fix(esp_tee): Snapshot input arguments in TEE memory before secure service execution

components/esp_security/src/esp_ds.c

@@ -326,11 +326,12 @@ esp_err_t esp_ds_start_sign(const void *message,
         return ESP_ERR_INVALID_ARG;
     }
 
-    if (!(data->rsa_length == ESP_DS_RSA_1024
-            || data->rsa_length == ESP_DS_RSA_2048
-            || data->rsa_length == ESP_DS_RSA_3072
+    const uint32_t rsa_length = data->rsa_length;
+    if (!(rsa_length == ESP_DS_RSA_1024
+            || rsa_length == ESP_DS_RSA_2048
+            || rsa_length == ESP_DS_RSA_3072
 #if SOC_RSA_MAX_BIT_LEN == 4096
-            || data->rsa_length == ESP_DS_RSA_4096
+            || rsa_length == ESP_DS_RSA_4096
 #endif
          )) {
         return ESP_ERR_INVALID_ARG;
@@ -384,7 +385,7 @@ esp_err_t esp_ds_start_sign(const void *message,
         return ESP_ERR_NO_MEM;
     }
 
-    size_t rsa_len = (data->rsa_length + 1) * 4;
+    size_t rsa_len = (rsa_length + 1) * 4;
     ds_hal_write_private_key_params(data->c);
     ds_hal_configure_iv((uint32_t *)data->iv);
     ds_hal_write_message(message, rsa_len);
@@ -409,20 +410,29 @@ esp_err_t esp_ds_finish_sign(void *signature, esp_ds_context_t *esp_ds_ctx)
     }
 
     const esp_ds_data_t *data = (const esp_ds_data_t *)esp_ds_ctx->data;
-    unsigned rsa_len = (data->rsa_length + 1) * 4;
+    esp_err_t return_value = ESP_ERR_INVALID_ARG;
 
     while (ds_hal_busy()) { }
 
-    ds_signature_check_t sig_check_result = ds_hal_read_result((uint8_t *) signature, (size_t) rsa_len);
+    uint32_t rsa_length = data->rsa_length;
+    if (rsa_length == ESP_DS_RSA_1024
+            || rsa_length == ESP_DS_RSA_2048
+            || rsa_length == ESP_DS_RSA_3072
+#if SOC_DS_SIGNATURE_MAX_BIT_LEN == 4096
+            || rsa_length == ESP_DS_RSA_4096
+#endif
+       ) {
+        unsigned rsa_len = (rsa_length + 1) * 4;
 
-    esp_err_t return_value = ESP_OK;
+        ds_signature_check_t res = ds_hal_read_result((uint8_t *) signature, (size_t) rsa_len);
 
-    if (sig_check_result == DS_SIGNATURE_MD_FAIL || sig_check_result == DS_SIGNATURE_PADDING_AND_MD_FAIL) {
-        return_value = ESP_ERR_HW_CRYPTO_DS_INVALID_DIGEST;
-    }
-
-    if (sig_check_result == DS_SIGNATURE_PADDING_FAIL) {
-        return_value = ESP_ERR_HW_CRYPTO_DS_INVALID_PADDING;
+        if (res == DS_SIGNATURE_MD_FAIL || res == DS_SIGNATURE_PADDING_AND_MD_FAIL) {
+            return_value = ESP_ERR_HW_CRYPTO_DS_INVALID_DIGEST;
+        } else if (res == DS_SIGNATURE_PADDING_FAIL) {
+            return_value = ESP_ERR_HW_CRYPTO_DS_INVALID_PADDING;
+        } else if (res == DS_SIGNATURE_OK) {
+            return_value = ESP_OK;
+        }
     }
 
 #if !ESP_TEE_BUILD

components/esp_tee/subproject/main/core/esp_secure_services.c

@@ -16,6 +16,8 @@
 #include "esp_crypto_periph_clk.h"
 #include "ecc_impl.h"
 
+#include "nvs.h"
+
 #include "esp_tee.h"
 #include "esp_tee_memory_utils.h"
 #include "esp_tee_aes_intr.h"
@@ -54,7 +56,8 @@ int _ss_esp_aes_crypt_cbc(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_cbc(ctx, mode, length, iv, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_cbc(&ctx_local, mode, length, iv, input, output);
 }
 
 int _ss_esp_aes_crypt_cfb128(esp_aes_context *ctx,
@@ -76,7 +79,8 @@ int _ss_esp_aes_crypt_cfb128(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_cfb128(ctx, mode, length, iv_off, iv, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_cfb128(&ctx_local, mode, length, iv_off, iv, input, output);
 }
 
 int _ss_esp_aes_crypt_cfb8(esp_aes_context *ctx,
@@ -96,7 +100,8 @@ int _ss_esp_aes_crypt_cfb8(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_cfb8(ctx, mode, length, iv, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_cfb8(&ctx_local, mode, length, iv, input, output);
 }
 
 int _ss_esp_aes_crypt_ctr(esp_aes_context *ctx,
@@ -119,7 +124,8 @@ int _ss_esp_aes_crypt_ctr(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_ctr(ctx, length, nc_off, nonce_counter, stream_block, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_ctr(&ctx_local, length, nc_off, nonce_counter, stream_block, input, output);
 }
 
