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, size_t ninbuf);

DESCRIPTION
     isencrypt uses heuristics to determine whether a buffer of characters is
     encrypted.  It requires two arguments: a pointer to an array of
     characters and the number of characters in the buffer.

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

     If the LC_CTYPE category is set to a value other than C or ascii, then
     isencrypt uses a combination of heuristics to determine if the buffer is
     encrypted.  If ninbuf 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.

DIAGNOSTICS
     If the buffer is encrypted, 1 is returned; otherwise zero is returned.

SEE ALSO
     setlocale(3C)