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diff --git a/man-pages-posix-2003/man3p/crypt.3p b/man-pages-posix-2003/man3p/crypt.3p new file mode 100644 index 0000000..833df2a --- /dev/null +++ b/man-pages-posix-2003/man3p/crypt.3p @@ -0,0 +1,137 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "CRYPT" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" crypt +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.SH NAME +crypt \- string encoding function (\fBCRYPT\fP) +.SH SYNOPSIS +.LP +\fB#include <unistd.h> +.br +.sp +char *crypt(const char *\fP\fIkey\fP\fB, const char *\fP\fIsalt\fP\fB); +\fP +\fB +.br +\fP +.SH DESCRIPTION +.LP +The \fIcrypt\fP() function is a string encoding function. The algorithm +is implementation-defined. +.LP +The \fIkey\fP argument points to a string to be encoded. The \fIsalt\fP +argument is a string chosen from the set: +.sp +.RS +.nf + +\fBa b c d e f g h i j k l m n o p q r s t u v w x y z +A B C D E F G H I J K L M N O P Q R S T U V W X Y Z +0 1 2 3 4 5 6 7 8 9 . / +\fP +.fi +.RE +.LP +The first two characters of this string may be used to perturb the +encoding algorithm. +.LP +The return value of \fIcrypt\fP() points to static data that is overwritten +by each call. +.LP +The \fIcrypt\fP() function need not be reentrant. A function that +is not required to be reentrant is not required to be +thread-safe. +.SH RETURN VALUE +.LP +Upon successful completion, \fIcrypt\fP() shall return a pointer to +the encoded string. The first two characters of the +returned value shall be those of the \fIsalt\fP argument. Otherwise, +it shall return a null pointer and set \fIerrno\fP to +indicate the error. +.SH ERRORS +.LP +The \fIcrypt\fP() function shall fail if: +.TP 7 +.B ENOSYS +The functionality is not supported on this implementation. +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.SS Encoding Passwords +.LP +The following example finds a user database entry matching a particular +user name and changes the current password to a new +password. The \fIcrypt\fP() function generates an encoded version +of each password. The first call to \fIcrypt\fP() produces an +encoded version of the old password; that encoded password is then +compared to the password stored in the user database. The second +call to \fIcrypt\fP() encodes the new password before it is stored. +.LP +The \fIputpwent\fP() function, used in the following example, is not +part of IEEE\ Std\ 1003.1-2001. +.sp +.RS +.nf + +\fB#include <unistd.h> +#include <pwd.h> +#include <string.h> +#include <stdio.h> +\&... +int valid_change; +int pfd; /* Integer for file descriptor returned by open(). */ +FILE *fpfd; /* File pointer for use in putpwent(). */ +struct passwd *p; +char user[100]; +char oldpasswd[100]; +char newpasswd[100]; +char savepasswd[100]; +\&... +valid_change = 0; +while ((p = getpwent()) != NULL) { + /* Change entry if found. */ + if (strcmp(p->pw_name, user) == 0) { + if (strcmp(p->pw_passwd, crypt(oldpasswd, p->pw_passwd)) == 0) { + strcpy(savepasswd, crypt(newpasswd, user)); + p->pw_passwd = savepasswd; + valid_change = 1; + } + else { + fprintf(stderr, "Old password is not valid\\n"); + } + } + /* Put passwd entry into ptmp. */ + putpwent(p, fpfd); +} +\fP +.fi +.RE +.SH APPLICATION USAGE +.LP +The values returned by this function need not be portable among XSI-conformant +systems. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIencrypt\fP(), \fIsetkey\fP(), the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, \fI<unistd.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |