bcrypt: Add support for retrieving DH parameters.

dlls/bcrypt/bcrypt_internal.h

@@ -285,6 +285,8 @@ struct key_asymmetric_verify_params
 
 #define KEY_EXPORT_FLAG_PUBLIC        0x00000001
 #define KEY_EXPORT_FLAG_RSA_FULL      0x00000002
+#define KEY_EXPORT_FLAG_DH_PARAMETERS 0x00000004
+
 struct key_asymmetric_export_params
 {
     struct key  *key;

dlls/bcrypt/bcrypt_main.c

@@ -917,6 +917,20 @@ static NTSTATUS get_hash_property( const struct hash *hash, const WCHAR *prop, U
     return status;
 }
 
+static NTSTATUS get_dh_property( const struct key *key, const WCHAR *prop, UCHAR *buf, ULONG size, ULONG *ret_size )
+{
+    struct key_asymmetric_export_params params;
+
+    if (wcscmp( prop, BCRYPT_DH_PARAMETERS )) return STATUS_NOT_SUPPORTED;
+
+    params.key     = (struct key *)key;
+    params.flags   = KEY_EXPORT_FLAG_DH_PARAMETERS;
+    params.buf     = buf;
+    params.len     = size;
+    params.ret_len = ret_size;
+    return UNIX_CALL( key_asymmetric_export, &params );
+}
+
 static NTSTATUS get_key_property( const struct key *key, const WCHAR *prop, UCHAR *buf, ULONG size, ULONG *ret_size )
 {
     if (!wcscmp( prop, BCRYPT_KEY_STRENGTH ))
@@ -940,6 +954,9 @@ static NTSTATUS get_key_property( const struct key *key, const WCHAR *prop, UCHA
         if (!wcscmp( prop, BCRYPT_AUTH_TAG_LENGTH )) return STATUS_NOT_SUPPORTED;
         return get_aes_property( key->u.s.mode, prop, buf, size, ret_size );
 
+    case ALG_ID_DH:
+        return get_dh_property( key, prop, buf, size, ret_size );
+
     default:
         FIXME( "unsupported algorithm %u\n", key->alg_id );
         return STATUS_NOT_IMPLEMENTED;

dlls/bcrypt/gnutls.c

@@ -1651,8 +1651,7 @@ static NTSTATUS key_export_dh( struct key *key, UCHAR *buf, ULONG len, ULONG *re
         return STATUS_INTERNAL_ERROR;
     }
 
-    ret = pgnutls_privkey_export_dh_raw( key_data(key)->a.privkey, params, &y, &x, 0 );
-    if (ret)
+    if ((ret = pgnutls_privkey_export_dh_raw( key_data(key)->a.privkey, params, &y, &x, 0 )))
     {
         pgnutls_perror( ret );
         pgnutls_dh_params_deinit( params );
@@ -1686,6 +1685,40 @@ static NTSTATUS key_export_dh( struct key *key, UCHAR *buf, ULONG len, ULONG *re
     return STATUS_SUCCESS;
 }
 
+static NTSTATUS key_export_dh_params( struct key *key, UCHAR *buf, ULONG len, ULONG *ret_len )
+{
+    BCRYPT_DH_PARAMETER_HEADER *hdr = (BCRYPT_DH_PARAMETER_HEADER *)buf;
+    unsigned int size = sizeof(*hdr) + key->u.a.bitlen / 8 * 2;
+    gnutls_datum_t p, g;
+    NTSTATUS status = STATUS_SUCCESS;
+    UCHAR *dst;
+    int ret;
+
+    if (!key_data(key)->a.dh_params) return STATUS_INVALID_PARAMETER;
+
+    if ((ret = pgnutls_dh_params_export_raw( key_data(key)->a.dh_params, &p, &g, NULL )))
+    {
+        pgnutls_perror( ret );
+        return STATUS_INTERNAL_ERROR;
+    }
+
+    *ret_len = size;
+    if (len < size) status = STATUS_BUFFER_TOO_SMALL;
+    else if (buf)
+    {
+        hdr->cbLength    = size;
+        hdr->dwMagic     = BCRYPT_DH_PARAMETERS_MAGIC;
+        hdr->cbKeyLength = key->u.a.bitlen / 8;
+
+        dst = (UCHAR *)(hdr + 1);
+        dst += export_gnutls_datum( dst, hdr->cbKeyLength, &p, 1 );
+        dst += export_gnutls_datum( dst, hdr->cbKeyLength, &g, 1 );
+    }
+
+    free( p.data ); free( g.data );
+    return status;
+}
+
 static NTSTATUS key_asymmetric_export( void *args )
 {
     const struct key_asymmetric_export_params *params = args;
@@ -1720,6 +1753,8 @@ static NTSTATUS key_asymmetric_export( void *args )
         return STATUS_NOT_IMPLEMENTED;
 
     case ALG_ID_DH:
+        if (flags & KEY_EXPORT_FLAG_DH_PARAMETERS)
+            return key_export_dh_params( key, params->buf, params->len, params->ret_len );
         if (flags & KEY_EXPORT_FLAG_PUBLIC)
             return key_export_dh_public( key, params->buf, params->len, params->ret_len );
         return key_export_dh( key, params->buf, params->len, params->ret_len );