Add multiple fixes for ffc key generation using invalid p,q,g parameters.

Fixes #11864

- The dsa keygen assumed valid p, q, g values were being passed. If this is not correct then it is
  possible that dsa keygen can either hang or segfault.
  The fix was to do a partial validation of p, q, and g inside the keygen.
- Fixed a potential double free in the dsa keypair test in the case when in failed (It should never fail!).
  It freed internal object members without setting them to NULL.
- Changed the FFC key validation to accept 1024 bit keys in non fips mode.
- Added tests that use both the default provider & fips provider to test these cases.
Reviewed-by: NDmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/12176)

crypto/dh/dh_key.c

@@ -287,6 +287,10 @@ static int generate_key(DH *dh)
             } else
 #endif
             {
+                /* Do a partial check for invalid p, q, g */
+                if (!ffc_params_simple_validate(dh->libctx, &dh->params,
+                                                FFC_PARAM_TYPE_DH))
+                    goto err;
                 /*
                  * For FFC FIPS 186-4 keygen
                  * security strength s = 112,

crypto/dsa/dsa_key.c

@@ -74,6 +74,11 @@ static int dsa_keygen(DSA *dsa, int pairwise_test)
         priv_key = dsa->priv_key;
     }
 
+    /* Do a partial check for invalid p, q, g */
+    if (!ffc_params_simple_validate(dsa->libctx, &dsa->params,
+                                    FFC_PARAM_TYPE_DSA))
+        goto err;
+
     /*
      * For FFC FIPS 186-4 keygen
      * security strength s = 112,
@@ -110,6 +115,8 @@ static int dsa_keygen(DSA *dsa, int pairwise_test)
         if (!ok) {
             BN_free(dsa->pub_key);
             BN_clear_free(dsa->priv_key);
+            dsa->pub_key = NULL;
+            dsa->priv_key = NULL;
             BN_CTX_free(ctx);
             return ok;
         }

crypto/ffc/ffc_params_generate.c

@@ -39,6 +39,11 @@
  */
 static int ffc_validate_LN(size_t L, size_t N, int type)
 {
+#ifndef FIPS_MODULE
+    if (L == 1024 && N == 160)
+        return 80;
+#endif
+
     if (type == FFC_PARAM_TYPE_DH) {
         /* Valid DH L,N parameters from SP800-56Ar3 5.5.1 Table 1 */
         if (L == 2048 && (N == 224 || N == 256))
@@ -498,6 +503,7 @@ int ffc_params_FIPS186_4_gen_verify(OPENSSL_CTX *libctx, FFC_PARAMS *params,
     EVP_MD *md = NULL;
     int verify = (mode == FFC_PARAM_MODE_VERIFY);
     unsigned int flags = verify ? params->flags : 0;
+    const char *def_name;
 
     *res = 0;
 
@@ -506,7 +512,10 @@ int ffc_params_FIPS186_4_gen_verify(OPENSSL_CTX *libctx, FFC_PARAMS *params,
     } else {
         if (N == 0)
             N = (L >= 2048 ? SHA256_DIGEST_LENGTH : SHA_DIGEST_LENGTH) * 8;
-        md = EVP_MD_fetch(libctx, default_mdname(N), NULL);
+        def_name = default_mdname(N);
+        if (def_name == NULL)
+            goto err;
+        md = EVP_MD_fetch(libctx, def_name, NULL);
     }
     if (md == NULL)
         goto err;

crypto/ffc/ffc_params_validate.c

@@ -78,3 +78,29 @@ int ffc_params_FIPS186_2_validate(OPENSSL_CTX *libctx, const FFC_PARAMS *params,
                                            FFC_PARAM_MODE_VERIFY, type,
                                            L, N, res, cb);
 }
+
+/*
+ * This does a simple check of L and N and partial g.
+ * It makes no attempt to do a full validation of p, q or g since these require
+ * extra parameters such as the digest and seed, which may not be available for
+ * this test.
+ */
+int ffc_params_simple_validate(OPENSSL_CTX *libctx, FFC_PARAMS *params, int type)
+{
+    int ret, res = 0;
+    int save_gindex;
+    unsigned int save_flags;
+
+    if (params == NULL)
+        return 0;
+
+    save_flags = params->flags;
+    save_gindex = params->gindex;
+    params->flags = FFC_PARAM_FLAG_VALIDATE_G;
+    params->gindex = FFC_UNVERIFIABLE_GINDEX;
+
+    ret = ffc_params_FIPS186_4_validate(libctx, params, type, &res, NULL);
+    params->flags = save_flags;
+    params->gindex = save_gindex;
+    return ret != FFC_PARAM_RET_STATUS_FAILED;
+}

include/internal/ffc.h

@@ -155,6 +155,7 @@ int ffc_params_FIPS186_2_gen_verify(OPENSSL_CTX *libctx, FFC_PARAMS *params,
                                     int mode, int type, size_t L, size_t N,
                                     int *res, BN_GENCB *cb);
 
