X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/58c9b4b7f61d49408c87d7f7b40bc2d3eef92906..d3d07a5e860f1cde0e234ec7a1aff7111a2c514f:/authenticate.c

diff --git a/authenticate.c b/authenticate.c
index 8f4d7d16..7f6f71d3 100644
--- a/authenticate.c
+++ b/authenticate.c
@@ -1,41 +1,38 @@
-/* -*- 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
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-   
-   This program 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., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-/* support rsync authentication */
+/*
+ * Support rsync daemon authentication.
+ *
+ * Copyright (C) 1998-2000 Andrew Tridgell
+ * Copyright (C) 2002-2008 Wayne Davison
+ *
+ * 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
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, visit the http://fsf.org website.
+ */
+
 #include "rsync.h"
 
 extern char *password_file;
-extern int am_root;
 
 /***************************************************************************
 encode a buffer using base64 - simple and slow algorithm. null terminates
 the result.
   ***************************************************************************/
-void base64_encode(char *buf, int len, char *out)
+void base64_encode(const char *buf, int len, char *out, int pad)
 {
 	char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 	int bit_offset, byte_offset, idx, i;
-	unsigned char *d = (unsigned char *)buf;
+	const uchar *d = (const uchar *)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;
@@ -49,36 +46,46 @@ void base64_encode(char *buf, int len, char *out)
 		}
 		out[i] = b64[idx];
 	}
+
+	while (pad && (i % 4))
+		out[i++] = '=';
+
+	out[i] = '\0';
 }
 
-/* create a 16 byte challenge buffer */
-static void gen_challenge(char *addr, char *challenge)
+/* Generate a challenge buffer and return it base64-encoded. */
+static void gen_challenge(const char *addr, char *challenge)
 {
 	char input[32];
+	char digest[MAX_DIGEST_LEN];
 	struct timeval tv;
+	int len;
 
 	memset(input, 0, sizeof input);
 
-	strlcpy((char *)input, addr, 17);
+	strlcpy(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_init(0);
 	sum_update(input, sizeof input);
-	sum_end(challenge);
+	len = sum_end(digest);
+
+	base64_encode(digest, len, challenge, 0);
 }
 
 
 /* Return the secret for a user from the secret file, null terminated.
  * Maximum length is len (not counting the null). */
-static int get_secret(int module, char *user, char *secret, int len)
+static int get_secret(int module, const char *user, char *secret, int len)
 {
-	char *fname = lp_secrets_file(module);
+	const char *fname = lp_secrets_file(module);
 	STRUCT_STAT st;
 	int fd, ok = 1;
-	char ch, *p;
+	const char *p;
+	char ch, *s;
 
 	if (!fname || !*fname)
 		return 0;
@@ -87,19 +94,19 @@ static int get_secret(int module, char *user, char *secret, int len)
 		return 0;
 
 	if (do_stat(fname, &st) == -1) {
-		rsyserr(FERROR, errno, "stat(%s)", fname);
+		rsyserr(FLOG, 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");
+			rprintf(FLOG, "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");
+		} else if (MY_UID() == 0 && st.st_uid != 0) {
+			rprintf(FLOG, "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");
+		rprintf(FLOG, "continuing without secrets file\n");
 		close(fd);
 		return 0;
 	}
@@ -130,156 +137,158 @@ static int get_secret(int module, char *user, char *secret, int len)
 	}
 
 	/* Slurp the secret into the "secret" buffer. */
-	p = secret;
+	s = secret;
 	while (len > 0) {
-		if (read(fd, p, 1) != 1 || *p == '\n')
+		if (read(fd, s, 1) != 1 || *s == '\n')
 			break;
-		if (*p == '\r')
+		if (*s == '\r')
 			continue;
-		p++;
+		s++;
 		len--;
 	}
-	*p = '\0';
+	*s = '\0';
 	close(fd);
 
 	return 1;
 }
 
-static char *getpassf(char *filename)
+static const char *getpassf(const char *filename)
 {
 	STRUCT_STAT st;
 	char buffer[512], *p;
 	int fd, n, ok = 1;
-	char *envpw = getenv("RSYNC_PASSWORD");
+	const char *envpw = getenv("RSYNC_PASSWORD");
 
 	if (!filename)
 		return NULL;
 
 	if ((fd = open(filename,O_RDONLY)) < 0) {
-		rsyserr(FERROR, errno, "could not open password file \"%s\"",filename);
+		rsyserr(FWARNING, errno, "could not open password file \"%s\"",
+			filename);
 		if (envpw)
-			rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n");	
+			rprintf(FINFO, "falling back to RSYNC_PASSWORD environment variable.\n");
 		return NULL;
 	}
-	
+
 	if (do_stat(filename, &st) == -1) {
-		rsyserr(FERROR, errno, "stat(%s)", filename);
+		rsyserr(FWARNING, errno, "stat(%s)", filename);
 		ok = 0;
 	} else if ((st.st_mode & 06) != 0) {
-		rprintf(FERROR,"password file must not be other-accessible\n");
+		rprintf(FWARNING, "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");
+	} else if (MY_UID() == 0 && st.st_uid != 0) {
+		rprintf(FWARNING, "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);
+		rprintf(FWARNING, "continuing without password file\n");
+		if (envpw)
+			rprintf(FINFO, "falling back to RSYNC_PASSWORD environment variable.\n");
 		return NULL;
 	}
 
-	if (envpw)
-		rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n");
-
 	n = read(fd, buffer, sizeof buffer - 1);
 	close(fd);
 	if (n > 0) {
 		buffer[n] = '\0';
 		if ((p = strtok(buffer, "\n\r")) != NULL)
 			return strdup(p);
-	}	
+	}
 
 	return NULL;
 }
 
-/* generate a 16 byte hash from a password and challenge */
-static void generate_hash(char *in, char *challenge, char *out)
+/* Generate an MD4 hash created from the combination of the password
+ * and the challenge string and return it base64-encoded. */
+static void generate_hash(const char *in, const char *challenge, char *out)
 {
-	char buf[16];
+	char buf[MAX_DIGEST_LEN];
+	int len;
 
-	sum_init();
+	sum_init(0);
 	sum_update(in, strlen(in));
 	sum_update(challenge, strlen(challenge));
-	sum_end(buf);
+	len = sum_end(buf);
 
-	base64_encode(buf, 16, out);
+	base64_encode(buf, len, out, 0);
 }
 
-/* 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)
+/* Possibly 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, const char *host,
+		  const char *addr, const 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;
+	char challenge[MAX_DIGEST_LEN*2];
+	char line[BIGPATHBUFLEN];
+	char secret[512];
+	char pass2[MAX_DIGEST_LEN*2];
+	char *tok, *pass;
 
 	/* 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);
+	io_printf(f_out, "%s%s\n", leader, challenge);
 
-	if (!read_line(f_in, line, sizeof line - 1))
+	if (!read_line_old(f_in, line, sizeof line)
+	 || (pass = strchr(line, ' ')) == NULL) {
+		rprintf(FLOG, "auth failed on module %s from %s (%s): "
+			"invalid challenge response\n",
+			lp_name(module), host, addr);
 		return NULL;
+	}
+	*pass++ = '\0';
 
-	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;
+	if (!(users = strdup(users)))
+		out_of_memory("auth_server");
 
-	for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
-		if (wildmatch(tok, user))
+	for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) {
+		if (wildmatch(tok, line))
 			break;
 	}
 	free(users);
 
-	if (!tok)
+	if (!tok) {
+		rprintf(FLOG, "auth failed on module %s from %s (%s): "
+			"unauthorized user\n",
+			lp_name(module), host, addr);
 		return NULL;
-	
+	}
+
 	memset(secret, 0, sizeof secret);
-	if (!get_secret(module, user, secret, sizeof secret - 1)) {
+	if (!get_secret(module, line, secret, sizeof secret - 1)) {
 		memset(secret, 0, sizeof secret);
+		rprintf(FLOG, "auth failed on module %s from %s (%s): "
+			"missing secret for user \"%s\"\n",
+			lp_name(module), host, addr, line);
 		return NULL;
 	}
 
-	generate_hash(secret, b64_challenge, pass2);
+	generate_hash(secret, challenge, pass2);
 	memset(secret, 0, sizeof secret);
-	
-	if (strcmp(pass, pass2) == 0)
-		return user;
 
-	return NULL;
-}
+	if (strcmp(pass, pass2) != 0) {
+		rprintf(FLOG, "auth failed on module %s from %s (%s): "
+			"password mismatch\n",
+			lp_name(module), host, addr);
+		return NULL;
+	}
 
+	return strdup(line);
+}
 
-void auth_client(int fd, char *user, char *challenge)
+void auth_client(int fd, const char *user, const char *challenge)
 {
-	char *pass;
-	char pass2[30];
+	const char *pass;
+	char pass2[MAX_DIGEST_LEN*2];
 
 	if (!user || !*user)
 		user = "nobody";
@@ -304,5 +313,3 @@ void auth_client(int fd, char *user, char *challenge)
 	generate_hash(pass, challenge, pass2);
 	io_printf(fd, "%s %s\n", user, pass2);
 }
-
-