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diff --git a/upstream/archlinux/man3p/crypt.3p b/upstream/archlinux/man3p/crypt.3p new file mode 100644 index 00000000..1a73079b --- /dev/null +++ b/upstream/archlinux/man3p/crypt.3p @@ -0,0 +1,165 @@ +'\" et +.TH CRYPT "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.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 +\(em string encoding function +(\fBCRYPT\fP) +.SH SYNOPSIS +.LP +.nf +#include <unistd.h> +.P +char *crypt(const char *\fIkey\fP, const char *\fIsalt\fP); +.fi +.SH DESCRIPTION +The +\fIcrypt\fR() +function is a string encoding function. The algorithm is +implementation-defined. +.P +The +.IR key +argument points to a string to be encoded. The +.IR salt +argument shall be a string of at least two bytes in length not +including the null character chosen from the set: +.sp +.RS 4 +.nf + +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 +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 . / +.fi +.P +.RE +.P +The first two bytes of this string may be used to perturb the +encoding algorithm. +.P +The return value of +\fIcrypt\fR() +points to static data that is overwritten by each call. +.P +The +\fIcrypt\fR() +function need not be thread-safe. +.SH "RETURN VALUE" +Upon successful completion, +\fIcrypt\fR() +shall return a pointer to the encoded string. The first two bytes +of the returned value shall be those of the +.IR salt +argument. Otherwise, it shall return a null pointer and set +.IR errno +to indicate the error. +.SH ERRORS +The +\fIcrypt\fR() +function shall fail if: +.TP +.BR ENOSYS +The functionality is not supported on this implementation. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +.SS "Encoding Passwords" +.P +The following example finds a user database entry matching a particular +user name and changes the current password to a new password. The +\fIcrypt\fR() +function generates an encoded version of each password. The +first call to +\fIcrypt\fR() +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\fR() +encodes the new password before it is stored. +.P +The +\fIputpwent\fR() +function, used in the following example, is not part of POSIX.1\(hy2008. +.sp +.RS 4 +.nf + +#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\en"); + } + } + /* Put passwd entry into ptmp. */ + putpwent(p, fpfd); +} +.fi +.P +.RE +.SH "APPLICATION USAGE" +The values returned by this function need not be portable among +XSI-conformant systems. +.P +Several implementations offer extensions via characters outside +of the set specified for the +.IR salt +argument for specifying alternative algorithms; while not portable, these +extensions may offer better security. The use of +\fIcrypt\fR() +for anything other than password hashing is not recommended. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIencrypt\fR\^(\|)", +.IR "\fIsetkey\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "\fB<unistd.h>\fP" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 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 . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |