diff --git a/ChangeLog.d/rfc8410.txt b/ChangeLog.d/rfc8410.txt
new file mode 100644
index 0000000..e2984ee
--- /dev/null
+++ b/ChangeLog.d/rfc8410.txt
@@ -0,0 +1,3 @@
+Features
+   * Add support for reading and writing X25519 and X448
+     public and private keys in RFC 8410 format using the existing PK APIs.
diff --git a/include/mbedtls/asn1write.h b/include/mbedtls/asn1write.h
index da73759..3c5072c 100644
--- a/include/mbedtls/asn1write.h
+++ b/include/mbedtls/asn1write.h
@@ -164,6 +164,27 @@
                                             size_t par_len);
 
 /**
+ * \brief           Write an AlgorithmIdentifier sequence in ASN.1 format.
+ *
+ * \note            This function works backwards in data buffer.
+ *
+ * \param p         The reference to the current position pointer.
+ * \param start     The start of the buffer, for bounds-checking.
+ * \param oid       The OID of the algorithm to write.
+ * \param oid_len   The length of the algorithm's OID.
+ * \param par_len   The length of the parameters, which must be already written.
+ * \param has_par   If there are any parameters. If 0, par_len must be 0. If 1
+ *                  and \p par_len is 0, NULL parameters are added.
+ *
+ * \return          The number of bytes written to \p p on success.
+ * \return          A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
+ */
+int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char **p,
+                                                const unsigned char *start,
+                                                const char *oid, size_t oid_len,
+                                                size_t par_len, int has_par);
+
+/**
  * \brief           Write a boolean tag (#MBEDTLS_ASN1_BOOLEAN) and value
  *                  in ASN.1 format.
  *
diff --git a/include/mbedtls/oid.h b/include/mbedtls/oid.h
index a72f51c..1cbf968 100644
--- a/include/mbedtls/oid.h
+++ b/include/mbedtls/oid.h
@@ -90,6 +90,9 @@
 #define MBEDTLS_OID_OIW_SECSIG                  MBEDTLS_OID_ORG_OIW "\x03"
 #define MBEDTLS_OID_OIW_SECSIG_ALG              MBEDTLS_OID_OIW_SECSIG "\x02"
 #define MBEDTLS_OID_OIW_SECSIG_SHA1             MBEDTLS_OID_OIW_SECSIG_ALG "\x1a"
+#define MBEDTLS_OID_ORG_THAWTE                  "\x65"          /* thawte(101) */
+#define MBEDTLS_OID_THAWTE                      MBEDTLS_OID_ISO_IDENTIFIED_ORG \
+        MBEDTLS_OID_ORG_THAWTE
 #define MBEDTLS_OID_ORG_CERTICOM                "\x81\x04"  /* certicom(132) */
 #define MBEDTLS_OID_CERTICOM                    MBEDTLS_OID_ISO_IDENTIFIED_ORG \
         MBEDTLS_OID_ORG_CERTICOM
@@ -437,6 +440,15 @@
  *   ecdsa-with-SHA2(3) 4 } */
 #define MBEDTLS_OID_ECDSA_SHA512            MBEDTLS_OID_ANSI_X9_62_SIG_SHA2 "\x04"
 
+/*
+ * EC key algorithms from RFC 8410
+ */
+
+#define MBEDTLS_OID_X25519                  MBEDTLS_OID_THAWTE "\x6e" /**< id-X25519    OBJECT IDENTIFIER ::= { 1 3 101 110 } */
+#define MBEDTLS_OID_X448                    MBEDTLS_OID_THAWTE "\x6f" /**< id-X448      OBJECT IDENTIFIER ::= { 1 3 101 111 } */
+#define MBEDTLS_OID_ED25519                 MBEDTLS_OID_THAWTE "\x70" /**< id-Ed25519   OBJECT IDENTIFIER ::= { 1 3 101 112 } */
+#define MBEDTLS_OID_ED448                   MBEDTLS_OID_THAWTE "\x71" /**< id-Ed448     OBJECT IDENTIFIER ::= { 1 3 101 113 } */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -531,6 +543,30 @@
  */
 int mbedtls_oid_get_oid_by_ec_grp(mbedtls_ecp_group_id grp_id,
                                   const char **oid, size_t *olen);
+
+/**
+ * \brief          Translate AlgorithmIdentifier OID into an EC group identifier,
+ *                 for curves that are directly encoded at this level
+ *
+ * \param oid      OID to use
+ * \param grp_id   place to store group id
+ *
+ * \return         0 if successful, or MBEDTLS_ERR_OID_NOT_FOUND
+ */
+int mbedtls_oid_get_ec_grp_algid(const mbedtls_asn1_buf *oid, mbedtls_ecp_group_id *grp_id);
+
+/**
+ * \brief          Translate EC group identifier into AlgorithmIdentifier OID,
+ *                 for curves that are directly encoded at this level
+ *
+ * \param grp_id   EC group identifier
+ * \param oid      place to store ASN.1 OID string pointer
+ * \param olen     length of the OID
+ *
+ * \return         0 if successful, or MBEDTLS_ERR_OID_NOT_FOUND
+ */
+int mbedtls_oid_get_oid_by_ec_grp_algid(mbedtls_ecp_group_id grp_id,
+                                        const char **oid, size_t *olen);
 #endif /* MBEDTLS_ECP_LIGHT */
 
 /**
diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index c579661..8d6d60f 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -40,7 +40,7 @@
 #include "mbedtls/ecdsa.h"
 #endif
 
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#if defined(MBEDTLS_USE_PSA_CRYPTO) || defined(MBEDTLS_PSA_CRYPTO_C)
 #include "psa/crypto.h"
 #endif
 
@@ -234,10 +234,17 @@
 
 /**
  * \brief           Public key container
+ *
+ * \note            The priv_id is guarded by MBEDTLS_PSA_CRYPTO_C and not
+ *                  by MBEDTLS_USE_PSA_CRYPTO because it can be used also
+ *                  in mbedtls_pk_sign_ext for RSA keys.
  */
 typedef struct mbedtls_pk_context {
     const mbedtls_pk_info_t *MBEDTLS_PRIVATE(pk_info);    /**< Public key information         */
     void *MBEDTLS_PRIVATE(pk_ctx);                        /**< Underlying public key context  */
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+    mbedtls_svc_key_id_t MBEDTLS_PRIVATE(priv_id);      /**< Key ID for opaque keys */
+#endif /* MBEDTLS_PSA_CRYPTO_C */
 } mbedtls_pk_context;
 
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
diff --git a/library/asn1write.c b/library/asn1write.c
index b9d586a..c65d937 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -195,13 +195,22 @@
                                             const char *oid, size_t oid_len,
                                             size_t par_len)
 {
+    return mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len, par_len, 1);
+}
+
+int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char **p, const unsigned char *start,
+                                                const char *oid, size_t oid_len,
+                                                size_t par_len, int has_par)
+{
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
 
-    if (par_len == 0) {
-        MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_null(p, start));
-    } else {
-        len += par_len;
+    if (has_par) {
+        if (par_len == 0) {
+            MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_null(p, start));
+        } else {
+            len += par_len;
+        }
     }
 
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
diff --git a/library/oid.c b/library/oid.c
index 80cadcd..8e57fe4 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -533,7 +533,7 @@
 
