| 1 | /* |
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| 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
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| 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
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| 4 | * All rights reserved |
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| 5 | * |
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| 6 | * As far as I am concerned, the code I have written for this software |
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| 7 | * can be used freely for any purpose. Any derived versions of this |
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| 8 | * software must be clearly marked as such, and if the derived work is |
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| 9 | * incompatible with the protocol description in the RFC file, it must be |
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| 10 | * called by a name other than "ssh" or "Secure Shell". |
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| 11 | */ |
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| 12 | |
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| 13 | #include "includes.h" |
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| 14 | RCSID("$OpenBSD: tildexpand.c,v 1.13 2002/06/23 03:25:50 deraadt Exp $"); |
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| 15 | |
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| 16 | #include "xmalloc.h" |
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| 17 | #include "log.h" |
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| 18 | #include "tildexpand.h" |
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| 19 | |
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| 20 | /* |
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| 21 | * Expands tildes in the file name. Returns data allocated by xmalloc. |
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| 22 | * Warning: this calls getpw*. |
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| 23 | */ |
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| 24 | char * |
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| 25 | tilde_expand_filename(const char *filename, uid_t my_uid) |
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| 26 | { |
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| 27 | const char *cp; |
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| 28 | u_int userlen; |
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| 29 | char *expanded; |
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| 30 | struct passwd *pw; |
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| 31 | char user[100]; |
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| 32 | int len; |
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| 33 | |
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| 34 | /* Return immediately if no tilde. */ |
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| 35 | if (filename[0] != '~') |
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| 36 | return xstrdup(filename); |
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| 37 | |
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| 38 | /* Skip the tilde. */ |
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| 39 | filename++; |
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| 40 | |
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| 41 | /* Find where the username ends. */ |
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| 42 | cp = strchr(filename, '/'); |
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| 43 | if (cp) |
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| 44 | userlen = cp - filename; /* Something after username. */ |
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| 45 | else |
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| 46 | userlen = strlen(filename); /* Nothing after username. */ |
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| 47 | if (userlen == 0) |
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| 48 | pw = getpwuid(my_uid); /* Own home directory. */ |
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| 49 | else { |
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| 50 | /* Tilde refers to someone elses home directory. */ |
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| 51 | if (userlen > sizeof(user) - 1) |
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| 52 | fatal("User name after tilde too long."); |
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| 53 | memcpy(user, filename, userlen); |
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| 54 | user[userlen] = 0; |
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| 55 | pw = getpwnam(user); |
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| 56 | } |
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| 57 | if (!pw) |
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| 58 | fatal("Unknown user %100s.", user); |
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| 59 | |
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| 60 | /* If referring to someones home directory, return it now. */ |
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| 61 | if (!cp) { |
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| 62 | /* Only home directory specified */ |
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| 63 | return xstrdup(pw->pw_dir); |
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| 64 | } |
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| 65 | /* Build a path combining the specified directory and path. */ |
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| 66 | len = strlen(pw->pw_dir) + strlen(cp + 1) + 2; |
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| 67 | if (len > MAXPATHLEN) |
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| 68 | fatal("Home directory too long (%d > %d", len-1, MAXPATHLEN-1); |
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| 69 | expanded = xmalloc(len); |
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| 70 | snprintf(expanded, len, "%s%s%s", pw->pw_dir, |
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| 71 | strcmp(pw->pw_dir, "/") ? "/" : "", cp + 1); |
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| 72 | return expanded; |
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| 73 | } |
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