lib: add crypt subsystem

Add the basic functionality required to support the standard crypt
format.
The files crypt-sha256.c and crypt-sha512.c originate from libxcrypt and
their formatting is therefor retained.
The integration is done via a crypt_compare() function in crypt.c.

```
libxcrypt $ git describe --long --always --all
tags/v4.4.17-0-g6b110bc
```

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/crypt/crypt-port.h b/lib/crypt/crypt-port.h
new file mode 100644
index 0000000000..680ffe9349
--- /dev/null
+++ b/lib/crypt/crypt-port.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright (C) 2020 Steffen Jaeckel <jaeckel-floss@eyet-services.de> */
+
+#include <linux/types.h>
+#include <vsprintf.h>
+
+#define NO_GENSALT
+#define CRYPT_OUTPUT_SIZE 384
+#define ALG_SPECIFIC_SIZE 8192
+
+#define ARG_UNUSED(x) (x)
+
+#define static_assert(a, b) _Static_assert(a, b)
+
+#define strtoul(cp, endp, base) simple_strtoul(cp, endp, base)
+
+extern const unsigned char ascii64[65];
+
+#define b64t ((const char *)ascii64)
+
+void crypt_sha256crypt_rn(const char *phrase, size_t phr_size,
+			  const char *setting, size_t ARG_UNUSED(set_size),
+			  uint8_t *output, size_t out_size, void *scratch,
+			  size_t scr_size);
+void crypt_sha512crypt_rn(const char *phrase, size_t phr_size,
+			  const char *setting, size_t ARG_UNUSED(set_size),
+			  uint8_t *output, size_t out_size, void *scratch,
+			  size_t scr_size);