-/*
- Copyright (C) Andrew Tridgell 1998
+/* -*- c-file-style: "linux"; -*-
+
+ Copyright (C) 1998-2000 by Andrew Tridgell
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
/* support rsync authentication */
#include "rsync.h"
+/***************************************************************************
+encode a buffer using base64 - simple and slow algorithm. null terminates
+the result.
+ ***************************************************************************/
+static void base64_encode(char *buf, int len, char *out)
+{
+ char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+ int bit_offset, byte_offset, idx, i;
+ unsigned char *d = (unsigned char *)buf;
+ int bytes = (len*8 + 5)/6;
+
+ memset(out, 0, bytes+1);
+
+ for (i=0;i<bytes;i++) {
+ byte_offset = (i*6)/8;
+ bit_offset = (i*6)%8;
+ if (bit_offset < 3) {
+ idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
+ } else {
+ idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
+ if (byte_offset+1 < len) {
+ idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
+ }
+ }
+ out[i] = b64[idx];
+ }
+}
+
+/* create a 16 byte challenge buffer */
+static void gen_challenge(char *addr, char *challenge)
+{
+ char input[32];
+ struct timeval tv;
+
+ memset(input, 0, sizeof(input));
+
+ strlcpy((char *)input, addr, 17);
+ sys_gettimeofday(&tv);
+ SIVAL(input, 16, tv.tv_sec);
+ SIVAL(input, 20, tv.tv_usec);
+ SIVAL(input, 24, getpid());
+
+ sum_init();
+ sum_update(input, sizeof(input));
+ sum_end(challenge);
+}
+
+
+/* return the secret for a user from the sercret file. maximum length
+ is len. null terminate it */
+static int get_secret(int module, char *user, char *secret, int len)
+{
+ char *fname = lp_secrets_file(module);
+ int fd, found=0;
+ char line[MAXPATHLEN];
+ char *p, *pass=NULL;
+ STRUCT_STAT st;
+ int ok = 1;
+ extern int am_root;
+
+ if (!fname || !*fname) return 0;
+
+ fd = open(fname,O_RDONLY);
+ if (fd == -1) return 0;
+
+ if (do_stat(fname, &st) == -1) {
+ rsyserr(FERROR, errno, "stat(%s)", fname);
+ ok = 0;
+ } else if (lp_strict_modes(module)) {
+ if ((st.st_mode & 06) != 0) {
+ rprintf(FERROR,"secrets file must not be other-accessible (see strict modes option)\n");
+ ok = 0;
+ } else if (am_root && (st.st_uid != 0)) {
+ rprintf(FERROR,"secrets file must be owned by root when running as root (see strict modes)\n");
+ ok = 0;
+ }
+ }
+ if (!ok) {
+ rprintf(FERROR,"continuing without secrets file\n");
+ close(fd);
+ return 0;
+ }
+
+ while (!found) {
+ int i = 0;
+ memset(line, 0, sizeof line);
+ while ((size_t) i < (sizeof(line)-1)) {
+ if (read(fd, &line[i], 1) != 1) {
+ memset(line, 0, sizeof(line));
+ close(fd);
+ return 0;
+ }
+ if (line[i] == '\r') continue;
+ if (line[i] == '\n') break;
+ i++;
+ }
+ line[i] = 0;
+ if (line[0] == '#') continue;
+ p = strchr(line,':');
+ if (!p) continue;
+ *p = 0;
+ if (strcmp(user, line)) continue;
+ pass = p+1;
+ found = 1;
+ }
+
+ close(fd);
+ if (!found) return 0;
+
+ strlcpy(secret, pass, len);
+ return 1;
+}
+
+static char *getpassf(char *filename)
+{
+ char buffer[100];
+ int fd=0;
+ STRUCT_STAT st;
+ int ok = 1;
+ extern int am_root;
+ char *envpw=getenv("RSYNC_PASSWORD");
+
+ if (!filename) return NULL;
+
+ if ( (fd=open(filename,O_RDONLY)) == -1) {
+ rsyserr(FERROR, errno, "could not open password file \"%s\"",filename);
+ if (envpw) rprintf(FERROR,"falling back to RSYNC_PASSWORD environment variable.\n");
