libtests: prefer sizeof() over strlen(), fix potential OOB read in 1591

- test1591: fix potential OOB read.
  Spotted by GitHub Code Quality
  Follow-up to f464535bfd #3350

Closes #22011

tests/libtest/lib1517.c

@@ -60,7 +60,7 @@ static CURLcode test_lib1517(const char *URL)
   struct t1517_WriteThis pooh;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = strlen(testdata);
+  pooh.sizeleft = sizeof(testdata) - 1;
 
   if(curl_global_init(CURL_GLOBAL_ALL)) {
     curl_mfprintf(stderr, "curl_global_init() failed\n");

tests/libtest/lib1591.c

@@ -34,15 +34,16 @@ static size_t consumed = 0;
 static size_t t1591_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
   static const char testdata[] = "Hello Cloud!\r\n";
+  static size_t const datalen = sizeof(testdata) - 1;
 
   size_t amount = nmemb * size; /* Total bytes curl wants */
 
-  if(consumed == strlen(testdata)) {
+  if(consumed == datalen) {
     return 0;
   }
 
-  if(amount > strlen(testdata) - consumed) {
-    amount = strlen(testdata);
+  if(amount > datalen - consumed) {
+    amount = datalen - consumed;
   }
 
   consumed += amount;

tests/libtest/lib1948.c

@@ -43,7 +43,7 @@ static CURLcode test_lib1948(const char *URL)
 {
   CURL *curl;
   CURLcode result = CURLE_OK;
-  static const char *testput = "This is test PUT data\n";
+  static const char testput[] = "This is test PUT data\n";
   struct put_buffer pbuf;
 
   curl_global_init(CURL_GLOBAL_DEFAULT);
@@ -55,9 +55,9 @@ static CURLcode test_lib1948(const char *URL)
   easy_setopt(curl, CURLOPT_HEADER, 1L);
   easy_setopt(curl, CURLOPT_READFUNCTION, put_callback);
   pbuf.buf = testput;
-  pbuf.len = strlen(testput);
+  pbuf.len = sizeof(testput) - 1;
   easy_setopt(curl, CURLOPT_READDATA, &pbuf);
-  easy_setopt(curl, CURLOPT_INFILESIZE, (long)strlen(testput));
+  easy_setopt(curl, CURLOPT_INFILESIZE, (long)(sizeof(testput) - 1));
   easy_setopt(curl, CURLOPT_URL, URL);
   result = curl_easy_perform(curl);
   if(result)
@@ -66,7 +66,7 @@ static CURLcode test_lib1948(const char *URL)
   /* POST */
   easy_setopt(curl, CURLOPT_POST, 1L);
   easy_setopt(curl, CURLOPT_POSTFIELDS, testput);
-  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(testput));
+  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)(sizeof(testput) - 1));
   result = curl_easy_perform(curl);
 
 test_cleanup:

tests/libtest/lib508.c

@@ -56,7 +56,7 @@ static CURLcode test_lib508(const char *URL)
   struct t508_WriteThis pooh;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = strlen(testdata);
+  pooh.sizeleft = sizeof(testdata) - 1;
 
   if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
     curl_mfprintf(stderr, "curl_global_init() failed\n");

tests/libtest/lib554.c

@@ -69,7 +69,7 @@ static CURLcode t554_test_once(const char *URL, bool oldstyle)
   struct t554_WriteThis pooh2;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = strlen(testdata);
+  pooh.sizeleft = sizeof(testdata) - 1;
 
   /* Fill in the file upload field */
   if(oldstyle) {
@@ -99,7 +99,7 @@ static CURLcode t554_test_once(const char *URL, bool oldstyle)
      a file upload but still using the callback */
 
   pooh2.readptr = testdata;
-  pooh2.sizeleft = strlen(testdata);
+  pooh2.sizeleft = sizeof(testdata) - 1;
 
   /* Fill in the file upload field */
   formrc = curl_formadd(&formpost,

tests/libtest/lib643.c

@@ -69,7 +69,7 @@ static CURLcode t643_test_once(const char *URL, bool oldstyle)
 
   pooh.readptr = testdata;
   if(testnum == 643)
-    datasize = (curl_off_t)strlen(testdata);
+    datasize = (curl_off_t)(sizeof(testdata) - 1);
   pooh.sizeleft = datasize;
 
   curl = curl_easy_init();
@@ -123,7 +123,7 @@ static CURLcode t643_test_once(const char *URL, bool oldstyle)
 
   pooh2.readptr = testdata;
   if(testnum == 643)
-    datasize = (curl_off_t)strlen(testdata);
+    datasize = (curl_off_t)(sizeof(testdata) - 1);
   pooh2.sizeleft = datasize;
 
   part = curl_mime_addpart(mime);

tests/libtest/lib650.c

@@ -95,7 +95,7 @@ static CURLcode test_lib650(const char *URL)
   formrc = curl_formadd(&formpost,
                         &lastptr,
                         CURLFORM_PTRNAME, testname,
-                        CURLFORM_NAMELENGTH, strlen(testname) - 1,
+                        CURLFORM_NAMELENGTH, sizeof(testname) - 2,
                         CURLFORM_ARRAY, formarray,
                         CURLFORM_FILENAME, "remotefile.txt",
                         CURLFORM_END);

tests/libtest/lib654.c

@@ -92,7 +92,7 @@ static CURLcode test_lib654(const char *URL)
 
   /* Prepare the callback structure. */
   pooh.readptr = testdata;
-  pooh.sizeleft = (curl_off_t)strlen(testdata);
+  pooh.sizeleft = (curl_off_t)(sizeof(testdata) - 1);
   pooh.freecount = 0;
 
   /* Build the mime tree. */

tests/libtest/lib667.c

@@ -82,7 +82,7 @@ static CURLcode test_lib667(const char *URL)
 
   /* Prepare the callback structure. */
   pooh.readptr = testdata;
-  pooh.sizeleft = (curl_off_t)strlen(testdata);
+  pooh.sizeleft = (curl_off_t)(sizeof(testdata) - 1);
 
   /* Build the mime tree. */
   mime = curl_mime_init(curl);

tests/libtest/lib668.c

@@ -76,7 +76,7 @@ static CURLcode test_lib668(const char *URL)
 
   /* Prepare the callback structures. */
   pooh1.readptr = testdata;
-  pooh1.sizeleft = (curl_off_t)strlen(testdata);
+  pooh1.sizeleft = (curl_off_t)(sizeof(testdata) - 1);
   pooh2 = pooh1;
 
   /* Build the mime tree. */
@@ -84,7 +84,7 @@ static CURLcode test_lib668(const char *URL)
   part = curl_mime_addpart(mime);
   curl_mime_name(part, "field1");
   /* Early end of data detection can be done because the data size is known. */
-  curl_mime_data_cb(part, (curl_off_t)strlen(testdata),
+  curl_mime_data_cb(part, (curl_off_t)(sizeof(testdata) - 1),
                     t668_read_cb, NULL, NULL, &pooh1);
   part = curl_mime_addpart(mime);
   curl_mime_name(part, "field2");