+int ffc_params_simple_validate(OPENSSL_CTX *libctx, FFC_PARAMS *params, int type);
 int ffc_params_FIPS186_4_validate(OPENSSL_CTX *libctx, const FFC_PARAMS *params,
                                   int type, int *res, BN_GENCB *cb);
 int ffc_params_FIPS186_2_validate(OPENSSL_CTX *libctx, const FFC_PARAMS *params,

test/build.info

@@ -36,7 +36,7 @@ IF[{- !$disabled{tests} -}]
           destest mdc2test \
           enginetest exptest \
           evp_pkey_provided_test evp_test evp_extra_test evp_extra_test2 \
-          evp_fetch_prov_test acvp_test \
+          evp_fetch_prov_test acvp_test evp_libctx_test \
           v3nametest v3ext \
           evp_pkey_provided_test evp_test evp_extra_test evp_extra_test2 \
           evp_fetch_prov_test v3nametest v3ext \
@@ -141,6 +141,10 @@ IF[{- !$disabled{tests} -}]
   INCLUDE[evp_extra_test2]=../include ../apps/include
   DEPEND[evp_extra_test2]=../libcrypto libtestutil.a
 
+  SOURCE[evp_libctx_test]=evp_libctx_test.c
+  INCLUDE[evp_libctx_test]=../include ../apps/include
+  DEPEND[evp_libctx_test]=../libcrypto.a libtestutil.a
+
   SOURCE[evp_fetch_prov_test]=evp_fetch_prov_test.c
   INCLUDE[evp_fetch_prov_test]=../include ../apps/include
   DEPEND[evp_fetch_prov_test]=../libcrypto libtestutil.a

