Add PSA PAKE buildin implementation

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/library/psa_crypto_pake.c b/library/psa_crypto_pake.c
new file mode 100644
index 0000000..9f91a5e
--- /dev/null
+++ b/library/psa_crypto_pake.c
@@ -0,0 +1,720 @@
+/*
+ *  PSA PAKE layer on top of Mbed TLS software crypto
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "common.h"
+
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+
+#include <psa/crypto.h>
+#include "psa_crypto_core.h"
+#include "psa_crypto_slot_management.h"
+
+#include <mbedtls/ecjpake.h>
+#include <mbedtls/psa_util.h>
+
+#include <mbedtls/platform.h>
+#include <mbedtls/error.h>
+#include <string.h>
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+#define PSA_PAKE_BUFFER_SIZE ( ( 69 + 66 + 33 ) * 2 )
+#endif
+
+/*
+ * State sequence:
+ *
+ *   psa_pake_setup()
+ *   |
+ *   |-- In any order:
+ *   |   | psa_pake_set_password_key()
+ *   |   | psa_pake_set_user()
+ *   |   | psa_pake_set_peer()
+ *   |   | psa_pake_set_role
+ *   |
+ *   |--- In any order: (First round input before or after first round output)
+ *   |   |
+ *   |   |------ In Order
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
+ *   |   |
+ *   |   |------ In Order:
+ *   |           | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
+ *   |
+ *   |--- In any order: (Second round input before or after second round output)
+ *   |   |
+ *   |   |------ In Order
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |   |       | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
+ *   |   |
+ *   |   |------ In Order:
+ *   |           | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
+ *   |           | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
+ *   |
+ *   psa_pake_get_implicit_key()
+ *   psa_pake_abort()
+ */
+
+enum psa_pake_step
+{
+    PSA_PAKE_STEP_INVALID       = 0,
+    PSA_PAKE_STEP_X1_X2         = 1,
+    PSA_PAKE_STEP_X2S           = 2,
+    PSA_PAKE_STEP_DERIVE        = 3,
+};
+
+enum psa_pake_state
+{
+    PSA_PAKE_STATE_INVALID      = 0,
+    PSA_PAKE_STATE_SETUP        = 1,
+    PSA_PAKE_STATE_READY        = 2,
+    PSA_PAKE_OUTPUT_X1_X2       = 3,
+    PSA_PAKE_OUTPUT_X2S         = 4,
+    PSA_PAKE_INPUT_X1_X2        = 5,
+    PSA_PAKE_INPUT_X4S          = 6,
+};
+
+enum psa_pake_sequence
+{
+    PSA_PAKE_SEQ_INVALID        = 0,
+    PSA_PAKE_X1_STEP_KEY_SHARE  = 1,    /* also X2S & X4S KEY_SHARE */
+    PSA_PAKE_X1_STEP_ZK_PUBLIC  = 2,    /* also X2S & X4S ZK_PUBLIC */
+    PSA_PAKE_X1_STEP_ZK_PROOF   = 3,    /* also X2S & X4S ZK_PROOF */
+    PSA_PAKE_X2_STEP_KEY_SHARE  = 4,
+    PSA_PAKE_X2_STEP_ZK_PUBLIC  = 5,
+    PSA_PAKE_X2_STEP_ZK_PROOF   = 6,
+    PSA_PAKE_SEQ_END            = 7,
+};
+
+#if defined(MBEDTLS_PSA_BUILTIN_PAKE)
+psa_status_t psa_pake_setup( psa_pake_operation_t *operation,
+                             const psa_pake_cipher_suite_t *cipher_suite)
+{
+    /* A context must be freshly initialized before it can be set up. */
+    if( operation->alg != 0 || operation->state != PSA_PAKE_STATE_INVALID )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( cipher_suite == NULL ||
+        PSA_ALG_IS_PAKE(cipher_suite->algorithm ) == 0 ||
+        ( cipher_suite->type != PSA_PAKE_PRIMITIVE_TYPE_ECC &&
+          cipher_suite->type != PSA_PAKE_PRIMITIVE_TYPE_DH ) ||
+        PSA_ALG_IS_HASH( cipher_suite->hash ) == 0 )
+    {
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    if( cipher_suite->algorithm != PSA_ALG_JPAKE ||
+        cipher_suite->type != PSA_PAKE_PRIMITIVE_TYPE_ECC ||
+        cipher_suite->family != PSA_ECC_FAMILY_SECP_R1 ||
+        cipher_suite->bits != 256 ||
+        cipher_suite->hash != PSA_ALG_SHA_256 )
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    operation->alg = cipher_suite->algorithm;
+
+    mbedtls_ecjpake_init( &operation->ctx.ecjpake );
+
+    operation->state = PSA_PAKE_STATE_SETUP;
+    operation->sequence = PSA_PAKE_SEQ_INVALID;
+    operation->input_step = PSA_PAKE_STEP_X1_X2;
+    operation->output_step = PSA_PAKE_STEP_X1_X2;
+
+    operation->buffer = NULL;
+    operation->buffer_length = 0;
+    operation->buffer_offset = 0;
+
+    return( PSA_SUCCESS );
+#else
+    return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+}
+
+psa_status_t psa_pake_set_password_key( psa_pake_operation_t *operation,
+                                        mbedtls_svc_key_id_t password )
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_attributes_t attributes = psa_key_attributes_init();
+    psa_key_type_t type;
+    psa_key_usage_t usage;
+
+    if( operation->alg == 0 ||
+        operation->state != PSA_PAKE_STATE_SETUP )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    status = psa_get_key_attributes( password, &attributes );
+    if( status != PSA_SUCCESS )
+        return status;
+
+    type = psa_get_key_type( &attributes );
+    usage = psa_get_key_usage_flags( &attributes );
+
+    psa_reset_key_attributes( &attributes );
+
+    if( type != PSA_KEY_TYPE_PASSWORD &&
+        type != PSA_KEY_TYPE_PASSWORD_HASH )
+    {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if( usage == 0 ||
+        ( usage & PSA_KEY_USAGE_DERIVE ) == 0 )
+    {
+        return PSA_ERROR_NOT_PERMITTED;
+    }
+
+    operation->password = password;
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_pake_set_user( psa_pake_operation_t *operation,
+                                const uint8_t *user_id,
+                                size_t user_id_len )
+{
+    if( operation->alg == 0 ||
+        operation->state != PSA_PAKE_STATE_SETUP )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( user_id_len == 0 || user_id == NULL )
+        return PSA_ERROR_INVALID_ARGUMENT;
+
+    return( PSA_ERROR_NOT_SUPPORTED );
+}
+
+psa_status_t psa_pake_set_peer( psa_pake_operation_t *operation,
+                                const uint8_t *peer_id,
+                                size_t peer_id_len )
+{
+    if( operation->alg == 0 ||
+        operation->state != PSA_PAKE_STATE_SETUP )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( peer_id_len == 0 || peer_id == NULL )
+        return PSA_ERROR_INVALID_ARGUMENT;
+
+    return( PSA_ERROR_NOT_SUPPORTED );
+}
+
+psa_status_t psa_pake_set_role( psa_pake_operation_t *operation,
+                                psa_pake_role_t role )
+{
+    if( operation->alg == 0 ||
+        operation->state != PSA_PAKE_STATE_SETUP )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( role != PSA_PAKE_ROLE_NONE &&
+        role != PSA_PAKE_ROLE_FIRST &&
+        role != PSA_PAKE_ROLE_SECOND &&
+        role != PSA_PAKE_ROLE_CLIENT &&
+        role != PSA_PAKE_ROLE_SERVER )
+    {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    if( operation->alg == PSA_ALG_JPAKE )
+    {
+        if( role != PSA_PAKE_ROLE_CLIENT &&
+            role != PSA_PAKE_ROLE_SERVER )
+            return PSA_ERROR_NOT_SUPPORTED;
+
+        operation->role = role;
+
+        return( PSA_SUCCESS );
+    }
+    else
+#endif
+        return( PSA_ERROR_NOT_SUPPORTED );
+}
