44ccfacbe3a3d4b300f80d48651c77837a4b571e
galt
  Tue Apr 26 11:12:02 2022 -0700
SQL INJECTION Prevention Version 2 - this improves our methods by making subclauses of SQL that get passed around be both easy and correct to use. The way that was achieved was by getting rid of the obscure and not well used functions sqlSafefFrag and sqlDyStringPrintfFrag and replacing them with the plain versions of those functions, since these are not needed anymore. The new version checks for NOSQLINJ in unquoted %-s which is used to include SQL clauses, and will give an error the NOSQLINJ clause is not present, and this will automatically require the correct behavior by developers. sqlDyStringPrint is a very useful function, however because it was not enforced, users could use various other dyString functions and they operated without any awareness or checking for SQL correct use. Now those dyString functions are prohibited and it will produce an error if you try to use a dyString function on a SQL string, which is simply detected by the presence of the NOSQLINJ prefix.

diff --git src/lib/dystring.c src/lib/dystring.c
index df111fe..9cebcff 100644
--- src/lib/dystring.c
+++ src/lib/dystring.c
@@ -1,250 +1,277 @@
 /* dystring - dynamically resizing string.
  *
  * This file is copyright 2002 Jim Kent, but license is hereby
  * granted for all use - public, private or commercial. */
 
 #include "common.h"
 #include "dystring.h"
 
 
 struct dyString *newDyString(long initialBufSize)
 /* Allocate dynamic string with initial buffer size.  (Pass zero for default) */
 {
 struct dyString *ds;
 AllocVar(ds);
 if (initialBufSize == 0)
     initialBufSize = 512;
 ds->string = needMem(initialBufSize+1);
 ds->bufSize = initialBufSize;
 return ds;
 }
 
-void freeDyString(struct dyString **pDs)
+void dyStringFree(struct dyString **pDs)
 /* Free up dynamic string. */
 {
 struct dyString *ds;
 if ((ds = *pDs) != NULL)
     {
     freeMem(ds->string);
     freez(pDs);
     }
 }
 
+static void checkNOSQLINJ(struct dyString *ds)
+/* Check if we are manipulating a special SQL source code string
+ * and abort with stackdump if so. This is forbidden for SQL Injection security. */
+{
+if (startsWith("NOSQLINJ ", ds->string))
+    {
+    char *dump = getenv("noSqlInj_dumpStack");
+    if (!(dump && sameString(dump, "off")))  // dump unless set to off
+	dumpStack("dyString functions are not allowed for SQL source code. Use sqlDy safe functions instead.\n");
+    char *level = getenv("noSqlInj_level");
+    if (!level) level = "abort"; // Default
+    if (sameString(level, "abort"))
+	errAbort("dyString is not allowed. use sqlDy functions that are safe instead.");
+    if (sameString(level, "warn"))
+	warn("dyString is not allowed. use sqlDy functions that are safe instead.");
+    if (sameString(level, "logOnly"))
+	fprintf(stderr, "dyString is not allowed. use sqlDy functions that are safe instead.");
+    }
+}
+
 char *dyStringCannibalize(struct dyString **pDy)
 /* Kill dyString, but return the string it is wrapping
  * (formerly dy->string).  This should be free'd at your
  * convenience. */
 {
 char *s;
 struct dyString *ds = *pDy;
 assert(ds != NULL);
 s = ds->string;
 freez(pDy);
 return s;
 }
 
-void freeDyStringList(struct dyString **pDs)
+void dyStringListFree(struct dyString **pDs)
 /* free up a list of dyStrings */
 {
 struct dyString *ds, *next;
 for(ds = *pDs; ds != NULL; ds = next)
     {
     next = ds->next;
-    freeDyString(&ds);
+    dyStringFree(&ds);
     }
 *pDs = NULL;
 }
 
 static void dyStringExpandBuf(struct dyString *ds, long newSize)
 /* Expand buffer to new size. */
 {
 ds->string = needMoreMem(ds->string, ds->stringSize+1, newSize+1);
 ds->bufSize = newSize;
 }
 
 void dyStringBumpBufSize(struct dyString *ds, long size)
 /* Force dyString buffer to be at least given size. */
 {
 if (ds->bufSize < size)
     dyStringExpandBuf(ds, size);
 }
 
 void dyStringAppendN(struct dyString *ds, char *string, long stringSize)
 /* Append string of given size to end of string. */
 {
 long oldSize = ds->stringSize;
 long newSize = oldSize + stringSize;
 char *buf;
 if (newSize > ds->bufSize)
     {
     long newAllocSize = newSize + oldSize;
     long oldSizeTimesOneAndAHalf = oldSize * 1.5;
     if (newAllocSize < oldSizeTimesOneAndAHalf)
         newAllocSize = oldSizeTimesOneAndAHalf;
     dyStringExpandBuf(ds,newAllocSize);
     }
 buf = ds->string;
 memcpy(buf+oldSize, string, stringSize);
 ds->stringSize = newSize;
 buf[newSize] = 0;
+checkNOSQLINJ(ds);
 }
 
 char dyStringAppendC(struct dyString *ds, char c)
 /* Append char to end of string. */
 {
 char *s;
 if (ds->stringSize >= ds->bufSize)
      dyStringExpandBuf(ds, ds->bufSize+256);
 s = ds->string + ds->stringSize++;
 *s++ = c;
 *s = 0;
 return c;
 }
 
 void dyStringAppendMultiC(struct dyString *ds, char c, int n)
 /* Append N copies of char to end of string. */
 {
 long oldSize = ds->stringSize;
 long newSize = oldSize + n;
 long newAllocSize = newSize + oldSize;
 char *buf;
 if (newSize > ds->bufSize)
     dyStringExpandBuf(ds,newAllocSize);
 buf = ds->string;
 memset(buf+oldSize, c, n);
 ds->stringSize = newSize;
 buf[newSize] = 0;
 }
 
 void dyStringAppend(struct dyString *ds, char *string)
 /* Append zero terminated string to end of dyString. */
 {
 dyStringAppendN(ds, string, strlen(string));
+checkNOSQLINJ(ds);
 }
 
-void dyStringAppendEscapeQuotes(struct dyString *dy, char *string,
+void dyStringAppendEscapeQuotes(struct dyString *ds, char *string,
 	char quot, char esc)
 /* Append escaped-for-quotation version of string to dy. */
 {
 char c;
 char *s = string;
 while ((c = *s++) != 0)
      {
      if (c == quot)
-         dyStringAppendC(dy, esc);
-     dyStringAppendC(dy, c);
+         dyStringAppendC(ds, esc);
+     dyStringAppendC(ds, c);
      }
+checkNOSQLINJ(ds);
 }
 
 void dyStringVaPrintf(struct dyString *ds, char *format, va_list args)
 /* VarArgs Printf to end of dyString. */
 {
 /* attempt to format the string in the current space.  If there
  * is not enough room, increase the buffer size and try again */
 long avail, sz;
 while (TRUE)
     {
     va_list argscp;
     va_copy(argscp, args);
     avail = ds->bufSize - ds->stringSize;
     if (avail <= 0)
         {
 	/* Don't pass zero sized buffers to vsnprintf, because who knows
 	 * if the library function will handle it. */
         dyStringExpandBuf(ds, ds->bufSize+ds->bufSize);
 	avail = ds->bufSize - ds->stringSize;
 	}
     sz = vsnprintf(ds->string + ds->stringSize, avail, format, argscp);
     va_end(argscp);
 
     /* note that some version return -1 if too small */
     if ((sz < 0) || (sz >= avail))
         dyStringExpandBuf(ds, ds->bufSize+ds->bufSize);
     else
         {
         ds->stringSize += sz;
         break;
         }
     }
 }
 
 void dyStringPrintf(struct dyString *ds, char *format, ...)
 /*  Printf to end of dyString. */
 {
 va_list args;
 va_start(args, format);
 dyStringVaPrintf(ds, format, args);
 va_end(args);
+checkNOSQLINJ(ds);
 }
 
 struct dyString *dyStringCreate(char *format, ...)
 /*  Create a dyString with a printf style initial content */
 {
 int len = strlen(format) * 3;
-struct dyString *ds = newDyString(len);
+struct dyString *ds = dyStringNew(len);
 va_list args;
 va_start(args, format);
 dyStringVaPrintf(ds, format, args);
 va_end(args);
+checkNOSQLINJ(ds);
 return ds;
 }
 
 struct dyString * dyStringSub(char *orig, char *in, char *out)
 /* Make up a duplicate of orig with all occurences of in substituted
  * with out. */
 {
 long inLen = strlen(in), outLen = strlen(out), origLen = strlen(orig);
-struct dyString *dy = newDyString(origLen + 2*outLen);
+struct dyString *ds = dyStringNew(origLen + 2*outLen);
 char *s, *e;
 
 if (orig == NULL) return NULL;
 for (s = orig; ;)
     {
     e = stringIn(in, s);
     if (e == NULL)
 	{
         e = orig + origLen;
-	dyStringAppendN(dy, s, e - s);
+	dyStringAppendN(ds, s, e - s);
 	break;
 	}
     else
         {
-	dyStringAppendN(dy, s, e - s);
-	dyStringAppendN(dy, out, outLen);
+	dyStringAppendN(ds, s, e - s);
+	dyStringAppendN(ds, out, outLen);
 	s = e + inLen;
 	}
     }
-return dy;
+checkNOSQLINJ(ds);
+return ds;
 }
 
 void dyStringResize(struct dyString *ds, long newSize)
 /* resize a string, if the string expands, blanks are appended */
 {
 long oldSize = ds->stringSize;
 if (newSize > oldSize)
     {
     /* grow */
     if (newSize > ds->bufSize)
         dyStringExpandBuf(ds, newSize + ds->stringSize);
     memset(ds->string+newSize, ' ', newSize);
     }
 ds->string[newSize] = '\0';
 ds->stringSize = newSize;
 }
 
-void dyStringQuoteString(struct dyString *dy, char quotChar, char *text)
+void dyStringQuoteString(struct dyString *ds, char quotChar, char *text)
 /* Append quotChar-quoted text (with any internal occurrences of quotChar
  * \-escaped) onto end of dy. */
 {
 char c;
 
-dyStringAppendC(dy, quotChar);
+dyStringAppendC(ds, quotChar);
 while ((c = *text++) != 0)
     {
     if (c == quotChar || c == '\\')
-        dyStringAppendC(dy, '\\');
-    dyStringAppendC(dy, c);
+        dyStringAppendC(ds, '\\');
+    dyStringAppendC(ds, c);
     }
-dyStringAppendC(dy, quotChar);
+dyStringAppendC(ds, quotChar);
+checkNOSQLINJ(ds);
 }