diff --git a/library/ssl_tls13_invasive.h b/library/ssl_tls13_invasive.h
index aa35784..a025dbe 100644
--- a/library/ssl_tls13_invasive.h
+++ b/library/ssl_tls13_invasive.h
@@ -29,6 +29,37 @@
 #if defined(MBEDTLS_PSA_CRYPTO_C)
 
 /**
+ *  \brief  Take the input keying material \p ikm and extract from it a
+ *          fixed-length pseudorandom key \p prk.
+ *
+ *  \param       alg       The HMAC algorithm to use
+ *                         (\c #PSA_ALG_HMAC( PSA_ALG_XXX ) value such that
+ *                         PSA_ALG_XXX is a hash algorithm and
+ *                         #PSA_ALG_IS_HMAC(\p alg) is true).
+ *  \param       salt      An optional salt value (a non-secret random value);
+ *                         if the salt is not provided, a string of all zeros
+ *                         of the length of the hash provided by \p alg is used
+ *                         as the salt.
+ *  \param       salt_len  The length in bytes of the optional \p salt.
+ *  \param       ikm       The input keying material.
+ *  \param       ikm_len   The length in bytes of \p ikm.
+ *  \param[out]  prk       A pseudorandom key of \p prk_len bytes.
+ *  \param       prk_size  Size of the \p prk buffer in bytes.
+ *  \param[out]  prk_len   On success, the length in bytes of the
+ *                         pseudorandom key in \p prk.
+ *
+ *  \return 0 on success.
+ *  \return #PSA_ERROR_INVALID_ARGUMENT when the parameters are invalid.
+ *  \return An PSA_ERROR_* error for errors returned from the underlying
+ *          PSA layer.
+ */
+psa_status_t mbedtls_psa_hkdf_extract( psa_algorithm_t alg,
+                                       const unsigned char *salt, size_t salt_len,
+                                       const unsigned char *ikm, size_t ikm_len,
+                                       unsigned char *prk, size_t prk_size,
+                                       size_t *prk_len );
+
+/**
  *  \brief  Expand the supplied \p prk into several additional pseudorandom
  *          keys, which is the output of the HKDF.
  *
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 10b3b7e..a5af590 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -139,6 +139,59 @@
 #if defined( MBEDTLS_TEST_HOOKS )
 
 MBEDTLS_STATIC_TESTABLE
+psa_status_t mbedtls_psa_hkdf_extract( psa_algorithm_t alg,
+                                       const unsigned char *salt, size_t salt_len,
+                                       const unsigned char *ikm, size_t ikm_len,
+                                       unsigned char *prk, size_t prk_size,
+                                       size_t *prk_len )
+{
+    unsigned char null_salt[PSA_MAC_MAX_SIZE] = { '\0' };
+    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
+    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t destroy_status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if( salt == NULL || salt_len == 0 )
+    {
+        size_t hash_len;
+
+        if( salt_len != 0 )
+        {
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+
+        hash_len = PSA_HASH_LENGTH( alg );
+
+        if( hash_len == 0 )
+        {
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+
+        /* salt_len <= sizeof( salt ) because
+           PSA_HASH_LENGTH( alg ) <= PSA_MAC_MAX_SIZE. */
+        salt = null_salt;
+        salt_len = hash_len;
+    }
+
+    psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_SIGN_MESSAGE );
+    psa_set_key_algorithm( &attributes, alg );
+    psa_set_key_type( &attributes, PSA_KEY_TYPE_HMAC );
+
+    status = psa_import_key( &attributes, salt, salt_len, &key );
+    if( status != PSA_SUCCESS )
+    {
+        goto cleanup;
+    }
+
+    status = psa_mac_compute( key, alg, ikm, ikm_len, prk, prk_size, prk_len );
+
+cleanup:
+    destroy_status = psa_destroy_key( key );
+
+    return( ( status == PSA_SUCCESS ) ? destroy_status : status );
+}
+
+MBEDTLS_STATIC_TESTABLE
 psa_status_t mbedtls_psa_hkdf_expand( psa_algorithm_t alg,
                                       const unsigned char *prk, size_t prk_len,
                                       const unsigned char *info, size_t info_len,
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
index feb1717..1ad6f3d 100644
--- a/tests/suites/test_suite_hkdf.function
+++ b/tests/suites/test_suite_hkdf.function
@@ -30,71 +30,57 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void test_hkdf_extract( int md_alg, char *hex_ikm_string,
-                        char *hex_salt_string, char *hex_prk_string )
+void test_hkdf_extract( int md_alg,
+                        data_t *ikm,
+                        data_t *salt,
+                        data_t *prk )
 {
     int ret;
-    unsigned char *ikm = NULL;
-    unsigned char *salt = NULL;
-    unsigned char *prk = NULL;
     unsigned char *output_prk = NULL;
-    size_t ikm_len, salt_len, prk_len, output_prk_len;
+    size_t output_prk_len;
 
     const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
     TEST_ASSERT( md != NULL );
 
     output_prk_len = mbedtls_md_get_size( md );
-    output_prk = mbedtls_calloc( 1, output_prk_len );
+    ASSERT_ALLOC( output_prk, output_prk_len );
 
