2 * Claws Mail -- a GTK+ based, lightweight, and fast e-mail client
3 * Copyright (C) 2016 The Claws Mail Team
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "claws-features.h"
25 #ifdef PASSWORD_CRYPTO_GNUTLS
26 # include <gnutls/gnutls.h>
27 # include <gnutls/crypto.h>
31 #include <glib/gi18n.h>
36 #elif defined G_OS_WIN32
41 #include "common/passcrypt.h"
42 #include "common/plugin.h"
43 #include "common/utils.h"
45 #include "alertpanel.h"
46 #include "inputdialog.h"
48 #include "passwordstore.h"
49 #include "prefs_common.h"
51 #ifndef PASSWORD_CRYPTO_OLD
52 static gchar *_master_passphrase = NULL;
54 static const gchar *master_passphrase()
59 if (!prefs_common_get_prefs()->use_master_passphrase) {
63 if (_master_passphrase != NULL) {
64 debug_print("Master passphrase is in memory, offering it.\n");
65 return _master_passphrase;
69 input = input_dialog_with_invisible(_("Input master passphrase"),
70 _("Input master passphrase"), NULL);
73 debug_print("Cancel pressed at master passphrase dialog.\n");
77 if (master_passphrase_is_correct(input)) {
78 debug_print("Entered master passphrase seems to be correct, remembering it.\n");
79 _master_passphrase = input;
82 alertpanel_error(_("Incorrect master passphrase."));
86 return _master_passphrase;
89 const gboolean master_passphrase_is_set()
91 if (prefs_common_get_prefs()->master_passphrase_hash == NULL
92 || strlen(prefs_common_get_prefs()->master_passphrase_hash) == 0)
98 const gboolean master_passphrase_is_correct(const gchar *input)
101 gchar *stored_hash = prefs_common_get_prefs()->master_passphrase_hash;
102 const GChecksumType hashtype = G_CHECKSUM_SHA512;
103 const gssize hashlen = g_checksum_type_get_length(hashtype);
106 g_return_val_if_fail(input != NULL, FALSE);
108 if (stored_hash == NULL)
111 debug_print("|stored_hash|%s|\n", stored_hash);
112 stored_len = strlen(stored_hash);
113 g_return_val_if_fail(stored_len == 2*hashlen, FALSE);
115 hash = g_compute_checksum_for_string(hashtype, input, -1);
117 if (!strncasecmp(hash, stored_hash, stored_len)) {
126 gboolean master_passphrase_is_entered()
128 return (_master_passphrase == NULL) ? FALSE : TRUE;
131 void master_passphrase_forget()
133 /* If master passphrase is currently in memory (entered by user),
134 * get rid of it. User will have to enter the new one again. */
135 if (_master_passphrase != NULL) {
136 memset(_master_passphrase, 0, strlen(_master_passphrase));
137 g_free(_master_passphrase);
139 _master_passphrase = NULL;
142 void master_passphrase_change(const gchar *oldp, const gchar *newp)
145 /* If oldp is NULL, make sure the user has to enter the
146 * current master passphrase before being able to change it. */
147 master_passphrase_forget();
148 oldp = master_passphrase();
150 g_return_if_fail(oldp != NULL);
152 /* Update master passphrase hash in prefs */
153 if (prefs_common_get_prefs()->master_passphrase_hash != NULL)
154 g_free(prefs_common_get_prefs()->master_passphrase_hash);
157 debug_print("Storing hash of new master passphrase\n");
158 prefs_common_get_prefs()->master_passphrase_hash =
159 g_compute_checksum_for_string(G_CHECKSUM_SHA512, newp, -1);
161 debug_print("Setting master_passphrase_hash to NULL\n");
162 prefs_common_get_prefs()->master_passphrase_hash = NULL;
165 /* Now go over all accounts, reencrypting their passwords using
166 * the new master passphrase. */
169 oldp = PASSCRYPT_KEY;
171 newp = PASSCRYPT_KEY;
173 debug_print("Reencrypting all account passwords...\n");
174 passwd_store_reencrypt_all(oldp, newp);
176 /* Now reencrypt all plugins passwords fields
177 * FIXME: Unloaded plugins won't be able to update their stored passwords
179 plugins_master_passphrase_change(oldp, newp);
181 master_passphrase_forget();
185 gchar *password_encrypt_old(const gchar *password)
187 if (!password || strlen(password) == 0) {
191 gchar *encrypted = g_strdup(password);
192 gchar *encoded, *result;
193 gsize len = strlen(password);
195 passcrypt_encrypt(encrypted, len);
196 encoded = g_base64_encode(encrypted, len);
198 result = g_strconcat("!", encoded, NULL);
204 gchar *password_decrypt_old(const gchar *password)
206 if (!password || strlen(password) == 0) {
210 if (*password != '!' || strlen(password) < 2) {
215 gchar *decrypted = g_base64_decode(password + 1, &len);
217 passcrypt_decrypt(decrypted, len);
221 #ifdef PASSWORD_CRYPTO_GNUTLS
224 gchar *password_encrypt_gnutls(const gchar *password,
225 const gchar *encryption_passphrase)
227 /* Another, slightly inferior combination is AES-128-CBC + SHA-256.
