Let ykp_AES_key_from_passphrase() take an optional salt as well

git-svn-id: https://yubikey-personalization.googlecode.com/svn/trunk@22 b62f149e-849f-11dd-9899-c7ba65f7c4c7

diff --git a/ykpers.c b/ykpers.c
index fc31aac212e38879e91d42c7d810e76f918a8542..de0c58dfce2165a123ff9002780b938d652f0907 100644 (file)
--- a/ykpers.c
+++ b/ykpers.c
@@ -68,7 +68,8 @@ int ykp_free_config(CONFIG *cfg)
        return 0;
 }
 
-int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase)
+int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase,
+                               const char *salt)
 {
        if (cfg) {
                char *random_places[] = {
@@ -78,31 +79,38 @@ int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase)
                        0
                };
                char **random_place;
-               uint8_t salt[8];
-               size_t salt_len = 0;
+               uint8_t _salt[8];
+               size_t _salt_len = 0;
 
-               for (random_place = random_places;
-                    *random_place;
-                    random_place++) {
-                       FILE *random_file = fopen(*random_place, "r");
-                       if (random_file) {
-                               size_t read_bytes = 0;
+               if (salt) {
+                       _salt_len = strlen(salt);
+                       if (_salt_len > 8)
+                               _salt_len = 8;
+                       memcpy(_salt, salt, _salt_len);
+               } else {
+                       for (random_place = random_places;
+                            *random_place;
+                            random_place++) {
+                               FILE *random_file = fopen(*random_place, "r");
+                               if (random_file) {
+                                       size_t read_bytes = 0;
 
-                               while (read_bytes < sizeof(salt)) {
-                                       size_t n = fread(&cfg->key[read_bytes],
-                                                        1, KEY_SIZE - read_bytes,
-                                                        random_file);
-                                       read_bytes += n;
-                               }
+                                       while (read_bytes < sizeof(_salt)) {
+                                               size_t n = fread(&cfg->key[read_bytes],
+                                                                1, KEY_SIZE - read_bytes,
+                                                                random_file);
+                                               read_bytes += n;
+                                       }
 
-                               fclose(random_file);
+                                       fclose(random_file);
 
-                               salt_len = sizeof(salt);
+                                       _salt_len = sizeof(_salt);
 
-                               break; /* from for loop */
+                                       break; /* from for loop */
+                               }
                        }
                }
-               if (salt_len == 0) {
+               if (_salt_len == 0) {
                        /* There was no randomness files, so create a cheap
                           salt from time */
 #                       include <ykpbkdf2.h>
@@ -113,12 +121,12 @@ int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase)
                        yk_hmac_sha1.prf_fn(passphrase, strlen(passphrase),
                                            (char *)&t, sizeof(t),
                                            output, sizeof(output));
-                       memcpy(salt, output, sizeof(salt));
-                       salt_len = sizeof(salt);
+                       memcpy(_salt, output, sizeof(_salt));
+                       _salt_len = sizeof(_salt);
                }
 
                return yk_pbkdf2(passphrase,
-                                salt, salt_len,
+                                _salt, _salt_len,
                                 1024,
                                 cfg->key, sizeof(cfg->key),
                                 &yk_hmac_sha1);

diff --git a/ykpers.h b/ykpers.h
index 02dad5ce9abb4b871203eb36d027b04716ce10b0..3438f2947a50f50500ceccab94b1dfbdc752d36b 100644 (file)
--- a/ykpers.h
+++ b/ykpers.h
@@ -36,7 +36,8 @@
 CONFIG *ykp_create_config(void);
 int ykp_free_config(CONFIG *cfg);
 
-int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase);
+int ykp_AES_key_from_passphrase(CONFIG *cfg, const char *passphrase,
+                               const char *salt);
 int ykp_set_access_code(CONFIG *cfg, unsigned char *access_code);
 
 int ykp_write_config(const CONFIG *cfg,