25519 psa single init

boot/bootutil/include/bootutil/crypto/backend.h

@@ -0,0 +1,33 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ */
+
+#ifndef __BOOTUTIL_CRYPTO_BACKEND_H__
+#define __BOOTUTIL_CRYPTO_BACKEND_H__
+
+#if defined(MCUBOOT_CRYPTO_BACKEND_HAS_INIT)
+/* Backend specific implementation for crypto subsystem
+ * initialization.
+ * MCUboot is supposed to call this function before
+ * any crypto operation, including sha functions,
+ * is executed.
+ * Returns true on success. The function can also just fault
+ * and topple entire boot process.
+ */
+bool bootutil_crypto_backend_init(void);
+
+/* Backend specific implementation for crypto subsystem
+ * deinitialization.
+ * No more cryptographic operations are expected to be
+ * invoked by MCUboot after this founction is called.
+ * Returns true on success.
+ */
+bool bootutil_crypto_backend_deinit(void);
+#else
+#define bootutil_crypto_backend_init() (true)
+#define bootutil_crypto_backend_deinit() (true)
+#endif
+
+#endif /* __BOOTUTIL_CRYPTO_BACKEND_H__ */

boot/bootutil/src/ed25519_psa.c

@@ -19,6 +19,16 @@ BOOT_LOG_MODULE_REGISTER(ed25519_psa);
 #define EDDSA_KEY_LENGTH        32
 #define EDDSA_SIGNAGURE_LENGTH  64
 
+int bootutil_crypto_backend_init(void)
+{
+    psa_status_t status = psa_crypto_init();
+    if (status != PSA_SUCCESS) {
+        BOOT_LOG_ERR("PSA crypto init failed %d\n", status);
+        return false;
+    }
+    return true;
+}
+
 int ED25519_verify(const uint8_t *message, size_t message_len,
                    const uint8_t signature[EDDSA_SIGNAGURE_LENGTH],
                    const uint8_t public_key[EDDSA_KEY_LENGTH])
@@ -31,13 +41,6 @@ int ED25519_verify(const uint8_t *message, size_t message_len,
 
     BOOT_LOG_DBG("ED25519_verify: PSA implementation");
 
-    /* Initialize PSA Crypto */
-    status = psa_crypto_init();
-    if (status != PSA_SUCCESS) {
-        BOOT_LOG_ERR("PSA crypto init failed %d\n", status);
-        return 0;
-    }
-
     status = PSA_ERROR_BAD_STATE;
 
     psa_set_key_type(&key_attr,

boot/bootutil/src/encrypted_psa.c

@@ -188,13 +188,6 @@ parse_priv_enckey(uint8_t **p, uint8_t *end, uint8_t *private_key)
 
 void bootutil_aes_ctr_init(bootutil_aes_ctr_context *ctx)
 {
-    psa_status_t psa_ret = psa_crypto_init();
-
-    if (psa_ret != PSA_SUCCESS) {
-        BOOT_LOG_ERR("AES init PSA crypto init failed %d", psa_ret);
-        assert(0);
-    }
-
     ctx->key = PSA_KEY_ID_NULL;
 }
 
@@ -266,12 +259,6 @@ boot_decrypt_key(const uint8_t *buf, uint8_t *enckey)
 
     BOOT_LOG_DBG("boot_decrypt_key: PSA ED25519");
 
-    psa_ret = psa_crypto_init();
-    if (psa_ret != PSA_SUCCESS) {
-        BOOT_LOG_ERR("PSA crypto init failed %d", psa_ret);
-        return -1;
-    }
-
     /*
      * * Load the stored decryption private key
      */
@@ -431,16 +418,6 @@ int bootutil_aes_ctr_encrypt(bootutil_aes_ctr_context *ctx, uint8_t *counter,
     psa_cipher_operation_t psa_op;
     size_t elen = 0;	/* Decrypted length */
 
-    /* Fixme: calling psa_crypto_init multiple times is not a problem,
-     * yet the code here is only present because there is not general
-     * crypto init. */
-    psa_ret = psa_crypto_init();
-    if (psa_ret != PSA_SUCCESS) {
-        BOOT_LOG_ERR("PSA crypto init failed %d", psa_ret);
-        ret = -1;
-        goto gone;
-    }
-
     psa_op = psa_cipher_operation_init();
 
     /* This could be done with psa_cipher_decrypt one-shot operation, but
@@ -488,16 +465,6 @@ int bootutil_aes_ctr_decrypt(bootutil_aes_ctr_context *ctx, uint8_t *counter,
     psa_cipher_operation_t psa_op;
     size_t dlen = 0;	/* Decrypted length */
 
-    /* Fixme: the init should already happen before calling the function, but
-     * somehow it does not, for example when recovering in swap.
-     */
-    psa_ret = psa_crypto_init();
-    if (psa_ret != PSA_SUCCESS) {
-        BOOT_LOG_ERR("PSA crypto init failed %d", psa_ret);
-        ret = -1;
-        goto gone;
-    }
-
     psa_op = psa_cipher_operation_init();
 
     /* This could be done with psa_cipher_decrypt one-shot operation, but

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -51,6 +51,10 @@
 #define MCUBOOT_USE_PSA_CRYPTO
 #endif
 
+#if defined(MCUBOOT_SIGN_ED25519) && defined(MCUBOOT_USE_PSA_CRYPTO)
+#define MCUBOOT_CRYPTO_BACKEND_HAS_INIT
+#endif
+
 #ifdef CONFIG_BOOT_IMG_HASH_ALG_SHA512
 #define MCUBOOT_SHA512
 #endif

boot/zephyr/main.c

@@ -46,6 +46,7 @@
 #include "bootutil/boot_hooks.h"
 #include "bootutil/fault_injection_hardening.h"
 #include "bootutil/mcuboot_status.h"
+#include "bootutil/crypto/backend.h"
 #include "flash_map_backend/flash_map_backend.h"
 
 #if defined(CONFIG_MCUBOOT_UUID_VID) || defined(CONFIG_MCUBOOT_UUID_CID)
@@ -496,6 +497,7 @@ static void boot_serial_enter()
 
 int main(void)
 {
+    bool crypto_ok;
     struct boot_rsp rsp;
     int rc;
 #if defined(CONFIG_BOOT_USB_DFU_GPIO) || defined(CONFIG_BOOT_USB_DFU_WAIT)
@@ -512,6 +514,12 @@ int main(void)
     BOOT_LOG_INF("Starting Direct-XIP bootloader");
 #endif
 
+    crypto_ok = bootutil_crypto_backend_init();
+    if (!crypto_ok) {
+        BOOT_LOG_ERR("Failed to initialize crypto backend");
+        FIH_PANIC;
+    }
+
 #ifdef CONFIG_MCUBOOT_INDICATION_LED
     /* LED init */
     io_led_init();