[PROV][KMGMT][KEXCH][EC] Implement EC keymgtm and ECDH

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10631)

7 files changed, 1273 insertions, 0 deletions

diff --git a/providers/defltprov.c b/providers/defltprov.c
index 6740a8e58f..3819c61659 100644
--- a/providers/defltprov.c
+++ b/providers/defltprov.c
@@ -373,6 +373,7 @@ static const OSSL_ALGORITHM deflt_keyexch[] = {
     { "DH:dhKeyAgreement", "default=yes", dh_keyexch_functions },
 #endif
 #ifndef OPENSSL_NO_EC
+    { "ECDH:id-ecPublicKey", "default=yes", ecdh_keyexch_functions },
     { "X25519", "default=yes", x25519_keyexch_functions },
     { "X448", "default=yes", x448_keyexch_functions },
 #endif
@@ -400,6 +401,7 @@ static const OSSL_ALGORITHM deflt_keymgmt[] = {
 #endif
     { "RSA:rsaEncryption", "default=yes", rsa_keymgmt_functions },
 #ifndef OPENSSL_NO_EC
+    { "EC:id-ecPublicKey", "default=yes", ec_keymgmt_functions },
     { "X25519", "default=yes", x25519_keymgmt_functions },
     { "X448", "default=yes", x448_keymgmt_functions },
 #endif
diff --git a/providers/implementations/exchange/build.info b/providers/implementations/exchange/build.info
index 51d32fc090..82b688def3 100644
--- a/providers/implementations/exchange/build.info
+++ b/providers/implementations/exchange/build.info
@@ -3,6 +3,7 @@
 
 $DH_GOAL=../../libimplementations.a
 $ECX_GOAL=../../libimplementations.a
+$ECDH_GOAL=../../libimplementations.a
 
 IF[{- !$disabled{dh} -}]
   SOURCE[$DH_GOAL]=dh_exch.c
@@ -21,4 +22,5 @@ ENDIF
 IF[{- !$disabled{ec} -}]
   SOURCE[$ECX_GOAL]=ecx_exch.c
   DEFINE[$ECX_GOAL]=$ECDEF
+  SOURCE[$ECDH_GOAL]=ecdh_exch.c
 ENDIF
diff --git a/providers/implementations/exchange/ecdh_exch.c b/providers/implementations/exchange/ecdh_exch.c
new file mode 100644
index 0000000000..bf353fa175
--- /dev/null
+++ b/providers/implementations/exchange/ecdh_exch.c
@@ -0,0 +1,533 @@
+/*
+ * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * ECDH low level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+
+#include <string.h>
+#include <openssl/crypto.h>
+#include <openssl/evp.h>
+#include <openssl/core_numbers.h>
+#include <openssl/core_names.h>
+#include <openssl/ec.h>
+#include <openssl/params.h>
+#include <openssl/err.h>
+#include "prov/provider_ctx.h"
+#include "prov/implementations.h"
+#include "crypto/ec.h" /* ecdh_KDF_X9_63() */
+
+static OSSL_OP_keyexch_newctx_fn ecdh_newctx;
+static OSSL_OP_keyexch_init_fn ecdh_init;
+static OSSL_OP_keyexch_set_peer_fn ecdh_set_peer;
+static OSSL_OP_keyexch_derive_fn ecdh_derive;
+static OSSL_OP_keyexch_freectx_fn ecdh_freectx;
+static OSSL_OP_keyexch_dupctx_fn ecdh_dupctx;
+static OSSL_OP_keyexch_set_ctx_params_fn ecdh_set_ctx_params;
+static OSSL_OP_keyexch_settable_ctx_params_fn ecdh_settable_ctx_params;
+static OSSL_OP_keyexch_get_ctx_params_fn ecdh_get_ctx_params;
+static OSSL_OP_keyexch_gettable_ctx_params_fn ecdh_gettable_ctx_params;
+
+enum kdf_type {
+    PROV_ECDH_KDF_NONE = 0,
+    PROV_ECDH_KDF_X9_63
+};
+
+/*
+ * What's passed as an actual key is defined by the KEYMGMT interface.
+ * We happen to know that our KEYMGMT simply passes EC_KEY structures, so
+ * we use that here too.
