bcrypt: Fix DSA public key export when we don't have a private key handle.

dlls/bcrypt/gnutls.c

@@ -107,6 +107,8 @@ static int (*pgnutls_pubkey_import_dsa_raw)(gnutls_pubkey_t, const gnutls_datum_
 static int (*pgnutls_pubkey_import_privkey)(gnutls_pubkey_t, gnutls_privkey_t, unsigned int, unsigned int);
 
 /* Not present in gnutls version < 3.3.0 */
+static int (*pgnutls_pubkey_export_dsa_raw)(gnutls_pubkey_t, gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *,
+                                            gnutls_datum_t *);
 static int (*pgnutls_pubkey_export_rsa_raw)(gnutls_pubkey_t, gnutls_datum_t *, gnutls_datum_t *);
 static int (*pgnutls_privkey_export_ecc_raw)(gnutls_privkey_t, gnutls_ecc_curve_t *,
                                              gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *);
@@ -167,6 +169,12 @@ static int compat_gnutls_pubkey_export_ecc_raw(gnutls_pubkey_t key, gnutls_ecc_c
     return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
 }
 
+static int compat_gnutls_pubkey_export_dsa_raw(gnutls_pubkey_t key, gnutls_datum_t *p, gnutls_datum_t *q,
+                                               gnutls_datum_t *g, gnutls_datum_t *y)
+{
+    return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
+}
+
 static int compat_gnutls_pubkey_export_rsa_raw(gnutls_pubkey_t key, gnutls_datum_t *m, gnutls_datum_t *e)
 {
     return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
@@ -305,6 +313,7 @@ static NTSTATUS gnutls_process_attach( void *args )
 
     LOAD_FUNCPTR_OPT(gnutls_cipher_tag)
     LOAD_FUNCPTR_OPT(gnutls_cipher_add_auth)
+    LOAD_FUNCPTR_OPT(gnutls_pubkey_export_dsa_raw)
     LOAD_FUNCPTR_OPT(gnutls_pubkey_export_ecc_raw)
     LOAD_FUNCPTR_OPT(gnutls_pubkey_export_rsa_raw)
     LOAD_FUNCPTR_OPT(gnutls_pubkey_import_ecc_raw)
@@ -740,7 +749,14 @@ static NTSTATUS key_export_dsa_public( struct key *key, UCHAR *buf, ULONG len, U
     UCHAR *dst;
     int ret;
 
-    if ((ret = pgnutls_privkey_export_dsa_raw( key_data(key)->a.privkey, &p, &q, &g, &y, NULL )))
+    if (key_data(key)->a.pubkey)
+        ret = pgnutls_pubkey_export_dsa_raw( key_data(key)->a.pubkey, &p, &q, &g, &y );
+    else if (key_data(key)->a.privkey)
+        ret = pgnutls_privkey_export_dsa_raw( key_data(key)->a.privkey, &p, &q, &g, &y, NULL );
+    else
+        return STATUS_INVALID_PARAMETER;
+
+    if (ret)
     {
         pgnutls_perror( ret );
         return STATUS_INTERNAL_ERROR;
@@ -805,7 +821,14 @@ static NTSTATUS key_export_dsa_capi_public( struct key *key, UCHAR *buf, ULONG l
         return STATUS_NOT_IMPLEMENTED;
     }
 
-    if ((ret = pgnutls_privkey_export_dsa_raw( key_data(key)->a.privkey, &p, &q, &g, &y, NULL )))
+    if (key_data(key)->a.pubkey)
+        ret = pgnutls_pubkey_export_dsa_raw( key_data(key)->a.pubkey, &p, &q, &g, &y );
+    else if (key_data(key)->a.privkey)
+        ret = pgnutls_privkey_export_dsa_raw( key_data(key)->a.privkey, &p, &q, &g, &y, NULL );
+    else
+        return STATUS_INVALID_PARAMETER;
+
+    if (ret)
     {
         pgnutls_perror( ret );
         return STATUS_INTERNAL_ERROR;
@@ -1123,6 +1146,8 @@ static NTSTATUS key_export_dsa_capi( struct key *key, UCHAR *buf, ULONG len, ULO
     UCHAR *dst;
     int ret, size;
 
+    if (!key_data(key)->a.privkey) return STATUS_INVALID_PARAMETER;
+
     if ((ret = pgnutls_privkey_export_dsa_raw( key_data(key)->a.privkey, &p, &q, &g, &y, &x )))
     {
         pgnutls_perror( ret );

dlls/bcrypt/tests/bcrypt.c

@@ -2902,7 +2902,7 @@ static void test_DSA(void)
     UCHAR sig[40], schemes;
     ULONG len, size;
     NTSTATUS ret;
-    BYTE *buf;
+    BYTE *buf, buf2[sizeof(BCRYPT_DSA_KEY_BLOB) + sizeof(dsaPublicBlob)];
 
     ret = BCryptOpenAlgorithmProvider(&alg, BCRYPT_DSA_ALGORITHM, NULL, 0);
     ok(!ret, "got %#lx\n", ret);
@@ -2917,6 +2917,17 @@ static void test_DSA(void)
     ret = BCryptImportKeyPair(alg, NULL, BCRYPT_DSA_PUBLIC_BLOB, &key, dsaPublicBlob, sizeof(dsaPublicBlob), 0);
     ok(!ret, "got %#lx\n", ret);
 
+    memset(buf2, 0xcc, sizeof(buf2));
+    ret = BCryptExportKey(key, NULL, BCRYPT_DSA_PUBLIC_BLOB, buf2, sizeof(buf2), &size, 0);
+    ok(!ret, "got %#lx\n", ret);
+    dsablob = (BCRYPT_DSA_KEY_BLOB *)buf2;
+    ok(dsablob->dwMagic == BCRYPT_DSA_PUBLIC_MAGIC, "got %#lx\n", dsablob->dwMagic);
+    ok(dsablob->cbKey == 64, "got %lu\n", dsablob->cbKey);
+    ok(size == sizeof(*dsablob) + dsablob->cbKey * 3, "got %lu\n", size);
+
+    ret = BCryptExportKey(key, NULL, BCRYPT_DSA_PRIVATE_BLOB, buf2, sizeof(buf2), &size, 0);
+    todo_wine ok(ret == STATUS_INVALID_PARAMETER, "got %#lx\n", ret);
+
     ret = BCryptVerifySignature(key, NULL, dsaHash, sizeof(dsaHash), dsaSignature, sizeof(dsaSignature), 0);
     ok(!ret, "got %#lx\n", ret);