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+static psa_status_t psa_pake_ecjpake_setup( psa_pake_operation_t *operation )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ecjpake_role role;
+    psa_key_slot_t *slot = NULL;
+
+    if( operation->role == PSA_PAKE_ROLE_CLIENT )
+        role = MBEDTLS_ECJPAKE_CLIENT;
+    else if( operation->role == PSA_PAKE_ROLE_SERVER )
+        role = MBEDTLS_ECJPAKE_SERVER;
+    else
+        return( PSA_ERROR_BAD_STATE );
+
+    if( psa_is_valid_key_id( operation->password, 1 ) == 0 )
+        return( PSA_ERROR_BAD_STATE );
+
+    status = psa_get_and_lock_key_slot( operation->password, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+
+    ret = mbedtls_ecjpake_setup( &operation->ctx.ecjpake,
+                                 role,
+                                 MBEDTLS_MD_SHA256,
+                                 MBEDTLS_ECP_DP_SECP256R1,
+                                 slot->key.data, slot->key.bytes );
+
+    psa_unlock_key_slot( slot );
+    slot = NULL;
+
+    if( ret != 0 )
+        return( mbedtls_to_psa_error( ret ) );
+
+    operation->buffer = mbedtls_calloc( 1, 512 );
+    if( operation->buffer == NULL )
+        return( PSA_ERROR_INSUFFICIENT_MEMORY );
+
+    operation->state = PSA_PAKE_STATE_READY;
+
+    return( PSA_SUCCESS );
+}
+#endif
+
+psa_status_t psa_pake_output( psa_pake_operation_t *operation,
+                              psa_pake_step_t step,
+                              uint8_t *output,
+                              size_t output_size,
+                              size_t *output_length )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t length;
+
+    if( operation->alg == 0 ||
+        operation->state == PSA_PAKE_STATE_INVALID )
+        return( PSA_ERROR_BAD_STATE );
+
+    if( step != PSA_PAKE_STEP_KEY_SHARE &&
+        step != PSA_PAKE_STEP_ZK_PUBLIC &&
+        step != PSA_PAKE_STEP_ZK_PROOF )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    if( operation->state == PSA_PAKE_STATE_SETUP ) {
+        status = psa_pake_ecjpake_setup( operation );
+        if( status != PSA_SUCCESS )
+        {
+            psa_pake_abort( operation );
+            return( status );
+        }
+    }
+
+    if( operation->state >= PSA_PAKE_STATE_READY &&
+        ( mbedtls_ecjpake_check( &operation->ctx.ecjpake ) != 0 ||
+          operation->buffer == NULL ) )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( operation->state != PSA_PAKE_STATE_READY &&
+        operation->state != PSA_PAKE_OUTPUT_X1_X2 &&
+        operation->state != PSA_PAKE_OUTPUT_X2S )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( operation->state == PSA_PAKE_STATE_READY )
+    {
+        if( step != PSA_PAKE_STEP_KEY_SHARE )
+            return( PSA_ERROR_BAD_STATE );
+
+        switch( operation->output_step )
+        {
+            case PSA_PAKE_STEP_X1_X2:
+                operation->state = PSA_PAKE_OUTPUT_X1_X2;
+                break;
+            case PSA_PAKE_STEP_X2S:
+                operation->state = PSA_PAKE_OUTPUT_X2S;
+                break;
+            default:
+                return( PSA_ERROR_BAD_STATE );
+        }
+
+        operation->sequence = PSA_PAKE_X1_STEP_KEY_SHARE;
+    }
+
+    /* Check if step matches current sequence */
+    switch( operation->sequence )
+    {
+        case PSA_PAKE_X1_STEP_KEY_SHARE:
+        case PSA_PAKE_X2_STEP_KEY_SHARE:
+            if( step != PSA_PAKE_STEP_KEY_SHARE )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        case PSA_PAKE_X1_STEP_ZK_PUBLIC:
+        case PSA_PAKE_X2_STEP_ZK_PUBLIC:
+            if( step != PSA_PAKE_STEP_ZK_PUBLIC )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        case PSA_PAKE_X1_STEP_ZK_PROOF:
+        case PSA_PAKE_X2_STEP_ZK_PROOF:
+            if( step != PSA_PAKE_STEP_ZK_PROOF )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        default:
+            return( PSA_ERROR_BAD_STATE );
+    }
+
+    /* Initialize & write round on KEY_SHARE sequences */
+    if( operation->state == PSA_PAKE_OUTPUT_X1_X2 &&
+        operation->sequence == PSA_PAKE_X1_STEP_KEY_SHARE )
+    {
+        ret = mbedtls_ecjpake_write_round_one( &operation->ctx.ecjpake,
+                                               operation->buffer,
+                                               PSA_PAKE_BUFFER_SIZE,
+                                               &operation->buffer_length,
+                                               mbedtls_psa_get_random,
+                                               MBEDTLS_PSA_RANDOM_STATE );
+        if( ret != 0 )
+        {
+            psa_pake_abort( operation );
+            return( mbedtls_to_psa_error( ret ) );
+        }
+
+        operation->buffer_offset = 0;
+    }
+    else if( operation->state == PSA_PAKE_OUTPUT_X2S &&
+             operation->sequence == PSA_PAKE_X1_STEP_KEY_SHARE )
+    {
+        ret = mbedtls_ecjpake_write_round_two( &operation->ctx.ecjpake,
+                                               operation->buffer,
+                                               PSA_PAKE_BUFFER_SIZE,
+                                               &operation->buffer_length,
+                                               mbedtls_psa_get_random,
+                                               MBEDTLS_PSA_RANDOM_STATE );
+        if( ret != 0 )
+        {
+            psa_pake_abort( operation );
+            return( mbedtls_to_psa_error( ret ) );
+        }
+
+        operation->buffer_offset = 0;
+    }
+
+    /* Load output sequence length */
+    if( operation->state == PSA_PAKE_OUTPUT_X2S &&
+        operation->sequence == PSA_PAKE_X1_STEP_KEY_SHARE )
+    {
+        if( operation->role == PSA_PAKE_ROLE_SERVER )
+            /* Length is stored after 3bytes curve */
+            length = 3 + operation->buffer[3] + 1;
+        else
+            /* Length is stored at the first byte */
+            length = operation->buffer[0] + 1;
+    }
+    else
+    {
+        /* Length is stored at the first byte */
+        length = operation->buffer[operation->buffer_offset] + 1;
+    }
+
+    if( length > operation->buffer_length )
+        return( PSA_ERROR_DATA_CORRUPT );
+
+    if( output_size < length )
+    {
+        psa_pake_abort( operation );
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+    }
+
+    memcpy( output,
+            operation->buffer +  operation->buffer_offset,
+            length );
+    *output_length = length;
+
+    operation->buffer_offset += length;
+
+    /* Reset buffer after ZK_PROOF sequence */
+    if( ( operation->state == PSA_PAKE_OUTPUT_X1_X2 &&
+          operation->sequence == PSA_PAKE_X2_STEP_ZK_PROOF ) ||
+        ( operation->state == PSA_PAKE_OUTPUT_X2S &&
+          operation->sequence == PSA_PAKE_X1_STEP_ZK_PROOF ) )
+    {
+        mbedtls_platform_zeroize( operation->buffer, PSA_PAKE_BUFFER_SIZE );
+        operation->buffer_length = 0;
+        operation->buffer_offset = 0;
+
+        operation->state = PSA_PAKE_STATE_READY;
+        operation->output_step++;
+        operation->sequence = 0;
+    }
+    else
+    {
+        operation->sequence++;
+    }
+
+    return( PSA_SUCCESS );
+#else
