1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * As far as I am concerned, the code I have written for this software 7 * can be used freely for any purpose. Any derived versions of this 8 * software must be clearly marked as such, and if the derived work is 9 * incompatible with the protocol description in the RFC file, it must be 10 * called by a name other than "ssh" or "Secure Shell". 11 */ 12 /* 13 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 14 * Use is subject to license terms. 15 */ 16 17 #include "includes.h" 18 RCSID("$OpenBSD: tildexpand.c,v 1.13 2002/06/23 03:25:50 deraadt Exp $"); 19 20 #include <libgen.h> 21 22 #include "xmalloc.h" 23 #include "log.h" 24 #include "tildexpand.h" 25 26 /* 27 * Expands tildes in the file name. Returns data allocated by xmalloc. 28 * Warning: this calls getpw*. 29 */ 30 char * 31 tilde_expand_filename(const char *filename, uid_t my_uid) 32 { 33 const char *cp; 34 uint_t userlen; 35 char *expanded; 36 struct passwd *pw; 37 char *pw_dir; 38 char user[100]; 39 int len; 40 41 /* Return immediately if no tilde. */ 42 if (filename[0] != '~') 43 return (xstrdup(filename)); 44 45 /* Skip the tilde. */ 46 filename++; 47 48 /* Find where the username ends. */ 49 cp = strchr(filename, '/'); 50 if (cp) 51 userlen = cp - filename; /* Something after username. */ 52 else 53 userlen = strlen(filename); /* Nothing after username. */ 54 55 /* This is the ~/xyz case with no ~username specification. */ 56 if (userlen == 0) 57 pw = getpwuid(my_uid); 58 else { 59 /* Tilde refers to someone elses home directory. */ 60 if (userlen > sizeof (user) - 1) 61 fatal("User name after tilde too long."); 62 memcpy(user, filename, userlen); 63 user[userlen] = 0; 64 pw = getpwnam(user); 65 } 66 67 /* Use the HOME variable now. */ 68 if (pw == NULL) { 69 debug("User account's password entry not found, trying to use " 70 "the HOME variable."); 71 if ((pw_dir = getenv("HOME")) == NULL) { 72 fatal("User account's password entry not found and " 73 "the HOME variable not set."); 74 } 75 } else { 76 pw_dir = pw->pw_dir; 77 } 78 79 /* If referring to someones home directory, return it now. */ 80 if (cp == NULL) { 81 /* Only home directory specified */ 82 return (xstrdup(pw_dir)); 83 } 84 85 /* Build a path combining the specified directory and path. */ 86 len = strlen(pw_dir) + strlen(cp + 1) + 2; 87 if (len > MAXPATHLEN) 88 fatal("Home directory too long (%d > %d)", len - 1, 89 MAXPATHLEN - 1); 90 91 expanded = xmalloc(len); 92 snprintf(expanded, len, "%s%s%s", pw_dir, 93 strcmp(pw_dir, "/") ? "/" : "", cp + 1); 94 return (expanded); 95 } 96