Remove MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED

Remove the configuration option MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED and all
code guarded by it. This remove support for the RSA-PSK key exchange in TLS
1.2.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/ssl_ciphersuites.c b/library/ssl_ciphersuites.c
index 1495950..e69c8e2 100644
--- a/library/ssl_ciphersuites.c
+++ b/library/ssl_ciphersuites.c
@@ -371,14 +371,6 @@
       0,
       MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
 #endif
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-    { MBEDTLS_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256,
-      "TLS-RSA-PSK-WITH-CHACHA20-POLY1305-SHA256",
-      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
-      MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
 #endif /* PSA_WANT_ALG_CHACHA20_POLY1305 &&
           PSA_WANT_ALG_SHA_256 &&
           MBEDTLS_SSL_PROTO_TLS1_2 */
@@ -1235,89 +1227,6 @@
 
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
 
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-#if defined(PSA_WANT_KEY_TYPE_AES)
-#if defined(PSA_WANT_ALG_GCM)
-#if defined(PSA_WANT_ALG_SHA_256)
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_128_GCM_SHA256, "TLS-RSA-PSK-WITH-AES-128-GCM-SHA256",
-      MBEDTLS_CIPHER_AES_128_GCM, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_256 */
-
-#if defined(PSA_WANT_ALG_SHA_384)
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384, "TLS-RSA-PSK-WITH-AES-256-GCM-SHA384",
-      MBEDTLS_CIPHER_AES_256_GCM, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_384 */
-#endif /* PSA_WANT_ALG_GCM */
-
-#if defined(PSA_WANT_ALG_CBC_NO_PADDING)
-#if defined(PSA_WANT_ALG_SHA_256)
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_128_CBC_SHA256, "TLS-RSA-PSK-WITH-AES-128-CBC-SHA256",
-      MBEDTLS_CIPHER_AES_128_CBC, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_256 */
-
-#if defined(PSA_WANT_ALG_SHA_384)
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384, "TLS-RSA-PSK-WITH-AES-256-CBC-SHA384",
-      MBEDTLS_CIPHER_AES_256_CBC, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_384 */
-
-#if defined(PSA_WANT_ALG_SHA_1)
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_128_CBC_SHA, "TLS-RSA-PSK-WITH-AES-128-CBC-SHA",
-      MBEDTLS_CIPHER_AES_128_CBC, MBEDTLS_MD_SHA1, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-
-    { MBEDTLS_TLS_RSA_PSK_WITH_AES_256_CBC_SHA, "TLS-RSA-PSK-WITH-AES-256-CBC-SHA",
-      MBEDTLS_CIPHER_AES_256_CBC, MBEDTLS_MD_SHA1, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_1 */
-#endif /* PSA_WANT_ALG_CBC_NO_PADDING */
-#endif /* PSA_WANT_KEY_TYPE_AES */
-
-#if defined(PSA_WANT_KEY_TYPE_CAMELLIA)
-#if defined(PSA_WANT_ALG_CBC_NO_PADDING)
-#if defined(PSA_WANT_ALG_SHA_256)
-    { MBEDTLS_TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256, "TLS-RSA-PSK-WITH-CAMELLIA-128-CBC-SHA256",
-      MBEDTLS_CIPHER_CAMELLIA_128_CBC, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_256 */
-
-#if defined(PSA_WANT_ALG_SHA_384)
-    { MBEDTLS_TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384, "TLS-RSA-PSK-WITH-CAMELLIA-256-CBC-SHA384",
-      MBEDTLS_CIPHER_CAMELLIA_256_CBC, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_384 */
-#endif /* PSA_WANT_ALG_CBC_NO_PADDING */
-
-#if defined(PSA_WANT_ALG_GCM)
-#if defined(PSA_WANT_ALG_SHA_256)
-    { MBEDTLS_TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256, "TLS-RSA-PSK-WITH-CAMELLIA-128-GCM-SHA256",
-      MBEDTLS_CIPHER_CAMELLIA_128_GCM, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_256 */
-
-#if defined(PSA_WANT_ALG_SHA_384)
-    { MBEDTLS_TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384, "TLS-RSA-PSK-WITH-CAMELLIA-256-GCM-SHA384",
-      MBEDTLS_CIPHER_CAMELLIA_256_GCM, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_384 */
-#endif /* PSA_WANT_ALG_GCM */
-#endif /* PSA_WANT_KEY_TYPE_CAMELLIA */
-
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
-
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
 #if defined(PSA_WANT_KEY_TYPE_AES)
 #if defined(PSA_WANT_ALG_CCM)
@@ -1421,29 +1330,6 @@
       MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
 #endif /* PSA_WANT_ALG_SHA_384 */
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
-
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-#if defined(PSA_WANT_ALG_SHA_1)
-    { MBEDTLS_TLS_RSA_PSK_WITH_NULL_SHA, "TLS-RSA-PSK-WITH-NULL-SHA",
-      MBEDTLS_CIPHER_NULL, MBEDTLS_MD_SHA1, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      MBEDTLS_CIPHERSUITE_WEAK,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_1 */
-
-#if defined(PSA_WANT_ALG_SHA_256)
-    { MBEDTLS_TLS_RSA_PSK_WITH_NULL_SHA256, "TLS-RSA-PSK-WITH-NULL-SHA256",
-      MBEDTLS_CIPHER_NULL, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      MBEDTLS_CIPHERSUITE_WEAK,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
-
-#if defined(PSA_WANT_ALG_SHA_384)
-    { MBEDTLS_TLS_RSA_PSK_WITH_NULL_SHA384, "TLS-RSA-PSK-WITH-NULL-SHA384",
-      MBEDTLS_CIPHER_NULL, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      MBEDTLS_CIPHERSUITE_WEAK,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif /* PSA_WANT_ALG_SHA_384 */
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
 #endif /* MBEDTLS_CIPHER_NULL_CIPHER */
 