 #if defined(MBEDTLS_ECP_LIGHT)
 /*
- * For namedCurve (RFC 5480)
+ * For elliptic curves that use namedCurve inside ECParams (RFC 5480)
  */
 typedef struct {
     mbedtls_oid_descriptor_t    descriptor;
@@ -621,6 +621,47 @@
                         oid_ecp_grp,
                         mbedtls_ecp_group_id,
                         grp_id)
+
+/*
+ * For Elliptic Curve algorithms that are directly
+ * encoded in the AlgorithmIdentifier (RFC 8410)
+ */
+typedef struct {
+    mbedtls_oid_descriptor_t    descriptor;
+    mbedtls_ecp_group_id        grp_id;
+} oid_ecp_grp_algid_t;
+
+static const oid_ecp_grp_algid_t oid_ecp_grp_algid[] =
+{
+#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
+    {
+        OID_DESCRIPTOR(MBEDTLS_OID_X25519,               "X25519",       "X25519"),
+        MBEDTLS_ECP_DP_CURVE25519,
+    },
+#endif /* MBEDTLS_ECP_DP_CURVE25519_ENABLED */
+#if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
+    {
+        OID_DESCRIPTOR(MBEDTLS_OID_X448,                 "X448",         "X448"),
+        MBEDTLS_ECP_DP_CURVE448,
+    },
+#endif /* MBEDTLS_ECP_DP_CURVE448_ENABLED */
+    {
+        NULL_OID_DESCRIPTOR,
+        MBEDTLS_ECP_DP_NONE,
+    },
+};
+
+FN_OID_TYPED_FROM_ASN1(oid_ecp_grp_algid_t, grp_id_algid, oid_ecp_grp_algid)
+FN_OID_GET_ATTR1(mbedtls_oid_get_ec_grp_algid,
+                 oid_ecp_grp_algid_t,
+                 grp_id_algid,
+                 mbedtls_ecp_group_id,
+                 grp_id)
+FN_OID_GET_OID_BY_ATTR1(mbedtls_oid_get_oid_by_ec_grp_algid,
+                        oid_ecp_grp_algid_t,
+                        oid_ecp_grp_algid,
+                        mbedtls_ecp_group_id,
+                        grp_id)
 #endif /* MBEDTLS_ECP_LIGHT */
 
 #if defined(MBEDTLS_CIPHER_C)
diff --git a/library/pk.c b/library/pk.c
index 4e2f218..71ab60d 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -60,6 +60,9 @@
 {
     ctx->pk_info = NULL;
     ctx->pk_ctx = NULL;
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+    ctx->priv_id = MBEDTLS_SVC_KEY_ID_INIT;
+#endif /* MBEDTLS_PSA_CRYPTO_C */
 }
 
 /*
@@ -71,7 +74,7 @@
         return;
     }
 
-    if (ctx->pk_info != NULL) {
+    if ((ctx->pk_info != NULL) && (ctx->pk_info->ctx_free_func != NULL)) {
         ctx->pk_info->ctx_free_func(ctx->pk_ctx);
     }
 
@@ -140,7 +143,8 @@
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
     }
 
-    if ((ctx->pk_ctx = info->ctx_alloc_func()) == NULL) {
+    if ((info->ctx_alloc_func == NULL) ||
+        ((ctx->pk_ctx = info->ctx_alloc_func()) == NULL)) {
         return MBEDTLS_ERR_PK_ALLOC_FAILED;
     }
 
@@ -158,7 +162,6 @@
 {
     const mbedtls_pk_info_t *info = NULL;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
-    mbedtls_svc_key_id_t *pk_ctx;
     psa_key_type_t type;
 
     if (ctx == NULL || ctx->pk_info != NULL) {
@@ -179,14 +182,8 @@
         return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
     }
 
-    if ((ctx->pk_ctx = info->ctx_alloc_func()) == NULL) {
-        return MBEDTLS_ERR_PK_ALLOC_FAILED;
-    }
-
     ctx->pk_info = info;
-
-    pk_ctx = (mbedtls_svc_key_id_t *) ctx->pk_ctx;
-    *pk_ctx = key;
+    ctx->priv_id = key;
 
     return 0;
 }
@@ -315,12 +312,11 @@
         return (key_usage & usage) == usage;
     }
 
-    const mbedtls_svc_key_id_t *key = (const mbedtls_svc_key_id_t *) ctx->pk_ctx;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     psa_algorithm_t key_alg, key_alg2;
     psa_status_t status;
 
-    status = psa_get_key_attributes(*key, &attributes);
+    status = psa_get_key_attributes(ctx->priv_id, &attributes);
     if (status != PSA_SUCCESS) {
         return 0;
     }
@@ -701,10 +697,9 @@
     }
 
     if (mbedtls_pk_get_type(ctx) == MBEDTLS_PK_OPAQUE) {
-        const mbedtls_svc_key_id_t *key = (const mbedtls_svc_key_id_t *) ctx->pk_ctx;
         psa_status_t status;
 
-        status = psa_sign_hash(*key, PSA_ALG_RSA_PSS(psa_md_alg),
+        status = psa_sign_hash(ctx->priv_id, PSA_ALG_RSA_PSS(psa_md_alg),
                                hash, hash_len,
                                sig, sig_size, sig_len);
         return PSA_PK_RSA_TO_MBEDTLS_ERR(status);
@@ -873,7 +868,7 @@
 #else /* !MBEDTLS_ECP_LIGHT && !MBEDTLS_RSA_C */
 #if defined(MBEDTLS_ECP_LIGHT)
     if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_ECKEY) {
-        const mbedtls_ecp_keypair *ec;
+        mbedtls_ecp_keypair *ec;
         unsigned char d[MBEDTLS_ECP_MAX_BYTES];
         size_t d_len;
         psa_ecc_family_t curve_id;
@@ -886,7 +881,7 @@
         /* export the private key material in the format PSA wants */
         ec = mbedtls_pk_ec(*pk);
         d_len = PSA_BITS_TO_BYTES(ec->grp.nbits);
-        if ((ret = mbedtls_mpi_write_binary(&ec->d, d, d_len)) != 0) {
+        if ((ret = mbedtls_ecp_write_key(ec, d, d_len)) != 0) {
             return ret;
         }
 
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 6c9f97b..0e5e120 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -1503,29 +1503,12 @@
 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-
-static void *pk_opaque_alloc_wrap(void)
-{
-    void *ctx = mbedtls_calloc(1, sizeof(mbedtls_svc_key_id_t));
-
-    /* no _init() function to call, as calloc() already zeroized */
-
-    return ctx;
-}
-
-static void pk_opaque_free_wrap(void *ctx)
-{
-    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_svc_key_id_t));
-    mbedtls_free(ctx);
-}
-
 static size_t pk_opaque_get_bitlen(mbedtls_pk_context *pk)
 {
-    const mbedtls_svc_key_id_t *key = pk->pk_ctx;
     size_t bits;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
 
-    if (PSA_SUCCESS != psa_get_key_attributes(*key, &attributes)) {
+    if (PSA_SUCCESS != psa_get_key_attributes(pk->priv_id, &attributes)) {
         return 0;
     }
 
@@ -1563,7 +1546,6 @@
     ((void) p_rng);
     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
 #else /* !MBEDTLS_PK_CAN_ECDSA_SIGN && !MBEDTLS_RSA_C */
-    const mbedtls_svc_key_id_t *key = pk->pk_ctx;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     psa_algorithm_t alg;
     psa_key_type_t type;
@@ -1573,7 +1555,7 @@
     (void) f_rng;
     (void) p_rng;
 
-    status = psa_get_key_attributes(*key, &attributes);
+    status = psa_get_key_attributes(pk->priv_id, &attributes);
     if (status != PSA_SUCCESS) {
         return PSA_PK_TO_MBEDTLS_ERR(status);
     }
@@ -1594,7 +1576,7 @@
     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
 
     /* make the signature */
-    status = psa_sign_hash(*key, alg, hash, hash_len,
+    status = psa_sign_hash(pk->priv_id, alg, hash, hash_len,
                            sig, sig_size, sig_len);
     if (status != PSA_SUCCESS) {
 #if defined(MBEDTLS_PK_CAN_ECDSA_SIGN)
@@ -1635,8 +1617,8 @@
     NULL, /* decrypt - not relevant */
     NULL, /* encrypt - not relevant */
     NULL, /* check_pair - could be done later or left NULL */
-    pk_opaque_alloc_wrap,
-    pk_opaque_free_wrap,
+    NULL, /* alloc - no need to allocate new data dynamically */
+    NULL, /* free - as for the alloc, there is no data to free */
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL, /* restart alloc - not relevant */
     NULL, /* restart free - not relevant */
@@ -1650,14 +1632,13 @@
                                  unsigned char *output, size_t *olen, size_t osize,
                                  int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
 {
-    const mbedtls_svc_key_id_t *key = pk->pk_ctx;
     psa_status_t status;
 
     /* PSA has its own RNG */
     (void) f_rng;
     (void) p_rng;
 
-    status = psa_asymmetric_decrypt(*key, PSA_ALG_RSA_PKCS1V15_CRYPT,
+    status = psa_asymmetric_decrypt(pk->priv_id, PSA_ALG_RSA_PKCS1V15_CRYPT,
                                     input, ilen,
                                     NULL, 0,
                                     output, osize, olen);
@@ -1687,8 +1668,8 @@
 #endif /* PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY */
     NULL, /* encrypt - will be done later */
     NULL, /* check_pair - could be done later or left NULL */
-    pk_opaque_alloc_wrap,
-    pk_opaque_free_wrap,
+    NULL, /* alloc - no need to allocate new data dynamically */
+    NULL, /* free - as for the alloc, there is no data to free */
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL, /* restart alloc - not relevant */
     NULL, /* restart free - not relevant */
diff --git a/library/pkparse.c b/library/pkparse.c
index 800e352..ade8a04 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -32,8 +32,9 @@
 #if defined(MBEDTLS_RSA_C)
 #include "mbedtls/rsa.h"
 #endif
-#if defined(MBEDTLS_ECP_C)
 #include "mbedtls/ecp.h"
+#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECP_C)
+#include "pkwrite.h"
 #endif
 #if defined(MBEDTLS_ECDSA_C)
 #include "mbedtls/ecdsa.h"
@@ -232,7 +233,7 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *p = params->p;
-    const unsigned char * const end = params->p + params->len;
+    const unsigned char *const end = params->p + params->len;
     const unsigned char *end_field, *end_curve;
     size_t len;
     int ver;
@@ -404,7 +405,6 @@
             mbedtls_mpi_get_bit(&grp->G.Y, 0) == mbedtls_mpi_get_bit(&ref.G.Y, 0)) {
             break;
         }
-
     }
 
 cleanup:
@@ -495,6 +495,119 @@
     return 0;
 }
 
+#if defined(MBEDTLS_ECP_LIGHT)
+/*
+ * Helper function for deriving a public key from its private counterpart.
+ */
+static int pk_derive_public_key(mbedtls_ecp_keypair *eck,
+                                const unsigned char *d, size_t d_len,
+                                int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
+{
+    int ret;
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_status_t status, destruction_status;
+    psa_key_attributes_t key_attr = PSA_KEY_ATTRIBUTES_INIT;
+    size_t curve_bits;
+    psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(eck->grp.id, &curve_bits);
+    /* This buffer is used to store the private key at first and then the
+     * public one (but not at the same time). Therefore we size it for the
+     * latter since it's bigger. */
+    unsigned char key_buf[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
+    size_t key_len;
+    mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
+
+    (void) f_rng;
+    (void) p_rng;
+
+    psa_set_key_type(&key_attr, PSA_KEY_TYPE_ECC_KEY_PAIR(curve));
+    psa_set_key_usage_flags(&key_attr, PSA_KEY_USAGE_EXPORT);
+
+    status = psa_import_key(&key_attr, d, d_len, &key_id);
+    ret = psa_pk_status_to_mbedtls(status);
+    if (ret != 0) {
+        return ret;
+    }
+
+    mbedtls_platform_zeroize(key_buf, sizeof(key_buf));
+
+    status = psa_export_public_key(key_id, key_buf, sizeof(key_buf), &key_len);
+    ret = psa_pk_status_to_mbedtls(status);
+    destruction_status = psa_destroy_key(key_id);
+    if (ret != 0) {
+        return ret;
+    } else if (destruction_status != PSA_SUCCESS) {
+        return psa_pk_status_to_mbedtls(destruction_status);
+    }
+
+    ret = mbedtls_ecp_point_read_binary(&eck->grp, &eck->Q, key_buf, key_len);
+#else /* MBEDTLS_USE_PSA_CRYPTO */
+    (void) d;
+    (void) d_len;
+
+    ret = mbedtls_ecp_mul(&eck->grp, &eck->Q, &eck->d, &eck->grp.G, f_rng, p_rng);
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+    return ret;
+}
+
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+
+/*
+ * Load an RFC8410 EC key, which doesn't have any parameters
+ */
+static int pk_use_ecparams_rfc8410(const mbedtls_asn1_buf *params,
+                                   mbedtls_ecp_group_id grp_id,
+                                   mbedtls_ecp_group *grp)
+{
+    if (params->tag != 0 || params->len != 0) {
+        return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
+    }
+
+    return mbedtls_ecp_group_load(grp, grp_id);
+}
+
+/*
+ * Parse an RFC 8410 encoded private EC key
+ *
+ * CurvePrivateKey ::= OCTET STRING
+ */
+static int pk_parse_key_rfc8410_der(mbedtls_ecp_keypair *eck,
+                                    unsigned char *key, size_t keylen, const unsigned char *end,
+                                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len;
+
+    if ((ret = mbedtls_asn1_get_tag(&key, (key + keylen), &len, MBEDTLS_ASN1_OCTET_STRING)) != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
+    }
+
+    if (key + len != end) {
+        return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
+    }
+
+    if ((ret = mbedtls_mpi_read_binary_le(&eck->d, key, len)) != 0) {
+        mbedtls_ecp_keypair_free(eck);
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
+    }
+
+    // pk_parse_key_pkcs8_unencrypted_der() only supports version 1 PKCS8 keys,
+    // which never contain a public key. As such, derive the public key
+    // unconditionally.
+    if ((ret = pk_derive_public_key(eck, key, len, f_rng, p_rng)) != 0) {
+        mbedtls_ecp_keypair_free(eck);
+        return ret;
+    }
+
+    if ((ret = mbedtls_ecp_check_privkey(&eck->grp, &eck->d)) != 0) {
+        mbedtls_ecp_keypair_free(eck);
+        return ret;
+    }
+
+    return 0;
+}
+#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
+#endif /* MBEDTLS_ECP_LIGHT */
+
 /*
  * EC public key is an EC point
  *
@@ -591,7 +704,8 @@
  */
 static int pk_get_pk_alg(unsigned char **p,
                          const unsigned char *end,
-                         mbedtls_pk_type_t *pk_alg, mbedtls_asn1_buf *params)
+                         mbedtls_pk_type_t *pk_alg, mbedtls_asn1_buf *params,
+                         mbedtls_ecp_group_id *ec_grp_id)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_asn1_buf alg_oid;
@@ -602,7 +716,18 @@
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_ALG, ret);
     }
 