+ */
+
+typedef struct {
+    OPENSSL_CTX *libctx;
+
+    EC_KEY *k;
+    EC_KEY *peerk;
+
+    /*
+     * ECDH cofactor mode:
+     *
+     *  . 0  disabled
+     *  . 1  enabled
+     *  . -1 use cofactor mode set for k
+     */
+    int cofactor_mode;
+
+    /************
+     * ECDH KDF *
+     ************/
+    /* KDF (if any) to use for ECDH */
+    enum kdf_type kdf_type;
+    /* Message digest to use for key derivation */
+    EVP_MD *kdf_md;
+    /* User key material */
+    unsigned char *kdf_ukm;
+    size_t kdf_ukmlen;
+    /* KDF output length */
+    size_t kdf_outlen;
+} PROV_ECDH_CTX;
+
+static
+void *ecdh_newctx(void *provctx)
+{
+    PROV_ECDH_CTX *pectx = OPENSSL_zalloc(sizeof(*pectx));
+
+    if (pectx == NULL)
+        return NULL;
+
+    pectx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
+    pectx->cofactor_mode = -1;
+    pectx->kdf_type = PROV_ECDH_KDF_NONE;
+
+    return (void *)pectx;
+}
+
+static
+int ecdh_init(void *vpecdhctx, void *vecdh)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+
+    if (pecdhctx == NULL || vecdh == NULL || !EC_KEY_up_ref(vecdh))
+        return 0;
+    EC_KEY_free(pecdhctx->k);
+    pecdhctx->k = vecdh;
+    pecdhctx->cofactor_mode = -1;
+    pecdhctx->kdf_type = PROV_ECDH_KDF_NONE;
+    return 1;
+}
+
+static
+int ecdh_set_peer(void *vpecdhctx, void *vecdh)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+
+    if (pecdhctx == NULL || vecdh == NULL || !EC_KEY_up_ref(vecdh))
+        return 0;
+    EC_KEY_free(pecdhctx->peerk);
+    pecdhctx->peerk = vecdh;
+    return 1;
+}
+
+static
+void ecdh_freectx(void *vpecdhctx)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+
+    EC_KEY_free(pecdhctx->k);
+    EC_KEY_free(pecdhctx->peerk);
+
+    EVP_MD_free(pecdhctx->kdf_md);
+    OPENSSL_clear_free(pecdhctx->kdf_ukm, pecdhctx->kdf_ukmlen);
+
+    OPENSSL_free(pecdhctx);
+}
+
+static
+void *ecdh_dupctx(void *vpecdhctx)
+{
+    PROV_ECDH_CTX *srcctx = (PROV_ECDH_CTX *)vpecdhctx;
+    PROV_ECDH_CTX *dstctx;
+
+    dstctx = OPENSSL_zalloc(sizeof(*srcctx));
+    if (dstctx == NULL)
+        return NULL;
+
+    *dstctx = *srcctx;
+
+    /* clear all pointers */
+
+    dstctx->k= NULL;
+    dstctx->peerk = NULL;
+    dstctx->kdf_md = NULL;
+    dstctx->kdf_ukm = NULL;
+
+    /* up-ref all ref-counted objects referenced in dstctx */
+
+    if (srcctx->k != NULL && !EC_KEY_up_ref(srcctx->k))
+        goto err;
+    else
+        dstctx->k = srcctx->k;
+
+    if (srcctx->peerk != NULL && !EC_KEY_up_ref(srcctx->peerk))
+        goto err;
+    else
+        dstctx->peerk = srcctx->peerk;
+
+    if (srcctx->kdf_md != NULL && !EVP_MD_up_ref(srcctx->kdf_md))
+        goto err;
+    else
+        dstctx->kdf_md = srcctx->kdf_md;
+
+    /* Duplicate UKM data if present */
+    if (srcctx->kdf_ukm != NULL && srcctx->kdf_ukmlen > 0) {
+        dstctx->kdf_ukm = OPENSSL_memdup(srcctx->kdf_ukm,
+                                         srcctx->kdf_ukmlen);
+        if (dstctx->kdf_ukm == NULL)
+            goto err;
+    }
+
+    return dstctx;
+
+ err:
+    ecdh_freectx(dstctx);
+    return NULL;
+}
+
+static
+int ecdh_set_ctx_params(void *vpecdhctx, const OSSL_PARAM params[])
+{
+    char name[80] = { '\0' }; /* should be big enough */
+    char *str = NULL;
+    PROV_ECDH_CTX *pectx = (PROV_ECDH_CTX *)vpecdhctx;
+    const OSSL_PARAM *p;
+
+    if (pectx == NULL || params == NULL)
+        return 0;
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE);
+    if (p != NULL) {
+        int mode;
+
+        if (!OSSL_PARAM_get_int(p, &mode))
+            return 0;
+
+        if (mode < -1 || mode > 1)
+            return 0;
+
+        pectx->cofactor_mode = mode;
+    }
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_TYPE);
+    if (p != NULL) {
+        str = name;
+        if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name)))
+            return 0;
+
+        if (name[0] == '\0')
+            pectx->kdf_type = PROV_ECDH_KDF_NONE;
+        else if (strcmp(name, OSSL_KDF_NAME_X963KDF) == 0)
+            pectx->kdf_type = PROV_ECDH_KDF_X9_63;
+        else
+            return 0;
+    }
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST);
+    if (p != NULL) {
+        char mdprops[80] = { '\0' }; /* should be big enough */
+
+        str = name;
+        if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name)))
+            return 0;
+
+        str = mdprops;
+        p = OSSL_PARAM_locate_const(params,
+                                    OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS);
+
+        if (p != NULL) {
+            if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
+                return 0;
+        }
+
+        EVP_MD_free(pectx->kdf_md);
+        pectx->kdf_md = EVP_MD_fetch(pectx->libctx, name, mdprops);
+
+        if (pectx->kdf_md == NULL)
+            return 0;
+    }
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN);
+    if (p != NULL) {
+        size_t outlen;
+
+        if (!OSSL_PARAM_get_size_t(p, &outlen))
+            return 0;
+        pectx->kdf_outlen = outlen;
+    }
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_UKM);
+    if (p != NULL) {
+        void *tmp_ukm = NULL;
+        size_t tmp_ukmlen;
+
+        if (!OSSL_PARAM_get_octet_string(p, &tmp_ukm, 0, &tmp_ukmlen))
+            return 0;
+        OPENSSL_free(pectx->kdf_ukm);
+        pectx->kdf_ukm = tmp_ukm;
+        pectx->kdf_ukmlen = tmp_ukmlen;
+    }
+
+    return 1;
+}
+
+static const OSSL_PARAM known_settable_ctx_params[] = {
+    OSSL_PARAM_int(OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE, NULL),
+    OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0),
+    OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0),
+    OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS, NULL, 0),
+    OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL),
+    OSSL_PARAM_octet_string(OSSL_EXCHANGE_PARAM_KDF_UKM, NULL, 0),
+    OSSL_PARAM_END
+};
+
+static
+const OSSL_PARAM *ecdh_settable_ctx_params(void)
+{
+    return known_settable_ctx_params;
+}
+
+static
+int ecdh_get_ctx_params(void *vpecdhctx, OSSL_PARAM params[])
+{
+    PROV_ECDH_CTX *pectx = (PROV_ECDH_CTX *)vpecdhctx;
+    OSSL_PARAM *p;
+
+    if (pectx == NULL || params == NULL)
+        return 0;
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE);
+    if (p != NULL) {
+        int mode = pectx->cofactor_mode;
+
+        if (mode == -1) {
+            /* check what is the default for pecdhctx->k */
+            mode = EC_KEY_get_flags(pectx->k) & EC_FLAG_COFACTOR_ECDH ? 1 : 0;
+        }
+
+        if (!OSSL_PARAM_set_int(p, mode))
+            return 0;
+    }
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_TYPE);
+    if (p != NULL) {
+        const char *kdf_type = NULL;
+
+        switch (pectx->kdf_type) {
+            case PROV_ECDH_KDF_NONE:
+                kdf_type = "";
+                break;
+            case PROV_ECDH_KDF_X9_63:
+                kdf_type = OSSL_KDF_NAME_X963KDF;
+                break;
+            default:
+                return 0;
+        }
+
+        if (!OSSL_PARAM_set_utf8_string(p, kdf_type))
+            return 0;
+    }
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST);
+    if (p != NULL
+            && !OSSL_PARAM_set_utf8_string(p, pectx->kdf_md == NULL
+                                           ? ""
+                                           : EVP_MD_name(pectx->kdf_md))){
+        return 0;
+    }