 int _ss_esp_aes_crypt_ecb(esp_aes_context *ctx,
@@ -136,7 +142,8 @@ int _ss_esp_aes_crypt_ecb(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_ecb(ctx, mode, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_ecb(&ctx_local, mode, input, output);
 }
 
 int _ss_esp_aes_crypt_ofb(esp_aes_context *ctx,
@@ -157,7 +164,8 @@ int _ss_esp_aes_crypt_ofb(esp_aes_context *ctx,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_aes_crypt_ofb(ctx, length, iv_off, iv, input, output);
+    esp_aes_context ctx_local = *ctx;
+    return esp_aes_crypt_ofb(&ctx_local, length, iv_off, iv, input, output);
 }
 
 /* ---------------------------------------------- SHA ------------------------------------------------- */
@@ -380,8 +388,10 @@ esp_err_t _ss_esp_ds_sign(const void *message,
         return ESP_ERR_INVALID_ARG;
     }
 
-    size_t n = get_ds_msg_sign_len(data->rsa_length);
-    valid_addr &= (n > 0) && esp_tee_buf_in_ree(message, n) && esp_tee_buf_in_ree(signature, n);
+    const size_t n_max = SOC_DS_SIGNATURE_MAX_BIT_LEN / 8;
+    valid_addr &= (get_ds_msg_sign_len(data->rsa_length) > 0) &&
+                  esp_tee_buf_in_ree(message, n_max) &&
+                  esp_tee_buf_in_ree(signature, n_max);
 
 #if CONFIG_SECURE_TEE_SEC_STG_MODE_RELEASE
     valid_addr &= (key_id != (hmac_key_id_t)CONFIG_SECURE_TEE_SEC_STG_EFUSE_HMAC_KEY_ID);
@@ -401,15 +411,21 @@ esp_err_t _ss_esp_ds_start_sign(const void *message,
                                 hmac_key_id_t key_id,
                                 esp_ds_context_t **esp_ds_ctx)
 {
-    bool valid_addr = (esp_tee_buf_in_ree(esp_ds_ctx, sizeof(esp_ds_context_t *)) &&
-                       esp_tee_buf_in_ree(*esp_ds_ctx, sizeof(esp_ds_context_t)) &&
+    if (!esp_tee_buf_in_ree(esp_ds_ctx, sizeof(esp_ds_context_t *))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    esp_ds_context_t *ds_ctx = *esp_ds_ctx;
+    const size_t n_max = SOC_DS_SIGNATURE_MAX_BIT_LEN / 8;
+
+    bool valid_addr = (esp_tee_buf_in_ree(ds_ctx, sizeof(esp_ds_context_t)) &&
                        esp_tee_buf_in_ree(data, sizeof(esp_ds_data_t)));
     if (!valid_addr) {
         return ESP_ERR_INVALID_ARG;
     }
 
-    size_t n = get_ds_msg_sign_len(data->rsa_length);
-    valid_addr &= (n > 0) && esp_tee_buf_in_ree(message, n);
+    valid_addr &= (get_ds_msg_sign_len(data->rsa_length) > 0) &&
+                  esp_tee_buf_in_ree(message, n_max);
 
 #if CONFIG_SECURE_TEE_SEC_STG_MODE_RELEASE
     valid_addr &= (key_id != (hmac_key_id_t)CONFIG_SECURE_TEE_SEC_STG_EFUSE_HMAC_KEY_ID);
@@ -421,7 +437,12 @@ esp_err_t _ss_esp_ds_start_sign(const void *message,
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_ds_start_sign(message, data, key_id, esp_ds_ctx);
+    esp_err_t err = esp_ds_start_sign(message, data, key_id, &ds_ctx);
+    if (err == ESP_OK) {
+        *esp_ds_ctx = ds_ctx;
+    }
+
+    return err;
 }
 
 bool _ss_esp_ds_is_busy(void)
@@ -431,14 +452,16 @@ bool _ss_esp_ds_is_busy(void)
 
 esp_err_t _ss_esp_ds_finish_sign(void *signature, esp_ds_context_t *esp_ds_ctx)
 {
-    const size_t max_sign = SOC_DS_SIGNATURE_MAX_BIT_LEN / 8;
-    bool valid_addr = (esp_tee_buf_in_ree(signature, max_sign) &&
+    const size_t n_max = SOC_DS_SIGNATURE_MAX_BIT_LEN / 8;
+    bool valid_addr = (esp_tee_buf_in_ree(signature, n_max) &&
                        esp_tee_buf_in_ree(esp_ds_ctx, sizeof(esp_ds_context_t)));
     if (!valid_addr) {
         return ESP_ERR_INVALID_ARG;
     }
 
-    const esp_ds_data_t *data = (const esp_ds_data_t *)esp_ds_ctx->data;
+    const esp_ds_context_t ctx_local = *esp_ds_ctx;
+
+    const esp_ds_data_t *data = (const esp_ds_data_t *)ctx_local.data;
     valid_addr &= esp_tee_buf_in_ree(data, sizeof(esp_ds_data_t)) &&
                   (get_ds_msg_sign_len(data->rsa_length) > 0);
 