-    if (mbedtls_oid_get_pk_alg(&alg_oid, pk_alg) != 0) {
+    ret = mbedtls_oid_get_pk_alg(&alg_oid, pk_alg);
+#if defined(MBEDTLS_ECP_LIGHT)
+    if (ret == MBEDTLS_ERR_OID_NOT_FOUND) {
+        ret = mbedtls_oid_get_ec_grp_algid(&alg_oid, ec_grp_id);
+        if (ret == 0) {
+            *pk_alg = MBEDTLS_PK_ECKEY;
+        }
+    }
+#else
+    (void) ec_grp_id;
+#endif
+    if (ret != 0) {
         return MBEDTLS_ERR_PK_UNKNOWN_PK_ALG;
     }
 
@@ -630,6 +755,7 @@
     size_t len;
     mbedtls_asn1_buf alg_params;
     mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
+    mbedtls_ecp_group_id ec_grp_id = MBEDTLS_ECP_DP_NONE;
     const mbedtls_pk_info_t *pk_info;
 
     if ((ret = mbedtls_asn1_get_tag(p, end, &len,
@@ -639,7 +765,7 @@
 
     end = *p + len;
 
-    if ((ret = pk_get_pk_alg(p, end, &pk_alg, &alg_params)) != 0) {
+    if ((ret = pk_get_pk_alg(p, end, &pk_alg, &alg_params, &ec_grp_id)) != 0) {
         return ret;
     }
 
@@ -667,7 +793,14 @@
 #endif /* MBEDTLS_RSA_C */
 #if defined(MBEDTLS_ECP_LIGHT)
     if (pk_alg == MBEDTLS_PK_ECKEY_DH || pk_alg == MBEDTLS_PK_ECKEY) {
-        ret = pk_use_ecparams(&alg_params, &mbedtls_pk_ec(*pk)->grp);
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+        if (mbedtls_pk_is_rfc8410_curve(ec_grp_id)) {
+            ret = pk_use_ecparams_rfc8410(&alg_params, ec_grp_id, &mbedtls_pk_ec(*pk)->grp);
+        } else
+#endif
+        {
+            ret = pk_use_ecparams(&alg_params, &mbedtls_pk_ec(*pk)->grp);
+        }
         if (ret == 0) {
             ret = pk_get_ecpubkey(p, end, mbedtls_pk_ec(*pk));
         }
@@ -877,57 +1010,6 @@
 #endif /* MBEDTLS_RSA_C */
 
 #if defined(MBEDTLS_ECP_LIGHT)
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
-/*
- * Helper function for deriving a public key from its private counterpart by
- * using PSA functions.
- */
-static int pk_derive_public_key(mbedtls_ecp_group *grp, mbedtls_ecp_point *Q,
-                                const mbedtls_mpi *d)
-{
-    psa_status_t status, destruction_status;
-    psa_key_attributes_t key_attr = PSA_KEY_ATTRIBUTES_INIT;
-    size_t curve_bits;
-    psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(grp->id, &curve_bits);
-    /* This buffer is used to store the private key at first and then the
-     * public one (but not at the same time). Therefore we size it for the
-     * latter since it's bigger. */
-    unsigned char key_buf[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
-    size_t key_len = PSA_BITS_TO_BYTES(curve_bits);
-    mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
-    int ret;
-
-    psa_set_key_type(&key_attr, PSA_KEY_TYPE_ECC_KEY_PAIR(curve));
-    psa_set_key_usage_flags(&key_attr, PSA_KEY_USAGE_EXPORT);
-
-    ret = mbedtls_mpi_write_binary(d, key_buf, key_len);
-    if (ret != 0) {
-        return ret;
-    }
-
-    status = psa_import_key(&key_attr, key_buf, key_len, &key_id);
-    ret = psa_pk_status_to_mbedtls(status);
-    if (ret != 0) {
-        return ret;
-    }
-
-    mbedtls_platform_zeroize(key_buf, sizeof(key_buf));
-
-    status = psa_export_public_key(key_id, key_buf, sizeof(key_buf), &key_len);
-    ret = psa_pk_status_to_mbedtls(status);
-    destruction_status = psa_destroy_key(key_id);
-    if (ret != 0) {
-        return ret;
-    } else if (destruction_status != PSA_SUCCESS) {
-        return psa_pk_status_to_mbedtls(destruction_status);
-    }
-
-    ret = mbedtls_ecp_point_read_binary(grp, Q, key_buf, key_len);
-
-    return ret;
-}
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
-
 /*
  * Parse a SEC1 encoded private EC key
  */
@@ -937,9 +1019,10 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int version, pubkey_done;
-    size_t len;
+    size_t len, d_len;
     mbedtls_asn1_buf params = { 0, 0, NULL };
     unsigned char *p = (unsigned char *) key;
+    unsigned char *d;
     unsigned char *end = p + keylen;
     unsigned char *end2;
 
@@ -972,6 +1055,8 @@
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
     }
 
+    d = p;
+    d_len = len;
     if ((ret = mbedtls_mpi_read_binary(&eck->d, p, len)) != 0) {
         mbedtls_ecp_keypair_free(eck);
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
@@ -1035,20 +1120,10 @@
     }
 
     if (!pubkey_done) {
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
-        (void) f_rng;
-        (void) p_rng;
-        if ((ret = pk_derive_public_key(&eck->grp, &eck->Q, &eck->d)) != 0) {
+        if ((ret = pk_derive_public_key(eck, d, d_len, f_rng, p_rng)) != 0) {
             mbedtls_ecp_keypair_free(eck);
             return ret;
         }
-#else /* MBEDTLS_USE_PSA_CRYPTO */
-        if ((ret = mbedtls_ecp_mul(&eck->grp, &eck->Q, &eck->d, &eck->grp.G,
-                                   f_rng, p_rng)) != 0) {
-            mbedtls_ecp_keypair_free(eck);
-            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
-        }
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
     }
 
     if ((ret = mbedtls_ecp_check_privkey(&eck->grp, &eck->d)) != 0) {
@@ -1084,9 +1159,10 @@
     unsigned char *p = (unsigned char *) key;
     unsigned char *end = p + keylen;
     mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
+    mbedtls_ecp_group_id ec_grp_id = MBEDTLS_ECP_DP_NONE;
     const mbedtls_pk_info_t *pk_info;
 
-#if !defined(MBEDTLS_ECP_C)
+#if !defined(MBEDTLS_ECP_LIGHT)
     (void) f_rng;
     (void) p_rng;
 #endif
@@ -1122,7 +1198,7 @@
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_VERSION, ret);
     }
 
-    if ((ret = pk_get_pk_alg(&p, end, &pk_alg, &params)) != 0) {
+    if ((ret = pk_get_pk_alg(&p, end, &pk_alg, &params, &ec_grp_id)) != 0) {
         return ret;
     }
 
@@ -1153,10 +1229,24 @@
 #endif /* MBEDTLS_RSA_C */
 #if defined(MBEDTLS_ECP_LIGHT)
     if (pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH) {
-        if ((ret = pk_use_ecparams(&params, &mbedtls_pk_ec(*pk)->grp)) != 0 ||
-            (ret = pk_parse_key_sec1_der(mbedtls_pk_ec(*pk), p, len, f_rng, p_rng)) != 0) {
-            mbedtls_pk_free(pk);
-            return ret;
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+        if (mbedtls_pk_is_rfc8410_curve(ec_grp_id)) {
+            if ((ret =
+                     pk_use_ecparams_rfc8410(&params, ec_grp_id, &mbedtls_pk_ec(*pk)->grp)) != 0 ||
+                (ret =
+                     pk_parse_key_rfc8410_der(mbedtls_pk_ec(*pk), p, len, end, f_rng,
+                                              p_rng)) != 0) {
+                mbedtls_pk_free(pk);
+                return ret;
+            }
+        } else
+#endif
+        {
+            if ((ret = pk_use_ecparams(&params, &mbedtls_pk_ec(*pk)->grp)) != 0 ||
+                (ret = pk_parse_key_sec1_der(mbedtls_pk_ec(*pk), p, len, f_rng, p_rng)) != 0) {
+                mbedtls_pk_free(pk);
+                return ret;
+            }
         }
     } else
 #endif /* MBEDTLS_ECP_LIGHT */
@@ -1557,7 +1647,7 @@
          */
         p = pem.buf;
 
-        ret = mbedtls_pk_parse_subpubkey(&p,  p + pem.buflen, ctx);
+        ret = mbedtls_pk_parse_subpubkey(&p, p + pem.buflen, ctx);
         mbedtls_pem_free(&pem);
         return ret;
     } else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
diff --git a/library/pkwrite.c b/library/pkwrite.c
index 3c1a408..8872953 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -131,14 +131,14 @@
  * }
  */
 static int pk_write_ec_param(unsigned char **p, unsigned char *start,
-                             mbedtls_ecp_keypair *ec)
+                             mbedtls_ecp_group_id grp_id)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
     const char *oid;
     size_t oid_len;
 
-    if ((ret = mbedtls_oid_get_oid_by_ec_grp(ec->grp.id, &oid, &oid_len)) != 0) {
+    if ((ret = mbedtls_oid_get_oid_by_ec_grp(grp_id, &oid, &oid_len)) != 0) {
         return ret;
     }
 
@@ -188,14 +188,13 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_OPAQUE) {
         size_t buffer_size;
-        mbedtls_svc_key_id_t *key_id = (mbedtls_svc_key_id_t *) key->pk_ctx;
 
         if (*p < start) {
             return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
         }
 
         buffer_size = (size_t) (*p - start);
-        if (psa_export_public_key(*key_id, start, buffer_size, &len)
+        if (psa_export_public_key(key->priv_id, start, buffer_size, &len)
             != PSA_SUCCESS) {
             return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
         } else {
@@ -213,8 +212,12 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *c;
-    size_t len = 0, par_len = 0, oid_len;
+    int has_par = 1;
+    size_t len = 0, par_len = 0, oid_len = 0;
     mbedtls_pk_type_t pk_type;
+#if defined(MBEDTLS_ECP_LIGHT)
+    mbedtls_ecp_group_id ec_grp_id = MBEDTLS_ECP_DP_NONE;
+#endif
     const char *oid;
 
     if (size == 0) {
@@ -243,61 +246,72 @@
     pk_type = mbedtls_pk_get_type(key);
 #if defined(MBEDTLS_ECP_LIGHT)
     if (pk_type == MBEDTLS_PK_ECKEY) {
-        MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, mbedtls_pk_ec(*key)));
+        ec_grp_id = mbedtls_pk_ec(*key)->grp.id;
     }
 #endif /* MBEDTLS_ECP_LIGHT */
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if (pk_type == MBEDTLS_PK_OPAQUE) {
         psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
         psa_key_type_t key_type;
-        mbedtls_svc_key_id_t key_id;
-        psa_ecc_family_t curve;
-        size_t bits;
 
-        key_id = *((mbedtls_svc_key_id_t *) key->pk_ctx);
-        if (PSA_SUCCESS != psa_get_key_attributes(key_id, &attributes)) {
+        if (PSA_SUCCESS != psa_get_key_attributes(key->priv_id,
+                                                  &attributes)) {
             return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
         }
         key_type = psa_get_key_type(&attributes);
-        bits = psa_get_key_bits(&attributes);
-        psa_reset_key_attributes(&attributes);
 
+#if defined(MBEDTLS_ECP_LIGHT)
         if (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type)) {
+            psa_ecc_family_t curve;
+
             curve = PSA_KEY_TYPE_ECC_GET_FAMILY(key_type);
-            if (curve == 0) {
-                return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
+            if (curve != 0) {
+                ec_grp_id = mbedtls_ecc_group_of_psa(curve, psa_get_key_bits(&attributes), 0);
+                if (ec_grp_id != MBEDTLS_ECP_DP_NONE) {
+                    /* The rest of the function works as for legacy EC contexts. */
+                    pk_type = MBEDTLS_PK_ECKEY;
+                }
             }
-
-            ret = mbedtls_psa_get_ecc_oid_from_id(curve, bits,
-                                                  &oid, &oid_len);
-            if (ret != 0) {
-                return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
-            }
-
-            /* Write EC algorithm parameters; that's akin
-             * to pk_write_ec_param() above. */
-            MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_oid(&c, buf,
-                                                                 oid,
-                                                                 oid_len));
-
-            /* The rest of the function works as for legacy EC contexts. */
-            pk_type = MBEDTLS_PK_ECKEY;
-        } else if (PSA_KEY_TYPE_IS_RSA(key_type)) {
+        }
+#endif /* MBEDTLS_ECP_LIGHT */
+        if (PSA_KEY_TYPE_IS_RSA(key_type)) {
             /* The rest of the function works as for legacy RSA contexts. */
             pk_type = MBEDTLS_PK_RSA;
-        } else {
-            return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
         }
+
+        psa_reset_key_attributes(&attributes);
+    }
+    /* `pk_type` will have been changed to non-opaque by here if this function can handle it */
+    if (pk_type == MBEDTLS_PK_OPAQUE) {
+        return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
     }
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
-    if ((ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid,
-                                             &oid_len)) != 0) {
-        return ret;
+#if defined(MBEDTLS_ECP_LIGHT)
+    if (pk_type == MBEDTLS_PK_ECKEY) {
+        /* Some groups have their own AlgorithmIdentifier OID, others are handled by mbedtls_oid_get_oid_by_pk_alg() below */
+        ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec_grp_id, &oid, &oid_len);
+
+        if (ret == 0) {
+            /* Currently, none of the supported algorithms that have their own AlgorithmIdentifier OID have any parameters */
+            has_par = 0;
+        } else if (ret == MBEDTLS_ERR_OID_NOT_FOUND) {
+            MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec_grp_id));
+        } else {
+            return ret;
+        }
+    }
+#endif /* MBEDTLS_ECP_LIGHT */
+
+    if (oid_len == 0) {
+        if ((ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid,
+                                                 &oid_len)) != 0) {
+            return ret;
+        }
     }
 
