snprintf: renamed and we now only use msnprintf()

The function does not return the same value as snprintf() normally does,
so readers may be mislead into thinking the code works differently than
it actually does. A different function name makes this easier to detect.

Reported-by: Tomas Hoger
Assisted-by: Daniel Gustafsson
Fixes #3296
Closes #3297

51 files changed, 394 insertions, 402 deletions

diff --git a/lib/asyn-thread.c b/lib/asyn-thread.c
index 4c8f88b14..74208d7ec 100644
--- a/lib/asyn-thread.c
+++ b/lib/asyn-thread.c
@@ -277,7 +277,7 @@ static unsigned int CURL_STDCALL getaddrinfo_thread(void *arg)
   char service[12];
   int rc;
 
-  snprintf(service, sizeof(service), "%d", tsd->port);
+  msnprintf(service, sizeof(service), "%d", tsd->port);
 
   rc = Curl_getaddrinfo_ex(tsd->hostname, service, &tsd->hints, &tsd->res);
 
@@ -679,7 +679,7 @@ Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
   hints.ai_family = pf;
   hints.ai_socktype = conn->socktype;
 
-  snprintf(sbuf, sizeof(sbuf), "%d", port);
+  msnprintf(sbuf, sizeof(sbuf), "%d", port);
 
   reslv->start = Curl_now();
   /* fire up a new resolver thread! */
diff --git a/lib/base64.c b/lib/base64.c
index 6370e4cdf..431b64357 100644
--- a/lib/base64.c
+++ b/lib/base64.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -233,24 +233,24 @@ static CURLcode base64_encode(const char *table64,
 
     switch(inputparts) {
     case 1: /* only one byte read */
-      snprintf(output, 5, "%c%c==",
-               table64[obuf[0]],
-               table64[obuf[1]]);
+      msnprintf(output, 5, "%c%c==",
+                table64[obuf[0]],
+                table64[obuf[1]]);
       break;
 
     case 2: /* two bytes read */
-      snprintf(output, 5, "%c%c%c=",
-               table64[obuf[0]],
-               table64[obuf[1]],
-               table64[obuf[2]]);
+      msnprintf(output, 5, "%c%c%c=",
+                table64[obuf[0]],
+                table64[obuf[1]],
+                table64[obuf[2]]);
       break;
 
     default:
-      snprintf(output, 5, "%c%c%c%c",
-               table64[obuf[0]],
-               table64[obuf[1]],
-               table64[obuf[2]],
-               table64[obuf[3]]);
+      msnprintf(output, 5, "%c%c%c%c",
+                table64[obuf[0]],
+                table64[obuf[1]],
+                table64[obuf[2]],
+                table64[obuf[3]]);
       break;
     }
     output += 4;
diff --git a/lib/conncache.c b/lib/conncache.c
index 6fbf3b1d2..08e9042a6 100644
--- a/lib/conncache.c
+++ b/lib/conncache.c
@@ -175,7 +175,7 @@ static void hashkey(struct connectdata *conn, char *buf,
   DEBUGASSERT(len > 32);
 
   /* put the number first so that the hostname gets cut off if too long */
-  snprintf(buf, len, "%ld%s", conn->port, hostname);
+  msnprintf(buf, len, "%ld%s", conn->port, hostname);
 }
 
 void Curl_conncache_unlock(struct connectdata *conn)
diff --git a/lib/connect.c b/lib/connect.c
index 18645b9b7..ae9c2de1e 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -655,7 +655,7 @@ bool Curl_getaddressinfo(struct sockaddr *sa, char *addr,
 #if defined(HAVE_SYS_UN_H) && defined(AF_UNIX)
     case AF_UNIX:
       su = (struct sockaddr_un*)sa;
-      snprintf(addr, MAX_IPADR_LEN, "%s", su->sun_path);
+      msnprintf(addr, MAX_IPADR_LEN, "%s", su->sun_path);
       *port = 0;
       return TRUE;
 #endif
diff --git a/lib/curl_gssapi.c b/lib/curl_gssapi.c
index f007986c0..d854ab0c7 100644
--- a/lib/curl_gssapi.c
+++ b/lib/curl_gssapi.c
@@ -97,9 +97,9 @@ static size_t display_gss_error(OM_uint32 status, int type,
                                   &msg_ctx,
                                   &status_string);
     if(GSS_LOG_BUFFER_LEN > len + status_string.length + 3) {
-      len += snprintf(buf + len, GSS_LOG_BUFFER_LEN - len,
-                      "%.*s. ", (int)status_string.length,
-                      (char *)status_string.value);
+      len += msnprintf(buf + len, GSS_LOG_BUFFER_LEN - len,
+                       "%.*s. ", (int)status_string.length,
+                       (char *)status_string.value);
     }
     gss_release_buffer(&min_stat, &status_string);
   } while(!GSS_ERROR(maj_stat) && msg_ctx != 0);
diff --git a/lib/curl_ntlm_core.c b/lib/curl_ntlm_core.c
index 6b6ff8295..9eb6c43c8 100644
--- a/lib/curl_ntlm_core.c
+++ b/lib/curl_ntlm_core.c
@@ -743,12 +743,12 @@ CURLcode Curl_ntlm_core_mk_ntlmv2_resp(unsigned char *ntlmv2hash,
     return CURLE_OUT_OF_MEMORY;
 
   /* Create the BLOB structure */
-  snprintf((char *)ptr + NTLM_HMAC_MD5_LEN, NTLMv2_BLOB_LEN,
-           "%c%c%c%c"   /* NTLMv2_BLOB_SIGNATURE */
-           "%c%c%c%c",  /* Reserved = 0 */
-           NTLMv2_BLOB_SIGNATURE[0], NTLMv2_BLOB_SIGNATURE[1],
-           NTLMv2_BLOB_SIGNATURE[2], NTLMv2_BLOB_SIGNATURE[3],
-           0, 0, 0, 0);
+  msnprintf((char *)ptr + NTLM_HMAC_MD5_LEN, NTLMv2_BLOB_LEN,
+            "%c%c%c%c"   /* NTLMv2_BLOB_SIGNATURE */
+            "%c%c%c%c",  /* Reserved = 0 */
+            NTLMv2_BLOB_SIGNATURE[0], NTLMv2_BLOB_SIGNATURE[1],
+            NTLMv2_BLOB_SIGNATURE[2], NTLMv2_BLOB_SIGNATURE[3],
+            0, 0, 0, 0);
 
   Curl_write64_le(tw, ptr + 24);
   memcpy(ptr + 32, challenge_client, 8);
diff --git a/lib/curl_printf.h b/lib/curl_printf.h
index 49857cdb0..0d37b8e57 100644
--- a/lib/curl_printf.h
+++ b/lib/curl_printf.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -31,7 +31,7 @@
 
 # undef printf
 # undef fprintf
-# undef snprintf
+# undef msnprintf
 # undef vprintf
 # undef vfprintf
 # undef vsnprintf
@@ -39,18 +39,10 @@
 # undef vaprintf
 # define printf curl_mprintf
 # define fprintf curl_mfprintf
-# define snprintf curl_msnprintf
+# define msnprintf curl_msnprintf
 # define vprintf curl_mvprintf
 # define vfprintf curl_mvfprintf
-# define vsnprintf curl_mvsnprintf
+# define mvsnprintf curl_mvsnprintf
 # define aprintf curl_maprintf
 # define vaprintf curl_mvaprintf
-
-/* We define away the sprintf functions unconditonally since we don't want
-   internal code to be using them, intentionally or by mistake!*/
-# undef sprintf
-# undef vsprintf
-# define sprintf sprintf_was_used
-# define vsprintf vsprintf_was_used
-
 #endif /* HEADER_CURL_PRINTF_H */
diff --git a/lib/curlx.h b/lib/curlx.h
index 4c77d4f2e..3e9b516f8 100644
--- a/lib/curlx.h
+++ b/lib/curlx.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -81,22 +81,21 @@
 # undef printf
 # undef fprintf
 # undef sprintf
-# undef snprintf
+# undef msnprintf
 # undef vprintf
 # undef vfprintf
 # undef vsprintf
-# undef vsnprintf
+# undef mvsnprintf
 # undef aprintf
 # undef vaprintf
 
 # define printf curlx_mprintf
 # define fprintf curlx_mfprintf
 # define sprintf curlx_msprintf
-# define snprintf curlx_msnprintf
+# define msnprintf curlx_msnprintf
 # define vprintf curlx_mvprintf
 # define vfprintf curlx_mvfprintf
-# define vsprintf curlx_mvsprintf
-# define vsnprintf curlx_mvsnprintf
+# define mvsnprintf curlx_mvsnprintf
 # define aprintf curlx_maprintf
 # define vaprintf curlx_mvaprintf
 #endif /* ENABLE_CURLX_PRINTF */
diff --git a/lib/doh.c b/lib/doh.c
index ef6013db9..497ad8d21 100644
--- a/lib/doh.c
+++ b/lib/doh.c
@@ -660,13 +660,13 @@ static void showdoh(struct Curl_easy *data,
       char buffer[128];
       char *ptr;
       size_t len;
-      snprintf(buffer, 128, "DOH AAAA: ");
+      msnprintf(buffer, 128, "DOH AAAA: ");
       ptr = &buffer[10];
       len = 118;
       for(j = 0; j < 16; j += 2) {
         size_t l;
-        snprintf(ptr, len, "%s%02x%02x", j?":":"", d->addr[i].ip.v6[j],
-                 d->addr[i].ip.v6[j + 1]);
+        msnprintf(ptr, len, "%s%02x%02x", j?":":"", d->addr[i].ip.v6[j],
+                  d->addr[i].ip.v6[j + 1]);
         l = strlen(ptr);
         len -= l;
         ptr += l;
diff --git a/lib/escape.c b/lib/escape.c
index afd3899f9..7121db31c 100644
--- a/lib/escape.c
+++ b/lib/escape.c
@@ -122,7 +122,7 @@ char *curl_easy_escape(struct Curl_easy *data, const char *string,
         return NULL;
       }
 
-      snprintf(&ns[strindex], 4, "%%%02X", in);
+      msnprintf(&ns[strindex], 4, "%%%02X", in);
 
       strindex += 3;
     }
diff --git a/lib/file.c b/lib/file.c
index 722b55e9d..8bba3b916 100644
--- a/lib/file.c
+++ b/lib/file.c
@@ -417,8 +417,9 @@ static CURLcode file_do(struct connectdata *conn, bool *done)
     struct tm buffer;
     const struct tm *tm = &buffer;
     char header[80];
-    snprintf(header, sizeof(header),
-             "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n", expected_size);
+    msnprintf(header, sizeof(header),
+              "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n",
+              expected_size);
     result = Curl_client_write(conn, CLIENTWRITE_HEADER, header, 0);
     if(result)
       return result;
@@ -434,16 +435,16 @@ static CURLcode file_do(struct connectdata *conn, bool *done)
       return result;
 
     /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */
-    snprintf(header, sizeof(header),
-             "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n%s",
-             Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
-             tm->tm_mday,
-             Curl_month[tm->tm_mon],
-             tm->tm_year + 1900,
-             tm->tm_hour,
-             tm->tm_min,
-             tm->tm_sec,
-             data->set.opt_no_body ? "": "\r\n");
+    msnprintf(header, sizeof(header),
+              "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n%s",
+              Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+              tm->tm_mday,
+              Curl_month[tm->tm_mon],
+              tm->tm_year + 1900,
+              tm->tm_hour,
+              tm->tm_min,
+              tm->tm_sec,
+              data->set.opt_no_body ? "": "\r\n");
     result = Curl_client_write(conn, CLIENTWRITE_HEADER, header, 0);
     if(result)
       return result;
diff --git a/lib/ftp.c b/lib/ftp.c
index 793d991cc..581df09d7 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -1272,7 +1272,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
         source++;
       }
       *dest = 0;
-      snprintf(dest, 20, ",%d,%d", (int)(port>>8), (int)(port&0xff));
+      msnprintf(dest, 20, ",%d,%d", (int)(port>>8), (int)(port&0xff));
 
       result = Curl_pp_sendf(&ftpc->pp, "%s %s", mode[fcmd], tmp);
       if(result) {
@@ -2061,9 +2061,9 @@ static CURLcode ftp_state_mdtm_resp(struct connectdata *conn,
         char timebuf[24];
         time_t secs = time(NULL);
 
-        snprintf(timebuf, sizeof(timebuf),
-                 "%04d%02d%02d %02d:%02d:%02d GMT",
-                 year, month, day, hour, minute, second);
+        msnprintf(timebuf, sizeof(timebuf),
+                  "%04d%02d%02d %02d:%02d:%02d GMT",
+                  year, month, day, hour, minute, second);
         /* now, convert this into a time() value: */
         data->info.filetime = curl_getdate(timebuf, &secs);
       }
@@ -2086,15 +2086,15 @@ static CURLcode ftp_state_mdtm_resp(struct connectdata *conn,
           return result;
 
         /* format: "Tue, 15 Nov 1994 12:45:26" */
-        snprintf(headerbuf, sizeof(headerbuf),
-                 "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
-                 Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
-                 tm->tm_mday,
-                 Curl_month[tm->tm_mon],
-                 tm->tm_year + 1900,
-                 tm->tm_hour,
-                 tm->tm_min,
-                 tm->tm_sec);
+        msnprintf(headerbuf, sizeof(headerbuf),
+                  "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
+                  Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+                  tm->tm_mday,
+                  Curl_month[tm->tm_mon],
+                  tm->tm_year + 1900,
+                  tm->tm_hour,
+                  tm->tm_min,
+                  tm->tm_sec);
         result = Curl_client_write(conn, CLIENTWRITE_BOTH, headerbuf, 0);
         if(result)
           return result;
@@ -2276,8 +2276,8 @@ static CURLcode ftp_state_size_resp(struct connectdata *conn,
 #ifdef CURL_FTP_HTTPSTYLE_HEAD
     if(-1 != filesize) {
       char clbuf[128];
-      snprintf(clbuf, sizeof(clbuf),
-               "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n", filesize);
+      msnprintf(clbuf, sizeof(clbuf),
+                "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n", filesize);
       result = Curl_client_write(conn, CLIENTWRITE_BOTH, clbuf, 0);
       if(result)
         return result;
diff --git a/lib/hostip4.c b/lib/hostip4.c
index 9d6f115ae..e6ba710d8 100644
--- a/lib/hostip4.c
+++ b/lib/hostip4.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -145,7 +145,7 @@ Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname,
     hints.ai_family = PF_INET;
     hints.ai_socktype = SOCK_STREAM;
     if(port) {
-      snprintf(sbuf, sizeof(sbuf), "%d", port);
+      msnprintf(sbuf, sizeof(sbuf), "%d", port);
       sbufptr = sbuf;
     }
 
diff --git a/lib/hostip6.c b/lib/hostip6.c
index 3bf47b467..e06d0343a 100644
--- a/lib/hostip6.c
+++ b/lib/hostip6.c
@@ -178,7 +178,7 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
 #endif
 
   if(port) {
-    snprintf(sbuf, sizeof(sbuf), "%d", port);
+    msnprintf(sbuf, sizeof(sbuf), "%d", port);
     sbufptr = sbuf;
   }
 
diff --git a/lib/http.c b/lib/http.c
index afc919b09..aed7aa80f 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -1478,14 +1478,14 @@ static CURLcode add_haproxy_protocol_header(struct connectdata *conn)
     strcpy(tcp_version, "TCP4");
   }
 
-  snprintf(proxy_header,
-           sizeof(proxy_header),
-           "PROXY %s %s %s %li %li\r\n",
-           tcp_version,
-           conn->data->info.conn_local_ip,
-           conn->data->info.conn_primary_ip,
-           conn->data->info.conn_local_port,
-           conn->data->info.conn_primary_port);
+  msnprintf(proxy_header,
+            sizeof(proxy_header),
+            "PROXY %s %s %s %li %li\r\n",
+            tcp_version,
+            conn->data->info.conn_local_ip,
+            conn->data->info.conn_primary_ip,
+            conn->data->info.conn_local_port,
+            conn->data->info.conn_primary_port);
 
   req_buffer = Curl_add_buffer_init();
   if(!req_buffer)
@@ -1849,16 +1849,16 @@ CURLcode Curl_add_timecondition(struct Curl_easy *data,
    */
 
   /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */
-  snprintf(datestr, sizeof(datestr),
-           "%s: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
-           condp,
-           Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
-           tm->tm_mday,
-           Curl_month[tm->tm_mon],
-           tm->tm_year + 1900,
-           tm->tm_hour,
-           tm->tm_min,
-           tm->tm_sec);
+  msnprintf(datestr, sizeof(datestr),
+            "%s: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
+            condp,
+            Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+            tm->tm_mday,
+            Curl_month[tm->tm_mon],
+            tm->tm_year + 1900,
+            tm->tm_hour,
+            tm->tm_min,
+            tm->tm_sec);
 
   result = Curl_add_buffer(&req_buffer, datestr, strlen(datestr));
 
@@ -2292,8 +2292,8 @@ CURLcode Curl_http(struct connectdata *conn, bool *done)
           if(!*data->state.up.path && path[strlen(path) - 1] != '/') {
             *p++ = '/';
           }
-          snprintf(p, sizeof(ftp_typecode) - 1, ";type=%c",
-                   data->set.prefer_ascii ? 'a' : 'i');
+          msnprintf(p, sizeof(ftp_typecode) - 1, ";type=%c",
+                    data->set.prefer_ascii ? 'a' : 'i');
         }
       }
       if(conn->bits.user_passwd && !conn->bits.userpwd_in_url)
diff --git a/lib/http2.c b/lib/http2.c
index 0c5f6db0b..c33bee3eb 100644
--- a/lib/http2.c
+++ b/lib/http2.c
@@ -350,7 +350,7 @@ static const struct Curl_handler Curl_handler_http2_ssl = {
 int Curl_http2_ver(char *p, size_t len)
 {
   nghttp2_info *h2 = nghttp2_version(0);
-  return snprintf(p, len, " nghttp2/%s", h2->version_str);
+  return msnprintf(p, len, " nghttp2/%s", h2->version_str);
 }
 
 /* HTTP/2 error code to name based on the Error Code Registry.
diff --git a/lib/if2ip.c b/lib/if2ip.c
index ce38ea117..566061a56 100644
--- a/lib/if2ip.c
+++ b/lib/if2ip.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -169,7 +169,7 @@ if2ip_result_t Curl_if2ip(int af, unsigned int remote_scope,
               }
 #endif
               if(scopeid)
-                snprintf(scope, sizeof(scope), "%%%u", scopeid);
+                msnprintf(scope, sizeof(scope), "%%%u", scopeid);
             }
             else
 #endif
@@ -177,7 +177,7 @@ if2ip_result_t Curl_if2ip(int af, unsigned int remote_scope,
                   &((struct sockaddr_in *)(void *)iface->ifa_addr)->sin_addr;
             res = IF2IP_FOUND;
             ip = (char *) Curl_inet_ntop(af, addr, ipstr, sizeof(ipstr));
-            snprintf(buf, buf_size, "%s%s", ip, scope);
+            msnprintf(buf, buf_size, "%s%s", ip, scope);
             break;
           }
         }
diff --git a/lib/imap.c b/lib/imap.c
index 3ef89097f..a8320e3f1 100644
--- a/lib/imap.c
+++ b/lib/imap.c
@@ -1749,8 +1749,8 @@ static CURLcode imap_sendf(struct connectdata *conn, const char *fmt, ...)
   imapc->cmdid = (imapc->cmdid + 1) % 1000;
 
   /* Calculate the tag based on the connection ID and command ID */
-  snprintf(imapc->resptag, sizeof(imapc->resptag), "%c%03d",
-           'A' + curlx_sltosi(conn->connection_id % 26), imapc->cmdid);
+  msnprintf(imapc->resptag, sizeof(imapc->resptag), "%c%03d",
+            'A' + curlx_sltosi(conn->connection_id % 26), imapc->cmdid);
 
   /* Prefix the format with the tag */
   taggedfmt = aprintf("%s %s", imapc->resptag, fmt);
diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c
index ac5d2d4d6..855981c66 100644
--- a/lib/inet_ntop.c
+++ b/lib/inet_ntop.c
@@ -55,11 +55,11 @@ static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
   DEBUGASSERT(size >= 16);
 
   tmp[0] = '\0';
-  (void)snprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
-                 ((int)((unsigned char)src[0])) & 0xff,
-                 ((int)((unsigned char)src[1])) & 0xff,
-                 ((int)((unsigned char)src[2])) & 0xff,
-                 ((int)((unsigned char)src[3])) & 0xff);
+  (void)msnprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
+                  ((int)((unsigned char)src[0])) & 0xff,
+                  ((int)((unsigned char)src[1])) & 0xff,
+                  ((int)((unsigned char)src[2])) & 0xff,
+                  ((int)((unsigned char)src[3])) & 0xff);
 
   len = strlen(tmp);
   if(len == 0 || len >= size) {
@@ -148,7 +148,7 @@ static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
       tp += strlen(tp);
       break;
     }
-    tp += snprintf(tp, 5, "%lx", words[i]);
+    tp += msnprintf(tp, 5, "%lx", words[i]);
   }
 
   /* Was it a trailing run of 0x00's?
diff --git a/lib/memdebug.c b/lib/memdebug.c
index 2b81c26a6..05590a8f8 100644
--- a/lib/memdebug.c
+++ b/lib/memdebug.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -504,7 +504,7 @@ void curl_memlog(const char *format, ...)
     return;
 
   va_start(ap, format);
-  nchars = vsnprintf(buf, LOGLINE_BUFSIZE, format, ap);
+  nchars = mvsnprintf(buf, LOGLINE_BUFSIZE, format, ap);
   va_end(ap);
 
   if(nchars > LOGLINE_BUFSIZE - 1)
diff --git a/lib/multi.c b/lib/multi.c
index fbd389716..c2ef6c19e 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -634,13 +634,13 @@ static CURLcode multi_done(struct connectdata **connp,
   else {
     char buffer[256];
     /* create string before returning the connection */
-    snprintf(buffer, sizeof(buffer),
-             "Connection #%ld to host %s left intact",
-             conn->connection_id,
-             conn->bits.socksproxy ? conn->socks_proxy.host.dispname :
-             conn->bits.httpproxy ? conn->http_proxy.host.dispname :
-             conn->bits.conn_to_host ? conn->conn_to_host.dispname :
-             conn->host.dispname);
+    msnprintf(buffer, sizeof(buffer),
+              "Connection #%ld to host %s left intact",
+              conn->connection_id,
+              conn->bits.socksproxy ? conn->socks_proxy.host.dispname :
+              conn->bits.httpproxy ? conn->http_proxy.host.dispname :
+              conn->bits.conn_to_host ? conn->conn_to_host.dispname :
+              conn->host.dispname);
 
     /* the connection is no longer in use by this transfer */
     if(Curl_conncache_return_conn(conn)) {
diff --git a/lib/openldap.c b/lib/openldap.c
index c6cb79434..bc007883e 100644
--- a/lib/openldap.c
+++ b/lib/openldap.c
@@ -220,8 +220,8 @@ static CURLcode ldap_connect(struct connectdata *conn, bool *done)
   ptr = hosturl + 4;
   if(conn->handler->flags & PROTOPT_SSL)
     *ptr++ = 's';
-  snprintf(ptr, sizeof(hosturl)-(ptr-hosturl), "://%s:%d",
-           conn->host.name, conn->remote_port);
+  msnprintf(ptr, sizeof(hosturl)-(ptr-hosturl), "://%s:%d",
+            conn->host.name, conn->remote_port);
 
 #ifdef CURL_OPENLDAP_DEBUG
   static int do_trace = 0;
diff --git a/lib/pop3.c b/lib/pop3.c
index c1f974d40..05853f001 100644
--- a/lib/pop3.c
+++ b/lib/pop3.c
@@ -443,7 +443,7 @@ static CURLcode pop3_perform_apop(struct connectdata *conn)
 
   /* Convert the calculated 16 octet digest into a 32 byte hex string */
   for(i = 0; i < MD5_DIGEST_LEN; i++)
-    snprintf(&secret[2 * i], 3, "%02x", digest[i]);
+    msnprintf(&secret[2 * i], 3, "%02x", digest[i]);
 
   result = Curl_pp_sendf(&pop3c->pp, "APOP %s %s", conn->user, secret);
 
diff --git a/lib/progress.c b/lib/progress.c
index a94668dc2..d37e1d5a6 100644
--- a/lib/progress.c
+++ b/lib/progress.c
@@ -44,8 +44,8 @@ static void time2str(char *r, curl_off_t seconds)
   if(h <= CURL_OFF_T_C(99)) {
     curl_off_t m = (seconds - (h*CURL_OFF_T_C(3600))) / CURL_OFF_T_C(60);
     curl_off_t s = (seconds - (h*CURL_OFF_T_C(3600))) - (m*CURL_OFF_T_C(60));
-    snprintf(r, 9, "%2" CURL_FORMAT_CURL_OFF_T ":%02" CURL_FORMAT_CURL_OFF_T
-             ":%02" CURL_FORMAT_CURL_OFF_T, h, m, s);
+    msnprintf(r, 9, "%2" CURL_FORMAT_CURL_OFF_T ":%02" CURL_FORMAT_CURL_OFF_T
+              ":%02" CURL_FORMAT_CURL_OFF_T, h, m, s);
   }
   else {
     /* this equals to more than 99 hours, switch to a more suitable output
@@ -53,10 +53,10 @@ static void time2str(char *r, curl_off_t seconds)
     curl_off_t d = seconds / CURL_OFF_T_C(86400);
     h = (seconds - (d*CURL_OFF_T_C(86400))) / CURL_OFF_T_C(3600);
     if(d <= CURL_OFF_T_C(999))
-      snprintf(r, 9, "%3" CURL_FORMAT_CURL_OFF_T
-               "d %02" CURL_FORMAT_CURL_OFF_T "h", d, h);
+      msnprintf(r, 9, "%3" CURL_FORMAT_CURL_OFF_T
+                "d %02" CURL_FORMAT_CURL_OFF_T "h", d, h);
     else
-      snprintf(r, 9, "%7" CURL_FORMAT_CURL_OFF_T "d", d);
+      msnprintf(r, 9, "%7" CURL_FORMAT_CURL_OFF_T "d", d);
   }
 }
 
@@ -72,40 +72,40 @@ static char *max5data(curl_off_t bytes, char *max5)
 #define ONE_PETABYTE (CURL_OFF_T_C(1024) * ONE_TERABYTE)
 
   if(bytes < CURL_OFF_T_C(100000))
-    snprintf(max5, 6, "%5" CURL_FORMAT_CURL_OFF_T, bytes);
+    msnprintf(max5, 6, "%5" CURL_FORMAT_CURL_OFF_T, bytes);
 
   else if(bytes < CURL_OFF_T_C(10000) * ONE_KILOBYTE)
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "k", bytes/ONE_KILOBYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "k", bytes/ONE_KILOBYTE);
 
   else if(bytes < CURL_OFF_T_C(100) * ONE_MEGABYTE)
     /* 'XX.XM' is good as long as we're less than 100 megs */
-    snprintf(max5, 6, "%2" CURL_FORMAT_CURL_OFF_T ".%0"
-             CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE,
-             (bytes%ONE_MEGABYTE) / (ONE_MEGABYTE/CURL_OFF_T_C(10)) );
+    msnprintf(max5, 6, "%2" CURL_FORMAT_CURL_OFF_T ".%0"
+              CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE,
+              (bytes%ONE_MEGABYTE) / (ONE_MEGABYTE/CURL_OFF_T_C(10)) );
 
 #if (CURL_SIZEOF_CURL_OFF_T > 4)
 
   else if(bytes < CURL_OFF_T_C(10000) * ONE_MEGABYTE)
     /* 'XXXXM' is good until we're at 10000MB or above */
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE);
 
   else if(bytes < CURL_OFF_T_C(100) * ONE_GIGABYTE)
     /* 10000 MB - 100 GB, we show it as XX.XG */
-    snprintf(max5, 6, "%2" CURL_FORMAT_CURL_OFF_T ".%0"
-             CURL_FORMAT_CURL_OFF_T "G", bytes/ONE_GIGABYTE,
-             (bytes%ONE_GIGABYTE) / (ONE_GIGABYTE/CURL_OFF_T_C(10)) );
+    msnprintf(max5, 6, "%2" CURL_FORMAT_CURL_OFF_T ".%0"
+              CURL_FORMAT_CURL_OFF_T "G", bytes/ONE_GIGABYTE,
+              (bytes%ONE_GIGABYTE) / (ONE_GIGABYTE/CURL_OFF_T_C(10)) );
 
   else if(bytes < CURL_OFF_T_C(10000) * ONE_GIGABYTE)
     /* up to 10000GB, display without decimal: XXXXG */
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "G", bytes/ONE_GIGABYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "G", bytes/ONE_GIGABYTE);
 
   else if(bytes < CURL_OFF_T_C(10000) * ONE_TERABYTE)
     /* up to 10000TB, display without decimal: XXXXT */
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "T", bytes/ONE_TERABYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "T", bytes/ONE_TERABYTE);
 
   else
     /* up to 10000PB, display without decimal: XXXXP */
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "P", bytes/ONE_PETABYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "P", bytes/ONE_PETABYTE);
 
     /* 16384 petabytes (16 exabytes) is the maximum a 64 bit unsigned number
        can hold, but our data type is signed so 8192PB will be the maximum. */
@@ -113,7 +113,7 @@ static char *max5data(curl_off_t bytes, char *max5)
 #else
 
   else
-    snprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE);
+    msnprintf(max5, 6, "%4" CURL_FORMAT_CURL_OFF_T "M", bytes/ONE_MEGABYTE);
 
 #endif
 
diff --git a/lib/security.c b/lib/security.c
index 6165d0af0..7f13071f6 100644
--- a/lib/security.c
+++ b/lib/security.c
@@ -10,7 +10,7 @@
  * Copyright (c) 1998, 1999, 2017 Kungliga Tekniska Högskolan
  * (Royal Institute of Technology, Stockholm, Sweden).
  *
- * Copyright (C) 2001 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2001 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * All rights reserved.
  *
@@ -120,7 +120,7 @@ static int ftp_send_command(struct connectdata *conn, const char *message, ...)
   char print_buffer[50];
 
   va_start(args, message);
-  vsnprintf(print_buffer, sizeof(print_buffer), message, args);
+  mvsnprintf(print_buffer, sizeof(print_buffer), message, args);
   va_end(args);
 
   if(Curl_ftpsend(conn, print_buffer)) {
diff --git a/lib/sendf.c b/lib/sendf.c
index 77eacdf5f..e8598e617 100644
--- a/lib/sendf.c
+++ b/lib/sendf.c
@@ -237,7 +237,7 @@ void Curl_infof(struct Curl_easy *data, const char *fmt, ...)
     size_t len;
     char print_buffer[2048 + 1];
     va_start(ap, fmt);
-    len = vsnprintf(print_buffer, sizeof(print_buffer), fmt, ap);
+    len = mvsnprintf(print_buffer, sizeof(print_buffer), fmt, ap);
     /*
      * Indicate truncation of the input by replacing the last 3 characters
      * with "...", and transfer the newline over in case the format had one.
@@ -245,9 +245,9 @@ void Curl_infof(struct Curl_easy *data, const char *fmt, ...)
     if(len >= sizeof(print_buffer)) {
       len = strlen(fmt);
       if(fmt[--len] == '\n')
-        snprintf(print_buffer + (sizeof(print_buffer) - 5), 5, "...\n");
+        msnprintf(print_buffer + (sizeof(print_buffer) - 5), 5, "...\n");
       else
-        snprintf(print_buffer + (sizeof(print_buffer) - 4), 4, "...");
+        msnprintf(print_buffer + (sizeof(print_buffer) - 4), 4, "...");
     }
     va_end(ap);
     len = strlen(print_buffer);
@@ -266,7 +266,7 @@ void Curl_failf(struct Curl_easy *data, const char *fmt, ...)
     size_t len;
     char error[CURL_ERROR_SIZE + 2];
     va_start(ap, fmt);
-    vsnprintf(error, CURL_ERROR_SIZE, fmt, ap);
+    mvsnprintf(error, CURL_ERROR_SIZE, fmt, ap);
     len = strlen(error);
 
     if(data->set.errorbuffer && !data->state.errorbuf) {
diff --git a/lib/socks_gssapi.c b/lib/socks_gssapi.c
index 96948ac4b..65294bbeb 100644
--- a/lib/socks_gssapi.c
+++ b/lib/socks_gssapi.c
@@ -6,7 +6,7 @@
  *                             \___|\___/|_| \_\_____|
  *
  * Copyright (C) 2009, Markus Moeller, <markus_moeller@compuserve.com>
- * Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2012 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -151,8 +151,8 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
       return CURLE_OUT_OF_MEMORY;
     service.length = serviceptr_length +
       strlen(conn->socks_proxy.host.name) + 1;
-    snprintf(service.value, service.length + 1, "%s@%s",
-             serviceptr, conn->socks_proxy.host.name);
+    msnprintf(service.value, service.length + 1, "%s@%s",
+              serviceptr, conn->socks_proxy.host.name);
 
     gss_major_status = gss_import_name(&gss_minor_status, &service,
                                        GSS_C_NT_HOSTBASED_SERVICE, &server);
diff --git a/lib/socks_sspi.c b/lib/socks_sspi.c
index 34699d374..bedb01ebb 100644
--- a/lib/socks_sspi.c
+++ b/lib/socks_sspi.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2012 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller@compuserve.com>
  *
  * This software is licensed as described in the file COPYING, which
@@ -107,9 +107,9 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
                           strlen(conn->socks_proxy.host.name) + 2);
     if(!service_name)
       return CURLE_OUT_OF_MEMORY;
-    snprintf(service_name, service_length +
-             strlen(conn->socks_proxy.host.name) + 2, "%s/%s",
-             service, conn->socks_proxy.host.name);
+    msnprintf(service_name, service_length +
+              strlen(conn->socks_proxy.host.name) + 2, "%s/%s",
+              service, conn->socks_proxy.host.name);
   }
 
   input_desc.cBuffers = 1;
diff --git a/lib/ssh-libssh.c b/lib/ssh-libssh.c
index 7d590891c..e38c01ac7 100644
--- a/lib/ssh-libssh.c
+++ b/lib/ssh-libssh.c
@@ -1342,8 +1342,8 @@ static CURLcode myssh_statemach_act(struct connectdata *conn, bool *block)
               break;
             }
 
-            snprintf(sshc->readdir_linkPath, PATH_MAX, "%s%s", protop->path,
-                     sshc->readdir_filename);
+            msnprintf(sshc->readdir_linkPath, PATH_MAX, "%s%s", protop->path,
+                      sshc->readdir_filename);
 
             state(conn, SSH_SFTP_READDIR_LINK);
             break;
@@ -1406,12 +1406,12 @@ static CURLcode myssh_statemach_act(struct connectdata *conn, bool *block)
       }
       sshc->readdir_line = new_readdir_line;
 
-      sshc->readdir_currLen += snprintf(sshc->readdir_line +
-                                        sshc->readdir_currLen,
-                                        sshc->readdir_totalLen -
-                                        sshc->readdir_currLen,
-                                        " -> %s",
-                                        sshc->readdir_filename);
+      sshc->readdir_currLen += msnprintf(sshc->readdir_line +
+                                         sshc->readdir_currLen,
+                                         sshc->readdir_totalLen -
+                                         sshc->readdir_currLen,
+                                         " -> %s",
+                                         sshc->readdir_filename);
 
       sftp_attributes_free(sshc->readdir_link_attrs);
       sshc->readdir_link_attrs = NULL;
@@ -1421,10 +1421,10 @@ static CURLcode myssh_statemach_act(struct connectdata *conn, bool *block)
       state(conn, SSH_SFTP_READDIR_BOTTOM);
       /* FALLTHROUGH */
     case SSH_SFTP_READDIR_BOTTOM:
-      sshc->readdir_currLen += snprintf(sshc->readdir_line +
-                                        sshc->readdir_currLen,
-                                        sshc->readdir_totalLen -
-                                        sshc->readdir_currLen, "\n");
+      sshc->readdir_currLen += msnprintf(sshc->readdir_line +
+                                         sshc->readdir_currLen,
+                                         sshc->readdir_totalLen -
+                                         sshc->readdir_currLen, "\n");
       result = Curl_client_write(conn, CLIENTWRITE_BODY,
                                  sshc->readdir_line,
                                  sshc->readdir_currLen);
diff --git a/lib/ssh.c b/lib/ssh.c
index da896196f..f3b0a58be 100644
--- a/lib/ssh.c
+++ b/lib/ssh.c
@@ -599,7 +599,7 @@ static CURLcode ssh_check_fingerprint(struct connectdata *conn)
   if(fingerprint) {
     /* The fingerprint points to static storage (!), don't free() it. */
     for(i = 0; i < 16; i++)
-      snprintf(&md5buffer[i*2], 3, "%02x", (unsigned char) fingerprint[i]);
+      msnprintf(&md5buffer[i*2], 3, "%02x", (unsigned char) fingerprint[i]);
     infof(data, "SSH MD5 fingerprint: %s\n", md5buffer);
   }
 
@@ -1999,8 +1999,8 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
               break;
             }
 
-            snprintf(sshc->readdir_linkPath, PATH_MAX, "%s%s", sftp_scp->path,
-                     sshc->readdir_filename);
+            msnprintf(sshc->readdir_linkPath, PATH_MAX, "%s%s", sftp_scp->path,
+                      sshc->readdir_filename);
             state(conn, SSH_SFTP_READDIR_LINK);
             break;
           }
@@ -2055,21 +2055,21 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
       }
       sshc->readdir_line = new_readdir_line;
 
-      sshc->readdir_currLen += snprintf(sshc->readdir_line +
-                                        sshc->readdir_currLen,
-                                        sshc->readdir_totalLen -
-                                        sshc->readdir_currLen,
-                                        " -> %s",
-                                        sshc->readdir_filename);
+      sshc->readdir_currLen += msnprintf(sshc->readdir_line +
+                                         sshc->readdir_currLen,
+                                         sshc->readdir_totalLen -
+                                         sshc->readdir_currLen,
+                                         " -> %s",
+                                         sshc->readdir_filename);
 
       state(conn, SSH_SFTP_READDIR_BOTTOM);
       break;
 
     case SSH_SFTP_READDIR_BOTTOM:
-      sshc->readdir_currLen += snprintf(sshc->readdir_line +
-                                        sshc->readdir_currLen,
-                                        sshc->readdir_totalLen -
-                                        sshc->readdir_currLen, "\n");
+      sshc->readdir_currLen += msnprintf(sshc->readdir_line +
+                                         sshc->readdir_currLen,
+                                         sshc->readdir_totalLen -
+                                         sshc->readdir_currLen, "\n");
       result = Curl_client_write(conn, CLIENTWRITE_BODY,
                                  sshc->readdir_line,
                                  sshc->readdir_currLen);
diff --git a/lib/strerror.c b/lib/strerror.c
index 47ef44a66..bf30c8907 100644
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 2004 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2004 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -681,7 +681,7 @@ const char *Curl_strerror(struct connectdata *conn, int err)
     if(!get_winsock_error(err, buf, max) &&
        !FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, err,
                        LANG_NEUTRAL, buf, (DWORD)max, NULL))
-      snprintf(buf, max, "Unknown error %d (%#x)", err, err);
+      msnprintf(buf, max, "Unknown error %d (%#x)", err, err);
   }
 #endif
 