228 * Any block cipher in CBC mode with keysize N and a hash algo with
229 * digest length 2*N would do. */
230 gnutls_cipher_algorithm_t algo = GNUTLS_CIPHER_AES_256_CBC;
231 gnutls_digest_algorithm_t digest = GNUTLS_DIG_SHA512;
232 gnutls_cipher_hd_t handle;
233 gnutls_datum_t key, iv;
234 int ivlen, keylen, digestlen, blocklen, ret, i;
235 unsigned char hashbuf[BUFSIZE], *buf, *encbuf, *base, *output;
236 #if defined G_OS_UNIX
238 #elif defined G_OS_WIN32
242 g_return_val_if_fail(password != NULL, NULL);
243 g_return_val_if_fail(encryption_passphrase != NULL, NULL);
245 ivlen = gnutls_cipher_get_iv_size(algo);
246 keylen = gnutls_cipher_get_key_size(algo);
247 blocklen = gnutls_cipher_get_block_size(algo);
248 digestlen = gnutls_hash_get_len(digest);
250 /* Prepare key for cipher - first half of hash of passkey XORed with
252 memset(&hashbuf, 0, BUFSIZE);
253 if ((ret = gnutls_hash_fast(digest, encryption_passphrase,
254 strlen(encryption_passphrase), &hashbuf)) < 0) {
255 debug_print("Hashing passkey failed: %s\n", gnutls_strerror(ret));
258 for (i = 0; i < digestlen/2; i++) {
259 hashbuf[i] = hashbuf[i] ^ hashbuf[i+digestlen/2];
262 key.data = malloc(keylen);
263 memcpy(key.data, &hashbuf, keylen);
266 /* Prepare our source of random data. */
267 #if defined G_OS_UNIX
268 rnd = open("/dev/urandom", O_RDONLY);
270 perror("fopen on /dev/urandom");
271 #elif defined G_OS_WIN32
272 if (!CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, 0) &&
273 !CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
274 debug_print("Could not acquire a CSP handle.\n");
281 /* Prepare random IV for cipher */
282 iv.data = malloc(ivlen);
284 #if defined G_OS_UNIX
285 ret = read(rnd, iv.data, ivlen);
287 perror("read into iv");
289 #elif defined G_OS_WIN32
290 if (!CryptGenRandom(rnd, ivlen, iv.data)) {
291 debug_print("Could not read random data for IV\n");
292 CryptReleaseContext(rnd, 0);
299 /* Initialize the encryption */
300 ret = gnutls_cipher_init(&handle, algo, &key, &iv);
304 #if defined G_OS_UNIX
306 #elif defined G_OS_WIN32
307 CryptReleaseContext(rnd, 0);
312 /* Fill buf with one block of random data, our password, pad the
313 * rest with zero bytes. */
314 buf = malloc(BUFSIZE + blocklen);
315 memset(buf, 0, BUFSIZE);
316 #if defined G_OS_UNIX
317 ret = read(rnd, buf, blocklen);
318 if (ret != blocklen) {
319 perror("read into buffer");
321 #elif defined G_OS_WIN32
322 if (!CryptGenRandom(rnd, blocklen, buf)) {
323 debug_print("Could not read random data for IV\n");
324 CryptReleaseContext(rnd, 0);
329 gnutls_cipher_deinit(handle);
333 /* We don't need any more random data. */
334 #if defined G_OS_UNIX
336 #elif defined G_OS_WIN32
337 CryptReleaseContext(rnd, 0);
340 memcpy(buf + blocklen, password, strlen(password));
342 /* Encrypt into encbuf */
343 encbuf = malloc(BUFSIZE + blocklen);
344 memset(encbuf, 0, BUFSIZE + blocklen);
345 ret = gnutls_cipher_encrypt2(handle, buf, BUFSIZE + blocklen,
346 encbuf, BUFSIZE + blocklen);
352 gnutls_cipher_deinit(handle);
357 gnutls_cipher_deinit(handle);
362 /* And finally prepare the resulting string:
363 * "{algorithm}base64encodedciphertext" */
364 base = g_base64_encode(encbuf, BUFSIZE);
366 output = g_strdup_printf("{%s}%s", gnutls_cipher_get_name(algo), base);
372 gchar *password_decrypt_gnutls(const gchar *password,
373 const gchar *decryption_passphrase)
375 gchar **tokens, *tmp;
376 gnutls_cipher_algorithm_t algo;
377 gnutls_digest_algorithm_t digest = GNUTLS_DIG_UNKNOWN;
378 gnutls_cipher_hd_t handle;
379 gnutls_datum_t key, iv;
380 int ivlen, keylen, digestlen, blocklen, ret, i;
382 unsigned char hashbuf[BUFSIZE], *buf;
383 #if defined G_OS_UNIX
385 #elif defined G_OS_WIN32
389 g_return_val_if_fail(password != NULL, NULL);
390 g_return_val_if_fail(decryption_passphrase != NULL, NULL);
392 tokens = g_strsplit_set(password, "{}", 3);
394 /* Parse the string, retrieving algorithm and encrypted data.
395 * We expect "{algorithm}base64encodedciphertext". */
396 if (strlen(tokens[0]) != 0 ||
397 (algo = gnutls_cipher_get_id(tokens[1])) == GNUTLS_CIPHER_UNKNOWN ||
398 strlen(tokens[2]) == 0)
401 /* Our hash algo needs to have digest length twice as long as our
402 * cipher algo's key length. */
403 if (algo == GNUTLS_CIPHER_AES_256_CBC) {
404 debug_print("Using AES-256-CBC + SHA-512 for decryption\n");
405 digest = GNUTLS_DIG_SHA512;
406 } else if (algo == GNUTLS_CIPHER_AES_128_CBC) {
407 debug_print("Using AES-128-CBC + SHA-256 for decryption\n");
408 digest = GNUTLS_DIG_SHA256;
410 if (digest == GNUTLS_DIG_UNKNOWN) {
411 debug_print("Password is encrypted with unsupported cipher, giving up.\n");
416 ivlen = gnutls_cipher_get_iv_size(algo);
417 keylen = gnutls_cipher_get_key_size(algo);
418 blocklen = gnutls_cipher_get_block_size(algo);
419 digestlen = gnutls_hash_get_len(digest);
421 /* Prepare key for cipher - first half of hash of passkey XORed with
422 * the second. AES-256 has key length 32 and length of SHA-512 hash
423 * is exactly twice that, 64. */
424 memset(&hashbuf, 0, BUFSIZE);
425 if ((ret = gnutls_hash_fast(digest, decryption_passphrase,
426 strlen(decryption_passphrase), &hashbuf)) < 0) {
427 debug_print("Hashing passkey failed: %s\n", gnutls_strerror(ret));
431 for (i = 0; i < digestlen/2; i++) {
432 hashbuf[i] = hashbuf[i] ^ hashbuf[i+digestlen/2];
435 key.data = malloc(keylen);
436 memcpy(key.data, &hashbuf, keylen);
439 /* Prepare our source of random data. */
440 #if defined G_OS_UNIX
441 rnd = open("/dev/urandom", O_RDONLY);
443 perror("fopen on /dev/urandom");
444 #elif defined G_OS_WIN32
445 if (!CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, 0) &&
446 !CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
447 debug_print("Could not acquire a CSP handle.\n");
455 /* Prepare random IV for cipher */
456 iv.data = malloc(ivlen);
458 #if defined G_OS_UNIX
459 ret = read(rnd, iv.data, ivlen);
461 perror("read into iv");
463 #elif defined G_OS_WIN32
464 if (!CryptGenRandom(rnd, ivlen, iv.data)) {
465 debug_print("Could not read random data for IV\n");
466 CryptReleaseContext(rnd, 0);
474 /* We don't need any more random data. */
475 #if defined G_OS_UNIX
477 #elif defined G_OS_WIN32
478 CryptReleaseContext(rnd, 0);
481 /* Prepare encrypted password string for decryption. */
482 tmp = g_base64_decode(tokens[2], &len);
485 /* Initialize the decryption */
486 ret = gnutls_cipher_init(&handle, algo, &key, &iv);
488 debug_print("Cipher init failed: %s\n", gnutls_strerror(ret));
494 buf = malloc(BUFSIZE + blocklen);
495 memset(buf, 0, BUFSIZE + blocklen);
496 ret = gnutls_cipher_decrypt2(handle, tmp, len,
497 buf, BUFSIZE + blocklen);
499 debug_print("Decryption failed: %s\n", gnutls_strerror(ret));
503 gnutls_cipher_deinit(handle);
508 gnutls_cipher_deinit(handle);
512 tmp = g_strndup(buf + blocklen, MIN(strlen(buf + blocklen), BUFSIZE));
521 gchar *password_encrypt(const gchar *password,
522 const gchar *encryption_passphrase)
524 if (password == NULL || strlen(password) == 0) {
528 #ifndef PASSWORD_CRYPTO_OLD
529 if (encryption_passphrase == NULL)
530 encryption_passphrase = master_passphrase();
532 return password_encrypt_real(password, encryption_passphrase);
535 return password_encrypt_old(password);
538 gchar *password_decrypt(const gchar *password,
539 const gchar *decryption_passphrase)
541 if (password == NULL || strlen(password) == 0) {
545 /* First, check if the password was possibly decrypted using old,
547 if (*password == '!') {
548 debug_print("Trying to decrypt password using the old method...\n");
549 return password_decrypt_old(password);
552 /* Try available crypto backend */
553 #ifndef PASSWORD_CRYPTO_OLD
554 if (decryption_passphrase == NULL)
555 decryption_passphrase = master_passphrase();
557 if (*password == '{') {
558 debug_print("Trying to decrypt password...\n");
559 return password_decrypt_real(password, decryption_passphrase);
563 /* Fallback, in case the configuration is really old and
564 * stored password in plaintext */
565 debug_print("Assuming password was stored plaintext, returning it unchanged\n");
566 return g_strdup(password);