-    ikm = mbedtls_test_unhexify_alloc( hex_ikm_string, &ikm_len );
-    salt = mbedtls_test_unhexify_alloc( hex_salt_string, &salt_len );
-    prk = mbedtls_test_unhexify_alloc( hex_prk_string, &prk_len );
-
-    ret = mbedtls_hkdf_extract( md, salt, salt_len, ikm, ikm_len, output_prk );
+    ret = mbedtls_hkdf_extract( md, salt->x, salt->len,
+                                ikm->x, ikm->len, output_prk );
     TEST_ASSERT( ret == 0 );
 
-    ASSERT_COMPARE( output_prk, output_prk_len, prk, prk_len );
+    ASSERT_COMPARE( output_prk, output_prk_len, prk->x, prk->len );
 
 exit:
-    mbedtls_free(ikm);
-    mbedtls_free(salt);
-    mbedtls_free(prk);
     mbedtls_free(output_prk);
 }
 /* END_CASE */
 
 /* BEGIN_CASE */
-void test_hkdf_expand( int md_alg, char *hex_info_string,
-                       char *hex_prk_string, char *hex_okm_string )
+void test_hkdf_expand( int md_alg,
+                       data_t *info,
+                       data_t *prk,
+                       data_t *okm )
 {
     enum { OKM_LEN  = 1024 };
     int ret;
-    unsigned char *info = NULL;
-    unsigned char *prk = NULL;
-    unsigned char *okm = NULL;
     unsigned char *output_okm = NULL;
-    size_t info_len, prk_len, okm_len;
 
     const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
     TEST_ASSERT( md != NULL );
 
     ASSERT_ALLOC( output_okm, OKM_LEN );
 
-    prk = mbedtls_test_unhexify_alloc( hex_prk_string, &prk_len );
-    info = mbedtls_test_unhexify_alloc( hex_info_string, &info_len );
-    okm = mbedtls_test_unhexify_alloc( hex_okm_string, &okm_len );
-    TEST_ASSERT( prk_len == mbedtls_md_get_size( md ) );
-    TEST_ASSERT( okm_len < OKM_LEN );
+    TEST_ASSERT( prk->len == mbedtls_md_get_size( md ) );
+    TEST_ASSERT( okm->len < OKM_LEN );
 
-    ret = mbedtls_hkdf_expand( md, prk, prk_len, info, info_len,
+    ret = mbedtls_hkdf_expand( md, prk->x, prk->len,
+                               info->x, info->len,
                                output_okm, OKM_LEN );
     TEST_ASSERT( ret == 0 );
-    ASSERT_COMPARE( output_okm, okm_len, okm, okm_len );
+    ASSERT_COMPARE( output_okm, okm->len, okm->x, okm->len );
 
 exit:
-    mbedtls_free(info);
-    mbedtls_free(prk);
-    mbedtls_free(okm);
     mbedtls_free(output_okm);
 }
 /* END_CASE */
@@ -113,7 +99,7 @@
     fake_md_info.type = MBEDTLS_MD_NONE;
     fake_md_info.size = hash_len;
 
-    prk = mbedtls_calloc( MBEDTLS_MD_MAX_SIZE, 1 );
+    ASSERT_ALLOC( prk, MBEDTLS_MD_MAX_SIZE);
     salt_len = 0;
     ikm_len = 0;
 
diff --git a/tests/suites/test_suite_ssl.data b/tests/suites/test_suite_ssl.data
index eb1b8f4..0c6e313 100644
--- a/tests/suites/test_suite_ssl.data
+++ b/tests/suites/test_suite_ssl.data
@@ -4392,6 +4392,37 @@
 # Handshake secret to Master Secret
 ssl_tls13_key_evolution:MBEDTLS_MD_SHA256:"fb9fc80689b3a5d02c33243bf69a1b1b20705588a794304a6e7120155edf149a":"":"7f2882bb9b9a46265941653e9c2f19067118151e21d12e57a7b6aca1f8150c8d"
 
