Fix PBKDF2 speed calculation for large passhrases.

- Do not reset key each iteration.
- Fix error path.

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@84 36d66b0a-2a48-0410-832c-cd162a569da5

diff --git a/ChangeLog b/ChangeLog
index c80b288..5799f5f 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+2009-08-17  Milan Broz  <mbroz@redhat.com>
+       * Fix PBKDF2 speed calculation for large passhrases
+
 2009-07-30  Milan Broz  <mbroz@redhat.com>
        * Fix errors when compiled with LUKS_DEBUG.
        * Print error when getline fails.

diff --git a/luks/pbkdf.c b/luks/pbkdf.c
index 5633cd1..9581095 100644 (file)
--- a/luks/pbkdf.c
+++ b/luks/pbkdf.c
@@ -81,18 +81,17 @@ static int pkcs5_pbkdf2(const char *hash,
                        char *DK, int perfcheck)
 {
        gcry_md_hd_t prf;
-       gcry_error_t err;
        char U[MAX_PRF_BLOCK_LEN];
        char T[MAX_PRF_BLOCK_LEN];
-       int PRF;
-       unsigned int u;
-       unsigned int hLen;
-       unsigned int l;
-       unsigned int r;
-       int rc;
+       int PRF, i, k, rc = -EINVAL;
+       unsigned int u, hLen, l, r;
        unsigned char *p;
-       int i;
-       int k;
+       size_t tmplen = Slen + 4;
+       char *tmp;
+
+       tmp = alloca(tmplen);
+       if (tmp == NULL)
+               return -ENOMEM;
 
        if (init_crypto())
                return -ENOSYS;
@@ -181,28 +180,19 @@ static int pkcs5_pbkdf2(const char *hash,
         *
         */
 
-       err = gcry_md_open(&prf, PRF, GCRY_MD_FLAG_HMAC);
-       if (err)
+       if(gcry_md_open(&prf, PRF, GCRY_MD_FLAG_HMAC))
                return -EINVAL;
 
+       if (gcry_md_setkey(prf, P, Plen))
+               goto out;
+
        for (i = 1; (uint) i <= l; i++) {
                memset(T, 0, hLen);
 
                for (u = 1; u <= c ; u++) {
                        gcry_md_reset(prf);
 
-                       rc = gcry_md_setkey(prf, P, Plen);
-                       if (rc)
-                               return -EINVAL;
-
                        if (u == 1) {
-                               char *tmp;
-                               size_t tmplen = Slen + 4;
-
-                               tmp = alloca(tmplen);
-                               if (tmp == NULL)
-                                       return -ENOMEM;
-
                                memcpy(tmp, S, Slen);
                                tmp[Slen + 0] = (i & 0xff000000) >> 24;
                                tmp[Slen + 1] = (i & 0x00ff0000) >> 16;
@@ -216,15 +206,17 @@ static int pkcs5_pbkdf2(const char *hash,
 
                        p = gcry_md_read(prf, PRF);
                        if (p == NULL)
-                               return -EINVAL;
+                               goto out;
 
                        memcpy(U, p, hLen);
 
                        for (k = 0; (uint) k < hLen; k++)
                                T[k] ^= U[k];
 
-                       if (perfcheck && __PBKDF2_performance)
+                       if (perfcheck && __PBKDF2_performance) {
+                               rc = 0;
                                goto out;
+                       }
 
                        if (perfcheck)
                                __PBKDF2_global_j--;
@@ -232,10 +224,10 @@ static int pkcs5_pbkdf2(const char *hash,
 
                memcpy(DK + (i - 1) * hLen, T, (uint) i == l ? r : hLen);
        }
+       rc = 0;
 out:
        gcry_md_close(prf);
-
-       return 0;
+       return rc;
 }
 
 int PBKDF2_HMAC(const char *hash,