psa: Add PSA Crypto configuration

Add an option that can enable the exposure of PSA Crypto APIs from
libmbedcrypto.

include/mbedtls/check_config.h

@@ -496,6 +496,12 @@
 #error "MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO and MBEDTLS_PLATFORM_STD_NV_SEED_WRITE cannot be defined simultaneously"
 #endif
 
+#if defined(MBEDTLS_PSA_CRYPTO_C) &&            \
+    !( defined(MBEDTLS_CTR_DRBG_C) &&           \
+       defined(MBEDTLS_ENTROPY_C) )
+#error "MBEDTLS_PSA_CRYPTO_C defined, but not all prerequisites"
+#endif
+
 #if defined(MBEDTLS_RSA_C) && ( !defined(MBEDTLS_BIGNUM_C) ||         \
     !defined(MBEDTLS_OID_C) )
 #error "MBEDTLS_RSA_C defined, but not all prerequisites"

include/mbedtls/config.h

@@ -2590,6 +2590,25 @@
  */
 #define MBEDTLS_POLY1305_C
 
+/**
+ * \def MBEDTLS_PSA_CRYPTO_C
+ *
+ * Enable the Platform Security Architecture cryptography API.
+ *
+ * \note This option only has an effect when the build option
+ * USE_CRYPTO_SUBMODULE is also in use.
+ *
+ * \warning This feature is experimental and available on an opt-in basis only.
+ * PSA APIs are subject to change at any time. The implementation comes with
+ * less assurance and support than the rest of Mbed TLS.
+ *
+ * Module:  crypto/library/psa_crypto.c
+ *
+ * Requires: MBEDTLS_CTR_DRBG_C, MBEDTLS_ENTROPY_C
+ *
+ */
+//#define MBEDTLS_PSA_CRYPTO_C
+
 /**
  * \def MBEDTLS_RIPEMD160_C
  *

library/version_features.c

@@ -681,6 +681,9 @@ static const char *features[] = {
 #if defined(MBEDTLS_POLY1305_C)
     "MBEDTLS_POLY1305_C",
 #endif /* MBEDTLS_POLY1305_C */
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+    "MBEDTLS_PSA_CRYPTO_C",
+#endif /* MBEDTLS_PSA_CRYPTO_C */
 #if defined(MBEDTLS_RIPEMD160_C)
     "MBEDTLS_RIPEMD160_C",
 #endif /* MBEDTLS_RIPEMD160_C */

scripts/config.pl

@@ -28,6 +28,7 @@
 #   MBEDTLS_ECP_DP_M511_ENABLED
 #   MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
 #   MBEDTLS_NO_PLATFORM_ENTROPY
+#   MBEDTLS_PSA_CRYPTO_C
 #   MBEDTLS_REMOVE_ARC4_CIPHERSUITES
 #   MBEDTLS_SSL_HW_RECORD_ACCEL
 #   MBEDTLS_RSA_NO_CRT
@@ -87,6 +88,7 @@ MBEDTLS_ECP_DP_M383_ENABLED
 MBEDTLS_ECP_DP_M511_ENABLED
 MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
 MBEDTLS_NO_PLATFORM_ENTROPY
+MBEDTLS_PSA_CRYPTO_C
 MBEDTLS_RSA_NO_CRT
 MBEDTLS_REMOVE_ARC4_CIPHERSUITES
 MBEDTLS_SSL_HW_RECORD_ACCEL