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN);
+    if (p != NULL && !OSSL_PARAM_set_size_t(p, pectx->kdf_outlen))
+        return 0;
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_UKM);
+    if (p != NULL && !OSSL_PARAM_set_octet_ptr(p, pectx->kdf_ukm, 0))
+        return 0;
+
+    p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_UKM_LEN);
+    if (p != NULL && !OSSL_PARAM_set_size_t(p, pectx->kdf_ukmlen))
+        return 0;
+
+    return 1;
+}
+
+static const OSSL_PARAM known_gettable_ctx_params[] = {
+    OSSL_PARAM_int(OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE, NULL),
+    OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0),
+    OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0),
+    OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL),
+    OSSL_PARAM_DEFN(OSSL_EXCHANGE_PARAM_KDF_UKM, OSSL_PARAM_OCTET_PTR,
+                    NULL, 0),
+    OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_UKM_LEN, NULL),
+    OSSL_PARAM_END
+};
+
+static
+const OSSL_PARAM *ecdh_gettable_ctx_params(void)
+{
+    return known_gettable_ctx_params;
+}
+
+static ossl_inline
+size_t ecdh_size(const EC_KEY *k)
+{
+    size_t degree = 0;
+    const EC_GROUP *group;
+
+    if (k == NULL
+            || (group = EC_KEY_get0_group(k)) == NULL)
+        return 0;
+
+    degree = EC_GROUP_get_degree(group);
+
+    return (degree + 7) / 8;
+}
+
+static ossl_inline
+int ecdh_plain_derive(void *vpecdhctx, unsigned char *secret,
+                      size_t *psecretlen, size_t outlen)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+    int retlen, ret = 0;
+    size_t ecdhsize, size;
+    const EC_POINT *ppubkey = NULL;
+    EC_KEY *privk = NULL;
+    const EC_GROUP *group;
+    const BIGNUM *cofactor;
+    int key_cofactor_mode;
+
+    if (pecdhctx->k == NULL || pecdhctx->peerk == NULL) {
+        ERR_raise(ERR_LIB_PROV, EC_R_KEYS_NOT_SET);
+        return 0;
+    }
+
+    ecdhsize = ecdh_size(pecdhctx->k);
+    if (secret == NULL) {
+        *psecretlen = ecdhsize;
+        return 1;
+    }
+
+    if ((group = EC_KEY_get0_group(pecdhctx->k)) == NULL
+            || (cofactor = EC_GROUP_get0_cofactor(group)) == NULL )
+        return 0;
+
+    /*
+     * NB: unlike PKCS#3 DH, if outlen is less than maximum size this is not
+     * an error, the result is truncated.
+     */
+    size = outlen < ecdhsize ? outlen : ecdhsize;
+
+    /*
+     * The ctx->cofactor_mode flag has precedence over the
+     * cofactor_mode flag set on ctx->k.
+     *
+     * - if ctx->cofactor_mode == -1, use ctx->k directly
+     * - if ctx->cofactor_mode == key_cofactor_mode, use ctx->k directly
+     * - if ctx->cofactor_mode != key_cofactor_mode:
+     *     - if ctx->k->cofactor == 1, the cofactor_mode flag is irrelevant, use
+     *          ctx->k directly
+     *     - if ctx->k->cofactor != 1, use a duplicate of ctx->k with the flag
+     *          set to ctx->cofactor_mode
+     */
+    key_cofactor_mode =
+        (EC_KEY_get_flags(pecdhctx->k) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;
+    if (pecdhctx->cofactor_mode != -1
+            && pecdhctx->cofactor_mode != key_cofactor_mode
+            && !BN_is_one(cofactor)) {
+        if ((privk = EC_KEY_dup(pecdhctx->k)) == NULL)
+            return 0;
+
+        if (pecdhctx->cofactor_mode == 1)
+            EC_KEY_set_flags(privk, EC_FLAG_COFACTOR_ECDH);
+        else
+            EC_KEY_clear_flags(privk, EC_FLAG_COFACTOR_ECDH);
+    } else {
+        privk = pecdhctx->k;
+    }
+
+    ppubkey = EC_KEY_get0_public_key(pecdhctx->peerk);
+
+    retlen = ECDH_compute_key(secret, size, ppubkey, privk, NULL);
+
+    if (retlen <= 0)
+        goto end;
+
+    *psecretlen = retlen;
+    ret = 1;
+
+ end:
+    if (privk != pecdhctx->k)
+        EC_KEY_free(privk);
+    return ret;
+}
+
+static ossl_inline
+int ecdh_X9_63_kdf_derive(void *vpecdhctx, unsigned char *secret,
+                          size_t *psecretlen, size_t outlen)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+    unsigned char *stmp = NULL;
+    size_t stmplen;
+    int ret = 0;
+
+    if (secret == NULL) {
+        *psecretlen = pecdhctx->kdf_outlen;
+        return 1;
+    }
+
+    if (pecdhctx->kdf_outlen > outlen)
+        return 0;
+    if (!ecdh_plain_derive(vpecdhctx, NULL, &stmplen, 0))
+        return 0;
+    if ((stmp = OPENSSL_secure_malloc(stmplen)) == NULL) {
+        ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+    if (!ecdh_plain_derive(vpecdhctx, stmp, &stmplen, stmplen))
+        goto err;
+
+    /* Do KDF stuff */
+    if (!ecdh_KDF_X9_63(secret, pecdhctx->kdf_outlen,
+                        stmp, stmplen,
+                        pecdhctx->kdf_ukm,
+                        pecdhctx->kdf_ukmlen,
+                        pecdhctx->kdf_md))
+        goto err;
+    *psecretlen = pecdhctx->kdf_outlen;
+    ret = 1;
+
+ err:
+    OPENSSL_secure_clear_free(stmp, stmplen);
+    return ret;
+}
+
+static
+int ecdh_derive(void *vpecdhctx, unsigned char *secret,
+                size_t *psecretlen, size_t outlen)
+{
+    PROV_ECDH_CTX *pecdhctx = (PROV_ECDH_CTX *)vpecdhctx;
+
+    switch (pecdhctx->kdf_type) {
+        case PROV_ECDH_KDF_NONE:
+            return ecdh_plain_derive(vpecdhctx, secret, psecretlen, outlen);
+        case PROV_ECDH_KDF_X9_63:
+            return ecdh_X9_63_kdf_derive(vpecdhctx, secret, psecretlen, outlen);
+    }
+
+    return 0;
+}
+
+
+
+const OSSL_DISPATCH ecdh_keyexch_functions[] = {
+    { OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))ecdh_newctx },
+    { OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))ecdh_init },
+    { OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))ecdh_derive },
+    { OSSL_FUNC_KEYEXCH_SET_PEER, (void (*)(void))ecdh_set_peer },
+    { OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))ecdh_freectx },
+    { OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))ecdh_dupctx },
+    { OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))ecdh_set_ctx_params },
+    { OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS,
+      (void (*)(void))ecdh_settable_ctx_params },
+    { OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS, (void (*)(void))ecdh_get_ctx_params },
+    { OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS,
+      (void (*)(void))ecdh_gettable_ctx_params },
+    { 0, NULL }
+};
diff --git a/providers/implementations/include/prov/implementations.h b/providers/implementations/include/prov/implementations.h
index f4e0dc9b02..ec0507d86b 100644
--- a/providers/implementations/include/prov/implementations.h
+++ b/providers/implementations/include/prov/implementations.h
@@ -259,11 +259,13 @@ extern const OSSL_DISPATCH dsa_keymgmt_functions[];
 extern const OSSL_DISPATCH rsa_keymgmt_functions[];
 extern const OSSL_DISPATCH x25519_keymgmt_functions[];
 extern const OSSL_DISPATCH x448_keymgmt_functions[];
+extern const OSSL_DISPATCH ec_keymgmt_functions[];
 
 /* Key Exchange */
 extern const OSSL_DISPATCH dh_keyexch_functions[];
 extern const OSSL_DISPATCH x25519_keyexch_functions[];
 extern const OSSL_DISPATCH x448_keyexch_functions[];
+extern const OSSL_DISPATCH ecdh_keyexch_functions[];
 
 /* Signature */
 extern const OSSL_DISPATCH dsa_signature_functions[];
diff --git a/providers/implementations/keymgmt/build.info b/providers/implementations/keymgmt/build.info
index 1e4146d15a..89d33e32f0 100644
--- a/providers/implementations/keymgmt/build.info
+++ b/providers/implementations/keymgmt/build.info
