+static int create_ec_explicit_trinomial_params_namedcurve(OSSL_PARAM_BLD *bld)
+{
+    static const unsigned char gen[] = {
+        0x04,
+        0x01, 0x72, 0x32, 0xBA, 0x85, 0x3A, 0x7E, 0x73, 0x1A, 0xF1, 0x29, 0xF2,
+        0x2F, 0xF4, 0x14, 0x95, 0x63, 0xA4, 0x19, 0xC2, 0x6B, 0xF5, 0x0A, 0x4C,
+        0x9D, 0x6E, 0xEF, 0xAD, 0x61, 0x26,
+        0x01, 0xDB, 0x53, 0x7D, 0xEC, 0xE8, 0x19, 0xB7, 0xF7, 0x0F, 0x55, 0x5A,
+        0x67, 0xC4, 0x27, 0xA8, 0xCD, 0x9B, 0xF1, 0x8A, 0xEB, 0x9B, 0x56, 0xE0,
+        0xC1, 0x10, 0x56, 0xFA, 0xE6, 0xA3
+    };
+    return do_create_ec_explicit_trinomial_params(bld, gen, sizeof(gen));
+}
+
+static int create_ec_explicit_trinomial_params(OSSL_PARAM_BLD *bld)
+{
+    static const unsigned char gen2[] = {
+        0x04,
+        0x00, 0xd7, 0xba, 0xd0, 0x26, 0x6c, 0x31, 0x6a, 0x78, 0x76, 0x01, 0xd1,
+        0x32, 0x4b, 0x8f, 0x30, 0x29, 0x2d, 0x78, 0x30, 0xca, 0x43, 0xaa, 0xf0,
+        0xa2, 0x5a, 0xd4, 0x0f, 0xb3, 0xf4,
+        0x00, 0x85, 0x4b, 0x1b, 0x8d, 0x50, 0x10, 0xa5, 0x1c, 0x80, 0xf7, 0x86,
+        0x40, 0x62, 0x4c, 0x87, 0xd1, 0x26, 0x7a, 0x9c, 0x5c, 0xe9, 0x82, 0x29,
+        0xd1, 0x67, 0x70, 0x41, 0xea, 0xcb
+    };
+    return do_create_ec_explicit_trinomial_params(bld, gen2, sizeof(gen2));
+}
+# endif /* OPENSSL_NO_EC2M */
+#endif /* OPENSSL_NO_EC */
+
 int setup_tests(void)
 {
     int ok = 1;
@@ -803,7 +1012,28 @@ int setup_tests(void)
         OSSL_PARAM_END
     };
 
+#ifndef OPENSSL_NO_EC
+    if (!TEST_ptr(bnctx = BN_CTX_new_ex(NULL))
+        || !TEST_ptr(bld_prime_nc = OSSL_PARAM_BLD_new())
+        || !TEST_ptr(bld_prime = OSSL_PARAM_BLD_new())
+        || !create_ec_explicit_prime_params_namedcurve(bld_prime_nc)
+        || !create_ec_explicit_prime_params(bld_prime)
+        || !TEST_ptr(ec_explicit_prime_params_nc = OSSL_PARAM_BLD_to_param(bld_prime_nc))
+        || !TEST_ptr(ec_explicit_prime_params_explicit = OSSL_PARAM_BLD_to_param(bld_prime))
+# ifndef OPENSSL_NO_EC2M
+        || !TEST_ptr(bld_tri_nc = OSSL_PARAM_BLD_new())
+        || !TEST_ptr(bld_tri = OSSL_PARAM_BLD_new())
+        || !create_ec_explicit_trinomial_params_namedcurve(bld_tri_nc)
+        || !create_ec_explicit_trinomial_params(bld_tri)
+        || !TEST_ptr(ec_explicit_tri_params_nc = OSSL_PARAM_BLD_to_param(bld_tri_nc))
+        || !TEST_ptr(ec_explicit_tri_params_explicit = OSSL_PARAM_BLD_to_param(bld_tri))
+# endif
+        )
+        return 0;
+#endif
+
     TEST_info("Generating keys...");
+
 #ifndef OPENSSL_NO_DH
     MAKE_DOMAIN_KEYS(DH, "DH", NULL);
     MAKE_DOMAIN_KEYS(DHX, "X9.42 DH", NULL);
@@ -813,6 +1043,12 @@ int setup_tests(void)
 #endif
 #ifndef OPENSSL_NO_EC
     MAKE_DOMAIN_KEYS(EC, "EC", EC_params);
+    MAKE_DOMAIN_KEYS(ECExplicitPrimeNamedCurve, "EC", ec_explicit_prime_params_nc);
+    MAKE_DOMAIN_KEYS(ECExplicitPrime2G, "EC", ec_explicit_prime_params_explicit);
+# ifndef OPENSSL_NO_EC2M
+    MAKE_DOMAIN_KEYS(ECExplicitTriNamedCurve, "EC", ec_explicit_tri_params_nc);
+    MAKE_DOMAIN_KEYS(ECExplicitTri2G, "EC", ec_explicit_tri_params_explicit);
+# endif
     MAKE_KEYS(ED25519, "ED25519", NULL);
     MAKE_KEYS(ED448, "ED448", NULL);
     MAKE_KEYS(X25519, "X25519", NULL);
@@ -836,6 +1072,12 @@ int setup_tests(void)
 #endif
 #ifndef OPENSSL_NO_EC
         ADD_TEST_SUITE(EC);
+        ADD_TEST_SUITE(ECExplicitPrimeNamedCurve);
+        ADD_TEST_SUITE(ECExplicitPrime2G);
+# ifndef OPENSSL_NO_EC2M
+        ADD_TEST_SUITE(ECExplicitTriNamedCurve);
+        ADD_TEST_SUITE(ECExplicitTri2G);
+# endif
         ADD_TEST_SUITE(ED25519);
         ADD_TEST_SUITE(ED448);
         ADD_TEST_SUITE(X25519);
@@ -856,6 +1098,20 @@ int setup_tests(void)
 
 void cleanup_tests(void)
 {
+#ifndef OPENSSL_NO_EC
+    OSSL_PARAM_BLD_free_params(ec_explicit_prime_params_nc);
+    OSSL_PARAM_BLD_free_params(ec_explicit_prime_params_explicit);
+    OSSL_PARAM_BLD_free(bld_prime_nc);
+    OSSL_PARAM_BLD_free(bld_prime);
+# ifndef OPENSSL_NO_EC2M
+    OSSL_PARAM_BLD_free_params(ec_explicit_tri_params_nc);
+    OSSL_PARAM_BLD_free_params(ec_explicit_tri_params_explicit);
+    OSSL_PARAM_BLD_free(bld_tri_nc);
+    OSSL_PARAM_BLD_free(bld_tri);
+# endif
+    BN_CTX_free(bnctx);
+#endif /* OPENSSL_NO_EC */
+
 #ifndef OPENSSL_NO_DH
     FREE_DOMAIN_KEYS(DH);
     FREE_DOMAIN_KEYS(DHX);
@@ -865,6 +1121,12 @@ void cleanup_tests(void)
 #endif
 #ifndef OPENSSL_NO_EC
     FREE_DOMAIN_KEYS(EC);
+    FREE_DOMAIN_KEYS(ECExplicitPrimeNamedCurve);
+    FREE_DOMAIN_KEYS(ECExplicitPrime2G);
+# ifndef OPENSSL_NO_EC2M
+    FREE_DOMAIN_KEYS(ECExplicitTriNamedCurve);
+    FREE_DOMAIN_KEYS(ECExplicitTri2G);
+# endif
     FREE_KEYS(ED25519);
     FREE_KEYS(ED448);
     FREE_KEYS(X25519);
diff --git a/test/recipes/15-test_genec.t b/test/recipes/15-test_genec.t
index 20ddd4026d..2dfed387ca 100644
--- a/test/recipes/15-test_genec.t
+++ b/test/recipes/15-test_genec.t
@@ -29,30 +29,12 @@ sub supported_pass {
     ok(run(@_), $str);
 }
 
-sub unsupported_pass {
-    my $str = shift;
- TODO: {
-        local $TODO = "Currently not supported";
-
-        ok(run(@_), $str);
-    }
-}
-
 sub supported_fail {
     my $str = shift;
 
     ok(!run(@_), $str);
 }
 
-sub unsupported_fail {
-    my $str = shift;
- TODO: {
-        local $TODO = "Currently not supported";
-
-        ok(!run(@_), $str);
-    }
-}
-
 setup("test_genec");
 
 plan skip_all => "This test is unsupported in a no-ec build"
@@ -183,7 +165,7 @@ push(@curve_list, @curve_aliases);
 my %params_encodings =
     (
      'named_curve'      => \&supported_pass,
-     'explicit'         => \&unsupported_pass
+     'explicit'         => \&supported_pass
     );
 
 my @output_formats = ('PEM', 'DER');
@@ -273,7 +255,7 @@ subtest "test curves that only support explicit parameters encoding" => sub {
     my %params_encodings =
         (
          'named_curve'      => \&supported_fail,
-         'explicit'         => \&unsupported_pass
+         'explicit'         => \&supported_pass
         );
 
     foreach my $curvename (@explicit_only_curves) {