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #1 Extract
+depends_on:PSA_WANT_ALG_SHA_256
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"077709362c2e32df0ddc3f0dc47bba6390b6c73bb50f9c3122ec844ad7c2b3e5"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #2 Extract
+depends_on:PSA_WANT_ALG_SHA_256
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_256):"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"06a6b88c5853361a06104c9ceb35b45cef760014904671014a193f40c15fc244"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #3 Extract
+depends_on:PSA_WANT_ALG_SHA_256
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"19ef24a32c717b167f33a91d6f648bdf96596776afdb6377ac434c1c293ccb04"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #4 Extract
+depends_on:PSA_WANT_ALG_SHA_1
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_1):"0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"9b6c18c432a7bf8f0e71c8eb88f4b30baa2ba243"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #5 Extract
+depends_on:PSA_WANT_ALG_SHA_1
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_1):"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"8adae09a2a307059478d309b26c4115a224cfaf6"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #6 Extract
+depends_on:PSA_WANT_ALG_SHA_1
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_1):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"da8c8a73c7fa77288ec6f5e7c297786aa0d32d01"
+
+SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #7 Extract
+depends_on:PSA_WANT_ALG_SHA_1
+psa_hkdf_extract:PSA_ALG_HMAC(PSA_ALG_SHA_1):"0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c":"":"2adccada18779e7c2077ad2eb19d3f3e731385dd"
+
+SSL TLS 1.3 Key schedule: HKDF extract fails with wrong hash alg
+psa_hkdf_extract_ret:0:PSA_ERROR_INVALID_ARGUMENT
+
 SSL TLS 1.3 Key schedule: HKDF RFC5869 Test Vector #1 Expand
 depends_on:PSA_WANT_ALG_SHA_256
 psa_hkdf_expand:PSA_ALG_HMAC(PSA_ALG_SHA_256):"f0f1f2f3f4f5f6f7f8f9":"077709362c2e32df0ddc3f0dc47bba6390b6c73bb50f9c3122ec844ad7c2b3e5":"3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865"
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 67f4d6e..855cfc7 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -3886,35 +3886,84 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_SSL_PROTO_TLS1_3 */
-void psa_hkdf_expand( int alg, char *hex_info_string,
-                      char *hex_prk_string, char *hex_okm_string )
+void psa_hkdf_extract( int alg,
+                       data_t *ikm,
+                       data_t *salt,
+                       data_t *prk )
+{
+    unsigned char *output_prk = NULL;
+    size_t output_prk_size, output_prk_len;
+
+    PSA_INIT( );
+
+    output_prk_size = PSA_HASH_LENGTH( alg );
+    ASSERT_ALLOC( output_prk, output_prk_size );
+
+    PSA_ASSERT( mbedtls_psa_hkdf_extract( alg, salt->x, salt->len,
+                                          ikm->x, ikm->len,
+                                          output_prk, output_prk_size,
+                                          &output_prk_len ) );
+
+    ASSERT_COMPARE( output_prk, output_prk_len, prk->x, prk->len );
+
+exit:
+    mbedtls_free( output_prk );
+
+    PSA_DONE( );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_SSL_PROTO_TLS1_3 */
+void psa_hkdf_extract_ret( int alg, int ret )
+{
+    int output_ret;
+    unsigned char *salt = NULL;
+    unsigned char *ikm = NULL;
+    unsigned char *prk = NULL;
+    size_t salt_len, ikm_len, prk_len;
+
+    PSA_INIT( );
+
+    ASSERT_ALLOC( prk, PSA_MAC_MAX_SIZE);
+    salt_len = 0;
+    ikm_len = 0;
+    prk_len = 0;
+
+    output_ret = mbedtls_psa_hkdf_extract( alg, salt, salt_len,
+                                           ikm, ikm_len,
+                                           prk, PSA_MAC_MAX_SIZE, &prk_len );
+    TEST_ASSERT( output_ret == ret );
+    TEST_ASSERT( prk_len == 0 );
+
+exit:
+    mbedtls_free( prk );
+
+    PSA_DONE( );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_SSL_PROTO_TLS1_3 */
+void psa_hkdf_expand( int alg,
+                      data_t *info,
+                      data_t *prk,
+                      data_t *okm )
 {
     enum { OKM_LEN  = 1024 };
-    unsigned char *info = NULL;
-    unsigned char *prk = NULL;
-    unsigned char *okm = NULL;
     unsigned char *output_okm = NULL;
-    size_t info_len, prk_len, okm_len;
 
     PSA_INIT( );
 
     ASSERT_ALLOC( output_okm, OKM_LEN );
+    TEST_ASSERT( prk->len == PSA_HASH_LENGTH( alg ) );
+    TEST_ASSERT( okm->len < OKM_LEN );
 
-    prk = mbedtls_test_unhexify_alloc( hex_prk_string, &prk_len );
-    info = mbedtls_test_unhexify_alloc( hex_info_string, &info_len );
-    okm = mbedtls_test_unhexify_alloc( hex_okm_string, &okm_len );
-    TEST_ASSERT( prk_len == PSA_HASH_LENGTH( alg ) );
-    TEST_ASSERT( okm_len < OKM_LEN );
-
-    PSA_ASSERT( mbedtls_psa_hkdf_expand( alg, prk, prk_len, info, info_len,
+    PSA_ASSERT( mbedtls_psa_hkdf_expand( alg, prk->x, prk->len,
+                                         info->x, info->len,
                                          output_okm, OKM_LEN ) );
 
-    ASSERT_COMPARE( output_okm, okm_len, okm, okm_len );
+    ASSERT_COMPARE( output_okm, okm->len, okm->x, okm->len );
 
 exit:
-    mbedtls_free( info );
-    mbedtls_free( prk );
-    mbedtls_free( okm );
     mbedtls_free( output_okm );
 
     PSA_DONE( );