@@ -3,6 +3,7 @@
 
 $DH_GOAL=../../libimplementations.a
 $DSA_GOAL=../../libimplementations.a
+$EC_GOAL=../../libimplementations.a
 $RSA_GOAL=../../libimplementations.a
 $ECX_GOAL=../../libimplementations.a
 
@@ -12,6 +13,9 @@ ENDIF
 IF[{- !$disabled{dsa} -}]
   SOURCE[$DSA_GOAL]=dsa_kmgmt.c
 ENDIF
+IF[{- !$disabled{ec} -}]
+  SOURCE[$EC_GOAL]=ec_kmgmt.c
+ENDIF
 SOURCE[$RSA_GOAL]=rsa_kmgmt.c
 IF[{- !$disabled{ec} -}]
   SOURCE[$ECX_GOAL]=ecx_kmgmt.c
diff --git a/providers/implementations/keymgmt/ec_kmgmt.c b/providers/implementations/keymgmt/ec_kmgmt.c
new file mode 100644
index 0000000000..81907476d9
--- /dev/null
+++ b/providers/implementations/keymgmt/ec_kmgmt.c
@@ -0,0 +1,630 @@
+/*
+ * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * ECDH/ECDSA low level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+
+#include <openssl/core_numbers.h>
+#include <openssl/core_names.h>
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/objects.h>
+#include <openssl/params.h>
+#include "internal/param_build.h"
+#include "prov/implementations.h"
+#include "prov/providercommon.h"
+
+static OSSL_OP_keymgmt_new_fn ec_newdata;
+static OSSL_OP_keymgmt_free_fn ec_freedata;
+static OSSL_OP_keymgmt_get_params_fn ec_get_params;
+static OSSL_OP_keymgmt_gettable_params_fn ec_gettable_params;
+static OSSL_OP_keymgmt_set_params_fn ec_set_params;
+static OSSL_OP_keymgmt_settable_params_fn ec_settable_params;
+static OSSL_OP_keymgmt_has_fn ec_has;
+static OSSL_OP_keymgmt_import_fn ec_import;
+static OSSL_OP_keymgmt_import_types_fn ec_import_types;
+static OSSL_OP_keymgmt_export_fn ec_export;
+static OSSL_OP_keymgmt_export_types_fn ec_export_types;
+static OSSL_OP_keymgmt_query_operation_name_fn ec_query_operation_name;
+
+#define EC_POSSIBLE_SELECTIONS                 \
+    (OSSL_KEYMGMT_SELECT_KEYPAIR | OSSL_KEYMGMT_SELECT_ALL_PARAMETERS )
+
+static
+const char *ec_query_operation_name(int operation_id)
+{
+    switch (operation_id) {
+    case OSSL_OP_KEYEXCH:
+        return "ECDH";
+#if 0
+    case OSSL_OP_SIGNATURE:
+        return deflt_signature;
+#endif
+    }
+    return NULL;
+}
+
+static ossl_inline
+int params_to_domparams(EC_KEY *ec, const OSSL_PARAM params[])
+{
+    const OSSL_PARAM *param_ec_name;
+    EC_GROUP *ecg = NULL;
+    char *curve_name = NULL;
+    int ok = 0;
+
+    if (ec == NULL)
+        return 0;
+
+    param_ec_name = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_NAME);
+    if (param_ec_name == NULL) {
+        /* explicit parameters */
+
+        /*
+         * TODO(3.0): should we support explicit parameters curves?
+         */
+        return 0;
+    } else {
+        /* named curve */
+        int curve_nid;
+
+        if (!OSSL_PARAM_get_utf8_string(param_ec_name, &curve_name, 0)
+                || curve_name == NULL
+                || (curve_nid = OBJ_sn2nid(curve_name)) == NID_undef)
+            goto err;
+
+        if ((ecg = EC_GROUP_new_by_curve_name(curve_nid)) == NULL)
+            goto err;
+    }
+
+    if (!EC_KEY_set_group(ec, ecg))
+        goto err;
+
+    /*
+     * TODO(3.0): if the group has changed, should we invalidate the private and
+     * public key?
+     */
+
+    ok = 1;
+
+ err:
+    OPENSSL_free(curve_name);
+    EC_GROUP_free(ecg);
+    return ok;
+}
+
+static ossl_inline
+int domparams_to_params(const EC_KEY *ec, OSSL_PARAM_BLD *tmpl)
+{
+    const EC_GROUP *ecg;
+    int curve_nid;
+
+    if (ec == NULL)
+        return 0;
+
+    ecg = EC_KEY_get0_group(ec);
+    if (ecg == NULL)
+        return 0;
+
+    curve_nid = EC_GROUP_get_curve_name(ecg);
+
+    if (curve_nid == NID_undef) {
+        /* explicit parameters */
+
+        /*
+         * TODO(3.0): should we support explicit parameters curves?
