crypto/gc-pbkdf2: New module.

* MODULES.html.sh (func_all_modules): Add gc-pbkdf2.
* NEWS: Deprecated gc-pbkdf2-sha1 in favor of gc-pbkdf2.
* lib/gc-pbkdf2.c: New file.
* lib/gc-pbkdf2-sha1.c: Use new interface.
* lib/gc.h (GC_MAX_DIGEST_SIZE, gc_pbkdf2_hmac): Add.
* modules/crypto/gc-pbkdf2: New file.
* modules/crypto/gc-pbkdf2-tests: New file.
* tests/test-gc-pbkdf2.c: New file.

1 files changed, 138 insertions, 0 deletions

diff --git a/lib/gc-pbkdf2.c b/lib/gc-pbkdf2.c
new file mode 100644
index 0000000000..297b348093
--- /dev/null
+++ b/lib/gc-pbkdf2.c
@@ -0,0 +1,138 @@
+/* gc-pbkdf2.c --- Password-Based Key Derivation Function a'la PKCS#5
+   Copyright (C) 2002-2006, 2009-2020 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Simon Josefsson. */
+
+#include <config.h>
+
+#include "gc.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+typedef Gc_rc (*gc_prf_func) (const void *key, size_t keylen,
+                              const void *in, size_t inlen, char *resbuf);
+
+static Gc_rc
+gc_pbkdf2_prf (gc_prf_func prf, size_t hLen,
+               const char *P, size_t Plen,
+               const char *S, size_t Slen,
+               unsigned int c,
+               char *DK, size_t dkLen)
+{
+  char U[GC_MAX_DIGEST_SIZE];
+  char T[GC_MAX_DIGEST_SIZE];
+  unsigned int u;
+  unsigned int l;
+  unsigned int r;
+  unsigned int i;
+  unsigned int k;
+  int rc;
+  char *tmp;
+  size_t tmplen = Slen + 4;
+
+  if (c == 0)
+    return GC_PKCS5_INVALID_ITERATION_COUNT;
+
+  if (dkLen == 0)
+    return GC_PKCS5_INVALID_DERIVED_KEY_LENGTH;
+
+  if (dkLen > 4294967295U)
+    return GC_PKCS5_DERIVED_KEY_TOO_LONG;
+
+  l = ((dkLen - 1) / hLen) + 1;
+  r = dkLen - (l - 1) * hLen;
+
+  tmp = malloc (tmplen);
+  if (tmp == NULL)
+    return GC_MALLOC_ERROR;
+
+  memcpy (tmp, S, Slen);
+
+  for (i = 1; i <= l; i++)
+    {
+      memset (T, 0, hLen);
+
+      for (u = 1; u <= c; u++)
+        {
+          if (u == 1)
+            {
+              tmp[Slen + 0] = (i & 0xff000000) >> 24;
+              tmp[Slen + 1] = (i & 0x00ff0000) >> 16;
+              tmp[Slen + 2] = (i & 0x0000ff00) >> 8;
+              tmp[Slen + 3] = (i & 0x000000ff) >> 0;
+
+              rc = prf (P, Plen, tmp, tmplen, U);
+            }
+          else
+            rc = prf (P, Plen, U, hLen, U);
+
+          if (rc != GC_OK)
+            {
+              free (tmp);
+              return rc;
+            }
+
+          for (k = 0; k < hLen; k++)
+            T[k] ^= U[k];
+        }
+
+      memcpy (DK + (i - 1) * hLen, T, i == l ? r : hLen);
+    }
+
+  free (tmp);
+
+  return GC_OK;
+}
+
+Gc_rc
+gc_pbkdf2_hmac (Gc_hash hash,
+                const char *P, size_t Plen,
+                const char *S, size_t Slen,
+                unsigned int c, char *DK, size_t dkLen)
+{
+  gc_prf_func prf;
+  size_t hLen;
+
+  switch (hash)
+    {
+#if GNULIB_GC_HMAC_SHA1
+    case GC_SHA1:
+      prf = gc_hmac_sha1;
+      hLen = GC_SHA1_DIGEST_SIZE;
+      break;
+#endif
+
+#if GNULIB_GC_HMAC_SHA256
+    case GC_SHA256:
+      prf = gc_hmac_sha256;
+      hLen = GC_SHA256_DIGEST_SIZE;
+      break;
+#endif
+
+#if GNULIB_GC_HMAC_SHA512
+    case GC_SHA512:
+      prf = gc_hmac_sha512;
+      hLen = GC_SHA512_DIGEST_SIZE;
+      break;
+#endif
+
+    default:
+      return GC_INVALID_HASH;
+    }
+
+  return gc_pbkdf2_prf (prf, hLen, P, Plen, S, Slen, c, DK, dkLen);
+}