tls: psa_pake: use a single function for round one and two in key exchange read/write

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 82a951a..0f43a18 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2378,6 +2378,11 @@
                             MBEDTLS_SSL_ECJPAKE_PSA_PRIMITIVE, \
                             step )
 
+typedef enum {
+    MBEDTLS_ECJPAKE_ROUND_ONE,
+    MBEDTLS_ECJPAKE_ROUND_TWO
+} mbedtls_ecjpake_rounds_t;
+
 /**
  * \brief       Parse the provided input buffer for getting the first round
  *              of key exchange. This code is common between server and client
@@ -2385,27 +2390,15 @@
  * \param  pake_ctx [in] the PAKE's operation/context structure
  * \param  buf      [in] input buffer to parse
  * \param  len      [in] length of the input buffer
+ * \param  round    [in] either MBEDTLS_ECJPAKE_ROUND_ONE or
+ *                       MBEDTLS_ECJPAKE_ROUND_TWO
  *
  * \return               0 on success or a negative error code in case of failure
  */
-int mbedtls_psa_ecjpake_read_round_one(
+int mbedtls_psa_ecjpake_read_round(
                                     psa_pake_operation_t *pake_ctx,
                                     const unsigned char *buf,
-                                    size_t len );
-
-/**
- * \brief       Parse the provided input buffer for getting the second round
- *              of key exchange. This code is common between server and client
- *
- * \param  pake_ctx [in] the PAKE's operation/context structure
- * \param  buf      [in] input buffer to parse
- * \param  len      [in] length of the input buffer
- *
- * \return               0 on success or a negative error code in case of failure
- */
-int mbedtls_psa_ecjpake_read_round_two(
-                                    psa_pake_operation_t *pake_ctx,
-                                    const unsigned char *buf, size_t len );
+                                    size_t len, mbedtls_ecjpake_rounds_t round );
 
 /**
  * \brief       Write the first round of key exchange into the provided output
@@ -2415,29 +2408,16 @@
  * \param  buf      [out] the output buffer in which data will be written to
  * \param  len      [in] length of the output buffer
  * \param  olen     [out] the length of the data really written on the buffer
+ * \param  round    [in] either MBEDTLS_ECJPAKE_ROUND_ONE or
+ *                       MBEDTLS_ECJPAKE_ROUND_TWO
  *
  * \return               0 on success or a negative error code in case of failure
  */
-int mbedtls_psa_ecjpake_write_round_one(
+int mbedtls_psa_ecjpake_write_round(
                                     psa_pake_operation_t *pake_ctx,
                                     unsigned char *buf,
-                                    size_t len, size_t *olen );
-
-/**
- * \brief       Write the second round of key exchange into the provided output
- *              buffer. This code is common between server and client
- *
- * \param  pake_ctx [in] the PAKE's operation/context structure
- * \param  buf      [out] the output buffer in which data will be written to
- * \param  len      [in] length of the output buffer
- * \param  olen     [out] the length of the data really written on the buffer
- *
- * \return               0 on success or a negative error code in case of failure
- */
-int mbedtls_psa_ecjpake_write_round_two(
-                                    psa_pake_operation_t *pake_ctx,
-                                    unsigned char *buf,
-                                    size_t len, size_t *olen );
+                                    size_t len, size_t *olen,
+                                    mbedtls_ecjpake_rounds_t round );
 
 #endif //MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED && MBEDTLS_USE_PSA_CRYPTO
 
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index ae12c7e..a1fa869 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -8196,16 +8196,20 @@
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) && \
     defined(MBEDTLS_USE_PSA_CRYPTO)
-int mbedtls_psa_ecjpake_read_round_one(
+int mbedtls_psa_ecjpake_read_round(
                                     psa_pake_operation_t *pake_ctx,
                                     const unsigned char *buf,
-                                    size_t len )
+                                    size_t len, mbedtls_ecjpake_rounds_t round )
 {
     psa_status_t status;
     size_t input_offset = 0;
+    /* 
+     * At round one repeat the KEY_SHARE, ZK_PUBLIC & ZF_PROOF twice
+     * At round two perform a single cycle
+     */
+    unsigned int remaining_steps = ( round == MBEDTLS_ECJPAKE_ROUND_ONE) ? 2 : 1;
 
-    /* Repeat the KEY_SHARE, ZK_PUBLIC & ZF_PROOF twice */
-    for( unsigned int x = 1; x <= 2; ++x )
+    for( ; remaining_steps > 0; remaining_steps-- )
     {
         for( psa_pake_step_t step = PSA_PAKE_STEP_KEY_SHARE;
              step <= PSA_PAKE_STEP_ZK_PROOF;
@@ -8237,59 +8241,25 @@
     return( 0 );
 }
 
-int mbedtls_psa_ecjpake_read_round_two(
-                                    psa_pake_operation_t *pake_ctx,
-                                    const unsigned char *buf,
-                                    size_t len )
-{
-    psa_status_t status;
-    size_t input_offset = 0;
-
-    for( psa_pake_step_t step = PSA_PAKE_STEP_KEY_SHARE ;
-            step <= PSA_PAKE_STEP_ZK_PROOF ;
-            ++step )
-    {
-        size_t length;
-
-        /* Length is stored at the first byte */
-        length = buf[input_offset];
-        input_offset += 1;
-
-        if( input_offset + length > len )
-        {
-            return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
-        }
-
-        status = psa_pake_input( pake_ctx, step,
-                                    buf + input_offset, length );
-        if( status != PSA_SUCCESS)
-        {
-            return psa_ssl_status_to_mbedtls( status );
-        }
-
-        input_offset += length;
-    }
-
-    if ( input_offset != len )
-        return PSA_ERROR_INVALID_ARGUMENT;
-
-    return( 0 );
-}
-
-int mbedtls_psa_ecjpake_write_round_one(
+int mbedtls_psa_ecjpake_write_round(
                                     psa_pake_operation_t *pake_ctx,
                                     unsigned char *buf,
-                                    size_t len, size_t *olen )
+                                    size_t len, size_t *olen,
+                                    mbedtls_ecjpake_rounds_t round )
 {
     psa_status_t status;
     size_t output_offset = 0;
     size_t output_len;
+    /* 
+     * At round one repeat the KEY_SHARE, ZK_PUBLIC & ZF_PROOF twice
+     * At round two perform a single cycle
+     */
+    unsigned int remaining_steps = ( round == MBEDTLS_ECJPAKE_ROUND_ONE) ? 2 : 1;
 
-    /* Repeat the KEY_SHARE, ZK_PUBLIC & ZF_PROOF twice */
-    for( unsigned int x = 1 ; x <= 2 ; ++x )
+    for( ; remaining_steps > 0; remaining_steps-- )
     {
-        for( psa_pake_step_t step = PSA_PAKE_STEP_KEY_SHARE ;
-            step <= PSA_PAKE_STEP_ZK_PROOF ;
+        for( psa_pake_step_t step = PSA_PAKE_STEP_KEY_SHARE;
+            step <= PSA_PAKE_STEP_ZK_PROOF;
             ++step )
         {
             /* For each step, prepend 1 byte with the length of the data */
@@ -8313,39 +8283,6 @@
 
     return( 0 );
 }
-
-int mbedtls_psa_ecjpake_write_round_two(
-                                    psa_pake_operation_t *pake_ctx,
-                                    unsigned char *buf,
-                                    size_t len, size_t *olen )
-{
-    psa_status_t status;
-    size_t output_offset = 0;
-    size_t output_len;
-
-    for( psa_pake_step_t step = PSA_PAKE_STEP_KEY_SHARE ;
-            step <= PSA_PAKE_STEP_ZK_PROOF ;
-            ++step )
-    {
-        /* For each step, prepend 1 byte with the length of the data */
-        *(buf + output_offset) = MBEDTLS_SSL_ECJPAKE_OUTPUT_SIZE( step );
-        output_offset += 1;
-        status = psa_pake_output( pake_ctx,
-                                    step, buf + output_offset,
-                                    len - output_offset,
-                                    &output_len );
-        if( status != PSA_SUCCESS )
-        {
-            return( psa_ssl_status_to_mbedtls( status ) );
-        }
-
-        output_offset += output_len;
-    }
-
-    *olen = output_offset;
-
-    return( 0 );
-}
 #endif //MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED && MBEDTLS_USE_PSA_CRYPTO
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 6dd8ef5..8fcf5a4 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -164,8 +164,9 @@
         MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-        ret = mbedtls_psa_ecjpake_write_round_one(&ssl->handshake->psa_pake_ctx,
-                                                p + 2, end - p - 2, &kkpp_len );
+        ret = mbedtls_psa_ecjpake_write_round(&ssl->handshake->psa_pake_ctx,
+                                                p + 2, end - p - 2, &kkpp_len,
+                                                MBEDTLS_ECJPAKE_ROUND_ONE );
         if ( ret != 0 )
         {
             psa_destroy_key( ssl->handshake->psa_pake_password );
@@ -908,8 +909,9 @@
     ssl->handshake->ecjpake_cache_len = 0;
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    if( ( ret = mbedtls_psa_ecjpake_read_round_one(
-                            &ssl->handshake->psa_pake_ctx, buf, len ) ) != 0 )
+    if( ( ret = mbedtls_psa_ecjpake_read_round(
+                            &ssl->handshake->psa_pake_ctx, buf, len,
+                            MBEDTLS_ECJPAKE_ROUND_ONE ) ) != 0 )
     {
         psa_destroy_key( ssl->handshake->psa_pake_password );
         psa_pake_abort( &ssl->handshake->psa_pake_ctx );
@@ -2356,8 +2358,9 @@
 
         p += 3;
 
-        if( ( ret = mbedtls_psa_ecjpake_read_round_two(
-                        &ssl->handshake->psa_pake_ctx, p, end - p ) ) != 0 )
+        if( ( ret = mbedtls_psa_ecjpake_read_round(
+                        &ssl->handshake->psa_pake_ctx, p, end - p,
+                        MBEDTLS_ECJPAKE_ROUND_TWO ) ) != 0 )
         {
             psa_destroy_key( ssl->handshake->psa_pake_password );
             psa_pake_abort( &ssl->handshake->psa_pake_ctx );
@@ -3314,8 +3317,9 @@
         unsigned char *out_p = ssl->out_msg + header_len;
         unsigned char *end_p = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN -
                                header_len;
-        ret = mbedtls_psa_ecjpake_write_round_two( &ssl->handshake->psa_pake_ctx,
-                                    out_p, end_p - out_p, &content_len );
+        ret = mbedtls_psa_ecjpake_write_round( &ssl->handshake->psa_pake_ctx,
+                                    out_p, end_p - out_p, &content_len,
+                                    MBEDTLS_ECJPAKE_ROUND_TWO );
         if ( ret != 0 )
         {
             psa_destroy_key( ssl->handshake->psa_pake_password );
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 3bc7217..e6dee49 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -305,8 +305,9 @@
     }
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    if ( ( ret = mbedtls_psa_ecjpake_read_round_one(
-                        &ssl->handshake->psa_pake_ctx, buf, len ) ) != 0 )
+    if ( ( ret = mbedtls_psa_ecjpake_read_round(
+                        &ssl->handshake->psa_pake_ctx, buf, len, 
+                        MBEDTLS_ECJPAKE_ROUND_ONE ) ) != 0 )
     {
         psa_destroy_key( ssl->handshake->psa_pake_password );
         psa_pake_abort( &ssl->handshake->psa_pake_ctx );
@@ -2019,8 +2020,9 @@
     p += 2;
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    ret = mbedtls_psa_ecjpake_write_round_one( &ssl->handshake->psa_pake_ctx,
-                                p + 2, end - p - 2, &kkpp_len );
+    ret = mbedtls_psa_ecjpake_write_round( &ssl->handshake->psa_pake_ctx,
+                                p + 2, end - p - 2, &kkpp_len,
+                                MBEDTLS_ECJPAKE_ROUND_ONE );
     if ( ret != 0 )
     {
         psa_destroy_key( ssl->handshake->psa_pake_password );
@@ -2867,9 +2869,10 @@
         MBEDTLS_PUT_UINT16_BE( curve_info->tls_id, out_p, 1 );
         output_offset += sizeof( uint8_t ) + sizeof( uint16_t );
 
-        ret = mbedtls_psa_ecjpake_write_round_two( &ssl->handshake->psa_pake_ctx,
+        ret = mbedtls_psa_ecjpake_write_round( &ssl->handshake->psa_pake_ctx,
                                     out_p + output_offset,
-                                    end_p - out_p - output_offset, &output_len );
+                                    end_p - out_p - output_offset, &output_len,
+                                    MBEDTLS_ECJPAKE_ROUND_TWO );
         if( ret != 0 )
         {
             psa_destroy_key( ssl->handshake->psa_pake_password );
@@ -4114,8 +4117,9 @@
     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
     {
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-        if( ( ret = mbedtls_psa_ecjpake_read_round_two(
-                        &ssl->handshake->psa_pake_ctx, p, end - p ) ) != 0 )
+        if( ( ret = mbedtls_psa_ecjpake_read_round(
+                        &ssl->handshake->psa_pake_ctx, p, end - p,
+                        MBEDTLS_ECJPAKE_ROUND_TWO ) ) != 0 )
         {
             psa_destroy_key( ssl->handshake->psa_pake_password );
             psa_pake_abort( &ssl->handshake->psa_pake_ctx );