paramhlp: fix CRLF-stripping files with "-d @file"

All CR and LF bytes should be stripped, as documented, and all other
bytes are inluded in the data. Starting now, it also excludes null bytes
as they would otherwise also cut the data short.

Reported-by: Simon K
Fixes #13063
Closes #13064

src/tool_paramhlp.c

@@ -63,6 +63,33 @@ struct getout *new_getout(struct OperationConfig *config)
   return node;
 }
 
+#define ISCRLF(x) (((x) == '\r') || ((x) == '\n') || ((x) == '\0'))
+
+/* memcrlf() has two modes. Both operate on a given memory area with
+   a specified size.
+
+   countcrlf FALSE - return number of bytes from the start that DO NOT include
+   any CR or LF or NULL
+
+   countcrlf TRUE - return number of bytes from the start that are ONLY CR or
+   LF or NULL.
+
+*/
+static size_t memcrlf(char *orig,
+                      bool countcrlf, /* TRUE if we count CRLF, FALSE
+                                         if we count non-CRLF */
+                      size_t max)
+{
+  char *ptr = orig;
+  size_t total = max;
+  for(ptr = orig; max; max--, ptr++) {
+    bool crlf = ISCRLF(*ptr);
+    if(countcrlf ^ crlf)
+      return ptr - orig;
+  }
+  return total; /* no delimiter found */
+}
+
 #define MAX_FILE2STRING (256*1024*1024) /* big enough ? */
 
 ParameterError file2string(char **bufp, FILE *file)
@@ -71,18 +98,30 @@ ParameterError file2string(char **bufp, FILE *file)
   DEBUGASSERT(MAX_FILE2STRING < INT_MAX); /* needs to fit in an int later */
   curlx_dyn_init(&dyn, MAX_FILE2STRING);
   if(file) {
-    char buffer[256];
+    do {
+      char buffer[4096];
+      char *ptr;
+      size_t nread = fread(buffer, 1, sizeof(buffer), file);
+      if(ferror(file)) {
+        curlx_dyn_free(&dyn);
+        *bufp = NULL;
+        return PARAM_READ_ERROR;
+      }
+      ptr = buffer;
+      while(nread) {
+        size_t nlen = memcrlf(ptr, FALSE, nread);
+        if(curlx_dyn_addn(&dyn, ptr, nlen))
+          return PARAM_NO_MEM;
+        nread -= nlen;
 
-    while(fgets(buffer, sizeof(buffer), file)) {
-      char *ptr = strchr(buffer, '\r');
-      if(ptr)
-        *ptr = '\0';
-      ptr = strchr(buffer, '\n');
-      if(ptr)
-        *ptr = '\0';
-      if(curlx_dyn_add(&dyn, buffer))
-        return PARAM_NO_MEM;
-    }
+        if(nread) {
+          ptr += nlen;
+          nlen = memcrlf(ptr, TRUE, nread);
+          ptr += nlen;
+          nread -= nlen;
+        }
+      }
+    } while(!feof(file));
   }
   *bufp = curlx_dyn_ptr(&dyn);
   return PARAM_OK;