Crypto: Align PSA headers entirely to Mbed TLS 3.6.0

This also simplifies the client attributes translation between
client view and service view and reorganized how the Mbed TLS
config files are handled between NS/S (client/service) sides.
At the same time, perform a CMake targets refactoring to allow
exporting a client side view of the config files.

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: I9a715f9ef40fc223992575ecbac5cf23d162a326
diff --git a/interface/include/mbedtls/base64.h b/interface/include/mbedtls/base64.h
new file mode 100644
index 0000000..8f459b7
--- /dev/null
+++ b/interface/include/mbedtls/base64.h
@@ -0,0 +1,82 @@
+/**
+ * \file base64.h
+ *
+ * \brief RFC 1521 base64 encoding/decoding
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+#ifndef MBEDTLS_BASE64_H
+#define MBEDTLS_BASE64_H
+
+#include "mbedtls/build_info.h"
+
+#include <stddef.h>
+
+/** Output buffer too small. */
+#define MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL               -0x002A
+/** Invalid character in input. */
+#define MBEDTLS_ERR_BASE64_INVALID_CHARACTER              -0x002C
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief          Encode a buffer into base64 format
+ *
+ * \param dst      destination buffer
+ * \param dlen     size of the destination buffer
+ * \param olen     number of bytes written
+ * \param src      source buffer
+ * \param slen     amount of data to be encoded
+ *
+ * \return         0 if successful, or MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL.
+ *                 *olen is always updated to reflect the amount
+ *                 of data that has (or would have) been written.
+ *                 If that length cannot be represented, then no data is
+ *                 written to the buffer and *olen is set to the maximum
+ *                 length representable as a size_t.
+ *
+ * \note           Call this function with dlen = 0 to obtain the
+ *                 required buffer size in *olen
+ */
+int mbedtls_base64_encode(unsigned char *dst, size_t dlen, size_t *olen,
+                          const unsigned char *src, size_t slen);
+
+/**
+ * \brief          Decode a base64-formatted buffer
+ *
+ * \param dst      destination buffer (can be NULL for checking size)
+ * \param dlen     size of the destination buffer
+ * \param olen     number of bytes written
+ * \param src      source buffer
+ * \param slen     amount of data to be decoded
+ *
+ * \return         0 if successful, MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL, or
+ *                 MBEDTLS_ERR_BASE64_INVALID_CHARACTER if the input data is
+ *                 not correct. *olen is always updated to reflect the amount
+ *                 of data that has (or would have) been written.
+ *
+ * \note           Call this function with *dst = NULL or dlen = 0 to obtain
+ *                 the required buffer size in *olen
+ */
+int mbedtls_base64_decode(unsigned char *dst, size_t dlen, size_t *olen,
+                          const unsigned char *src, size_t slen);
+
+#if defined(MBEDTLS_SELF_TEST)
+/**
+ * \brief          Checkup routine
+ *
+ * \return         0 if successful, or 1 if the test failed
+ */
+int mbedtls_base64_self_test(int verbose);
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* base64.h */