@@ -695,7 +695,7 @@ const char *Curl_strerror(struct connectdata *conn, int err)
   */
   if(0 != strerror_r(err, buf, max)) {
     if('\0' == buf[0])
-      snprintf(buf, max, "Unknown error %d", err);
+      msnprintf(buf, max, "Unknown error %d", err);
   }
 #elif defined(HAVE_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R)
  /*
@@ -709,7 +709,7 @@ const char *Curl_strerror(struct connectdata *conn, int err)
     if(msg)
       strncpy(buf, msg, max);
     else
-      snprintf(buf, max, "Unknown error %d", err);
+      msnprintf(buf, max, "Unknown error %d", err);
   }
 #elif defined(HAVE_STRERROR_R) && defined(HAVE_VXWORKS_STRERROR_R)
  /*
@@ -721,7 +721,7 @@ const char *Curl_strerror(struct connectdata *conn, int err)
     if(OK == strerror_r(err, buffer))
       strncpy(buf, buffer, max);
     else
-      snprintf(buf, max, "Unknown error %d", err);
+      msnprintf(buf, max, "Unknown error %d", err);
   }
 #else
   {
@@ -729,7 +729,7 @@ const char *Curl_strerror(struct connectdata *conn, int err)
     if(msg)
       strncpy(buf, msg, max);
     else
-      snprintf(buf, max, "Unknown error %d", err);
+      msnprintf(buf, max, "Unknown error %d", err);
   }
 #endif
 
@@ -1032,14 +1032,14 @@ const char *Curl_sspi_strerror (struct connectdata *conn, int err)
   if(err == SEC_E_OK)
     strncpy(outbuf, txt, outmax);
   else if(err == SEC_E_ILLEGAL_MESSAGE)
-    snprintf(outbuf, outmax,
-             "SEC_E_ILLEGAL_MESSAGE (0x%08X) - This error usually occurs "
-             "when a fatal SSL/TLS alert is received (e.g. handshake failed). "
-             "More detail may be available in the Windows System event log.",
-             err);
+    msnprintf(outbuf, outmax,
+              "SEC_E_ILLEGAL_MESSAGE (0x%08X) - This error usually occurs "
+              "when a fatal SSL/TLS alert is received (e.g. handshake failed)."
+              " More detail may be available in the Windows System event log.",
+              err);
   else {
     str = txtbuf;
-    snprintf(txtbuf, sizeof(txtbuf), "%s (0x%08X)", txt, err);
+    msnprintf(txtbuf, sizeof(txtbuf), "%s (0x%08X)", txt, err);
     txtbuf[sizeof(txtbuf)-1] = '\0';
 
 #ifdef _WIN32_WCE
@@ -1075,7 +1075,7 @@ const char *Curl_sspi_strerror (struct connectdata *conn, int err)
       msg = msgbuf;
     }
     if(msg)
-      snprintf(outbuf, outmax, "%s - %s", str, msg);
+      msnprintf(outbuf, outmax, "%s - %s", str, msg);
     else
       strncpy(outbuf, str, outmax);
   }
diff --git a/lib/telnet.c b/lib/telnet.c
index 05fe744db..e4c0bac3d 100644
--- a/lib/telnet.c
+++ b/lib/telnet.c
@@ -829,7 +829,7 @@ static CURLcode check_telnet_options(struct connectdata *conn)
   /* Add the user name as an environment variable if it
      was given on the command line */
   if(conn->bits.user_passwd) {
-    snprintf(option_arg, sizeof(option_arg), "USER,%s", conn->user);
+    msnprintf(option_arg, sizeof(option_arg), "USER,%s", conn->user);
     beg = curl_slist_append(tn->telnet_vars, option_arg);
     if(!beg) {
       curl_slist_free_all(tn->telnet_vars);
@@ -935,9 +935,9 @@ static void suboption(struct connectdata *conn)
   switch(CURL_SB_GET(tn)) {
     case CURL_TELOPT_TTYPE:
       len = strlen(tn->subopt_ttype) + 4 + 2;
-      snprintf((char *)temp, sizeof(temp),
-               "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_TTYPE,
-               CURL_TELQUAL_IS, tn->subopt_ttype, CURL_IAC, CURL_SE);
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_TTYPE,
+                CURL_TELQUAL_IS, tn->subopt_ttype, CURL_IAC, CURL_SE);
       bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
       if(bytes_written < 0) {
         err = SOCKERRNO;
@@ -947,9 +947,9 @@ static void suboption(struct connectdata *conn)
       break;
     case CURL_TELOPT_XDISPLOC:
       len = strlen(tn->subopt_xdisploc) + 4 + 2;
-      snprintf((char *)temp, sizeof(temp),
-               "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_XDISPLOC,
-               CURL_TELQUAL_IS, tn->subopt_xdisploc, CURL_IAC, CURL_SE);
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_XDISPLOC,
+                CURL_TELQUAL_IS, tn->subopt_xdisploc, CURL_IAC, CURL_SE);
       bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
       if(bytes_written < 0) {
         err = SOCKERRNO;
@@ -958,9 +958,9 @@ static void suboption(struct connectdata *conn)
       printsub(data, '>', &temp[2], len-2);
       break;
     case CURL_TELOPT_NEW_ENVIRON:
-      snprintf((char *)temp, sizeof(temp),
-               "%c%c%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_NEW_ENVIRON,
-               CURL_TELQUAL_IS);
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_NEW_ENVIRON,
+                CURL_TELQUAL_IS);
       len = 4;
 
       for(v = tn->telnet_vars; v; v = v->next) {
@@ -968,15 +968,15 @@ static void suboption(struct connectdata *conn)
         /* Add the variable only if it fits */
         if(len + tmplen < (int)sizeof(temp)-6) {
           if(sscanf(v->data, "%127[^,],%127s", varname, varval)) {
-            snprintf((char *)&temp[len], sizeof(temp) - len,
-                     "%c%s%c%s", CURL_NEW_ENV_VAR, varname,
-                     CURL_NEW_ENV_VALUE, varval);
+            msnprintf((char *)&temp[len], sizeof(temp) - len,
+                      "%c%s%c%s", CURL_NEW_ENV_VAR, varname,
+                      CURL_NEW_ENV_VALUE, varval);
             len += tmplen;
           }
         }
       }
-      snprintf((char *)&temp[len], sizeof(temp) - len,
-               "%c%c", CURL_IAC, CURL_SE);
+      msnprintf((char *)&temp[len], sizeof(temp) - len,
+                "%c%c", CURL_IAC, CURL_SE);
       len += 2;
       bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
       if(bytes_written < 0) {
diff --git a/lib/tftp.c b/lib/tftp.c
index 5b74e8e08..269b3cde4 100644
--- a/lib/tftp.c
+++ b/lib/tftp.c
@@ -496,9 +496,9 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
       return CURLE_TFTP_ILLEGAL; /* too long file name field */
     }
 
-    snprintf((char *)state->spacket.data + 2,
-             state->blksize,
-             "%s%c%s%c", filename, '\0',  mode, '\0');
+    msnprintf((char *)state->spacket.data + 2,
+              state->blksize,
+              "%s%c%s%c", filename, '\0',  mode, '\0');
     sbytes = 4 + strlen(filename) + strlen(mode);
 
     /* optional addition of TFTP options */
@@ -506,8 +506,8 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
       char buf[64];
       /* add tsize option */
       if(data->set.upload && (data->state.infilesize != -1))
-        snprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
-                 data->state.infilesize);
+        msnprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
+                  data->state.infilesize);
       else
         strcpy(buf, "0"); /* the destination is large enough */
 
@@ -517,7 +517,7 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
       sbytes += tftp_option_add(state, sbytes,
                                 (char *)state->spacket.data + sbytes, buf);
       /* add blksize option */
-      snprintf(buf, sizeof(buf), "%d", state->requested_blksize);
+      msnprintf(buf, sizeof(buf), "%d", state->requested_blksize);
       sbytes += tftp_option_add(state, sbytes,
                                 (char *)state->spacket.data + sbytes,
                                 TFTP_OPTION_BLKSIZE);
@@ -525,7 +525,7 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
                                 (char *)state->spacket.data + sbytes, buf);
 
       /* add timeout option */
-      snprintf(buf, sizeof(buf), "%d", state->retry_time);
+      msnprintf(buf, sizeof(buf), "%d", state->retry_time);
       sbytes += tftp_option_add(state, sbytes,
                                 (char *)state->spacket.data + sbytes,
                                 TFTP_OPTION_INTERVAL);
diff --git a/lib/transfer.c b/lib/transfer.c
index 32ca5a496..5b1af4ebe 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -218,8 +218,8 @@ CURLcode Curl_fillreadbuffer(struct connectdata *conn, size_t bytes,
       endofline_native  = "\r\n";
       endofline_network = "\x0d\x0a";
     }
-    hexlen = snprintf(hexbuffer, sizeof(hexbuffer),
-                      "%x%s", nread, endofline_native);
+    hexlen = msnprintf(hexbuffer, sizeof(hexbuffer),
+                       "%x%s", nread, endofline_native);
 
