fix mspid and channelid value once set

Signed-off-by: Bruno Vavala <bruno.vavala@intel.com>

ecc_enclave/enclave/CMakeLists.txt

@@ -10,6 +10,7 @@ set(SOURCE_FILES
     enclave.cpp
     enclave_t.c
     shim.cpp
+    shim_internals.cpp
     ${COMMON_SOURCE_DIR}/enclave/common.cpp
     ${COMMON_SOURCE_DIR}/base64/base64.cpp
     ${COMMON_SOURCE_DIR}/utils.c

ecc_enclave/enclave/shim.cpp

@@ -39,22 +39,14 @@ void get_creator_name(
 
 void get_channel_id(char* channel_id, uint32_t max_channel_id_len, shim_ctx_ptr_t ctx)
 {
-    if (max_channel_id_len > 0)
-    {
-        channel_id[0] = '\0';
-        ocall_get_channel_id(channel_id, max_channel_id_len, ctx->u_shim_ctx);
-        channel_id[max_channel_id_len - 1] = '\0';
-    }
+    memset(channel_id, 0, max_channel_id_len);
+    internal_get_channel_id(channel_id, max_channel_id_len, ctx);
 }
 
 void get_msp_id(char* msp_id, uint32_t max_msp_id_len, shim_ctx_ptr_t ctx)
 {
-    if (max_msp_id_len > 0)
-    {
-        msp_id[0] = '\0';
-        ocall_get_msp_id(msp_id, max_msp_id_len, ctx->u_shim_ctx);
-        msp_id[max_msp_id_len - 1] = '\0';
-    }
+    memset(msp_id, 0, max_msp_id_len);
+    internal_get_msp_id(msp_id, max_msp_id_len, ctx);
 }
 
 void get_state(

ecc_enclave/enclave/shim.h

@@ -149,14 +149,6 @@ int get_func_and_params(
 // transaction APIs
 //-------------------------------------------------
 
-// - getChannelID
-// // TOD0 (possible extensions): might be useful to support and should be easy?
-// //     If this is just the name, would it be useful also to have a variant which
-// //     has the unique id ("content-addressable"/genesis-block-hash)?
-// void get_channel_id(char* channel_id,
-//     uint32_t max_channel_id_len,
-//     shim_ctx_ptr_t ctx);
-
 // - TxID
 // // TODO (possible extensions): at least coming from a Sawtooth/PDO perspective,
 // //   i would think access to this info might be important for cross-cc transactions?

ecc_enclave/enclave/shim_internals.cpp

@@ -0,0 +1,133 @@
+/*
+ * Copyright 2020 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "shim_internals.h"
+#include "enclave_t.h"  // for ocalls
+#include "logging.h"    // for LOG_*
+
+/******************************************************************************
+ * The channel id is set once, and then maintained fixed for consistency.
+ * The value is meant to be either provided by the Fabric shim on enclave
+ * creation, or set after unsealing the chaincode parameters.
+ * In both cases, the value is not verified. The verification is performed
+ * by the Enclave Registry when the chaincode/enclave parameters are registered.
+ *****************************************************************************/
+
+static char g_channel_id[MAX_CHANNEL_ID_LENGTH];
+static uint32_t g_channel_id_length;
+static bool g_channel_id_set = false;
+
+bool internal_set_channel_id(char* channel_id, uint32_t channel_id_length)
+{
+    if (g_channel_id_set)
+    {
+        LOG_ERROR("channel id already set");
+        return false;
+    }
+
+    if (channel_id_length + 1 > MAX_CHANNEL_ID_LENGTH)
+    {
+        LOG_ERROR("channel id %s (length %u) too long", channel_id_length);
+        return false;
+    }
+
+    strncpy(g_channel_id, channel_id, channel_id_length);
+    g_channel_id_length = channel_id_length;
+    g_channel_id[g_channel_id_length + 1] = '\0';
+    g_channel_id_set = true;
+    return true;
+}
+
+bool internal_get_channel_id(char* channel_id, uint32_t max_channel_id_len, shim_ctx_ptr_t ctx)
+{
+    if (!g_channel_id_set)
+    {
+        // get channel id
+        char local_channel_id[MAX_CHANNEL_ID_LENGTH];
+        ocall_get_channel_id(local_channel_id, MAX_CHANNEL_ID_LENGTH, ctx->u_shim_ctx);
+        // make sure string is null terminated
+        local_channel_id[MAX_CHANNEL_ID_LENGTH - 1] = '\0';
+        // set internal channel id
+        if (!internal_set_channel_id(local_channel_id, strlen(local_channel_id)))
+        {
+            return false;
+        }
+    }
+
+    // channel id is set
+
+    if (max_channel_id_len < g_channel_id_length + 1)
+    {
+        LOG_ERROR("input channel id buffer length is insufficient");
+        return false;
+    }
+
+    strncpy(channel_id, g_channel_id, g_channel_id_length);
+    channel_id[g_channel_id_length + 1] = '\0';
+    return true;
+}
+
+/******************************************************************************
+ * The msp id is set once, and then maintained fixed for consistency.
+ * The value is meant to be either provided by the Fabric shim on enclave
+ * creation, or set after unsealing the chaincode parameters.
+ * In both cases, the value is not verified. The verification is performed
+ * by the Enclave Registry when the chaincode/enclave parameters are registered.
+ *****************************************************************************/
+
+static char g_msp_id[MAX_MSP_ID_LENGTH];
+static uint32_t g_msp_id_length;
+static bool g_msp_id_set = false;
+
+bool internal_set_msp_id(char* msp_id, uint32_t msp_id_length)
+{
+    if (g_msp_id_set)
+    {
+        LOG_ERROR("msp id already set");
+        return false;
+    }
+
+    if (msp_id_length + 1 > MAX_CHANNEL_ID_LENGTH)
+    {
+        LOG_ERROR("msp id %s (length %u) too long", msp_id_length);
+        return false;
+    }
+
+    strncpy(g_msp_id, msp_id, msp_id_length);
+    g_msp_id_length = msp_id_length;
+    g_msp_id[g_msp_id_length + 1] = '\0';
+    g_msp_id_set = true;
+    return true;
+}
+
+bool internal_get_msp_id(char* msp_id, uint32_t max_msp_id_len, shim_ctx_ptr_t ctx)
+{
+    if (!g_msp_id_set)
+    {
+        // get msp id
+        char local_msp_id[MAX_CHANNEL_ID_LENGTH];
+        ocall_get_msp_id(local_msp_id, MAX_CHANNEL_ID_LENGTH, ctx->u_shim_ctx);
+        // make sure string is null terminated
+        local_msp_id[MAX_CHANNEL_ID_LENGTH - 1] = '\0';
+        // set internal msp id
+        if (!internal_set_msp_id(local_msp_id, strlen(local_msp_id)))
+        {
+            return false;
+        }
+    }
+
+    // msp id is set
+
+    if (max_msp_id_len < g_msp_id_length + 1)
+    {
+        LOG_ERROR("input msp id buffer length is insufficient");
+        return false;
+    }
+
+    strncpy(msp_id, g_msp_id, g_msp_id_length);
+    msp_id[g_msp_id_length + 1] = '\0';
+    return true;
+}

ecc_enclave/enclave/shim_internals.h

@@ -10,6 +10,10 @@
 #include <map>
 #include <set>
 #include <string>
+#include "shim.h"  // for shim_ctx_ptr_t
+
+#define MAX_CHANNEL_ID_LENGTH 1024
+#define MAX_MSP_ID_LENGTH 1024
 
 // read/writeset
 typedef std::map<std::string, std::string> write_set_t;
@@ -24,3 +28,9 @@ typedef struct t_shim_ctx
     const char* encoded_args;  // args as passed from client-side shim, potentially encrypted
     const char* json_args;     // clear-text args from client-side shim
 } t_shim_ctx_t;
+
+bool internal_set_channel_id(char* channel_id, uint32_t channel_id_length);
+bool internal_get_channel_id(char* channel_id, uint32_t max_channel_id_len, shim_ctx_ptr_t ctx);
+
+bool internal_set_msp_id(char* msp_id, uint32_t msp_id_length);
+bool internal_get_msp_id(char* msp_id, uint32_t max_msp_id_len, shim_ctx_ptr_t ctx);