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Annotation of dietlibc/README.security, revision 1.1

1.1     ! leitner     1: The diet libc is not especially focused on providing a secure
        !             2: environment, but where it is possible to do something, we try to do it.
        !             3: 
        !             4:   1. WANT_STACKGAP in dietfeatures.h
        !             5:      This will randomize the stack layout slightly.  The real memory
        !             6:      cost is about one page of real memory.  The code size increase is
        !             7:      about 100 bytes, 86 for i386.  The benefit is that buffer overflow
        !             8:      exploits are harder because the address of the buffer fluctuates.
        !             9: 
        !            10:   2. WANT_CRYPT_MD5 in dietfeatures.h
        !            11:      This will enable MD5 style passwords in crypt(3).  The standard
        !            12:      Unix password mechanism is DES based and thus insecure by today's
        !            13:      standards.  Adding MD5 makes the code larger by some 5k.
        !            14: 
        !            15:   3. WANT_NON_COMPLIANT_STRNCAT in dietfeatures.h
        !            16:      strncat and strncpy are very user unfriendly.  They copy zero
        !            17:      terminated strings, and you can give them a limit on how much to
        !            18:      copy, but they will not make sure the result is zero terminated,
        !            19:      which most programmers would expect who are not familiar with the
        !            20:      API.  So, in the diet libc you can set this #define in
        !            21:      dietfeatures.h to get the expected behaviour.  Since the fix for
        !            22:      the normal behaviour usually is to write \0 over the last byte of
        !            23:      the buffer, this does not hurt usually (but is not standards
        !            24:      compliant).
        !            25: 
        !            26:   4. printf does not support %n.
        !            27:      %n in printf is the attack vector for format string
        !            28:      vulnerabilities.  Almost nobody uses it anyway (except some part of
        !            29:      the gcc build process, apparently).
        !            30: