[openssl.org #2954] [PATCH] avoid memcpy for overlapping regions

[Nickolai Zeldovich via RT]

Using memcpy on overlapping regions of memory is undefined behavior in C. 
In engines/ccgost/gosthash.c, the circle_xor8() function uses memcpy to 
copy data between the two arrays passed as arguments, but in some cases 
(e.g., the third call to circle_xor8 in hash_step() in the same file) the 
two arguments are identical.  Use memmove instead to avoid any problems.

Nickolai.

--- openssl-1.0.1c/engines/ccgost/gosthash.c    2009-12-22 06:52:15.000000000 
-0500
+++ openssl-1.0.1c/engines/ccgost/gosthash.c    2013-01-07 15:56:39.716975869 
-0500
@@ -42,7 +42,7 @@
        byte buf[8];
        int i;
        memcpy(buf,w,8);
-       memcpy(k,w+8,24);
+       memmove(k,w+8,24);
        for(i=0;i<8;i++)
                k[i+24]=buf[i]^k[i];
        }

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