+ return NULL;
+ }
+
+ if (do_stat(filename, &st) == -1) {
+ rsyserr(FERROR, errno, "stat(%s)", filename);
+ ok = 0;
+ } else if ((st.st_mode & 06) != 0) {
+ rprintf(FERROR,"password file must not be other-accessible\n");
+ ok = 0;
+ } else if (am_root && (st.st_uid != 0)) {
+ rprintf(FERROR,"password file must be owned by root when running as root\n");
+ ok = 0;
+ }
+ if (!ok) {
+ rprintf(FERROR,"continuing without password file\n");
+ if (envpw) rprintf(FERROR,"using RSYNC_PASSWORD environment variable.\n");
+ close(fd);
+ return NULL;
+ }
+
+ if (envpw) rprintf(FERROR,"RSYNC_PASSWORD environment variable ignored\n");
+
+ buffer[sizeof(buffer)-1]='\0';
+ if (read(fd,buffer,sizeof(buffer)-1) > 0)
+ {
+ char *p = strtok(buffer,"\n\r");
+ close(fd);
+ if (p) p = strdup(p);
+ return p;
+ }
+
+ return NULL;
+}
+
+/* generate a 16 byte hash from a password and challenge */
+static void generate_hash(char *in, char *challenge, char *out)
+{
+ char buf[16];
+
+ sum_init();
+ sum_update(in, strlen(in));
+ sum_update(challenge, strlen(challenge));
+ sum_end(buf);
+
+ base64_encode(buf, 16, out);
+}
+
+/* possible negotiate authentication with the client. Use "leader" to
+ start off the auth if necessary
+
+ return NULL if authentication failed
+
+ return "" if anonymous access
+
+ otherwise return username
+*/
+char *auth_server(int f_in, int f_out, int module, char *addr, char *leader)
+{
+ char *users = lp_auth_users(module);
+ char challenge[16];
+ char b64_challenge[30];
+ char line[MAXPATHLEN];
+ static char user[100];
+ char secret[100];
+ char pass[30];
+ char pass2[30];
+ char *tok;
+
+ /* if no auth list then allow anyone in! */
+ if (!users || !*users) return "";
+
+ gen_challenge(addr, challenge);
+
+ base64_encode(challenge, 16, b64_challenge);
+
+ io_printf(f_out, "%s%s\n", leader, b64_challenge);
+
+ if (!read_line(f_in, line, sizeof(line)-1)) {
+ return NULL;
+ }
+
+ memset(user, 0, sizeof(user));
+ memset(pass, 0, sizeof(pass));
+
+ if (sscanf(line,"%99s %29s", user, pass) != 2) {
+ return NULL;
+ }
+
+ users = strdup(users);
+ if (!users) return NULL;
+
+ for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
+ if (wildmatch(tok, user)) break;
+ }
+ free(users);
+
+ if (!tok) {
+ return NULL;
+ }
+
+ memset(secret, 0, sizeof(secret));
+ if (!get_secret(module, user, secret, sizeof(secret)-1)) {
+ memset(secret, 0, sizeof(secret));
+ return NULL;
+ }
+
+ generate_hash(secret, b64_challenge, pass2);
+ memset(secret, 0, sizeof(secret));
+
+ if (strcmp(pass, pass2) == 0)
+ return user;
+
+ return NULL;
+}
+
+
+void auth_client(int fd, char *user, char *challenge)
+{
+ char *pass;
+ char pass2[30];
+ extern char *password_file;
+
+ if (!user || !*user) return;
+
+ if (!(pass=getpassf(password_file)) && !(pass=getenv("RSYNC_PASSWORD"))) {
+ /* XXX: cyeoh says that getpass is deprecated, because
+ * it may return a truncated password on some systems,
+ * and it is not in the LSB.
+ *
+ * Andrew Klein says that getpassphrase() is present
+ * on Solaris and reads up to 256 characters.
+ *
+ * OpenBSD has a readpassphrase() that might be more suitable.
+ */
+ pass = getpass("Password: ");
+ }
+
+ if (!pass || !*pass) {
+ pass = "";
+ }
+
+ generate_hash(pass, challenge, pass2);
+ io_printf(fd, "%s %s\n", user, pass2);
+}
+
+
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff