From 821880a8d6d999afc16161e83fd0b51fda0687ab Mon Sep 17 00:00:00 2001
From: Conor Patrick <conorpp94@gmail.com>
Date: Wed, 20 Mar 2019 15:45:10 -0400
Subject: [PATCH] parse extension info in MC

---
 fido2/ctap.c       | 21 +++++++++++++---
 fido2/ctap.h       |  6 +++++
 fido2/ctap_parse.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/fido2/ctap.c b/fido2/ctap.c
index f110ef3..ea14e62 100644
--- a/fido2/ctap.c
+++ b/fido2/ctap.c
@@ -69,6 +69,8 @@ uint8_t verify_pin_auth(uint8_t * pinAuth, uint8_t * clientDataHash)
 
 }
 
+
+
 uint8_t ctap_get_info(CborEncoder * encoder)
 {
     int ret;
@@ -77,16 +79,14 @@ uint8_t ctap_get_info(CborEncoder * encoder)
     CborEncoder options;
     CborEncoder pins;
 
-    const int number_of_versions = 2;
-
-    ret = cbor_encoder_create_map(encoder, &map, 5);
+    ret = cbor_encoder_create_map(encoder, &map, 6);
     check_ret(ret);
     {
 
         ret = cbor_encode_uint(&map, RESP_versions);     //  versions key
         check_ret(ret);
         {
-            ret = cbor_encoder_create_array(&map, &array, number_of_versions);
+            ret = cbor_encoder_create_array(&map, &array, 2);
             check_ret(ret);
             {
                 ret = cbor_encode_text_stringz(&array, "U2F_V2");
@@ -98,6 +98,19 @@ uint8_t ctap_get_info(CborEncoder * encoder)
             check_ret(ret);
         }
 
+        ret = cbor_encode_uint(&map, RESP_extensions);
+        check_ret(ret);
+        {
+            ret = cbor_encoder_create_array(&map, &array, 1);
+            check_ret(ret);
+            {
+                ret = cbor_encode_text_stringz(&array, "hmac-secret");
+                check_ret(ret);
+            }
+            ret = cbor_encoder_close_container(&map, &array);
+            check_ret(ret);
+        }
+
         ret = cbor_encode_uint(&map, RESP_aaguid);
         check_ret(ret);
         {
diff --git a/fido2/ctap.h b/fido2/ctap.h
index a3a8783..797df60 100644
--- a/fido2/ctap.h
+++ b/fido2/ctap.h
@@ -181,6 +181,11 @@ struct rpId
     uint8_t name[RP_NAME_LIMIT];
 };
 
+typedef struct
+{
+    uint8_t hmac_secret;
+} CTAP_extensions;
+
 typedef struct
 {
     uint32_t paramsParsed;
@@ -201,6 +206,7 @@ typedef struct
     uint8_t pinAuth[16];
     uint8_t pinAuthPresent;
     int pinProtocol;
+    CTAP_extensions extensions;
 
 } CTAP_makeCredential;
 
diff --git a/fido2/ctap_parse.c b/fido2/ctap_parse.c
index c432e70..43287e1 100644
--- a/fido2/ctap_parse.c
+++ b/fido2/ctap_parse.c
@@ -556,6 +556,67 @@ uint8_t parse_options(CborValue * val, uint8_t * rk, uint8_t * uv, uint8_t * up)
     return 0;
 }
 
+uint8_t ctap_parse_extensions(CTAP_extensions * ext, CborValue * val)
+{
+    CborValue map;
+    size_t sz, map_length;
+    uint8_t key[16];
+    uint8_t ret;
+    int i;
+    bool b;
+
+    if (cbor_value_get_type(val) != CborMapType)
+    {
+        printf2(TAG_ERR,"error, wrong type\n");
+        return CTAP2_ERR_INVALID_CBOR_TYPE;
+    }
+
+    ret = cbor_value_enter_container(val, &map);
+    check_ret(ret);
+
+    ret = cbor_value_get_map_length(val, &map_length);
+    check_ret(ret);
+
+    for (i = 0; i < map_length; i++)
+    {
+        if (cbor_value_get_type(&map) != CborTextStringType)
+        {
+            printf2(TAG_ERR,"Error, expecting text string type for options map key, got %s\n", cbor_value_get_type_string(&map));
+            return CTAP2_ERR_INVALID_CBOR_TYPE;
+        }
+        sz = sizeof(key);
+        ret = cbor_value_copy_text_string(&map, key, &sz, NULL);
+
+        if (ret == CborErrorOutOfMemory)
+        {
+            printf2(TAG_ERR,"Error, rp map key is too large. Ignoring.\n");
+            cbor_value_advance(&map);
+            cbor_value_advance(&map);
+            continue;
+        }
+        check_ret(ret);
+        key[sizeof(key) - 1] = 0;
+
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+
+        if (cbor_value_get_type(&map) == CborBooleanType)
+        {
+            if (strncmp(key, "hmac-secret",11) == 0)
+            {
+                ret = cbor_value_get_boolean(&map, &b);
+                check_ret(ret);
+                ext->hmac_secret = b;
+                printf1(TAG_CTAP, "set hmac-secret to %d\r\n", b);
+            }
+        }
+
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+    }
+    return 0;
+}
+
 uint8_t ctap_parse_make_credential(CTAP_makeCredential * MC, CborEncoder * encoder, uint8_t * request, int length)
 {
     int ret;
@@ -665,6 +726,8 @@ uint8_t ctap_parse_make_credential(CTAP_makeCredential * MC, CborEncoder * encod
                 {
                     return CTAP2_ERR_INVALID_CBOR_TYPE;
                 }
+                ret = ctap_parse_extensions(&MC->extensions, &map);
+                check_retr(ret);
                 break;
 
             case MC_options: