PBKDF2 updates to conform to SP800-132

The existing code used PKCS5 specifications.
SP800-132 adds the following additional constraints for:
  - the range of the key length.
  - the minimum iteration count (1000 recommended).
  - salt length (at least 128 bits).
These additional constraints may cause errors (in scrypt, and
some PKCS5 related test vectors). To disable the new
constraints use the new ctrl string "pkcs5".
For backwards compatability, the checks are only enabled by
default for fips mode.

Reviewed-by: Matt Caswell <[email protected]>
(Merged from openssl#8868)

CHANGES

@@ -9,6 +9,15 @@
 
  Changes between 1.1.1 and 3.0.0 [xx XXX xxxx]
 
+  *) Change PBKDF2 to conform to SP800-132 instead of the older PKCS5 RFC2898.
+     This checks that the salt length is at least 128 bits, the derived key
+     length is at least 112 bits, and that the iteration count is at least 1000.
+     For backwards compatibility these checks are disabled by default in the
+     default provider, but are enabled by default in the fips provider.
+     To enable or disable these checks use the control
+     EVP_KDF_CTRL_SET_PBKDF2_PKCS5_MODE.
+     [Shane Lontis]
+
   *) Default cipher lists/suites are now avaialble via a function, the
      #defines are deprecated.
      [Todd Short]
@@ -30,7 +39,7 @@
   *) Added command 'openssl kdf' that uses the EVP_KDF API.
      [Shane Lontis]
 
-   *) Added command 'openssl mac' that uses the EVP_MAC API.
+  *) Added command 'openssl mac' that uses the EVP_MAC API.
      [Shane Lontis]
 
   *) Added OPENSSL_info() to get diverse built-in OpenSSL data, such

crypto/err/openssl.txt

@@ -895,6 +895,7 @@ KDF_F_KDF_HKDF_DERIVE:113:kdf_hkdf_derive
 KDF_F_KDF_HKDF_NEW:114:kdf_hkdf_new
 KDF_F_KDF_HKDF_SIZE:115:kdf_hkdf_size
 KDF_F_KDF_MD2CTRL:116:kdf_md2ctrl
+KDF_F_KDF_PBKDF2_CTRL:140:kdf_pbkdf2_ctrl
 KDF_F_KDF_PBKDF2_CTRL_STR:117:kdf_pbkdf2_ctrl_str
 KDF_F_KDF_PBKDF2_DERIVE:118:kdf_pbkdf2_derive
 KDF_F_KDF_PBKDF2_NEW:119:kdf_pbkdf2_new
@@ -910,6 +911,7 @@ KDF_F_KDF_SSHKDF_NEW:133:kdf_sshkdf_new
 KDF_F_KDF_TLS1_PRF_CTRL_STR:125:kdf_tls1_prf_ctrl_str
 KDF_F_KDF_TLS1_PRF_DERIVE:126:kdf_tls1_prf_derive
 KDF_F_KDF_TLS1_PRF_NEW:127:kdf_tls1_prf_new
+KDF_F_PBKDF2_DERIVE:141:pbkdf2_derive
 KDF_F_PBKDF2_SET_MEMBUF:128:pbkdf2_set_membuf
 KDF_F_PKEY_HKDF_CTRL_STR:103:pkey_hkdf_ctrl_str
 KDF_F_PKEY_HKDF_DERIVE:102:pkey_hkdf_derive
@@ -2458,7 +2460,10 @@ EVP_R_WRONG_FINAL_BLOCK_LENGTH:109:wrong final block length
 EVP_R_XTS_DATA_UNIT_IS_TOO_LARGE:191:xts data unit is too large
 EVP_R_XTS_DUPLICATED_KEYS:192:xts duplicated keys
 KDF_R_INVALID_DIGEST:100:invalid digest
+KDF_R_INVALID_ITERATION_COUNT:119:invalid iteration count
+KDF_R_INVALID_KEY_LEN:120:invalid key len
 KDF_R_INVALID_MAC_TYPE:116:invalid mac type
+KDF_R_INVALID_SALT_LEN:121:invalid salt len
 KDF_R_MISSING_ITERATION_COUNT:109:missing iteration count
 KDF_R_MISSING_KEY:104:missing key
 KDF_R_MISSING_MESSAGE_DIGEST:105:missing message digest

crypto/evp/p5_crpt2.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1999-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -40,6 +40,7 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
     if (kctx == NULL)
         return 0;
     if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_PASS, pass, (size_t)passlen) != 1
+            || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_PBKDF2_PKCS5_MODE, 1) != 1
             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SALT,
                             salt, (size_t)saltlen) != 1
             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_ITER, iter) != 1

crypto/kdf/kdf_err.c

@@ -19,6 +19,7 @@ static const ERR_STRING_DATA KDF_str_functs[] = {
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_HKDF_NEW, 0), "kdf_hkdf_new"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_HKDF_SIZE, 0), "kdf_hkdf_size"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_MD2CTRL, 0), "kdf_md2ctrl"},
+    {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_PBKDF2_CTRL, 0), "kdf_pbkdf2_ctrl"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_PBKDF2_CTRL_STR, 0),
      "kdf_pbkdf2_ctrl_str"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_PBKDF2_DERIVE, 0), "kdf_pbkdf2_derive"},
@@ -41,6 +42,7 @@ static const ERR_STRING_DATA KDF_str_functs[] = {
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_TLS1_PRF_DERIVE, 0),
      "kdf_tls1_prf_derive"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_KDF_TLS1_PRF_NEW, 0), "kdf_tls1_prf_new"},
+    {ERR_PACK(ERR_LIB_KDF, KDF_F_PBKDF2_DERIVE, 0), "pbkdf2_derive"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_PBKDF2_SET_MEMBUF, 0), "pbkdf2_set_membuf"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_PKEY_HKDF_CTRL_STR, 0), "pkey_hkdf_ctrl_str"},
     {ERR_PACK(ERR_LIB_KDF, KDF_F_PKEY_HKDF_DERIVE, 0), "pkey_hkdf_derive"},
@@ -71,7 +73,11 @@ static const ERR_STRING_DATA KDF_str_functs[] = {
 
 static const ERR_STRING_DATA KDF_str_reasons[] = {
     {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_INVALID_DIGEST), "invalid digest"},
+    {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_INVALID_ITERATION_COUNT),
+    "invalid iteration count"},
+    {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_INVALID_KEY_LEN), "invalid key len"},
     {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_INVALID_MAC_TYPE), "invalid mac type"},
+    {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_INVALID_SALT_LEN), "invalid salt len"},
     {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_MISSING_ITERATION_COUNT),
     "missing iteration count"},
     {ERR_PACK(ERR_LIB_KDF, 0, KDF_R_MISSING_KEY), "missing key"},

crypto/kdf/pbkdf2.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2018-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -17,12 +17,27 @@
 #include "internal/evp_int.h"
 #include "kdf_local.h"
 
+/* Constants specified in SP800-132 */
+#define KDF_PBKDF2_MIN_KEY_LEN_BITS  112
+#define KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO 0xFFFFFFFF
+#define KDF_PBKDF2_MIN_ITERATIONS 1000
+#define KDF_PBKDF2_MIN_SALT_LEN   (128 / 8)
+/*
+ * For backwards compatibility reasons,
+ * Extra checks are done by default in fips mode only.
+ */
+#ifdef FIPS_MODE
+# define KDF_PBKDF2_DEFAULT_CHECKS 1
+#else
+# define KDF_PBKDF2_DEFAULT_CHECKS 0
+#endif /* FIPS_MODE */
+
 static void kdf_pbkdf2_reset(EVP_KDF_IMPL *impl);
 static void kdf_pbkdf2_init(EVP_KDF_IMPL *impl);
-static int pkcs5_pbkdf2_alg(const char *pass, size_t passlen,
-                            const unsigned char *salt, int saltlen, int iter,
-                            const EVP_MD *digest, unsigned char *key,
-                            size_t keylen);
+static int  pbkdf2_derive(const char *pass, size_t passlen,
+                          const unsigned char *salt, int saltlen, int iter,
+                          const EVP_MD *digest, unsigned char *key,
+                          size_t keylen, int extra_checks);
 
 struct evp_kdf_impl_st {
     unsigned char *pass;
@@ -31,6 +46,7 @@ struct evp_kdf_impl_st {
     size_t salt_len;
     int iter;
     const EVP_MD *md;
+    int lower_bound_checks;
 };
 
 static EVP_KDF_IMPL *kdf_pbkdf2_new(void)
@@ -64,6 +80,7 @@ static void kdf_pbkdf2_init(EVP_KDF_IMPL *impl)
 {
     impl->iter = PKCS5_DEFAULT_ITER;
     impl->md = EVP_sha1();
+    impl->lower_bound_checks = KDF_PBKDF2_DEFAULT_CHECKS;
 }
 
 static int pbkdf2_set_membuf(unsigned char **buffer, size_t *buflen,
@@ -91,12 +108,16 @@ static int pbkdf2_set_membuf(unsigned char **buffer, size_t *buflen,
 
 static int kdf_pbkdf2_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
 {
-    int iter;
+    int iter, pkcs5, min_iter;
     const unsigned char *p;
     size_t len;
     const EVP_MD *md;
 
     switch (cmd) {
+    case EVP_KDF_CTRL_SET_PBKDF2_PKCS5_MODE:
+        pkcs5 = va_arg(args, int);
+        impl->lower_bound_checks = (pkcs5 == 0) ? 1 : 0;
+        return 1;
     case EVP_KDF_CTRL_SET_PASS:
         p = va_arg(args, const unsigned char *);
         len = va_arg(args, size_t);
@@ -105,20 +126,28 @@ static int kdf_pbkdf2_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
     case EVP_KDF_CTRL_SET_SALT:
         p = va_arg(args, const unsigned char *);
         len = va_arg(args, size_t);
+        if (impl->lower_bound_checks != 0 && len < KDF_PBKDF2_MIN_SALT_LEN) {
+            KDFerr(KDF_F_KDF_PBKDF2_CTRL, KDF_R_INVALID_SALT_LEN);
+            return 0;
+        }
         return pbkdf2_set_membuf(&impl->salt, &impl->salt_len, p, len);
 
     case EVP_KDF_CTRL_SET_ITER:
         iter = va_arg(args, int);
-        if (iter < 1)
+        min_iter = impl->lower_bound_checks != 0 ? KDF_PBKDF2_MIN_ITERATIONS : 1;
+        if (iter < min_iter) {
+            KDFerr(KDF_F_KDF_PBKDF2_CTRL, KDF_R_INVALID_ITERATION_COUNT);
             return 0;
-
+        }
         impl->iter = iter;
         return 1;
 
     case EVP_KDF_CTRL_SET_MD:
         md = va_arg(args, const EVP_MD *);
-        if (md == NULL)
+        if (md == NULL) {
+            KDFerr(KDF_F_KDF_PBKDF2_CTRL, KDF_R_VALUE_MISSING);
             return 0;
+        }
 
         impl->md = md;
         return 1;
@@ -159,6 +188,9 @@ static int kdf_pbkdf2_ctrl_str(EVP_KDF_IMPL *impl, const char *type,
     if (strcmp(type, "digest") == 0)
         return kdf_md2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_MD, value);
 
+    if (strcmp(type, "pkcs5") == 0)
+        return kdf_str2ctrl(impl, kdf_pbkdf2_ctrl,
+                            EVP_KDF_CTRL_SET_PBKDF2_PKCS5_MODE, value);
     return -2;
 }
 
@@ -175,9 +207,9 @@ static int kdf_pbkdf2_derive(EVP_KDF_IMPL *impl, unsigned char *key,
         return 0;
     }
 
-    return pkcs5_pbkdf2_alg((char *)impl->pass, impl->pass_len,
-                            impl->salt, impl->salt_len, impl->iter,
-                            impl->md, key, keylen);
+    return pbkdf2_derive((char *)impl->pass, impl->pass_len,
+                         impl->salt, impl->salt_len, impl->iter,
+                         impl->md, key, keylen, impl->lower_bound_checks);
 }
 
 const EVP_KDF pbkdf2_kdf_meth = {
@@ -195,12 +227,16 @@ const EVP_KDF pbkdf2_kdf_meth = {
  * This is an implementation of PKCS#5 v2.0 password based encryption key
  * derivation function PBKDF2. SHA1 version verified against test vectors
  * posted by Peter Gutmann to the PKCS-TNG mailing list.
+ *
+ * The constraints specified by SP800-132 have been added i.e.
+ *  - Check the range of the key length.
+ *  - Minimum iteration count of 1000.
+ *  - Randomly-generated portion of the salt shall be at least 128 bits.
  */
-
-static int pkcs5_pbkdf2_alg(const char *pass, size_t passlen,
-                            const unsigned char *salt, int saltlen, int iter,
-                            const EVP_MD *digest, unsigned char *key,
-                            size_t keylen)
+static int pbkdf2_derive(const char *pass, size_t passlen,
+                         const unsigned char *salt, int saltlen, int iter,
+                         const EVP_MD *digest, unsigned char *key,
+                         size_t keylen, int lower_bound_checks)
 {
     int ret = 0;
     unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
@@ -209,8 +245,32 @@ static int pkcs5_pbkdf2_alg(const char *pass, size_t passlen,
     HMAC_CTX *hctx_tpl = NULL, *hctx = NULL;
 
     mdlen = EVP_MD_size(digest);
-    if (mdlen < 0)
+    if (mdlen <= 0)
+        return 0;
+
+    /*
+     * This check should always be done because keylen / mdlen >= (2^32 - 1)
+     * results in an overflow of the loop counter 'i'.
+     */
+    if ((keylen / mdlen) >= KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO) {
+        KDFerr(KDF_F_PBKDF2_DERIVE, KDF_R_INVALID_KEY_LEN);
         return 0;
+    }
+
+    if (lower_bound_checks) {
+         if ((keylen * 8) < KDF_PBKDF2_MIN_KEY_LEN_BITS) {
+             KDFerr(KDF_F_PBKDF2_DERIVE, KDF_R_INVALID_KEY_LEN);
+             return 0;
+         }
+         if (saltlen < KDF_PBKDF2_MIN_SALT_LEN) {
+             KDFerr(KDF_F_PBKDF2_DERIVE, KDF_R_INVALID_SALT_LEN);
+            return 0;
+         }
+         if (iter < KDF_PBKDF2_MIN_ITERATIONS) {
+             KDFerr(KDF_F_PBKDF2_DERIVE, KDF_R_INVALID_ITERATION_COUNT);
+             return 0;
+         }
+    }
 
     hctx_tpl = HMAC_CTX_new();
     if (hctx_tpl == NULL)

doc/man7/EVP_KDF_PBKDF2.pod

@@ -10,7 +10,7 @@ Support for computing the B<PBKDF2> password-based KDF through the B<EVP_KDF>
 API.
 
 The EVP_KDF_PBKDF2 algorithm implements the PBKDF2 password-based key
-derivation function, as described in RFC 2898; it derives a key from a password
+derivation function, as described in SP800-132; it derives a key from a password
 using a salt and iteration count.
 
 =head2 Numeric identity
@@ -30,13 +30,38 @@ The supported controls are:
 
 =item B<EVP_KDF_CTRL_SET_ITER>
 
+This control has a default value of 2048.
+
 =item B<EVP_KDF_CTRL_SET_MD>
 
 These controls work as described in L<EVP_KDF_CTX(3)/CONTROLS>.
 
-B<iter> is the iteration count and its value should be greater than or equal to
-1. RFC 2898 suggests an iteration count of at least 1000.  The default value is
-2048.  Any B<iter> less than 1 is treated as a single iteration.
+=item B<EVP_KDF_CTRL_SET_PBKDF2_PKCS5_MODE>
+
+This control expects one argument: C<int mode>
+
+This control can be used to enable or disable SP800-132 compliance checks.
+
+Setting the mode to 0 enables the compliance checks.
+
+The checks performed are:
+
+=over 4
+
+=item - the iteration count is at least 1000.
+
+=item - the salt length is at least 128 bits.
+
+=item - the derived key length is at least 112 bits.
+
+=back
+
+The default provider uses a default mode of 1 for backwards compatibility,
+and the fips provider uses a default mode of 0.
+
+EVP_KDF_ctrl_str() type string: "pkcs5"
+
+The value string is expected to be a decimal number 0 or 1.
 
 =back
 
@@ -55,7 +80,7 @@ byte sequence.
 
 =head1 CONFORMING TO
 
-RFC 2898
+SP800-132
 
 =head1 SEE ALSO
 
@@ -66,9 +91,13 @@ L<EVP_KDF_ctrl(3)>,
 L<EVP_KDF_derive(3)>,
 L<EVP_KDF_CTX(3)/CONTROLS>
 
+=head1 HISTORY
+
+This functionality was added to OpenSSL 3.0.0.
+
 =head1 COPYRIGHT
 
-Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2018-2019 The OpenSSL Project Authors. All Rights Reserved.
 
 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy