isencrypt(3G)                                                 isencrypt(3G)

NAME
     isencrypt - determine whether a character buffer is encrypted

SYNOPSIS
     cc [flag ...] file ... -lgen [library ...]

     #include <libgen.h>

     int isencrypt(const char *fbuf, sizet ninbuf);

DESCRIPTION
     isencrypt() can be used to determine whether a buffer of characters is
     encrypted.

     isencrypt() assumes that the file is not encrypted if all the charac-
     ters in the first block are ASCII characters. If there are non-ASCII
     characters in the first ninbuf characters, and if the setlocale
     LCCTYPE category is set to C or ascii, the buffer is not encrypted.

     If the LCCTYPE category is set to a value other than C or ascii, then
     isencrypt() uses a heuristic to determine if the buffer is encrypted.
     If the buffer has at least 64 characters, a chi-square test is used to
     determine if the bytes in the buffer have a uniform distribution; and
     isencrypt() assumes the buffer is encrypted if it does. If the buffer
     has less than 64 characters, a check is made for null characters and a
     terminating new-line to determine whether the buffer is encrypted.

RESULT
     If the buffer is encrypted, 1 is returned; otherwise 0 is returned.

SEE ALSO
     setlocale(3C).























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