     /* move buffer pointer */
     data->req.upload_fromhere -= hexlen;
diff --git a/lib/url.c b/lib/url.c
index 3625bcdce..7839dfa7c 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -2997,7 +2997,7 @@ static CURLcode parse_remote_port(struct Curl_easy *data,
     char portbuf[16];
     CURLUcode uc;
     conn->remote_port = (unsigned short)data->set.use_port;
-    snprintf(portbuf, sizeof(portbuf), "%u", conn->remote_port);
+    msnprintf(portbuf, sizeof(portbuf), "%u", conn->remote_port);
     uc = curl_url_set(data->state.uh, CURLUPART_PORT, portbuf, 0);
     if(uc)
       return CURLE_OUT_OF_MEMORY;
diff --git a/lib/urlapi.c b/lib/urlapi.c
index 2830dc163..be9958cd8 100644
--- a/lib/urlapi.c
+++ b/lib/urlapi.c
@@ -203,7 +203,7 @@ void Curl_strcpy_url(char *output, const char *url, bool relative)
       /* FALLTHROUGH */
     default:
       if(urlchar_needs_escaping(*iptr)) {
-        snprintf(optr, 4, "%%%02x", *iptr);
+        msnprintf(optr, 4, "%%%02x", *iptr);
         optr += 3;
       }
       else
@@ -531,7 +531,7 @@ static CURLUcode parse_port(struct Curl_URL *u, char *hostname)
       *portptr++ = '\0'; /* cut off the name there */
       *rest = 0;
       /* generate a new to get rid of leading zeroes etc */
-      snprintf(portbuf, sizeof(portbuf), "%ld", port);
+      msnprintf(portbuf, sizeof(portbuf), "%ld", port);
       u->portnum = port;
       u->port = strdup(portbuf);
       if(!u->port)
@@ -964,7 +964,7 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
       const struct Curl_handler *h =
         Curl_builtin_scheme(u->scheme);
       if(h) {
-        snprintf(portbuf, sizeof(portbuf), "%ld", h->defport);
+        msnprintf(portbuf, sizeof(portbuf), "%ld", h->defport);
         ptr = portbuf;
       }
     }
@@ -1023,7 +1023,7 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
           /* there's no stored port number, but asked to deliver
              a default one for the scheme */
           if(h) {
-            snprintf(portbuf, sizeof(portbuf), "%ld", h->defport);
+            msnprintf(portbuf, sizeof(portbuf), "%ld", h->defport);
             port = portbuf;
           }
         }
@@ -1287,7 +1287,7 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
           o++;
         }
         else {
-          snprintf(o, 4, "%%%02x", *i);
+          msnprintf(o, 4, "%%%02x", *i);
           o += 3;
         }
       }
diff --git a/lib/vauth/digest.c b/lib/vauth/digest.c
index ab5156eb7..0f2e6509e 100644
--- a/lib/vauth/digest.c
+++ b/lib/vauth/digest.c
@@ -143,7 +143,7 @@ static void auth_digest_md5_to_ascii(unsigned char *source, /* 16 bytes */
 {
   int i;
   for(i = 0; i < 16; i++)
-    snprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
+    msnprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
 }
 
 /* Convert sha256 chunk to RFC7616 -suitable ascii string*/
@@ -152,7 +152,7 @@ static void auth_digest_sha256_to_ascii(unsigned char *source, /* 32 bytes */
 {
   int i;
   for(i = 0; i < 32; i++)
-    snprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
+    msnprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
 }
 
 /* Perform quoted-string escaping as described in RFC2616 and its errata */
@@ -432,7 +432,7 @@ CURLcode Curl_auth_create_digest_md5_message(struct Curl_easy *data,
 
   /* Convert calculated 16 octet hex into 32 bytes string */
   for(i = 0; i < MD5_DIGEST_LEN; i++)
-    snprintf(&HA1_hex[2 * i], 3, "%02x", digest[i]);
+    msnprintf(&HA1_hex[2 * i], 3, "%02x", digest[i]);
 
   /* Generate our SPN */
   spn = Curl_auth_build_spn(service, realm, NULL);
@@ -455,7 +455,7 @@ CURLcode Curl_auth_create_digest_md5_message(struct Curl_easy *data,
   Curl_MD5_final(ctxt, digest);
 
   for(i = 0; i < MD5_DIGEST_LEN; i++)
-    snprintf(&HA2_hex[2 * i], 3, "%02x", digest[i]);
+    msnprintf(&HA2_hex[2 * i], 3, "%02x", digest[i]);
 
   /* Now calculate the response hash */
   ctxt = Curl_MD5_init(Curl_DIGEST_MD5);
@@ -485,7 +485,7 @@ CURLcode Curl_auth_create_digest_md5_message(struct Curl_easy *data,
   Curl_MD5_final(ctxt, digest);
 
   for(i = 0; i < MD5_DIGEST_LEN; i++)
-    snprintf(&resp_hash_hex[2 * i], 3, "%02x", digest[i]);
+    msnprintf(&resp_hash_hex[2 * i], 3, "%02x", digest[i]);
 
   /* Generate the response */
   response = aprintf("username=\"%s\",realm=\"%s\",nonce=\"%s\","
diff --git a/lib/vauth/ntlm.c b/lib/vauth/ntlm.c
index 11f42f504..458b27253 100644
--- a/lib/vauth/ntlm.c
+++ b/lib/vauth/ntlm.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -409,38 +409,38 @@ CURLcode Curl_auth_create_ntlm_type1_message(struct Curl_easy *data,
 #else
 #define NTLM2FLAG 0
 #endif
-  snprintf((char *)ntlmbuf, NTLM_BUFSIZE,
-           NTLMSSP_SIGNATURE "%c"
-           "\x01%c%c%c" /* 32-bit type = 1 */
-           "%c%c%c%c"   /* 32-bit NTLM flag field */
-           "%c%c"       /* domain length */
-           "%c%c"       /* domain allocated space */
-           "%c%c"       /* domain name offset */
-           "%c%c"       /* 2 zeroes */
-           "%c%c"       /* host length */
-           "%c%c"       /* host allocated space */
-           "%c%c"       /* host name offset */
-           "%c%c"       /* 2 zeroes */
-           "%s"         /* host name */
-           "%s",        /* domain string */
-           0,           /* trailing zero */
-           0, 0, 0,     /* part of type-1 long */
-
-           LONGQUARTET(NTLMFLAG_NEGOTIATE_OEM |
-                       NTLMFLAG_REQUEST_TARGET |
-                       NTLMFLAG_NEGOTIATE_NTLM_KEY |
-                       NTLM2FLAG |
-                       NTLMFLAG_NEGOTIATE_ALWAYS_SIGN),
-           SHORTPAIR(domlen),
-           SHORTPAIR(domlen),
-           SHORTPAIR(domoff),
-           0, 0,
-           SHORTPAIR(hostlen),
-           SHORTPAIR(hostlen),
-           SHORTPAIR(hostoff),
-           0, 0,
-           host,  /* this is empty */
-           domain /* this is empty */);
+  msnprintf((char *)ntlmbuf, NTLM_BUFSIZE,
+            NTLMSSP_SIGNATURE "%c"
+            "\x01%c%c%c" /* 32-bit type = 1 */
+            "%c%c%c%c"   /* 32-bit NTLM flag field */
+            "%c%c"       /* domain length */
+            "%c%c"       /* domain allocated space */
+            "%c%c"       /* domain name offset */
+            "%c%c"       /* 2 zeroes */
+            "%c%c"       /* host length */
+            "%c%c"       /* host allocated space */
+            "%c%c"       /* host name offset */
+            "%c%c"       /* 2 zeroes */
+            "%s"         /* host name */
+            "%s",        /* domain string */
+            0,           /* trailing zero */
+            0, 0, 0,     /* part of type-1 long */
+
+            LONGQUARTET(NTLMFLAG_NEGOTIATE_OEM |
+                        NTLMFLAG_REQUEST_TARGET |
+                        NTLMFLAG_NEGOTIATE_NTLM_KEY |
+                        NTLM2FLAG |
+                        NTLMFLAG_NEGOTIATE_ALWAYS_SIGN),
+            SHORTPAIR(domlen),
+            SHORTPAIR(domlen),
+            SHORTPAIR(domoff),
+            0, 0,
+            SHORTPAIR(hostlen),
+            SHORTPAIR(hostlen),
+            SHORTPAIR(hostoff),
+            0, 0,
+            host,  /* this is empty */
+            domain /* this is empty */);
 
   /* Initial packet length */
   size = 32 + hostlen + domlen;
@@ -678,88 +678,88 @@ CURLcode Curl_auth_create_ntlm_type3_message(struct Curl_easy *data,
   hostoff = useroff + userlen;
 
   /* Create the big type-3 message binary blob */
-  size = snprintf((char *)ntlmbuf, NTLM_BUFSIZE,
-                  NTLMSSP_SIGNATURE "%c"
-                  "\x03%c%c%c"  /* 32-bit type = 3 */
-
-                  "%c%c"  /* LanManager length */
-                  "%c%c"  /* LanManager allocated space */
-                  "%c%c"  /* LanManager offset */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c"  /* NT-response length */
-                  "%c%c"  /* NT-response allocated space */
-                  "%c%c"  /* NT-response offset */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c"  /* domain length */
-                  "%c%c"  /* domain allocated space */
-                  "%c%c"  /* domain name offset */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c"  /* user length */
-                  "%c%c"  /* user allocated space */
-                  "%c%c"  /* user offset */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c"  /* host length */
-                  "%c%c"  /* host allocated space */
-                  "%c%c"  /* host offset */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c"  /* session key length (unknown purpose) */
-                  "%c%c"  /* session key allocated space (unknown purpose) */
-                  "%c%c"  /* session key offset (unknown purpose) */
-                  "%c%c"  /* 2 zeroes */
-
-                  "%c%c%c%c",  /* flags */
-
-                  /* domain string */
-                  /* user string */
-                  /* host string */
-                  /* LanManager response */
-                  /* NT response */
-
-                  0,                /* zero termination */
-                  0, 0, 0,          /* type-3 long, the 24 upper bits */
-
-                  SHORTPAIR(0x18),  /* LanManager response length, twice */
-                  SHORTPAIR(0x18),
-                  SHORTPAIR(lmrespoff),
-                  0x0, 0x0,
+  size = msnprintf((char *)ntlmbuf, NTLM_BUFSIZE,
+                   NTLMSSP_SIGNATURE "%c"
+                   "\x03%c%c%c"  /* 32-bit type = 3 */
+
+                   "%c%c"  /* LanManager length */
+                   "%c%c"  /* LanManager allocated space */
+                   "%c%c"  /* LanManager offset */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c"  /* NT-response length */
+                   "%c%c"  /* NT-response allocated space */
+                   "%c%c"  /* NT-response offset */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c"  /* domain length */
+                   "%c%c"  /* domain allocated space */
+                   "%c%c"  /* domain name offset */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c"  /* user length */
+                   "%c%c"  /* user allocated space */
+                   "%c%c"  /* user offset */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c"  /* host length */
+                   "%c%c"  /* host allocated space */
+                   "%c%c"  /* host offset */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c"  /* session key length (unknown purpose) */
+                   "%c%c"  /* session key allocated space (unknown purpose) */
+                   "%c%c"  /* session key offset (unknown purpose) */
+                   "%c%c"  /* 2 zeroes */
+
+                   "%c%c%c%c",  /* flags */
+
+                   /* domain string */
+                   /* user string */
+                   /* host string */
+                   /* LanManager response */
+                   /* NT response */
+
+                   0,                /* zero termination */
+                   0, 0, 0,          /* type-3 long, the 24 upper bits */
+
+                   SHORTPAIR(0x18),  /* LanManager response length, twice */
+                   SHORTPAIR(0x18),
+                   SHORTPAIR(lmrespoff),
+                   0x0, 0x0,
 
 #ifdef USE_NTRESPONSES
-                  SHORTPAIR(ntresplen),  /* NT-response length, twice */
-                  SHORTPAIR(ntresplen),
-                  SHORTPAIR(ntrespoff),
-                  0x0, 0x0,
+                   SHORTPAIR(ntresplen),  /* NT-response length, twice */
+                   SHORTPAIR(ntresplen),
+                   SHORTPAIR(ntrespoff),
+                   0x0, 0x0,
 #else
-                  0x0, 0x0,
-                  0x0, 0x0,
-                  0x0, 0x0,
-                  0x0, 0x0,
+                   0x0, 0x0,
+                   0x0, 0x0,
+                   0x0, 0x0,
+                   0x0, 0x0,
 #endif
-                  SHORTPAIR(domlen),
-                  SHORTPAIR(domlen),
-                  SHORTPAIR(domoff),
-                  0x0, 0x0,
-
-                  SHORTPAIR(userlen),
-                  SHORTPAIR(userlen),
-                  SHORTPAIR(useroff),
-                  0x0, 0x0,
-
-                  SHORTPAIR(hostlen),
-                  SHORTPAIR(hostlen),
-                  SHORTPAIR(hostoff),
-                  0x0, 0x0,
-
-                  0x0, 0x0,
-                  0x0, 0x0,
-                  0x0, 0x0,
-                  0x0, 0x0,
-
-                  LONGQUARTET(ntlm->flags));
+                   SHORTPAIR(domlen),
+                   SHORTPAIR(domlen),
+                   SHORTPAIR(domoff),
+                   0x0, 0x0,
+
+                   SHORTPAIR(userlen),
+                   SHORTPAIR(userlen),
+                   SHORTPAIR(useroff),
+                   0x0, 0x0,
+
+                   SHORTPAIR(hostlen),
+                   SHORTPAIR(hostlen),
+                   SHORTPAIR(hostoff),
+                   0x0, 0x0,
+
+                   0x0, 0x0,
+                   0x0, 0x0,
+                   0x0, 0x0,
+                   0x0, 0x0,
+
+                   LONGQUARTET(ntlm->flags));
 
   DEBUGASSERT(size == 64);
   DEBUGASSERT(size == (size_t)lmrespoff);
diff --git a/lib/version.c b/lib/version.c
index 05c2cd8b0..e553100c2 100644
--- a/lib/version.c
+++ b/lib/version.c
@@ -95,7 +95,7 @@ static size_t brotli_version(char *buf, size_t bufsz)
   unsigned int minor = (brotli_version & 0x00FFFFFF) >> 12;
   unsigned int patch = brotli_version & 0x00000FFF;
 
-  return snprintf(buf, bufsz, "%u.%u.%u", major, minor, patch);
+  return msnprintf(buf, bufsz, "%u.%u.%u", major, minor, patch);
 }
 #endif
 
@@ -126,12 +126,12 @@ char *curl_version(void)
   }
 
 #ifdef HAVE_LIBZ
-  len = snprintf(ptr, left, " zlib/%s", zlibVersion());
+  len = msnprintf(ptr, left, " zlib/%s", zlibVersion());
   left -= len;
   ptr += len;
 #endif
 #ifdef HAVE_BROTLI
-  len = snprintf(ptr, left, "%s", " brotli/");
+  len = msnprintf(ptr, left, "%s", " brotli/");
   left -= len;
   ptr += len;
   len = brotli_version(ptr, left);
@@ -140,45 +140,45 @@ char *curl_version(void)
 #endif
 #ifdef USE_ARES
   /* this function is only present in c-ares, not in the original ares */
-  len = snprintf(ptr, left, " c-ares/%s", ares_version(NULL));
+  len = msnprintf(ptr, left, " c-ares/%s", ares_version(NULL));
   left -= len;
   ptr += len;
 #endif
 #ifdef USE_LIBIDN2
   if(idn2_check_version(IDN2_VERSION)) {
-    len = snprintf(ptr, left, " libidn2/%s", idn2_check_version(NULL));
+    len = msnprintf(ptr, left, " libidn2/%s", idn2_check_version(NULL));
     left -= len;
     ptr += len;
   }
 #endif
 #ifdef USE_LIBPSL
-  len = snprintf(ptr, left, " libpsl/%s", psl_get_version());
+  len = msnprintf(ptr, left, " libpsl/%s", psl_get_version());
   left -= len;
   ptr += len;
 #endif
 #ifdef USE_WIN32_IDN
-  len = snprintf(ptr, left, " WinIDN");
+  len = msnprintf(ptr, left, " WinIDN");
   left -= len;
   ptr += len;
 #endif
 #if defined(HAVE_ICONV) && defined(CURL_DOES_CONVERSIONS)
 #ifdef _LIBICONV_VERSION
-  len = snprintf(ptr, left, " iconv/%d.%d",
-                 _LIBICONV_VERSION >> 8, _LIBICONV_VERSION & 255);
+  len = msnprintf(ptr, left, " iconv/%d.%d",
+                  _LIBICONV_VERSION >> 8, _LIBICONV_VERSION & 255);
 #else
   /* version unknown */
-  len = snprintf(ptr, left, " iconv");
+  len = msnprintf(ptr, left, " iconv");
 #endif /* _LIBICONV_VERSION */
   left -= len;
   ptr += len;
 #endif
 #ifdef USE_LIBSSH2
-  len = snprintf(ptr, left, " libssh2/%s", CURL_LIBSSH2_VERSION);
+  len = msnprintf(ptr, left, " libssh2/%s", CURL_LIBSSH2_VERSION);
   left -= len;
   ptr += len;
 #endif
 #ifdef USE_LIBSSH
-  len = snprintf(ptr, left, " libssh/%s", CURL_LIBSSH_VERSION);
+  len = msnprintf(ptr, left, " libssh/%s", CURL_LIBSSH_VERSION);
   left -= len;
   ptr += len;
 #endif
@@ -197,14 +197,14 @@ char *curl_version(void)
     else
       suff[0] = '\0';
 
-    snprintf(ptr, left, " librtmp/%d.%d%s",
-             RTMP_LIB_VERSION >> 16, (RTMP_LIB_VERSION >> 8) & 0xff,
-             suff);
+    msnprintf(ptr, left, " librtmp/%d.%d%s",
+              RTMP_LIB_VERSION >> 16, (RTMP_LIB_VERSION >> 8) & 0xff,
+              suff);
 /*
   If another lib version is added below this one, this code would
   also have to do:
 
-    len = what snprintf() returned
+    len = what msnprintf() returned
 
     left -= len;
     ptr += len;
@@ -436,10 +436,10 @@ curl_version_info_data *curl_version_info(CURLversion stamp)
 #endif
 
 #if defined(USE_LIBSSH2)
-  snprintf(ssh_buffer, sizeof(ssh_buffer), "libssh2/%s", LIBSSH2_VERSION);
+  msnprintf(ssh_buffer, sizeof(ssh_buffer), "libssh2/%s", LIBSSH2_VERSION);
   version_info.libssh_version = ssh_buffer;
 #elif defined(USE_LIBSSH)
-  snprintf(ssh_buffer, sizeof(ssh_buffer), "libssh/%s", CURL_LIBSSH_VERSION);
+  msnprintf(ssh_buffer, sizeof(ssh_buffer), "libssh/%s", CURL_LIBSSH_VERSION);
   version_info.libssh_version = ssh_buffer;
 #endif
 
diff --git a/lib/vtls/cyassl.c b/lib/vtls/cyassl.c
index e10398ac3..0d45afbf0 100644
--- a/lib/vtls/cyassl.c
+++ b/lib/vtls/cyassl.c
@@ -777,13 +777,13 @@ static void Curl_cyassl_session_free(void *ptr)
 static size_t Curl_cyassl_version(char *buffer, size_t size)
 {
 #if LIBCYASSL_VERSION_HEX >= 0x03006000
-  return snprintf(buffer, size, "wolfSSL/%s", wolfSSL_lib_version());
+  return msnprintf(buffer, size, "wolfSSL/%s", wolfSSL_lib_version());
 #elif defined(WOLFSSL_VERSION)
-  return snprintf(buffer, size, "wolfSSL/%s", WOLFSSL_VERSION);
+  return msnprintf(buffer, size, "wolfSSL/%s", WOLFSSL_VERSION);
 #elif defined(CYASSL_VERSION)
-  return snprintf(buffer, size, "CyaSSL/%s", CYASSL_VERSION);
+  return msnprintf(buffer, size, "CyaSSL/%s", CYASSL_VERSION);
 #else
-  return snprintf(buffer, size, "CyaSSL/%s", "<1.8.8");
+  return msnprintf(buffer, size, "CyaSSL/%s", "<1.8.8");
 #endif
 }
 
diff --git a/lib/vtls/darwinssl.c b/lib/vtls/darwinssl.c
index bae221a3d..25b101282 100644
--- a/lib/vtls/darwinssl.c
+++ b/lib/vtls/darwinssl.c
@@ -3015,7 +3015,7 @@ static void Curl_darwinssl_session_free(void *ptr)
 
 static size_t Curl_darwinssl_version(char *buffer, size_t size)
 {
-  return snprintf(buffer, size, "SecureTransport");
+  return msnprintf(buffer, size, "SecureTransport");
 }
 
 /*
diff --git a/lib/vtls/gskit.c b/lib/vtls/gskit.c
index 8d1b3d6af..c4afc8904 100644
--- a/lib/vtls/gskit.c
+++ b/lib/vtls/gskit.c
@@ -1314,7 +1314,7 @@ static int Curl_gskit_shutdown(struct connectdata *conn, int sockindex)
 
 static size_t Curl_gskit_version(char *buffer, size_t size)
 {
-  return snprintf(buffer, size, "GSKit");
+  return msnprintf(buffer, size, "GSKit");
 }
 