-    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier(&c, buf, oid, oid_len,
-                                                                      par_len));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier_ext(&c, buf, oid, oid_len,
+                                                                          par_len, has_par));
 
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
@@ -306,6 +320,55 @@
     return (int) len;
 }
 
+#if defined(MBEDTLS_ECP_LIGHT)
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+/*
+ * RFC8410
+ *
+ * OneAsymmetricKey ::= SEQUENCE {
+ *    version Version,
+ *    privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
+ *    privateKey PrivateKey,
+ *    attributes [0] IMPLICIT Attributes OPTIONAL,
+ *    ...,
+ *    [[2: publicKey [1] IMPLICIT PublicKey OPTIONAL ]],
+ *    ...
+ * }
+ *
+ * CurvePrivateKey ::= OCTET STRING
+ */
+static int pk_write_ec_rfc8410_der(unsigned char **p, unsigned char *buf,
+                                   mbedtls_ecp_keypair *ec)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len = 0;
+    size_t oid_len = 0;
+    const char *oid;
+
+    /* privateKey */
+    MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(p, buf, ec));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_OCTET_STRING));
+
+    /* privateKeyAlgorithm */
+    if ((ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec->grp.id, &oid, &oid_len)) != 0) {
+        return ret;
+    }
+    MBEDTLS_ASN1_CHK_ADD(len,
+                         mbedtls_asn1_write_algorithm_identifier_ext(p, buf, oid, oid_len, 0, 0));
+
+    /* version */
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 0));
+
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_CONSTRUCTED |
+                                                     MBEDTLS_ASN1_SEQUENCE));
+
+    return (int) len;
+}
+#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
+#endif /* MBEDTLS_ECP_LIGHT */
+
 int mbedtls_pk_write_key_der(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -409,6 +472,12 @@
         mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*key);
         size_t pub_len = 0, par_len = 0;
 
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+        if (mbedtls_pk_is_rfc8410_curve(ec->grp.id)) {
+            return pk_write_ec_rfc8410_der(&c, buf, ec);
+        }
+#endif
+
         /*
          * RFC 5915, or SEC1 Appendix C.4
          *
@@ -439,7 +508,7 @@
         len += pub_len;
 
         /* parameters */
-        MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec));
+        MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec->grp.id));
 
         MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_len(&c, buf, par_len));
         MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_tag(&c, buf,
@@ -472,6 +541,8 @@
 #define PEM_END_PRIVATE_KEY_RSA     "-----END RSA PRIVATE KEY-----\n"
 #define PEM_BEGIN_PRIVATE_KEY_EC    "-----BEGIN EC PRIVATE KEY-----\n"
 #define PEM_END_PRIVATE_KEY_EC      "-----END EC PRIVATE KEY-----\n"
+#define PEM_BEGIN_PRIVATE_KEY_PKCS8 "-----BEGIN PRIVATE KEY-----\n"
+#define PEM_END_PRIVATE_KEY_PKCS8   "-----END PRIVATE KEY-----\n"
 
 #define PUB_DER_MAX_BYTES                                                   \
     (MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES > MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES ? \
@@ -519,8 +590,16 @@
 #endif
 #if defined(MBEDTLS_ECP_LIGHT)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
-        begin = PEM_BEGIN_PRIVATE_KEY_EC;
-        end = PEM_END_PRIVATE_KEY_EC;
+#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
+        if (mbedtls_pk_is_rfc8410_curve(mbedtls_pk_ec(*key)->grp.id)) {
+            begin = PEM_BEGIN_PRIVATE_KEY_PKCS8;
+            end = PEM_END_PRIVATE_KEY_PKCS8;
+        } else
+#endif
+        {
+            begin = PEM_BEGIN_PRIVATE_KEY_EC;
+            end = PEM_END_PRIVATE_KEY_EC;
+        }
     } else
 #endif
     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
diff --git a/library/pkwrite.h b/library/pkwrite.h
index 8aebd0c..537bd0f 100644
--- a/library/pkwrite.h
+++ b/library/pkwrite.h
@@ -105,4 +105,27 @@
 
 #endif /* MBEDTLS_ECP_C */
 
+#if defined(MBEDTLS_ECP_LIGHT)
+#include "mbedtls/ecp.h"
+
+#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) || defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
+#define MBEDTLS_PK_HAVE_RFC8410_CURVES
+
+static inline int mbedtls_pk_is_rfc8410_curve(mbedtls_ecp_group_id id)
+{
+#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
+    if (id == MBEDTLS_ECP_DP_CURVE25519) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
+    if (id == MBEDTLS_ECP_DP_CURVE448) {
+        return 1;
+    }
+#endif
+    return 0;
+}
+#endif /* MBEDTLS_ECP_DP_CURVE25519_ENABLED || MBEDTLS_ECP_DP_CURVE448_ENABLED */
+#endif /* MBEDTLS_ECP_LIGHT */
+
 #endif /* MBEDTLS_PK_WRITE_H */
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 331bb79..cd87164 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4973,7 +4973,7 @@
     MBEDTLS_SSL_IANA_TLS_GROUP_NONE
 };
 
-static int ssl_preset_suiteb_ciphersuites[] = {
+static const int ssl_preset_suiteb_ciphersuites[] = {
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
     0
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 42f5fe9..ac6c10d 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -2614,8 +2614,7 @@
                 return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
             }
 
-            ssl->handshake->ecdh_psa_privkey =
-                *((mbedtls_svc_key_id_t *) pk->pk_ctx);
+            ssl->handshake->ecdh_psa_privkey = pk->priv_id;
 
             /* Key should not be destroyed in the TLS library */
             ssl->handshake->ecdh_psa_privkey_is_external = 1;
diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index 773c538..226faf3 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -363,7 +363,7 @@
 #endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
           __GNUC__ && __ia64__ */
 
-#if !defined(HAVE_HARDCLOCK) && defined(_MSC_VER) && \
+#if !defined(HAVE_HARDCLOCK) && defined(_WIN32) && \
     !defined(EFIX64) && !defined(EFI32)
 
 #define HAVE_HARDCLOCK
@@ -376,7 +376,7 @@
 
     return (unsigned long) (offset.QuadPart);
 }
-#endif /* !HAVE_HARDCLOCK && _MSC_VER && !EFIX64 && !EFI32 */
+#endif /* !HAVE_HARDCLOCK && _WIN32 && !EFIX64 && !EFI32 */
 
 #if !defined(HAVE_HARDCLOCK)
 
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 257903c..bf61706 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -1003,6 +1003,38 @@
 	$(OPENSSL) ec -pubin -in $< -out $@ -conv_form compressed
 all_final += ec_bp512_pub.comp.pem
 
+ec_x25519_prv.der:
+	$(OPENSSL) genpkey -algorithm X25519 -out $@ -outform DER
+all_final += ec_x25519_prv.der
+
+ec_x25519_pub.der: ec_x25519_pub.der
+	$(OPENSSL) pkey -in $< -inform DER -out $@ -outform DER
+all_final += ec_x25519_pub.der
+
+ec_x25519_prv.pem: ec_x25519_prv.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x25519_prv.pem
+
+ec_x25519_pub.pem: ec_x25519_pub.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x25519_pub.pem
+
+ec_x448_prv.der:
+	$(OPENSSL) genpkey -algorithm X448 -out $@ -outform DER
+all_final += ec_x448_prv.der
+
+ec_x448_pub.der: ec_x448_pub.der
+	$(OPENSSL) pkey -in $< -inform DER -out $@ -outform DER
+all_final += ec_x448_pub.der
+
+ec_x448_prv.pem: ec_x448_prv.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x448_prv.pem
+
+ec_x448_pub.pem: ec_x448_pub.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x448_pub.pem
+
 ################################################################
 #### Convert PEM keys to DER format
 ################################################################
diff --git a/tests/data_files/ec_x25519_prv.der b/tests/data_files/ec_x25519_prv.der
new file mode 100644
index 0000000..ea23733
--- /dev/null
+++ b/tests/data_files/ec_x25519_prv.der
Binary files differ
diff --git a/tests/data_files/ec_x25519_prv.pem b/tests/data_files/ec_x25519_prv.pem
new file mode 100644
index 0000000..0072240
--- /dev/null
+++ b/tests/data_files/ec_x25519_prv.pem
@@ -0,0 +1,3 @@
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VuBCIEILBtgpZVVDpRy6NuU1IrwKz9YK9ZRmVV+z4eeWhyqxpZ
+-----END PRIVATE KEY-----
diff --git a/tests/data_files/ec_x25519_pub.der b/tests/data_files/ec_x25519_pub.der
new file mode 100644
index 0000000..922cb76
--- /dev/null
+++ b/tests/data_files/ec_x25519_pub.der
Binary files differ
diff --git a/tests/data_files/ec_x25519_pub.pem b/tests/data_files/ec_x25519_pub.pem
new file mode 100644
index 0000000..2a36b5b
--- /dev/null
+++ b/tests/data_files/ec_x25519_pub.pem
@@ -0,0 +1,3 @@
+-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VuAyEAm8Ow6T2CM/5qi6YTiUjMEqkTYtXC7YFYTbBatUGcnRE=
+-----END PUBLIC KEY-----
diff --git a/tests/data_files/ec_x448_prv.der b/tests/data_files/ec_x448_prv.der
new file mode 100644
index 0000000..f6d52f7
--- /dev/null
+++ b/tests/data_files/ec_x448_prv.der
Binary files differ
diff --git a/tests/data_files/ec_x448_prv.pem b/tests/data_files/ec_x448_prv.pem
new file mode 100644
index 0000000..7bca661
--- /dev/null
+++ b/tests/data_files/ec_x448_prv.pem
@@ -0,0 +1,4 @@
+-----BEGIN PRIVATE KEY-----
+MEYCAQAwBQYDK2VvBDoEOGTpCDYD9atLDMYwDnjdwUTkjO4ZMB/uacXKw+4iUiED
+oe50tXsIxi5REqWe2YOoL7eD7npOGRPt
+-----END PRIVATE KEY-----
diff --git a/tests/data_files/ec_x448_pub.der b/tests/data_files/ec_x448_pub.der
new file mode 100644
index 0000000..7c44c91
--- /dev/null
+++ b/tests/data_files/ec_x448_pub.der
Binary files differ
diff --git a/tests/data_files/ec_x448_pub.pem b/tests/data_files/ec_x448_pub.pem
new file mode 100644
index 0000000..306e10c
--- /dev/null
+++ b/tests/data_files/ec_x448_pub.pem
@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MEIwBQYDK2VvAzkAlrVhn5KDNBt3nL38B9mqGKqrPwnah3ynJgaWQ5IcLzv6zZT+
+TIjhGQ1NFGWwgtOV8UqU2tO4pYQ=
+-----END PUBLIC KEY-----
diff --git a/tests/src/test_helpers/ssl_helpers.c b/tests/src/test_helpers/ssl_helpers.c
index e79d152..fbf9ea5 100644
--- a/tests/src/test_helpers/ssl_helpers.c
+++ b/tests/src/test_helpers/ssl_helpers.c
@@ -595,8 +595,7 @@
         if (cert->pkey != NULL) {
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
             if (mbedtls_pk_get_type(cert->pkey) == MBEDTLS_PK_OPAQUE) {
-                mbedtls_svc_key_id_t *key_slot = cert->pkey->pk_ctx;
-                psa_destroy_key(*key_slot);
+                psa_destroy_key(cert->pkey->priv_id);
             }
 #endif
             mbedtls_pk_free(cert->pkey);
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 2bbd34a..cfb0bab 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -11783,8 +11783,7 @@
             -c "got a certificate request" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY" \
-            -c "no suitable signature algorithm" \
-            -C "unknown pk type"
+            -c "no suitable signature algorithm"
 
 requires_gnutls_tls1_3
 requires_gnutls_next_no_ticket
@@ -11801,8 +11800,7 @@
             -c "got a certificate request" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY" \
-            -c "no suitable signature algorithm" \
-            -C "unknown pk type"
+            -c "no suitable signature algorithm"
 
 # Test using an opaque private key for client authentication
 requires_openssl_tls1_3
@@ -12055,8 +12053,7 @@
             -c "got a certificate request" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY" \
-            -c "no suitable signature algorithm" \
-            -C "unkown pk type"
+            -c "no suitable signature algorithm"
 
 requires_gnutls_tls1_3
 requires_gnutls_next_no_ticket
@@ -12074,8 +12071,7 @@
             -c "got a certificate request" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE" \
             -c "client state: MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY" \
-            -c "no suitable signature algorithm" \
-            -C "unkown pk type"
+            -c "no suitable signature algorithm"
 
 requires_openssl_tls1_3
 requires_config_enabled MBEDTLS_DEBUG_C
diff --git a/tests/suites/test_suite_pkparse.data b/tests/suites/test_suite_pkparse.data
index 3a53dc0..1bd1af2 100644
--- a/tests/suites/test_suite_pkparse.data
+++ b/tests/suites/test_suite_pkparse.data
@@ -974,6 +974,22 @@
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_BP512R1_ENABLED
 pk_parse_public_keyfile_ec:"data_files/ec_bp512_pub.comp.pem":0
 
+Parse Public EC Key #10 (RFC 8410, DER, X25519)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_parse_public_keyfile_ec:"data_files/ec_x25519_pub.der":0
+
+Parse Public EC Key #11 (RFC 8410, DER, X448)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_parse_public_keyfile_ec:"data_files/ec_x448_pub.der":0
+
+Parse Public EC Key #12 (RFC 8410, PEM, X25519)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_parse_public_keyfile_ec:"data_files/ec_x25519_pub.pem":0
+
+Parse Public EC Key #13 (RFC 8410, PEM, X448)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_parse_public_keyfile_ec:"data_files/ec_x448_pub.pem":0
+
 Parse EC Key #1 (SEC1 DER)
 depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 pk_parse_keyfile_ec:"data_files/ec_prv.sec1.der":"NULL":0
@@ -1082,6 +1098,22 @@
 depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_SECP256K1_ENABLED:MBEDTLS_PK_PARSE_EC_EXTENDED
 pk_parse_keyfile_ec:"data_files/ec_prv.specdom.der":"NULL":0
 
+Parse EC Key #16 (RFC 8410, DER, X25519)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_parse_keyfile_ec:"data_files/ec_x25519_prv.der":"NULL":0
+
+Parse EC Key #17 (RFC 8410, DER, X448)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_parse_keyfile_ec:"data_files/ec_x448_prv.der":"NULL":0
+
+Parse EC Key #18 (RFC 8410, PEM, X25519)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_parse_keyfile_ec:"data_files/ec_x25519_prv.pem":"NULL":0
+
+Parse EC Key #19 (RFC 8410, PEM, X448)
+depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_parse_keyfile_ec:"data_files/ec_x448_prv.pem":"NULL":0
+
 Key ASN1 (No data)
 pk_parse_key:"":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
 
@@ -1163,3 +1195,30 @@
 Key ASN1 (ECPrivateKey, empty parameters)
 depends_on:MBEDTLS_ECP_LIGHT
 pk_parse_key:"30070201010400a000":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, doesn't match masking requirements, from RFC8410 Appendix A but made into version 0)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"302e020100300506032b656e04220420f8ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff3f":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, with invalid optional AlgorithIdentifier parameters)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"3030020100300706032b656e050004220420b06d829655543a51cba36e53522bc0acfd60af59466555fb3e1e796872ab1a59":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, with NULL private key)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"300e020100300506032b656e04020500":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey with invalid AlgorithIdentifier)
+pk_parse_key:"3013020100300a06082b0601040181fd5904020500":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, with unsupported attributes)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"304f020100300506032b656e04220420b06d829655543a51cba36e53522bc0acfd60af59466555fb3e1e796872ab1a59a01f301d060a2a864886f70d01090914310f0c0d437572646c6520436861697273":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, unsupported version 2 with public key)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"3051020101300506032b656e04220420b06d829655543a51cba36e53522bc0acfd60af59466555fb3e1e796872ab1a598121009bc3b0e93d8233fe6a8ba6138948cc12a91362d5c2ed81584db05ab5419c9d11":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
+
+Key ASN1 (OneAsymmetricKey X25519, unsupported version 2 with public key and unsupported attributes)
+depends_on:MBEDTLS_ECP_LIGHT
+pk_parse_key:"3072020101300506032b656e04220420b06d829655543a51cba36e53522bc0acfd60af59466555fb3e1e796872ab1a59a01f301d060a2a864886f70d01090914310f0c0d437572646c65204368616972738121009bc3b0e93d8233fe6a8ba6138948cc12a91362d5c2ed81584db05ab5419c9d11":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
diff --git a/tests/suites/test_suite_pkwrite.data b/tests/suites/test_suite_pkwrite.data
index 34bf0da..4199ff2 100644
--- a/tests/suites/test_suite_pkwrite.data
+++ b/tests/suites/test_suite_pkwrite.data
@@ -38,6 +38,22 @@
 depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_BP512R1_ENABLED
 pk_write_pubkey_check:"data_files/ec_bp512_pub.der":TEST_DER
 
+Public key write check EC X25519
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_write_pubkey_check:"data_files/ec_x25519_pub.pem":TEST_PEM
+
+Public key write check EC X25519 (DER)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_write_pubkey_check:"data_files/ec_x25519_pub.der":TEST_DER
+
+Public key write check EC X448
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_write_pubkey_check:"data_files/ec_x448_pub.pem":TEST_PEM
+
+Public key write check EC X448 (DER)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_write_pubkey_check:"data_files/ec_x448_pub.der":TEST_DER
+
 Private key write check RSA
 depends_on:MBEDTLS_RSA_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_PEM_WRITE_C
 pk_write_key_check:"data_files/server1.key":TEST_PEM
@@ -94,6 +110,22 @@
 depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_BP512R1_ENABLED
 pk_write_key_check:"data_files/ec_bp512_prv.der":TEST_DER
 
+Private key write check EC X25519
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_write_key_check:"data_files/ec_x25519_prv.pem":TEST_PEM
+
+Private key write check EC X25519 (DER)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_write_key_check:"data_files/ec_x25519_prv.der":TEST_DER
+
+Private key write check EC X448
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_write_key_check:"data_files/ec_x448_prv.pem":TEST_PEM
+
+Private key write check EC X448 (DER)
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_write_key_check:"data_files/ec_x448_prv.der":TEST_DER
+
 Derive public key RSA
 depends_on:MBEDTLS_RSA_C
 pk_write_public_from_private:"data_files/server1.key.der":"data_files/server1.pubkey.der"
@@ -113,3 +145,11 @@
 Derive public key EC Brainpool 512 bits
 depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_BP512R1_ENABLED
 pk_write_public_from_private:"data_files/ec_bp512_prv.der":"data_files/ec_bp512_pub.der"
+
+Derive public key EC X25519
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+pk_write_public_from_private:"data_files/ec_x25519_prv.der":"data_files/ec_x25519_pub.der"
+
+Derive public key EC X448
+depends_on:MBEDTLS_ECP_LIGHT:MBEDTLS_ECP_DP_CURVE448_ENABLED
+pk_write_public_from_private:"data_files/ec_x448_prv.der":"data_files/ec_x448_pub.der"
diff --git a/tests/suites/test_suite_platform.data b/tests/suites/test_suite_platform.data
index 39b423f..4276b8f 100644
--- a/tests/suites/test_suite_platform.data
+++ b/tests/suites/test_suite_platform.data
@@ -4,6 +4,3 @@
 
 Time: get seconds
 time_get_seconds:
-
-Time: delay milliseconds
-time_delay_milliseconds:1000
diff --git a/tests/suites/test_suite_platform.function b/tests/suites/test_suite_platform.function
index 7453c32..61681b8 100644
--- a/tests/suites/test_suite_platform.function
+++ b/tests/suites/test_suite_platform.function
@@ -10,7 +10,8 @@
 #if defined(MBEDTLS_HAVE_TIME)
 #include "mbedtls/platform_time.h"
 
-#ifdef WIN32
+#if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || \
+    defined(__MINGW32__) || defined(_WIN64)
 #include <windows.h>
 #elif _POSIX_C_SOURCE >= 199309L
 #include <time.h>
@@ -19,7 +20,8 @@
 #endif
 void sleep_ms(int milliseconds)
 {
-#ifdef WIN32
+#if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || \
+    defined(__MINGW32__) || defined(_WIN64)
     Sleep(milliseconds);
 #elif _POSIX_C_SOURCE >= 199309L
     struct timespec ts;
@@ -64,6 +66,13 @@
     mbedtls_ms_time_t current = mbedtls_ms_time();
     mbedtls_ms_time_t elapsed_ms;
 
+    /*
+     * WARNING: DO NOT ENABLE THIS TEST. We keep the code here to document the
+     *          reason.
+     *
+     *          Windows CI reports random test fail on platform-suite. It might
+     *          be caused by this case.
+     */
     sleep_ms(delay_ms);
 
     elapsed_ms = mbedtls_ms_time() - current;