Clean up Blowfish Cryptography

Remove dead code and Vultraz' quick hacks for MSVC. The bcrypt.c file is now compliant ISO Standard C and should port anywhere. Added a Markdown file with full documentation on how to obtain and install updates should that ever become necessary.
wesnoth · Feb 22, 2018 · e0fda9a · e0fda9a
1 parent 5f1005d
commit e0fda9a
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Showing 5 changed files with 103 additions and 350 deletions.
diff --git a/src/bcrypt/bcrypt.c b/src/bcrypt/bcrypt.c
@@ -11,64 +11,20 @@
  * with this software. If not, see
  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
+
+/*
+ * 21FEB2018 - Gregory A Lundberg
+ * 
+ * Deleted all unneeded code. This converts this source file from POSIX-only
+ * to fully portable, strictly compliant ISO Standard C.
+ */
+
+#include <stddef.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#ifndef _WIN32
-#include <unistd.h>
-#else
-#include <io.h>
-#endif
-#include <errno.h>
 
 #include "bcrypt.h"
 #include "crypt_blowfish/ow-crypt.h"
 
-#define RANDBYTES (16)
-
-static int try_close(int fd)
-{
-	int ret;
-	for (;;) {
-		errno = 0;
-		ret = close(fd);
-		if (ret == -1 && errno == EINTR)
-			continue;
-		break;
-	}
-	return ret;
-}
-
-static int try_read(int fd, char *out, size_t count)
-{
-	size_t total;
-#ifndef _WIN32
-	ssize_t partial;
-#else
-	int partial;
-#endif
-
-	total = 0;
-	while (total < count)
-	{
-		for (;;) {
-			errno = 0;
-			partial = read(fd, out + total, count - total);
-			if (partial == -1 && errno == EINTR)
-				continue;
-			break;
-		}
-
-		if (partial < 1)
-			return -1;
-
-		total += partial;
-	}
-
-	return 0;
-}
-
 /*
  * This is a best effort implementation. Nothing prevents a compiler from
  * optimizing this function and making it vulnerable to timing attacks, but
@@ -102,33 +58,6 @@ static int timing_safe_strcmp(const char *str1, const char *str2)
 	return ret;
 }
 
-int bcrypt_gensalt(int factor, char salt[BCRYPT_HASHSIZE])
-{
-	int fd;
-	char input[RANDBYTES];
-	int workf;
-	char *aux;
-
-	fd = open("/dev/urandom", O_RDONLY);
-	if (fd == -1)
-		return 1;
-
-	if (try_read(fd, input, RANDBYTES) != 0) {
-		if (try_close(fd) != 0)
-			return 4;
-		return 2;
-	}
-
-	if (try_close(fd) != 0)
-		return 3;
-
-	/* Generate salt. */
-	workf = (factor < 4 || factor > 31)?12:factor;
-	aux = crypt_gensalt_rn("$2a$", workf, input, RANDBYTES,
-			       salt, BCRYPT_HASHSIZE);
-	return (aux == NULL)?5:0;
-}
-
 int bcrypt_hashpw(const char *passwd, const char salt[BCRYPT_HASHSIZE], char hash[BCRYPT_HASHSIZE])
 {
 	char *aux;
@@ -147,57 +76,3 @@ int bcrypt_checkpw(const char *passwd, const char hash[BCRYPT_HASHSIZE])
 
 	return timing_safe_strcmp(hash, outhash);
 }
-
-#ifdef TEST_BCRYPT
-#include <assert.h>
-#include <stdio.h>
-#include <string.h>
-#include <time.h>
-
-int main(void)
-{
-	clock_t before;
-	clock_t after;
-	char salt[BCRYPT_HASHSIZE];
-	char hash[BCRYPT_HASHSIZE];
-	int ret;
-
-	const char pass[] = "hi,mom";
-	const char hash1[] = "$2a$10$VEVmGHy4F4XQMJ3eOZJAUeb.MedU0W10pTPCuf53eHdKJPiSE8sMK";
-	const char hash2[] = "$2a$10$3F0BVk5t8/aoS.3ddaB3l.fxg5qvafQ9NybxcpXLzMeAt.nVWn.NO";
-
-	ret = bcrypt_gensalt(12, salt);
-	assert(ret == 0);
-	printf("Generated salt: %s\n", salt);
-	before = clock();
-	ret = bcrypt_hashpw("testtesttest", salt, hash);
-	assert(ret == 0);
-	after = clock();
-	printf("Hashed password: %s\n", hash);
-	printf("Time taken: %f seconds\n",
-	       (double)(after - before) / CLOCKS_PER_SEC);
-
-	ret = bcrypt_hashpw(pass, hash1, hash);
-	assert(ret == 0);
-	printf("First hash check: %s\n", (strcmp(hash1, hash) == 0)?"OK":"FAIL");
-	ret = bcrypt_hashpw(pass, hash2, hash);
-	assert(ret == 0);
-	printf("Second hash check: %s\n", (strcmp(hash2, hash) == 0)?"OK":"FAIL");
-
-	before = clock();
-	ret = (bcrypt_checkpw(pass, hash1) == 0);
-	after = clock();
-	printf("First hash check with bcrypt_checkpw: %s\n", ret?"OK":"FAIL");
-	printf("Time taken: %f seconds\n",
-	       (double)(after - before) / CLOCKS_PER_SEC);
-
-	before = clock();
-	ret = (bcrypt_checkpw(pass, hash2) == 0);
-	after = clock();
-	printf("Second hash check with bcrypt_checkpw: %s\n", ret?"OK":"FAIL");
-	printf("Time taken: %f seconds\n",
-	       (double)(after - before) / CLOCKS_PER_SEC);
-
-	return 0;
-}
-#endif
diff --git a/src/bcrypt/bcrypt.h b/src/bcrypt/bcrypt.h
@@ -14,24 +14,19 @@
  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
 
+/*
+ * 21FEB2018 - Gregory A Lundberg
+ * 
+ * Deleted all unneeded code. This converts this source file from POSIX-only
+ * to fully portable, strictly compliant ISO Standard C.
+ */
+
 #define BCRYPT_HASHSIZE	(64)
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/*
- * This function expects a work factor between 4 and 31 and a char array to
- * store the resulting generated salt. The char array should typically have
- * BCRYPT_HASHSIZE bytes at least. If the provided work factor is not in the
- * previous range, it will default to 12.
- *
- * The return value is zero if the salt could be correctly generated and
- * nonzero otherwise.
- *
- */
-int bcrypt_gensalt(int workfactor, char salt[BCRYPT_HASHSIZE]);
-
 /*
  * This function expects a password to be hashed, a salt to hash the password
  * with and a char array to leave the result. Both the salt and the hash

diff --git a/src/bcrypt/crypt_blowfish.md b/src/bcrypt/crypt_blowfish.md
@@ -0,0 +1,87 @@
+# Blowfish Cryptography
+
+This document describes the process used to install Blowfish Cryptography 1.3 for Wesnoth.
+
+The goal of this process was, as much as possible, install clean, unchanged sources.
+Traditionally, Wesnoth maintainers are tempted to make changes directly to the Blowfish source kit.
+__This is strongly discouraged.__
+Future maintainers should strive, as much as possible, to follow a similar process.
+
+Future maintainers are expected to update this document as appropriate.
+
+## 1) Before you begin
+
+Be sure you are using a copy of the current master.
+And be sure you are working in a private branch.
+
+        $ cd ~/wesnoth
+        $ git checkout master
+        $ git pull --rebase upstream master
+        $ git checkout -b Upgrade_to_Blowfish_1.3
+
+## 2) Update Blowfish Source
+
+Download the current source kit from [the maintainers](http://www.openwall.com/crypt/).
+For Blowfish Cryptography 1.3, this was <http://www.openwall.com/crypt/crypt_blowfish-1.3.tar.gz>.
+The following presumes you are working on Unix.
+Windows is a bit more work, but generally follows the same process.
+
+        $ cd ~
+        $ wget http://www.openwall.com/crypt/crypt_blowfish-1.3.tar.gz
+
+Unpack into your home folder.
+Note that, while the filename implies the file is compressed using GNU zip, it is actually just a plain tarball.
+
+        $ tar -xf crypt_blowfish-1.3.tar.gz
+
+Change into the Blowfish Cryptography folder.
+
+        $ cd ~/crypt_blowfish-1.3
+
+We do not need, or want, the GNU libc patch files, the man page, or the x86 Assember source file, so delete them.
+
+        $ rm *.diff crypt.3 x86.S
+
+Next, delete the current copy of Blowfish Cryptography in Wesnoth.
+
+        $ cd ~/wesnoth/src/bcrypt
+        $ rm -fR crypt_blowfish
+
+Finally, move the new sources into place.
+
+        $ mv ~/crypt_blowfish-1.3 crypt_blowfish
+
+## 3) Update SCons and CMake
+
+Remember to review the source kit for added and removed files, and change the SCons and CMake configuration, as needed.
+Both build systems' build lists are in `~/wesnoth/source_lists/libwesnoth_core`.
+Verify the files listed match the C source files just copied in; order is not important, headers are not listed.
+The source list lists many files; you may have to search a bit.
+The Blowfish Cryptography files, however, should all have names beginning with `bcrypt/crypt_blowfish/`.
+
+Updating the project files for other target platforms is optional at this point.
+
+## 4) Commit the changes
+
+        $ cd ~/wesnoth
+        $ git add .
+        $ git commit -m 'Upgrade to Blowfish Cryptography 1.3'
+
+## 5) Build Wesnoth
+
+Run a test build.
+Rarely, when upgrading Blwofish Cryptography, there are changes to the API.
+Be sure to carefully check the build for errors and warnings about changed or missing Blowfish cryptography functions.
+Make any adjustments necessary.
+Generally, if needed, changes will appear in `~/wesnoth/src/bcrypt/bcrypt.c`.
+
+__Separately commit these adjustments.__
+
+## 6) Create a Pull Request
+
+Even if you have direct access to the Wesnoth master repository, you should __never upgrade Blowfish Cryptography immediately__.
+Push your local branch up to GitHub and create a Pull Request.
+
+Don't forget to monitor Travis/CI for your pull request to ensure a clean test run.
+
+Have someone else review your changes and merge them when all issues have been addressed.
diff --git a/src/bcrypt/crypt_blowfish/wrapper.c b/src/bcrypt/crypt_blowfish/wrapper.c
@@ -14,7 +14,6 @@
  * See crypt_blowfish.c for more information.
  */
 
-#define _GNU_SOURCE 1
 #include <stdlib.h>
 #include <string.h>