test/evp_libctx_test.c

+/*
+ * Copyright 2020 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
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+
+ * These tests are setup to load null into the default library context.
+ * Any tests are expected to use the created 'libctx' to find algorithms.
+ * The framework runs the tests twice using the 'default' provider or
+ * 'fips' provider as inputs.
+ */
+
+/*
+ * DSA/DH low level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+#include <openssl/evp.h>
+#include <openssl/provider.h>
+#include <openssl/dsa.h>
+#include "testutil.h"
+#include "internal/nelem.h"
+#include "crypto/bn_dh.h"        /* _bignum_ffdhe2048_p */
+
+static OPENSSL_CTX *libctx = NULL;
+static OSSL_PROVIDER *nullprov = NULL;
+static OSSL_PROVIDER *libprov = NULL;
+
+typedef enum OPTION_choice {
+    OPT_ERR = -1,
+    OPT_EOF = 0,
+    OPT_CONFIG_FILE,
+    OPT_PROVIDER_NAME,
+    OPT_TEST_ENUM
+} OPTION_CHOICE;
+
+const OPTIONS *test_get_options(void)
+{
+    static const OPTIONS test_options[] = {
+        OPT_TEST_OPTIONS_DEFAULT_USAGE,
+        { "config", OPT_CONFIG_FILE, '<',
+          "The configuration file to use for the libctx" },
+        { "provider", OPT_PROVIDER_NAME, 's',
+          "The provider to load (The default value is 'default'" },
+        { NULL }
+    };
+    return test_options;
+}
+
+#if !defined(OPENSSL_NO_DSA) || !defined(OPENSSL_NO_DH)
+static const char *getname(int id)
+{
+    const char *name[] = {"p", "q", "g" };
+
+    if (id >= 0 && id < 3)
+        return name[id];
+    return "?";
+}
+#endif
+
+#ifndef OPENSSL_NO_DSA
+
+static int test_dsa_param_keygen(int tstid)
+{
+    int ret = 0;
+    int expected;
+    EVP_PKEY_CTX *gen_ctx = NULL;
+    EVP_PKEY *pkey_parm = NULL;
+    EVP_PKEY *pkey = NULL;
+    DSA *dsa = NULL;
+    int pind, qind, gind;
+    BIGNUM *p = NULL, *q = NULL, *g = NULL;
+
+    /*
+     * Just grab some fixed dh p, q, g values for testing,
+     * these 'safe primes' should not be used normally for dsa *.
+     */
+    static const BIGNUM *bn[] = {
+        &_bignum_dh2048_256_p,  &_bignum_dh2048_256_q, &_bignum_dh2048_256_g
+    };
+
+    /*
+     * These tests are using bad values for p, q, g by reusing the values.
+     * A value of 0 uses p, 1 uses q and 2 uses g.
+     * There are 27 different combinations, with only the 1 valid combination.
+     */
+    pind = tstid / 9;
+    qind = (tstid / 3) % 3;
+    gind = tstid % 3;
+    expected  = (pind == 0 && qind == 1 && gind == 2);
+
+    TEST_note("Testing with (p, q, g) = (%s, %s, %s)\n", getname(pind),
+              getname(qind), getname(gind));
+
+    if (!TEST_ptr(pkey_parm = EVP_PKEY_new())
+        || !TEST_ptr(dsa = DSA_new())
+        || !TEST_ptr(p = BN_dup(bn[pind]))
+        || !TEST_ptr(q = BN_dup(bn[qind]))
+        || !TEST_ptr(g = BN_dup(bn[gind]))
+        || !TEST_true(DSA_set0_pqg(dsa, p, q, g)))
+        goto err;
+    p = q = g = NULL;
+
+    if (!TEST_true(EVP_PKEY_assign_DSA(pkey_parm, dsa)))
+        goto err;
+    dsa = NULL;
+
+    if (!TEST_ptr(gen_ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey_parm, NULL))
+        || !TEST_int_gt(EVP_PKEY_keygen_init(gen_ctx), 0)
+        || !TEST_int_eq(EVP_PKEY_keygen(gen_ctx, &pkey), expected))
+        goto err;
+    ret = 1;
+err:
+    EVP_PKEY_free(pkey);
+    EVP_PKEY_CTX_free(gen_ctx);
+    EVP_PKEY_free(pkey_parm);
+    DSA_free(dsa);
+    BN_free(g);
+    BN_free(q);
+    BN_free(p);
+    return ret;
+}
+#endif /* OPENSSL_NO_DSA */
+
+#ifndef OPENSSL_NO_DH
+static int do_dh_param_keygen(int tstid, const BIGNUM **bn)
+{
+    int ret = 0;
+    int expected;
+    EVP_PKEY_CTX *gen_ctx = NULL;
+    EVP_PKEY *pkey_parm = NULL;
+    EVP_PKEY *pkey = NULL;
+    DH *dh = NULL;
+    int pind, qind, gind;
+    BIGNUM *p = NULL, *q = NULL, *g = NULL;
+
+    /*
+     * These tests are using bad values for p, q, g by reusing the values.
+     * A value of 0 uses p, 1 uses q and 2 uses g.
+     * There are 27 different combinations, with only the 1 valid combination.
+     */
+    pind = tstid / 9;
+    qind = (tstid / 3) % 3;
+    gind = tstid % 3;
+    expected  = (pind == 0 && qind == 1 && gind == 2);
+
+    TEST_note("Testing with (p, q, g) = (%s, %s, %s)", getname(pind),
+              getname(qind), getname(gind));
+
+    if (!TEST_ptr(pkey_parm = EVP_PKEY_new())
+        || !TEST_ptr(dh = DH_new())
+        || !TEST_ptr(p = BN_dup(bn[pind]))
+        || !TEST_ptr(q = BN_dup(bn[qind]))
+        || !TEST_ptr(g = BN_dup(bn[gind]))
+        || !TEST_true(DH_set0_pqg(dh, p, q, g)))
+        goto err;
+    p = q = g = NULL;
+
+    if (!TEST_true(EVP_PKEY_assign_DH(pkey_parm, dh)))
+        goto err;
+    dh = NULL;
+
+    if (!TEST_ptr(gen_ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey_parm, NULL))
+        || !TEST_int_gt(EVP_PKEY_keygen_init(gen_ctx), 0)
+        || !TEST_int_eq(EVP_PKEY_keygen(gen_ctx, &pkey), expected))
+        goto err;
+    ret = 1;
+err:
+    EVP_PKEY_free(pkey);
+    EVP_PKEY_CTX_free(gen_ctx);
+    EVP_PKEY_free(pkey_parm);
+    DH_free(dh);
+    BN_free(g);
+    BN_free(q);
+    BN_free(p);
+    return ret;
+}
+
+/*
+ * Note that we get the fips186-4 path being run for most of these cases since
+ * the internal code will detect that the p, q, g does not match a safe prime
+ * group (Except for when tstid = 5, which sets the correct p, q, g)
+ */
+static int test_dh_safeprime_param_keygen(int tstid)
+{
+    static const BIGNUM *bn[] = {
+        &_bignum_ffdhe2048_p,  &_bignum_ffdhe2048_q, &_bignum_const_2
+    };
+    return do_dh_param_keygen(tstid, bn);
+}
+
+#endif /* OPENSSL_NO_DH */
+
+int setup_tests(void)
+{
+    const char *prov_name = "default";
+    char *config_file = NULL;
+    OPTION_CHOICE o;
+
+    while ((o = opt_next()) != OPT_EOF) {
+        switch (o) {
+        case OPT_PROVIDER_NAME:
+            prov_name = opt_arg();
+            break;
+        case OPT_CONFIG_FILE:
+            config_file = opt_arg();
+            break;
+        case OPT_TEST_CASES:
+           break;
+        default:
+        case OPT_ERR:
+            return 0;
+        }
+    }
+
+    nullprov = OSSL_PROVIDER_load(NULL, "null");
+    if (!TEST_ptr(nullprov))
+        return 0;
+
+    libctx = OPENSSL_CTX_new();
+
+    if (!TEST_ptr(libctx))
+        return 0;
+
+    if (config_file != NULL) {
+        if (!TEST_true(OPENSSL_CTX_load_config(libctx, config_file)))
+            return 0;
+    }
+
+    libprov = OSSL_PROVIDER_load(libctx, prov_name);
+    if (!TEST_ptr(libprov))
+        return 0;
+
+#ifndef OPENSSL_NO_DSA
+    ADD_ALL_TESTS(test_dsa_param_keygen, 3 * 3 * 3);
+#endif
+#ifndef OPENSSL_NO_DH
+    ADD_ALL_TESTS(test_dh_safeprime_param_keygen, 3 * 3 * 3);
+#endif
+    return 1;
+}
+
+void cleanup_tests(void)
+{
+    OSSL_PROVIDER_unload(libprov);
+    OPENSSL_CTX_free(libctx);
+    OSSL_PROVIDER_unload(nullprov);
+}