 #if defined(PSA_WANT_KEY_TYPE_ARIA)
@@ -1483,41 +1369,6 @@
 
 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
 
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-
-#if (defined(PSA_WANT_ALG_GCM) && defined(PSA_WANT_ALG_SHA_384))
-    { MBEDTLS_TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384,
-      "TLS-RSA-PSK-WITH-ARIA-256-GCM-SHA384",
-      MBEDTLS_CIPHER_ARIA_256_GCM, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
-#if (defined(PSA_WANT_ALG_CBC_NO_PADDING) && \
-    defined(PSA_WANT_ALG_SHA_384))
-    { MBEDTLS_TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384,
-      "TLS-RSA-PSK-WITH-ARIA-256-CBC-SHA384",
-      MBEDTLS_CIPHER_ARIA_256_CBC, MBEDTLS_MD_SHA384, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
-#if (defined(PSA_WANT_ALG_GCM) && defined(PSA_WANT_ALG_SHA_256))
-    { MBEDTLS_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256,
-      "TLS-RSA-PSK-WITH-ARIA-128-GCM-SHA256",
-      MBEDTLS_CIPHER_ARIA_128_GCM, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
-#if (defined(PSA_WANT_ALG_CBC_NO_PADDING) && \
-    defined(PSA_WANT_ALG_SHA_256))
-    { MBEDTLS_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256,
-      "TLS-RSA-PSK-WITH-ARIA-128-CBC-SHA256",
-      MBEDTLS_CIPHER_ARIA_128_CBC, MBEDTLS_MD_SHA256, MBEDTLS_KEY_EXCHANGE_RSA_PSK,
-      0,
-      MBEDTLS_SSL_VERSION_TLS1_2, MBEDTLS_SSL_VERSION_TLS1_2 },
-#endif
-
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
-
 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
 
 #if (defined(PSA_WANT_ALG_GCM) && defined(PSA_WANT_ALG_SHA_384))
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 39c7a2e..1e51bc7 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7357,21 +7357,6 @@
         p += psk_len;
     } else
 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-    if (key_ex == MBEDTLS_KEY_EXCHANGE_RSA_PSK) {
-        /*
-         * other_secret already set by the ClientKeyExchange message,
-         * and is 48 bytes long
-         */
-        if (end - p < 2) {
-            return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
-        }
-
-        *p++ = 0;
-        *p++ = 48;
-        p += 48;
-    } else
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
     if (key_ex == MBEDTLS_KEY_EXCHANGE_DHE_PSK) {
         int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 0affc91..8591103 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -1900,8 +1900,7 @@
 }
 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) ||                           \
-    defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
 /*
  * Generate a pre-master secret and encrypt it with the server's RSA key
  */
@@ -1976,8 +1975,7 @@
 #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
     return 0;
 }
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
-          MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
@@ -2188,14 +2186,12 @@
     } /* FALLTHROUGH */
 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
-#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) ||                       \
-    defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
     if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) {
         ; /* nothing more to do */
     } else
-#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED ||
-          MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
     defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
     if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
@@ -3050,14 +3046,6 @@
             content_len = 0;
         } else
 #endif
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-        if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) {
-            if ((ret = ssl_write_encrypted_pms(ssl, header_len,
-                                               &content_len, 2)) != 0) {
-                return ret;
-            }
-        } else
-#endif
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
         if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK) {
             /*
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 76200be..5811de5 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -3414,8 +3414,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
           MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
 
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) ||                           \
-    defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
 
 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
 MBEDTLS_CHECK_RETURN_CRITICAL
@@ -3601,8 +3600,7 @@
 
     return 0;
 }
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
-          MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
@@ -3671,8 +3669,7 @@
     MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse client key exchange"));
 
 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) && \
-    (defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
-    defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED))
+    defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
     if ((ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
          ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA) &&
         (ssl->handshake->async_in_progress != 0)) {
@@ -3842,39 +3839,6 @@
 #endif /* !MBEDTLS_USE_PSA_CRYPTO */
     } else
 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
-    if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) {
-#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
-        if (ssl->handshake->async_in_progress != 0) {
-            /* There is an asynchronous operation in progress to
-             * decrypt the encrypted premaster secret, so skip
-             * directly to resuming this operation. */
-            MBEDTLS_SSL_DEBUG_MSG(3, ("PSK identity already parsed"));
-            /* Update p to skip the PSK identity. ssl_parse_encrypted_pms
-             * won't actually use it, but maintain p anyway for robustness. */
-            p += ssl->conf->psk_identity_len + 2;
-        } else
-#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
-        if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) {
-            MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret);
-            return ret;
-        }
-
-        if ((ret = ssl_parse_encrypted_pms(ssl, p, end, 2)) != 0) {
-            MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_encrypted_pms"), ret);
-            return ret;
-        }
-
-#if !defined(MBEDTLS_USE_PSA_CRYPTO)
-        if ((ret = mbedtls_ssl_psk_derive_premaster(ssl,
-                                                    (mbedtls_key_exchange_type_t) ciphersuite_info->
-                                                    key_exchange)) != 0) {
-            MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_psk_derive_premaster", ret);
-            return ret;
-        }
-#endif /* !MBEDTLS_USE_PSA_CRYPTO */
-    } else
-#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
     if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK) {
         if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) {