kdf: Add One-Step KDF with hash.

* src/gcrypt.h.in (GCRY_KDF_ONESTEP_KDF): New.
* cipher/kdf.c (onestep_kdf_open, onestep_kdf_compute): New.
(onestep_kdf_final): New.
(_gcry_kdf_open, _gcry_kdf_compute, _gcry_kdf_final): Add
GCRY_KDF_ONESTEP_KDF support.
* tests/t-kdf.c (check_onestep_kdf): Add the test.
(main): Call check_onestep_kdf.

--

GnuPG-bug-id: 5964
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

3 files changed, 237 insertions, 6 deletions

diff --git a/cipher/kdf.c b/cipher/kdf.c
index 0e196432..01a28667 100644
--- a/cipher/kdf.c
+++ b/cipher/kdf.c
@@ -1382,8 +1382,123 @@ balloon_close (balloon_ctx_t b)
   wipememory (b, n);
   xfree (b);
 }
+
+typedef struct onestep_kdf_context *onestep_kdf_ctx_t;
+
+/* OneStepKDF context */
+struct onestep_kdf_context {
+  int algo;
+  gcry_md_hd_t md;
+  unsigned int blklen;
+  unsigned int outlen;
+  const void *input;
+  size_t inputlen;
+  const void *fixedinfo;
+  size_t fixedinfolen;
+};
+
+static gpg_err_code_t
+onestep_kdf_open (gcry_kdf_hd_t *hd, int hashalgo,
+                  const unsigned long *param, unsigned int paramlen,
+                  const void *input, size_t inputlen,
+                  const void *fixedinfo, size_t fixedinfolen)
+{
+  gpg_err_code_t ec;
+  unsigned int outlen;
+  onestep_kdf_ctx_t o;
+  size_t n;
+
+  if (paramlen != 1)
+    return GPG_ERR_INV_VALUE;
+  else
+    outlen = (unsigned int)param[0];
+
+  n = sizeof (struct onestep_kdf_context);
+  o = xtrymalloc (n);
+  if (!o)
+    return gpg_err_code_from_errno (errno);
 
+  o->blklen = _gcry_md_get_algo_dlen (hashalgo);
+  if (!o->blklen)
+    {
+      xfree (o);
+      return GPG_ERR_DIGEST_ALGO;
+    }
+  ec = _gcry_md_open (&o->md, hashalgo, 0);
+  if (ec)
+    {
+      xfree (o);
+      return ec;
+    }
+  o->algo = GCRY_KDF_ONESTEP_KDF;
+  o->outlen = outlen;
+  o->input = input;
+  o->inputlen = inputlen;
+  o->fixedinfo = fixedinfo;
+  o->fixedinfolen = fixedinfolen;
+
+  *hd = (void *)o;
+  return 0;
+}
 
+
+static gpg_err_code_t
+onestep_kdf_compute (onestep_kdf_ctx_t o, const struct gcry_kdf_thread_ops *ops)
+{
+  (void)o;
+
+  if (ops != NULL)
+    return GPG_ERR_INV_VALUE;
+
+  return 0;
+}
+
+static gpg_err_code_t
+onestep_kdf_final (onestep_kdf_ctx_t o, size_t resultlen, void *result)
+{
+  u32 counter = 0;
+  unsigned char cnt[4];
+  int i;
+
+  if (resultlen != o->outlen)
+    return GPG_ERR_INV_VALUE;
+
+  for (i = 0; i < o->outlen / o->blklen; i++)
+    {
+      counter++;
+      buf_put_be32 (cnt, counter);
+      _gcry_md_write (o->md, cnt, sizeof (cnt));
+      _gcry_md_write (o->md, o->input, o->inputlen);
+      _gcry_md_write (o->md, o->fixedinfo, o->fixedinfolen);
+      _gcry_md_final (o->md);
+      memcpy ((char *)result + o->blklen * i,
+              _gcry_md_read (o->md, 0), o->blklen);
+      resultlen -= o->blklen;
+      _gcry_md_reset (o->md);
+    }
+
+  if (resultlen)
+    {
+      counter++;
+      buf_put_be32 (cnt, counter);
+      _gcry_md_write (o->md, cnt, sizeof (cnt));
+      _gcry_md_write (o->md, o->input, o->inputlen);
+      _gcry_md_write (o->md, o->fixedinfo, o->fixedinfolen);
+      _gcry_md_final (o->md);
+      memcpy ((char *)result + o->blklen * i,
+              _gcry_md_read (o->md, 0), resultlen);
+    }
+
+  return 0;
+}
+
+static void
+onestep_kdf_close (onestep_kdf_ctx_t o)
+{
+  _gcry_md_close (o->md);
+  xfree (o);
+}
+
 struct gcry_kdf_handle {
   int algo;
   /* And algo specific parts come.  */
@@ -1392,7 +1507,7 @@ struct gcry_kdf_handle {
 gpg_err_code_t
 _gcry_kdf_open (gcry_kdf_hd_t *hd, int algo, int subalgo,
                 const unsigned long *param, unsigned int paramlen,
-                const void *passphrase, size_t passphraselen,
+                const void *input, size_t inputlen,
                 const void *salt, size_t saltlen,
                 const void *key, size_t keylen,
                 const void *ad, size_t adlen)
@@ -1402,23 +1517,35 @@ _gcry_kdf_open (gcry_kdf_hd_t *hd, int algo, int subalgo,
   switch (algo)
     {
     case GCRY_KDF_ARGON2:
-      if (!passphraselen || !saltlen)
+      if (!inputlen || !saltlen)
         ec = GPG_ERR_INV_VALUE;
       else
         ec = argon2_open (hd, subalgo, param, paramlen,
-                          passphrase, passphraselen, salt, saltlen,
+                          input, inputlen, salt, saltlen,
                           key, keylen, ad, adlen);
       break;
 
     case GCRY_KDF_BALLOON:
-      if (!passphraselen || !saltlen || keylen || adlen)
+      if (!inputlen || !saltlen || keylen || adlen)
         ec = GPG_ERR_INV_VALUE;
       else
         {
           (void)key;
           (void)ad;
           ec = balloon_open (hd, subalgo, param, paramlen,
-                             passphrase, passphraselen, salt, saltlen);
+                             input, inputlen, salt, saltlen);
+        }
+      break;
+
+    case GCRY_KDF_ONESTEP_KDF:
+      if (!inputlen || !paramlen || !adlen)
+        ec = GPG_ERR_INV_VALUE;
+      else
+        {
+          (void)salt;
+          (void)key;
+          ec = onestep_kdf_open (hd, subalgo, param, paramlen,
+                                 input, inputlen, ad, adlen);
         }
       break;
 
@@ -1445,6 +1572,10 @@ _gcry_kdf_compute (gcry_kdf_hd_t h, const struct gcry_kdf_thread_ops *ops)
       ec = balloon_compute_all ((balloon_ctx_t)(void *)h, ops);
       break;
 
+    case GCRY_KDF_ONESTEP_KDF:
+      ec = onestep_kdf_compute ((onestep_kdf_ctx_t)(void *)h, ops);
+      break;
+
     default:
       ec = GPG_ERR_UNKNOWN_ALGORITHM;
       break;
@@ -1469,6 +1600,10 @@ _gcry_kdf_final (gcry_kdf_hd_t h, size_t resultlen, void *result)
       ec = balloon_final ((balloon_ctx_t)(void *)h, resultlen, result);
       break;
 
+    case GCRY_KDF_ONESTEP_KDF:
+      ec = onestep_kdf_final ((onestep_kdf_ctx_t)(void *)h, resultlen, result);
+      break;
+
     default:
       ec = GPG_ERR_UNKNOWN_ALGORITHM;
       break;
@@ -1490,6 +1625,10 @@ _gcry_kdf_close (gcry_kdf_hd_t h)
       balloon_close ((balloon_ctx_t)(void *)h);
       break;
 
+    case GCRY_KDF_ONESTEP_KDF:
+      onestep_kdf_close ((onestep_kdf_ctx_t)(void *)h);
+      break;
+
     default:
       break;
     }
diff --git a/src/gcrypt.h.in b/src/gcrypt.h.in
index b17e242f..5879acaf 100644
--- a/src/gcrypt.h.in
+++ b/src/gcrypt.h.in
@@ -1592,8 +1592,21 @@ enum gcry_kdf_algos
     GCRY_KDF_PBKDF1 = 33,
     GCRY_KDF_PBKDF2 = 34,
     GCRY_KDF_SCRYPT = 48,
+    /**/
     GCRY_KDF_ARGON2   = 64,
-    GCRY_KDF_BALLOON  = 65
+    GCRY_KDF_BALLOON  = 65,
+    /**/
+    /* In the original SP 800-56A, it's called
+     * "Concatenation Key Derivation Function".
+     * Now (as of 2022), it's defined in SP 800-56C rev.2, as
+     * "One-Step Key Derivation".
+     */
+    GCRY_KDF_ONESTEP_KDF = 96, /* One-Step Key Derivation with hash */
+    /* One-Step Key Derivation with HMAC */
+    /* One-Step Key Derivation with KMAC */
+    /* Two-Step Key Derivation with HMAC */
+    /* Two-Step Key Derivation with CMAC */
+    /* KDF PRF in SP 800-108r1 */
   };
 
 enum gcry_kdf_subalgo_argon2
diff --git a/tests/t-kdf.c b/tests/t-kdf.c
index 234bbac6..49116d20 100644
--- a/tests/t-kdf.c
+++ b/tests/t-kdf.c
@@ -1603,6 +1603,84 @@ check_balloon (void)
 }
 
 
+static void
+check_onestep_kdf (void)
+{
+  gcry_error_t err;
+  const unsigned long param[2] = { 38, 68 };
+  unsigned char out[68];
+  unsigned char input[2][16] = {
+    {
+      0x3f, 0x89, 0x2b, 0xd8, 0xb8, 0x4d, 0xae, 0x64,
+      0xa7, 0x82, 0xa3, 0x5f, 0x6e, 0xaa, 0x8f, 0x00
+    },
+    {
+      0xe6, 0x5b, 0x19, 0x05, 0x87, 0x8b, 0x95, 0xf6,
+      0x8b, 0x55, 0x35, 0xbd, 0x3b, 0x2b, 0x10, 0x13
+    }
+  };
+  unsigned char other[2][12] = {
+    {
+      0xec, 0x3f, 0x1c, 0xd8, 0x73, 0xd2, 0x88, 0x58,
+      0xa5, 0x8c, 0xc3, 0x9e
+    },
+    {
+      0x83, 0x02, 0x21, 0xb1, 0x73, 0x0d, 0x91, 0x76,
+      0xf8, 0x07, 0xd4, 0x07
+    }
+  };
+  unsigned char expected[2][68] = {
+    {
+      0xa7, 0xc0, 0x66, 0x52, 0x98, 0x25, 0x25, 0x31,
+      0xe0, 0xdb, 0x37, 0x73, 0x7a, 0x37, 0x46, 0x51,
+      0xb3, 0x68, 0x27, 0x5f, 0x20, 0x48, 0x28, 0x4d,
+      0x16, 0xa1, 0x66, 0xc6, 0xd8, 0xa9, 0x0a, 0x91,
+      0xa4, 0x91, 0xc1, 0x6f, 0x49, 0x64
+    },
+    {
+      0xb8, 0xc4, 0x4b, 0xdf, 0x0b, 0x85, 0xa6, 0x4b,
+      0x6a, 0x51, 0xc1, 0x2a, 0x06, 0x71, 0x0e, 0x37,
+      0x3d, 0x82, 0x9b, 0xb1, 0xfd, 0xa5, 0xb4, 0xe1,
+      0xa2, 0x07, 0x95, 0xc6, 0x19, 0x95, 0x94, 0xf6,
+      0xfa, 0x65, 0x19, 0x8a, 0x72, 0x12, 0x57, 0xf7,
+      0xd5, 0x8c, 0xb2, 0xf6, 0xf6, 0xdb, 0x9b, 0xb5,
+      0x69, 0x9f, 0x73, 0x86, 0x30, 0x45, 0x90, 0x90,
+      0x54, 0xb2, 0x38, 0x9e, 0x06, 0xec, 0x00, 0xfe,
+      0x31, 0x8c, 0xab, 0xd9
+    },
+  };
+  int i;
+  int hashalgo[2] = { GCRY_MD_SHA256, GCRY_MD_SHA512 };
+  int count = 0;
+
+ again:
+
+  if (verbose)
+    fprintf (stderr, "checking OneStepKDF test vector %d\n", count);
+
+  err = my_kdf_derive (0,
+                       GCRY_KDF_ONESTEP_KDF, hashalgo[count], &param[count], 1,
+                       input[count], 16, NULL, 0, NULL, 0,
+                       other[count], 12,
+                       param[count], out);
+  if (err)
+    fail ("OneStepKDF test %d failed: %s\n", count, gpg_strerror (err));
+  else if (memcmp (out, expected[count], param[count]))
+    {
+      fail ("OneStepKDF test %d failed: mismatch\n", count*2+0);
+      fputs ("got:", stderr);
+      for (i=0; i < param[count]; i++)
+        fprintf (stderr, " %02x", out[i]);
+      putc ('\n', stderr);
+    }
+
+  /* Next test vector */
+  count++;
+  if (count < 2)
+    goto again;
+}
+
+
 int
 main (int argc, char **argv)
 {
@@ -1681,6 +1759,7 @@ main (int argc, char **argv)
       check_scrypt ();
       check_argon2 ();
       check_balloon ();
+      check_onestep_kdf ();
     }
 
   return error_count ? 1 : 0;