test/ffc_internal_test.c

@@ -399,13 +399,6 @@ static int ffc_params_fips186_2_gen_validate_test(void)
                                                  FFC_PARAM_TYPE_DH,
                                                  &res, NULL)))
         goto err;
-    /* FIPS 186-4 L,N pair test will fail for DH */
-    if (!TEST_false(ffc_params_FIPS186_4_validate(NULL, &params,
-                                                  FFC_PARAM_TYPE_DH,
-                                                  &res, NULL)))
-        goto err;
-    if (!TEST_int_eq(res, FFC_CHECK_BAD_LN_PAIR))
-        goto err;
 
     /*
      * The fips186-2 generation should produce a different q compared to

test/recipes/30-test_evp_libctx.t

+#! /usr/bin/env perl
+# Copyright 2020 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
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+use strict;
+use warnings;
+
+use OpenSSL::Test qw(:DEFAULT bldtop_dir srctop_dir srctop_file bldtop_file);
+use OpenSSL::Test::Utils;
+
+BEGIN {
+    setup("test_evp_libctx");
+}
+
+my $no_fips = disabled('fips') || ($ENV{NO_FIPS} // 0);
+
+use lib srctop_dir('Configurations');
+use lib bldtop_dir('.');
+use platform;
+
+my $infile = bldtop_file('providers', platform->dso('fips'));
+# If no fips then run the test with no extra arguments.
+my @test_args = ( );
+
+plan tests =>
+    ($no_fips ? 0 : 1)          # FIPS install test
+    + 1;
+
+unless ($no_fips) {
+    @test_args = ("-config", srctop_file("test","fips.cnf"),
+                  "-provider", "fips");
+
+    ok(run(app(['openssl', 'fipsinstall',
+               '-out', bldtop_file('providers', 'fipsmodule.cnf'),
+               '-module', $infile,
+               '-provider_name', 'fips', '-mac_name', 'HMAC',
+               '-macopt', 'digest:SHA256', '-macopt', 'hexkey:00',
+               '-section_name', 'fips_sect'])),
+       "fipsinstall");
+}
+
+ok(run(test(["evp_libctx_test", @test_args])), "running evp_libctx_test");