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Diffstat (limited to 'krfb/libvncserver/vncauth.c')
-rw-r--r-- | krfb/libvncserver/vncauth.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/krfb/libvncserver/vncauth.c b/krfb/libvncserver/vncauth.c new file mode 100644 index 00000000..ef27e356 --- /dev/null +++ b/krfb/libvncserver/vncauth.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved. + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This software is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + */ + +/* + * vncauth.c - Functions for VNC password management and authentication. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <time.h> +#ifdef WIN32 +#define srandom srand +#define random rand +#else +#include <sys/time.h> +#endif +#include "rfb.h" +#include "d3des.h" + + +/* + * We use a fixed key to store passwords, since we assume that our local + * file system is secure but nonetheless don't want to store passwords + * as plaintext. + */ + +unsigned char fixedkey[8] = {23,82,107,6,35,78,88,7}; + + +/* + * Encrypt a password and store it in a file. Returns 0 if successful, + * 1 if the file could not be written. + */ + +int +vncEncryptAndStorePasswd(char *passwd, char *fname) +{ + FILE *fp; + unsigned int i; + unsigned char encryptedPasswd[8]; + + if ((fp = fopen(fname,"w")) == NULL) return 1; + + /* windows security sux */ +#ifndef WIN32 + chmod(fname, S_IRUSR|S_IWUSR); +#endif + + /* pad password with nulls */ + + for (i = 0; i < 8; i++) { + if (i < strlen(passwd)) { + encryptedPasswd[i] = passwd[i]; + } else { + encryptedPasswd[i] = 0; + } + } + + /* Do encryption in-place - this way we overwrite our copy of the plaintext + password */ + + deskey(fixedkey, EN0); + des(encryptedPasswd, encryptedPasswd); + + for (i = 0; i < 8; i++) { + putc(encryptedPasswd[i], fp); + } + + fclose(fp); + return 0; +} + + +/* + * Decrypt a password from a file. Returns a pointer to a newly allocated + * string containing the password or a null pointer if the password could + * not be retrieved for some reason. + */ + +char * +vncDecryptPasswdFromFile(char *fname) +{ + FILE *fp; + int i, ch; + unsigned char *passwd = (unsigned char *)malloc(9); + + if ((fp = fopen(fname,"r")) == NULL) return NULL; + + for (i = 0; i < 8; i++) { + ch = getc(fp); + if (ch == EOF) { + fclose(fp); + return NULL; + } + passwd[i] = ch; + } + + fclose(fp); + + deskey(fixedkey, DE1); + des(passwd, passwd); + + passwd[8] = 0; + + return (char *)passwd; +} + + +/* + * Generate CHALLENGESIZE random bytes for use in challenge-response + * authentication. + */ + +void +vncRandomBytes(unsigned char *bytes) +{ + int i; + unsigned int seed = (unsigned int) time(0); + + srandom(seed); + for (i = 0; i < CHALLENGESIZE; i++) { + bytes[i] = (unsigned char)(random() & 255); + } +} + + +/* + * Encrypt CHALLENGESIZE bytes in memory using a password. + */ + +void +vncEncryptBytes(unsigned char *bytes, char *passwd) +{ + unsigned char key[8]; + unsigned int i; + + /* key is simply password padded with nulls */ + + for (i = 0; i < 8; i++) { + if (i < strlen(passwd)) { + key[i] = passwd[i]; + } else { + key[i] = 0; + } + } + + deskey(key, EN0); + + for (i = 0; i < CHALLENGESIZE; i += 8) { + des(bytes+i, bytes+i); + } +} |