 
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index 84331a425..9035ec483 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -227,17 +227,17 @@ static void showtime(struct Curl_easy *data,
   if(result)
     return;
 
-  snprintf(str,
-           sizeof(str),
-           "\t %s: %s, %02d %s %4d %02d:%02d:%02d GMT",
-           text,
-           Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
-           tm->tm_mday,
-           Curl_month[tm->tm_mon],
-           tm->tm_year + 1900,
-           tm->tm_hour,
-           tm->tm_min,
-           tm->tm_sec);
+  msnprintf(str,
+            sizeof(str),
+            "\t %s: %s, %02d %s %4d %02d:%02d:%02d GMT",
+            text,
+            Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+            tm->tm_mday,
+            Curl_month[tm->tm_mon],
+            tm->tm_year + 1900,
+            tm->tm_hour,
+            tm->tm_min,
+            tm->tm_sec);
   infof(data, "%s\n", str);
 }
 #endif
@@ -1748,7 +1748,7 @@ static void Curl_gtls_session_free(void *ptr)
 
 static size_t Curl_gtls_version(char *buffer, size_t size)
 {
-  return snprintf(buffer, size, "GnuTLS/%s", gnutls_check_version(NULL));
+  return msnprintf(buffer, size, "GnuTLS/%s", gnutls_check_version(NULL));
 }
 
 #ifndef USE_GNUTLS_NETTLE
diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index 6adafff8b..6a20e276e 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -812,8 +812,8 @@ static void Curl_mbedtls_session_free(void *ptr)
 static size_t Curl_mbedtls_version(char *buffer, size_t size)
 {
   unsigned int version = mbedtls_version_get_number();
-  return snprintf(buffer, size, "mbedTLS/%u.%u.%u", version>>24,
-                  (version>>16)&0xff, (version>>8)&0xff);
+  return msnprintf(buffer, size, "mbedTLS/%u.%u.%u", version>>24,
+                   (version>>16)&0xff, (version>>8)&0xff);
 }
 
 static CURLcode Curl_mbedtls_random(struct Curl_easy *data,
diff --git a/lib/vtls/mesalink.c b/lib/vtls/mesalink.c
index 6a2b67e63..db1411559 100644
--- a/lib/vtls/mesalink.c
+++ b/lib/vtls/mesalink.c
@@ -5,8 +5,8 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 2017-2018, Yiming Jing, <jingyiming@baidu.com>
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2017 - 2018, Yiming Jing, <jingyiming@baidu.com>
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -424,7 +424,7 @@ mesalink_recv(struct connectdata *conn, int num, char *buf, size_t buffersize,
 static size_t
 Curl_mesalink_version(char *buffer, size_t size)
 {
-  return snprintf(buffer, size, "MesaLink/%s", MESALINK_VERSION_STRING);
+  return msnprintf(buffer, size, "MesaLink/%s", MESALINK_VERSION_STRING);
 }
 
 static int
diff --git a/lib/vtls/nss.c b/lib/vtls/nss.c
index 3da66249c..ef200514f 100644
--- a/lib/vtls/nss.c
+++ b/lib/vtls/nss.c
@@ -2270,7 +2270,7 @@ static ssize_t nss_recv(struct connectdata *conn,  /* connection data */
 
 static size_t Curl_nss_version(char *buffer, size_t size)
 {
-  return snprintf(buffer, size, "NSS/%s", NSS_VERSION);
+  return msnprintf(buffer, size, "NSS/%s", NSS_VERSION);
 }
 
 /* data might be NULL */
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 01305372b..720e87d81 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -1974,7 +1974,7 @@ static void ssl_tls_trace(int direction, int ssl_ver, int content_type,
   case 0:
     break;
   default:
-    snprintf(unknown, sizeof(unknown), "(%x)", ssl_ver);
+    msnprintf(unknown, sizeof(unknown), "(%x)", ssl_ver);
     verstr = unknown;
     break;
   }
@@ -2018,9 +2018,9 @@ static void ssl_tls_trace(int direction, int ssl_ver, int content_type,
       msg_name = ssl_msg_type(ssl_ver, msg_type);
     }
 
-    txt_len = snprintf(ssl_buf, sizeof(ssl_buf), "%s (%s), %s, %s (%d):\n",
-                       verstr, direction?"OUT":"IN",
-                       tls_rt_name, msg_name, msg_type);
+    txt_len = msnprintf(ssl_buf, sizeof(ssl_buf), "%s (%s), %s, %s (%d):\n",
+                        verstr, direction?"OUT":"IN",
+                        tls_rt_name, msg_name, msg_type);
     if(0 <= txt_len && (unsigned)txt_len < sizeof(ssl_buf)) {
       Curl_debug(data, CURLINFO_TEXT, ssl_buf, (size_t)txt_len);
     }
@@ -2833,9 +2833,9 @@ static CURLcode ossl_connect_step2(struct connectdata *conn, int sockindex)
         lerr = SSL_get_verify_result(BACKEND->handle);
         if(lerr != X509_V_OK) {
           *certverifyresult = lerr;
-          snprintf(error_buffer, sizeof(error_buffer),
-                   "SSL certificate problem: %s",
-                   X509_verify_cert_error_string(lerr));
+          msnprintf(error_buffer, sizeof(error_buffer),
+                    "SSL certificate problem: %s",
+                    X509_verify_cert_error_string(lerr));
         }
         else
           /* strcpy() is fine here as long as the string fits within
@@ -2946,7 +2946,7 @@ static void pubkey_show(struct Curl_easy *data,
   char *ptr;
   char namebuf[32];
 
-  snprintf(namebuf, sizeof(namebuf), "%s(%s)", type, name);
+  msnprintf(namebuf, sizeof(namebuf), "%s(%s)", type, name);
 
   if(bn)
     BN_print(mem, bn);
@@ -3007,8 +3007,8 @@ static int X509V3_ext(struct Curl_easy *data,
       while((j<(size_t)biomem->length) && (biomem->data[j] == ' '))
         j++;
       if(j<(size_t)biomem->length)
-        ptr += snprintf(ptr, sizeof(buf)-(ptr-buf), "%s%c", sep,
-                        biomem->data[j]);
+        ptr += msnprintf(ptr, sizeof(buf)-(ptr-buf), "%s%c", sep,
+                         biomem->data[j]);
     }
 
     Curl_ssl_push_certinfo(data, certnum, namebuf, buf);
@@ -3774,7 +3774,7 @@ static ssize_t ossl_recv(struct connectdata *conn, /* connection data */
 static size_t Curl_ossl_version(char *buffer, size_t size)
 {
 #ifdef OPENSSL_IS_BORINGSSL
-  return snprintf(buffer, size, OSSL_PACKAGE);
+  return msnprintf(buffer, size, OSSL_PACKAGE);
 #else /* OPENSSL_IS_BORINGSSL */
   char sub[3];
   unsigned long ssleay_value;
@@ -3801,12 +3801,12 @@ static size_t Curl_ossl_version(char *buffer, size_t size)
       sub[0]='\0';
   }
 
-  return snprintf(buffer, size, "%s/%lx.%lx.%lx%s",
-                  OSSL_PACKAGE,
-                  (ssleay_value>>28)&0xf,
-                  (ssleay_value>>20)&0xff,
-                  (ssleay_value>>12)&0xff,
-                  sub);
+  return msnprintf(buffer, size, "%s/%lx.%lx.%lx%s",
+                   OSSL_PACKAGE,
+                   (ssleay_value>>28)&0xf,
+                   (ssleay_value>>20)&0xff,
+                   (ssleay_value>>12)&0xff,
+                   sub);
 #endif /* OPENSSL_IS_BORINGSSL */
 }
 
diff --git a/lib/vtls/polarssl.c b/lib/vtls/polarssl.c
index cb038ecbb..6ecabe94b 100644
--- a/lib/vtls/polarssl.c
+++ b/lib/vtls/polarssl.c
@@ -716,9 +716,9 @@ static void Curl_polarssl_session_free(void *ptr)
 static size_t Curl_polarssl_version(char *buffer, size_t size)
 {
   unsigned int version = version_get_number();
-  return snprintf(buffer, size, "%s/%d.%d.%d",
-                  version >= 0x01030A00?"mbedTLS":"PolarSSL",
-                  version>>24, (version>>16)&0xff, (version>>8)&0xff);
+  return msnprintf(buffer, size, "%s/%d.%d.%d",
+                   version >= 0x01030A00?"mbedTLS":"PolarSSL",
+                   version>>24, (version>>16)&0xff, (version>>8)&0xff);
 }
 
 static CURLcode
diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index befc97fbd..56fd93e1e 100644
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -2049,7 +2049,7 @@ static void Curl_schannel_cleanup(void)
 
 static size_t Curl_schannel_version(char *buffer, size_t size)
 {
-  size = snprintf(buffer, size, "WinSSL");
+  size = msnprintf(buffer, size, "WinSSL");
 
   return size;
 }
diff --git a/lib/vtls/vtls.c b/lib/vtls/vtls.c
index 144768c74..fc4384b2f 100644
--- a/lib/vtls/vtls.c
+++ b/lib/vtls/vtls.c
@@ -700,7 +700,7 @@ CURLcode Curl_ssl_push_certinfo_len(struct Curl_easy *data,
     return CURLE_OUT_OF_MEMORY;
 
   /* sprintf the label and colon */
-  snprintf(output, outlen, "%s:", label);
+  msnprintf(output, outlen, "%s:", label);
 
   /* memcpy the value (it might not be zero terminated) */
   memcpy(&output[labellen + 1], value, valuelen);
diff --git a/lib/x509asn1.c b/lib/x509asn1.c
index a576fc703..746e1e8e8 100644
--- a/lib/x509asn1.c
+++ b/lib/x509asn1.c
@@ -209,7 +209,7 @@ static const char *octet2str(const char *beg, const char *end)
     buf = malloc(3 * n + 1);
     if(buf)
       for(n = 0; beg < end; n += 3)
-        snprintf(buf + n, 4, "%02x:", *(const unsigned char *) beg++);
+        msnprintf(buf + n, 4, "%02x:", *(const unsigned char *) beg++);
   }
   return buf;
 }