Attachment 5255 Details for Bug 6411 – fix for samba 3.4.5 now also works for %n in old password

[patch] fix for samba 3.4.5 now also works for %n in old password

samba-3.4.5-fix-chgpasswd-token-handling.diff (text/plain), 6.87 KB, created by Carsten Dumke on 2010-02-02 03:49:06 UTC

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Creator: Carsten Dumke

Created: 2010-02-02 03:49:06 UTC

Size: 6.87 KB

patch

obsolete

>diff -Nurbd samba-3.4.5.orig/source3/smbd/chgpasswd.c samba-3.4.5/source3/smbd/chgpasswd.c
>--- samba-3.4.5.orig/source3/smbd/chgpasswd.c	2010-01-18 12:38:09.000000000 +0100
>+++ samba-3.4.5/source3/smbd/chgpasswd.c	2010-01-29 16:45:02.000000000 +0100
>@@ -239,20 +239,160 @@
> 	return (True);
> }
> 
>-static int expect(int master, char *issue, char *expected)
>+static char *expand_pass_pattern(char *target, size_t target_len,
>+				 const char *source,
>+				 const char *pattern_old_pass,
>+				 const char *old_pass,
>+				 const char *pattern_new_pass,
>+				 const char *new_pass)
>+{
>+	/* we expand target in portions of chunk_size */
>+	size_t chunk_size = 10;
>+	size_t chars_to_copy = 0;
>+	size_t skip_source_chars = 0;
>+	size_t old_pass_len = 0;
>+	size_t new_pass_len = 0;
>+	size_t pattern_old_pass_len = 0;
>+	size_t pattern_new_pass_len = 0;
>+	size_t target_size = target_len;
>+	size_t target_used = 0;
>+	char *target_start = target;
>+	char *pattern_starter_found;
>+	char pattern_starter = '\0';
>+	char empty[] = "";
>+	const char *chars_source;
>+	TALLOC_CTX *ctx = talloc_tos();
>+
>+	if ((target == NULL) || (target_len == 0)) {
>+		return;
>+	}
>+	if (source == NULL) {
>+		source = empty;
>+	}
>+	if (pattern_old_pass != NULL) {
>+		pattern_old_pass_len = strlen(pattern_old_pass);
>+		pattern_starter = *pattern_old_pass;
>+	}
>+	if (pattern_new_pass != NULL) {
>+		pattern_new_pass_len = strlen(pattern_new_pass);
>+		pattern_starter = *pattern_new_pass;
>+	}
>+	if (old_pass != NULL) {
>+		old_pass_len = strlen(old_pass);
>+	}
>+	else {
>+		old_pass = empty;
>+	}
>+	if (new_pass != NULL) {
>+		new_pass_len = strlen(new_pass);
>+	}
>+	else {
>+		new_pass = empty;
>+	}
>+
>+	while (*source) {
>+		/* find possible start of pattern in source */
>+		pattern_starter_found = strchr(source, pattern_starter);
>+		chars_source = source;
>+		if (pattern_starter_found == NULL) {
>+			/* pattern not found - copy whole source */
>+			chars_to_copy = strlen(source);
>+		}
>+		else {
>+			chars_to_copy = pattern_starter_found - chars_source;
>+		}
>+		skip_source_chars = chars_to_copy;
>+
>+		if (chars_to_copy == 0) {
>+			/* current source char may start a pattern */
>+			if ((pattern_old_pass) && (*pattern_old_pass)
>+			    && (strncmp(source, pattern_old_pass,
>+					pattern_old_pass_len) == 0)) {
>+				/* insert old password */
>+				chars_source = old_pass;
>+				chars_to_copy = old_pass_len;
>+				skip_source_chars = pattern_old_pass_len;
>+			}
>+			else if ((pattern_new_pass) && (*pattern_new_pass)
>+				 && (strncmp(source, pattern_new_pass,
>+					     pattern_new_pass_len) == 0)) {
>+				/* insert new password */
>+				chars_source = new_pass;
>+				chars_to_copy = new_pass_len;
>+				skip_source_chars = pattern_new_pass_len;
>+			}
>+			else {
>+				/* no pattern matched - copy char to target */
>+				chars_to_copy = 1;
>+				skip_source_chars = chars_to_copy;
>+			}
>+		}
>+		while (chars_to_copy > target_len) {
>+			target_used = target - target_start;
>+			target_size += chunk_size;
>+			target_start = talloc_realloc(ctx, target_start, char,
>+						      target_size);
>+			if (!target_start) {
>+				DEBUG(1,("expand_pass_pattern: talloc fail\n"));
>+				return NULL;
>+			}
>+			target = target_start + target_used;
>+			target_len = target_size - target_used;
>+		}
>+		strncpy(target, chars_source , chars_to_copy);
>+		target_len -= chars_to_copy;
>+		target += chars_to_copy;
>+		source += skip_source_chars;
>+	}
>+	/* terminate target */
>+	if (target_len == 0) {
>+		target_used = target - target_start;
>+		target_size += chunk_size;
>+		target_start = talloc_realloc(ctx, target_start, char,
>+					      target_size);
>+		if (!target_start) {
>+			DEBUG(1,("expand_pass_pattern: talloc fail\n"));
>+			return NULL;
>+		}
>+		target = target_start + target_used;
>+		target_len = target_size - target_used;
>+	}
>+	*target = '\0';
>+	return target_start;
>+}
>+
>+static int expect(int master, const char *issue, const char *expected,
>+		  const char *oldpass, const char *newpass)
> {
> 	char buffer[1024];
> 	int attempts, timeout, nread;
> 	size_t len;
> 	bool match = False;
>+	char *newissue;
>+	size_t newissue_len;
>+
>+	/*
>+	 * We know we're safe allowing "unsafe" characters here
>+	 * as we know there are no embedded control characters.
>+	 */
>+	newissue = talloc(talloc_tos(), char);
>+	newissue = expand_pass_pattern(newissue, sizeof(char), issue,
>+				       "%o", oldpass,
>+				       "%n", newpass);
>+
>+	if (!newissue) {
>+		DEBUG(1,("expect: talloc fail\n"));
>+		return false;
>+	}
>+	newissue_len = strlen(newissue);
> 
> 	for (attempts = 0; attempts < 2; attempts++) {
> 		NTSTATUS status;
>-		if (!strequal(issue, ".")) {
>+		if (!strequal(newissue, ".")) {
> 			if (lp_passwd_chat_debug())
>-				DEBUG(100, ("expect: sending [%s]\n", issue));
>+				DEBUG(100, ("expect: sending [%s]\n", newissue));
> 
>-			if ((len = sys_write(master, issue, strlen(issue))) != strlen(issue)) {
>+			if ((len = sys_write(master, newissue, newissue_len)) != newissue_len) {
> 				DEBUG(2,("expect: (short) write returned %d\n",
> 					 (int)len ));
> 				return False;
>@@ -308,6 +448,7 @@
> 			return False;
> 		}
> 	}
>+	talloc_free(newissue);
> 
> 	DEBUG(10,("expect: returning %s\n", match ? "True" : "False" ));
> 	return match;
>@@ -321,7 +462,8 @@
> 	all_string_sub(buf, "\\t", "\t", 0);
> }
> 
>-static int talktochild(int master, const char *seq)
>+static int talktochild(int master, const char *seq,
>+			const char *oldpass, const char *newpass)
> {
> 	TALLOC_CTX *frame = talloc_stackframe();
> 	int count = 0;
>@@ -338,7 +480,7 @@
> 		pwd_sub(expected);
> 		count++;
> 
>-		if (!expect(master, issue, expected)) {
>+		if (!expect(master, issue, expected, oldpass, newpass)) {
> 			DEBUG(3, ("Response %d incorrect\n", count));
> 			TALLOC_FREE(frame);
> 			return false;
>@@ -361,7 +503,7 @@
> 			TALLOC_FREE(frame);
> 			return false;
> 		}
>-		if (!expect(master, issue, expected)) {
>+		if (!expect(master, issue, expected, oldpass, newpass)) {
> 			TALLOC_FREE(frame);
> 			return False;
> 		}
>@@ -371,7 +513,8 @@
> }
> 
> static bool chat_with_program(char *passwordprogram, const struct passwd *pass,
>-			      char *chatsequence, bool as_root)
>+				char *chatsequence, bool as_root,
>+				const char *oldpass, const char *newpass)
> {
> 	char *slavedev = NULL;
> 	int master;
>@@ -410,7 +553,7 @@
> 		/* Don't need this anymore in parent. */
> 		SAFE_FREE(slavedev);
> 
>-		if ((chstat = talktochild(master, chatsequence)) == False) {
>+		if ((chstat = talktochild(master, chatsequence, oldpass, newpass)) == False) {
> 			DEBUG(3, ("chat_with_program: Child failed to change password: %s\n", pass->pw_name));
> 			kill(pid, SIGKILL);	/* be sure to end this process */
> 		}
>@@ -605,21 +748,12 @@
> 	if (!chatsequence) {
> 		return false;
> 	}
>-	chatsequence = talloc_all_string_sub(ctx,
>-					chatsequence,
>-					"%o",
>-					oldpass);
>-	if (!chatsequence) {
>-		return false;
>-	}
>-	chatsequence = talloc_all_string_sub(ctx,
>-					chatsequence,
>-					"%n",
>-					newpass);
> 	return chat_with_program(passwordprogram,
> 				pass,
> 				chatsequence,
>-				as_root);
>+				as_root,
>+				oldpass,
>+				newpass);
> }
> 
> #else /* ALLOW_CHANGE_PASSWORD */

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Attachments on bug 6411: 4208 | 4213 | 4238 | 4239 | 5255 | 5797 | 5799