Merge pull request #26 from ejohnstown/banner-config

Update the banner

examples/echoserver/echoserver.c

@@ -40,6 +40,8 @@
 #endif
 
 
+static const char echoserverBanner[] = "wolfSSH Example Echo Server\n";
+
 typedef int SOCKET_T;
 #ifdef TEST_IPV6
     typedef struct sockaddr_in6 SOCKADDR_IN_T;
@@ -650,6 +652,7 @@ int main(void)
 
     memset(&pwMapList, 0, sizeof(pwMapList));
     wolfSSH_SetUserAuth(ctx, wsUserAuth);
+    wolfSSH_CTX_SetBanner(ctx, echoserverBanner);
 
     {
         uint8_t buf[SCRATCH_BUFFER_SIZE];

src/internal.c

@@ -227,6 +227,19 @@ static void HandshakeInfoFree(HandshakeInfo* hs, void* heap)
 }
 
 
+#ifdef DEBUG_WOLFSSH
+
+static const char cannedBanner[] =
+    "CANNED BANNER\r\n"
+    "This server is an example test server. "
+    "It should have its own banner, but\r\n"
+    "it is currently using a canned one in "
+    "the library. Be happy or not.\r\n";
+static const uint32_t cannedBannerSz = sizeof(cannedBanner) - 1;
+
+#endif /* DEBUG_WOLFSSH */
+
+
 WOLFSSH_CTX* CtxInit(WOLFSSH_CTX* ctx, void* heap)
 {
     WLOG(WS_LOG_DEBUG, "Entering CtxInit()");
@@ -245,6 +258,10 @@ WOLFSSH_CTX* CtxInit(WOLFSSH_CTX* ctx, void* heap)
 #endif /* WOLFSSH_USER_IO */
     ctx->highwaterMark = DEFAULT_HIGHWATER_MARK;
     ctx->highwaterCb = wsHighwater;
+#ifdef DEBUG_WOLFSSH
+    ctx->banner = cannedBanner;
+    ctx->bannerSz = cannedBannerSz;
+#endif /* DEBUG_WOLFSSH */
 
     return ctx;
 }
@@ -4001,37 +4018,36 @@ int SendUserAuthPkOk(WOLFSSH* ssh,
 }
 
 
-static const char cannedBanner[] =
-    "CANNED BANNER\r\n"
-    "This server is an example test server. "
-    "It should have its own banner, but\r\n"
-    "it is currently using a canned one in "
-    "the library. Be happy or not.\r\n";
-static const uint32_t cannedBannerSz = sizeof(cannedBanner) - 1;
-
-
 int SendUserAuthBanner(WOLFSSH* ssh)
 {
     uint8_t* output;
     uint32_t idx;
     int      ret = WS_SUCCESS;
+    const char* banner;
+    uint32_t bannerSz = 0;
 
     if (ssh == NULL)
         ret = WS_BAD_ARGUMENT;
 
+    if (ssh->ctx->banner != NULL && ssh->ctx->bannerSz > 0) {
+        banner = ssh->ctx->banner;
+        bannerSz = ssh->ctx->bannerSz;
+    }
+
     if (ret == WS_SUCCESS)
         ret = PreparePacket(ssh, MSG_ID_SZ + (LENGTH_SZ * 2) +
-                            cannedBannerSz + cannedLangTagSz);
+                            bannerSz + cannedLangTagSz);
 
     if (ret == WS_SUCCESS) {
         output = ssh->outputBuffer.buffer;
         idx = ssh->outputBuffer.length;
 
         output[idx++] = MSGID_USERAUTH_BANNER;
-        c32toa(cannedBannerSz, output + idx);
+        c32toa(bannerSz, output + idx);
         idx += LENGTH_SZ;
-        WMEMCPY(output + idx, cannedBanner, cannedBannerSz);
-        idx += cannedBannerSz;
+        if (bannerSz > 0)
+            WMEMCPY(output + idx, banner, bannerSz);
+        idx += bannerSz;
         c32toa(cannedLangTagSz, output + idx);
         idx += LENGTH_SZ;
         WMEMCPY(output + idx, cannedLangTag, cannedLangTagSz);

src/ssh.c

@@ -527,6 +527,28 @@ static int ProcessBuffer(WOLFSSH_CTX* ctx, const uint8_t* in, uint32_t inSz,
 }
 
 
+int wolfSSH_CTX_SetBanner(WOLFSSH_CTX* ctx,
+                          const char* newBanner)
+{
+    uint32_t newBannerSz = 0;
+
+    WLOG(WS_LOG_DEBUG, "Entering wolfSSH_CTX_SetBanner()");
+
+    if (ctx == NULL)
+        return WS_BAD_ARGUMENT;
+
+    if (newBanner != NULL) {
+        WLOG(WS_LOG_INFO, "  setting banner to: \"%s\"", newBanner);
+        newBannerSz = (uint32_t)WSTRLEN(newBanner);
+    }
+
+    ctx->banner = newBanner;
+    ctx->bannerSz = newBannerSz;
+
+    return WS_SUCCESS;
+}
+
+
 int wolfSSH_CTX_UsePrivateKey_buffer(WOLFSSH_CTX* ctx,
                                    const uint8_t* in, uint32_t inSz, int format)
 {

wolfssh/internal.h

@@ -153,6 +153,8 @@ struct WOLFSSH_CTX {
     uint8_t*            privateKey;  /* Owned by CTX */
     uint32_t            privateKeySz;
     uint32_t            highwaterMark;
+    const char*         banner;
+    uint32_t            bannerSz;
 };
 
 

wolfssh/ssh.h

@@ -124,6 +124,7 @@ WOLFSSH_API void wolfSSH_SetUserAuth(WOLFSSH_CTX*, WS_CallbackUserAuth);
 WOLFSSH_API void wolfSSH_SetUserAuthCtx(WOLFSSH*, void*);
 WOLFSSH_API void* wolfSSH_GetUserAuthCtx(WOLFSSH*);
 
+WOLFSSH_API int wolfSSH_CTX_SetBanner(WOLFSSH_CTX*, const char*);
 WOLFSSH_API int wolfSSH_CTX_UsePrivateKey_buffer(WOLFSSH_CTX*,
                                                  const uint8_t*, uint32_t, int);