+    return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+}
+
+psa_status_t psa_pake_input( psa_pake_operation_t *operation,
+                             psa_pake_step_t step,
+                             const uint8_t *input,
+                             size_t input_length )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t buffer_remain;
+
+    if( operation->alg == 0 ||
+        operation->state == PSA_PAKE_STATE_INVALID )
+        return( PSA_ERROR_BAD_STATE );
+
+    if( step != PSA_PAKE_STEP_KEY_SHARE &&
+        step != PSA_PAKE_STEP_ZK_PUBLIC &&
+        step != PSA_PAKE_STEP_ZK_PROOF )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    if( operation->state == PSA_PAKE_STATE_SETUP ) {
+        status = psa_pake_ecjpake_setup( operation );
+        if( status != PSA_SUCCESS )
+        {
+            psa_pake_abort( operation );
+            return( status );
+        }
+    }
+
+    if( operation->state >= PSA_PAKE_STATE_READY &&
+        ( mbedtls_ecjpake_check( &operation->ctx.ecjpake ) != 0 ||
+          operation->buffer == NULL ) )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( operation->state != PSA_PAKE_STATE_READY &&
+        operation->state != PSA_PAKE_INPUT_X1_X2 &&
+        operation->state != PSA_PAKE_INPUT_X4S )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( operation->state == PSA_PAKE_STATE_READY )
+    {
+        if( step != PSA_PAKE_STEP_KEY_SHARE )
+            return( PSA_ERROR_BAD_STATE );
+
+        switch( operation->input_step )
+        {
+            case PSA_PAKE_STEP_X1_X2:
+                operation->state = PSA_PAKE_INPUT_X1_X2;
+                break;
+            case PSA_PAKE_STEP_X2S:
+                operation->state = PSA_PAKE_INPUT_X4S;
+                break;
+            default:
+                return( PSA_ERROR_BAD_STATE );
+        }
+
+        operation->sequence = PSA_PAKE_X1_STEP_KEY_SHARE;
+    }
+
+    buffer_remain = PSA_PAKE_BUFFER_SIZE - operation->buffer_length;
+
+    if( input_length == 0 ||
+        input_length > buffer_remain )
+    {
+        psa_pake_abort( operation );
+        return( PSA_ERROR_INSUFFICIENT_MEMORY );
+    }
+
+    /* Check if step matches current sequence */
+    switch( operation->sequence )
+    {
+        case PSA_PAKE_X1_STEP_KEY_SHARE:
+        case PSA_PAKE_X2_STEP_KEY_SHARE:
+            if( step != PSA_PAKE_STEP_KEY_SHARE )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        case PSA_PAKE_X1_STEP_ZK_PUBLIC:
+        case PSA_PAKE_X2_STEP_ZK_PUBLIC:
+            if( step != PSA_PAKE_STEP_ZK_PUBLIC )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        case PSA_PAKE_X1_STEP_ZK_PROOF:
+        case PSA_PAKE_X2_STEP_ZK_PROOF:
+            if( step != PSA_PAKE_STEP_ZK_PROOF )
+                return( PSA_ERROR_BAD_STATE );
+            break;
+
+        default:
+            return( PSA_ERROR_BAD_STATE );
+    }
+
+    /* Copy input to local buffer */
+    memcpy( operation->buffer + operation->buffer_length,
+            input, input_length );
+    operation->buffer_length += input_length;
+
+    /* Load buffer at each last round ZK_PROOF */
+    if( operation->state == PSA_PAKE_INPUT_X1_X2 &&
+        operation->sequence == PSA_PAKE_X2_STEP_ZK_PROOF )
+    {
+        ret = mbedtls_ecjpake_read_round_one( &operation->ctx.ecjpake,
+                                              operation->buffer,
+                                              operation->buffer_length );
+
+        mbedtls_platform_zeroize( operation->buffer, PSA_PAKE_BUFFER_SIZE );
+        operation->buffer_length = 0;
