[nrf fromlist] modules: mbedtls: Expose MBEDTLS_PLATFORM_NO_STD_FUNCTIONS

The commit adds Kconfig options that allows users to select
MBEDTLS_PLATFORM_NO_STD_FUNCTIONS configuration options.
Currently selecting the CONFIG_MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
will enable MBEDTLS_PLATFORM_NO_STD_FUNCTIONS and
MBEDTLS_PLATFORM_SNPRINTF_ALT.

Upstream PR #: 87135

Signed-off-by: Dominik Ermel <[email protected]>

Author: de-nordic

modules/mbedtls/Kconfig.tls-generic

@@ -406,6 +406,14 @@ config MBEDTLS_GENPRIME_ENABLED
 config MBEDTLS_ASN1_PARSE_C
 	bool "Support for ASN1 parser functions"
 
+config MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
+	bool "Use mbedTLS provided standard functions"
+	help
+	  This replaces, within mbedTLS, usage of functions like alloc, calloc,
+	  free, snprintf, or printf with mbedTLS specific implantations.
+	  This option may be useful if system is compiled in without some
+	  of these functions, as mbedTLS may provide own implementations.
+
 config MBEDTLS_PEM_CERTIFICATE_FORMAT
 	bool "Support for PEM certificate format"
 	help

modules/mbedtls/configs/config-tls-generic.h

@@ -23,6 +23,11 @@
 #define MBEDTLS_PLATFORM_ZEROIZE_ALT
 #endif
 
+#if defined(CONFIG_MBEDTLS_PLATFORM_NO_STD_FUNCTIONS)
+#define MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
+#define MBEDTLS_PLATFORM_SNPRINTF_ALT
+#endif
+
 #if defined(CONFIG_MBEDTLS_ENTROPY_POLL_ZEPHYR)
 #define MBEDTLS_ENTROPY_HARDWARE_ALT
 #else