+         */
+        return 0;
+    } else {
+        /* named curve */
+        const char *curve_name = NULL;
+
+        if ((curve_name = OBJ_nid2sn(curve_nid)) == NULL)
+            return 0;
+
+        if (!ossl_param_bld_push_utf8_string(tmpl, OSSL_PKEY_PARAM_EC_NAME, curve_name, 0))
+            return 0;
+    }
+
+    return 1;
+}
+
+/*
+ * Callers of params_to_key MUST make sure that params_to_domparams has been
+ * called before!
+ *
+ * This function only imports the bare keypair, domain parameters and other
+ * parameters are imported separately, and domain parameters are required to
+ * define a keypair.
+ */
+static ossl_inline
+int params_to_key(EC_KEY *ec, const OSSL_PARAM params[], int include_private)
+{
+    const OSSL_PARAM *param_priv_key, *param_pub_key;
+    BIGNUM *priv_key = NULL;
+    unsigned char *pub_key = NULL;
+    size_t pub_key_len;
+    const EC_GROUP *ecg = NULL;
+    EC_POINT *pub_point = NULL;
+    int ok = 0;
+
+    ecg = EC_KEY_get0_group(ec);
+    if (ecg == NULL)
+        return 0;
+
+    param_priv_key =
+        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
+    param_pub_key =
+        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
+
+    /*
+     * We want to have at least a public key either way, so we end up
+     * requiring it unconditionally.
+     */
+    if (param_pub_key == NULL
+            || !OSSL_PARAM_get_octet_string(param_pub_key,
+                                            (void **)&pub_key, 0, &pub_key_len)
+            || (pub_point = EC_POINT_new(ecg)) == NULL
+            || !EC_POINT_oct2point(ecg, pub_point,
+                                   pub_key, pub_key_len, NULL))
+        goto err;
+
+    if (param_priv_key != NULL && include_private
+            && !OSSL_PARAM_get_BN(param_priv_key, &priv_key))
+        goto err;
+
+    if (priv_key != NULL
+            && !EC_KEY_set_private_key(ec, priv_key))
+        goto err;
+
+    if (!EC_KEY_set_public_key(ec, pub_point))
+        goto err;
+
+    ok = 1;
+
+ err:
+    BN_clear_free(priv_key);
+    OPENSSL_free(pub_key);
+    EC_POINT_free(pub_point);
+    return ok;
+}
+
+/*
+ * Callers of key_to_params MUST make sure that domparams_to_params is also
+ * called!
+ *
+ * This function only exports the bare keypair, domain parameters and other
+ * parameters are exported separately.
+ */
+static ossl_inline
+int key_to_params(const EC_KEY *eckey, OSSL_PARAM_BLD *tmpl, int include_private)
+{
+    const BIGNUM *priv_key = NULL;
+    const EC_POINT *pub_point = NULL;
+    const EC_GROUP *ecg = NULL;
+    unsigned char *pub_key = NULL;
+    size_t pub_key_len = 0;
+    int ret = 0;
+
+    if (eckey == NULL)
+        return 0;
+
+    ecg = EC_KEY_get0_group(eckey);
+    priv_key = EC_KEY_get0_private_key(eckey);
+    pub_point = EC_KEY_get0_public_key(eckey);
+
+    /* group and public_key must be present, priv_key is optional */
+    if (ecg == NULL || pub_point == NULL)
+        return 0;
+    if ((pub_key_len = EC_POINT_point2buf(ecg, pub_point,
+                                          POINT_CONVERSION_COMPRESSED,
+                                          &pub_key, NULL)) == 0)
+        return 0;
+
+    if (!ossl_param_bld_push_octet_string(tmpl,
+                                          OSSL_PKEY_PARAM_PUB_KEY,
+                                          pub_key, pub_key_len))
+        goto err;
+
+    if (priv_key != NULL && include_private
+            && !ossl_param_bld_push_BN(tmpl,
+                                       OSSL_PKEY_PARAM_PRIV_KEY,
+                                       priv_key))
+        goto err;
+
+    ret = 1;
+
+ err:
+    OPENSSL_free(pub_key);
+    return ret;
+}
+
+static ossl_inline
+int ec_set_param_ecdh_cofactor_mode(EC_KEY *ec, const OSSL_PARAM *p)
+{
+    const EC_GROUP *ecg = EC_KEY_get0_group(ec);
+    const BIGNUM *cofactor;
+    int mode;
+
+    if (!OSSL_PARAM_get_int(p, &mode))
+        return 0;
+
+    /*
+     * mode can be only 0 for disable, or 1 for enable here.