+
+        if( ret != 0 )
+        {
+            psa_pake_abort( operation );
+            return( mbedtls_to_psa_error( ret ) );
+        }
+    }
+    else if( operation->state == PSA_PAKE_INPUT_X4S &&
+             operation->sequence == PSA_PAKE_X1_STEP_ZK_PROOF )
+    {
+        ret = mbedtls_ecjpake_read_round_two( &operation->ctx.ecjpake,
+                                              operation->buffer,
+                                              operation->buffer_length );
+
+        mbedtls_platform_zeroize( operation->buffer, PSA_PAKE_BUFFER_SIZE );
+        operation->buffer_length = 0;
+
+        if( ret != 0 )
+        {
+            psa_pake_abort( operation );
+            return( mbedtls_to_psa_error( ret ) );
+        }
+    }
+
+    if( ( operation->state == PSA_PAKE_INPUT_X1_X2 &&
+          operation->sequence == PSA_PAKE_X2_STEP_ZK_PROOF ) ||
+        ( operation->state == PSA_PAKE_INPUT_X4S &&
+          operation->sequence == PSA_PAKE_X1_STEP_ZK_PROOF ) )
+    {
+        operation->state = PSA_PAKE_STATE_READY;
+        operation->input_step++;
+        operation->sequence = 0;
+    }
+    else
+    {
+        operation->sequence++;
+    }
+
+    return( PSA_SUCCESS );
+#else
+    return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+}
+
+psa_status_t psa_pake_get_implicit_key(psa_pake_operation_t *operation,
+                                       psa_key_derivation_operation_t *output)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if( operation->alg == 0 ||
+        operation->state != PSA_PAKE_STATE_READY ||
+        ( operation->input_step != PSA_PAKE_STEP_DERIVE  &&
+          operation->output_step != PSA_PAKE_STEP_DERIVE ) )
+        return( PSA_ERROR_BAD_STATE );
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    ret = mbedtls_ecjpake_derive_secret( &operation->ctx.ecjpake,
+                                         operation->buffer,
+                                         PSA_PAKE_BUFFER_SIZE,
+                                         &operation->buffer_length,
+                                         mbedtls_psa_get_random,
+                                         MBEDTLS_PSA_RANDOM_STATE );
+    if( ret != 0)
+    {
+        psa_pake_abort( operation );
+        return( mbedtls_to_psa_error( ret ) );
+    }
+
+    status = psa_key_derivation_input_bytes( output,
+                                             PSA_KEY_DERIVATION_INPUT_SECRET,
+                                             operation->buffer,
+                                             operation->buffer_length );
+
+    mbedtls_platform_zeroize( operation->buffer, PSA_PAKE_BUFFER_SIZE );
+
+    psa_pake_abort( operation );
+
+    return( status );
+#else
+    return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+}
+
+psa_status_t psa_pake_abort(psa_pake_operation_t * operation)
+{
+    if( operation->alg == 0 )
+    {
+        return( PSA_SUCCESS );
+    }
+
+    operation->alg = 0;
+    operation->state = 0;
+    operation->sequence = 0;
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECJPAKE)
+    operation->input_step = 0;
+    operation->output_step = 0;
+    operation->password = MBEDTLS_SVC_KEY_ID_INIT;
+    operation->role = 0;
+    mbedtls_free( operation->buffer );
+    operation->buffer = NULL;
+    operation->buffer_length = 0;
+    operation->buffer_offset = 0;
+    mbedtls_ecjpake_free( &operation->ctx.ecjpake );
+#endif
+
+    return( PSA_SUCCESS );
+}
+
+#endif /* MBEDTLS_PSA_BUILTIN_PAKE */
+
+#endif /* MBEDTLS_PSA_CRYPTO_C */