problem: errx(1, "Corrupt patch\n");

[hanleirx]

I bsdiff the file by command on PC and I want to bspatch the file on the iphone,but when I run the code,I found here:
/* Check for appropriate magic */
if (memcmp(header, "ENDSLEY/BSDIFF43", 16) != 0)
errx(1, "Corrupt patch\n");
I will go into if, so it won't ran following code.
I want to know why,please help me!