+     *
+     * This is in contrast with the same parameter on an ECDH EVP_PKEY_CTX that
+     * also supports mode == -1 with the meaning of "reset to the default for
+     * the associated key".
+     */
+    if (mode < 0 || mode > 1)
+        return 0;
+
+    if ((cofactor = EC_GROUP_get0_cofactor(ecg)) == NULL )
+        return 0;
+
+    /* ECDH cofactor mode has no effect if cofactor is 1 */
+    if (BN_is_one(cofactor))
+        return 1;
+
+    if (mode == 1)
+        EC_KEY_set_flags(ec, EC_FLAG_COFACTOR_ECDH);
+    else if (mode == 0)
+        EC_KEY_clear_flags(ec, EC_FLAG_COFACTOR_ECDH);
+
+    return 1;
+}
+
+static ossl_inline
+int params_to_otherparams(EC_KEY *ec, const OSSL_PARAM params[])
+{
+    const OSSL_PARAM *p;
+
+    if (ec == NULL)
+        return 0;
+
+    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_USE_COFACTOR_ECDH);
+    if (p != NULL && !ec_set_param_ecdh_cofactor_mode(ec, p))
+        return 0;
+
+    return 1;
+}
+
+static ossl_inline
+int otherparams_to_params(const EC_KEY *ec, OSSL_PARAM_BLD *tmpl)
+{
+    int ecdh_cofactor_mode = 0;
+
+    if (ec == NULL)
+        return 0;
+
+    ecdh_cofactor_mode =
+        (EC_KEY_get_flags(ec) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;
+    if (!ossl_param_bld_push_int(tmpl,
+                OSSL_PKEY_PARAM_USE_COFACTOR_ECDH,
+                ecdh_cofactor_mode))
+        return 0;
+
+    return 1;
+}
+
+static
+void *ec_newdata(void *provctx)
+{
+    return EC_KEY_new();
+}
+
+static
+void ec_freedata(void *keydata)
+{
+    EC_KEY_free(keydata);
+}
+
+static
+int ec_has(void *keydata, int selection)
+{
+    EC_KEY *ec = keydata;
+    int ok = 0;
+
+    if ((selection & EC_POSSIBLE_SELECTIONS) != 0)
+        ok = 1;
+
+    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
+        ok = ok && (EC_KEY_get0_public_key(ec) != NULL);
+    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
+        ok = ok && (EC_KEY_get0_private_key(ec) != NULL);
+    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)
+        ok = ok && (EC_KEY_get0_group(ec) != NULL);
+    /*
+     * We consider OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS to always be available,
+     * so no extra check is needed other than the previous one against
+     * EC_POSSIBLE_SELECTIONS.
+     */
+
+    return ok;
+}
+
+static
+int ec_import(void *keydata, int selection, const OSSL_PARAM params[])
+{
+    EC_KEY *ec = keydata;
+    int ok = 0;
+
+    if (ec == NULL)
+        return 0;
+
+    /*
+     * In this implementation, we can export/import only keydata in the
+     * following combinations:
+     *   - domain parameters only
+     *   - public key with associated domain parameters (+optional other params)
+     *   - private key with associated public key and domain parameters
+     *         (+optional other params)
+     *
+     * This means:
+     *   - domain parameters must always be requested
+     *   - private key must be requested alongside public key
+     *   - other parameters must be requested only alongside a key
+     */
+    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) == 0)
+        return 0;
+    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
+            && (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) == 0)
+        return 0;
+    if ((selection & OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS) != 0
+            && (selection & OSSL_KEYMGMT_SELECT_KEYPAIR) == 0)
+        return 0;
+
+    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)
+        ok = ok && params_to_domparams(ec, params);
+    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {
+        int include_private =
+            selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;
+
+        ok = ok && params_to_key(ec, params, include_private);
+    }
+    if ((selection & OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS) != 0)
+        ok = ok && params_to_otherparams(ec, params);
+
+    return ok;
+}
+
+static
+int ec_export(void *keydata, int selection, OSSL_CALLBACK *param_cb,
+              void *cbarg)
+{
+    EC_KEY *ec = keydata;
+    OSSL_PARAM_BLD tmpl;
+    OSSL_PARAM *params = NULL;