@@ -447,7 +470,7 @@ esp_err_t _ss_esp_ds_finish_sign(void *signature, esp_ds_context_t *esp_ds_ctx)
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_ds_finish_sign(signature, esp_ds_ctx);
+    return esp_ds_finish_sign(signature, (esp_ds_context_t *)&ctx_local);
 }
 
 esp_err_t _ss_esp_ds_encrypt_params(esp_ds_data_t *data,
@@ -536,15 +559,11 @@ int _ss_esp_tee_ota_end(void)
 
 /* ---------------------------------------------- Secure Storage ------------------------------------------------- */
 
-/* NOTE: The key-name pointers here (cfg->id/ctx->key_id) are REE-supplied, NULL-terminated
- * NVS key names used read-only for key lookup (NVS compares them with strncmp bounded to
- * NVS_KEY_NAME_MAX_SIZE-1) — never written through, never used as a register base.
- * Pointing one at TEE memory yields at most a load-fault DoS or a useless presence oracle,
- * so they are left unchecked. Argument checks cost code size and add latency to every
- * service call, so we keep only the ones that close a real REE->TEE read/write/control-flow gap.
- */
 esp_err_t _ss_esp_tee_sec_storage_clear_key(const char *key_id)
 {
+    char id_buf[NVS_KEY_NAME_MAX_SIZE];
+    tee_snapshot_ree_str(&key_id, id_buf, sizeof(id_buf));
+
     bool valid_arg = !esp_tee_sec_storage_is_key_tee_owned(key_id);
     if (!valid_arg) {
         return ESP_ERR_INVALID_ARG;
@@ -556,13 +575,20 @@ esp_err_t _ss_esp_tee_sec_storage_clear_key(const char *key_id)
 
 esp_err_t _ss_esp_tee_sec_storage_gen_key(const esp_tee_sec_storage_key_cfg_t *cfg)
 {
-    bool valid_arg = esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t)) &&
-                     !(cfg->flags & SEC_STORAGE_FLAG_TEE_ONLY) &&
-                     !esp_tee_sec_storage_is_key_tee_owned(cfg->id);
+    if (!esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    esp_tee_sec_storage_key_cfg_t cfg_local = *cfg;
+    char id_buf[NVS_KEY_NAME_MAX_SIZE];
+    tee_snapshot_ree_str(&cfg_local.id, id_buf, sizeof(id_buf));
+
+    bool valid_arg = !(cfg_local.flags & SEC_STORAGE_FLAG_TEE_ONLY) &&
+                     !esp_tee_sec_storage_is_key_tee_owned(cfg_local.id);
     if (!valid_arg) {
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(valid_arg);
 
-    return esp_tee_sec_storage_gen_key(cfg);
+    return esp_tee_sec_storage_gen_key(&cfg_local);
 }

components/esp_tee/subproject/main/core/esp_secure_services_iram.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 #include <stdarg.h>
+#include <string.h>
 #include <sys/param.h>
 
 #include "esp_err.h"
@@ -165,57 +166,70 @@ void _ss_wdt_hal_init(wdt_hal_context_t *hal, wdt_inst_t wdt_inst, uint32_t pres
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    wdt_hal_init(hal, wdt_inst, prescaler, enable_intr);
+    wdt_hal_context_t hal_local;
+    wdt_hal_init(&hal_local, wdt_inst, prescaler, enable_intr);
+
+    *hal = hal_local;
 }
 
 void _ss_wdt_hal_deinit(wdt_hal_context_t *hal)
 {
-    bool valid_addr = (esp_tee_buf_in_ree(hal, sizeof(wdt_hal_context_t)) &&
-                       is_wdt_dev_valid(hal->mwdt_dev));
+    if (!esp_tee_buf_in_ree(hal, sizeof(wdt_hal_context_t))) {
+        return;
+    }
 
+    wdt_hal_context_t hal_snap = *hal;
+
+    bool valid_addr = is_wdt_dev_valid(hal_snap.mwdt_dev);
     if (!valid_addr) {
         return;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    wdt_hal_deinit(hal);
+    wdt_hal_deinit(&hal_snap);
 }
 
 /* ---------------------------------------------- Secure Storage ------------------------------------------------- */
 
-/* NOTE: The key-name pointers here (cfg->id/ctx->key_id) are REE-supplied, NULL-terminated
- * NVS key names used read-only for key lookup (NVS compares them with strncmp bounded to
- * NVS_KEY_NAME_MAX_SIZE-1) — never written through, never used as a register base.
- * Pointing one at TEE memory yields at most a load-fault DoS or a useless presence oracle,
- * so they are left unchecked. Argument checks cost code size and add latency to every
- * service call, so we keep only the ones that close a real REE->TEE read/write/control-flow gap.
- * The buffers alongside these ARE validated, since the TEE reads/writes them.
- */
 esp_err_t _ss_esp_tee_sec_storage_ecdsa_sign(const esp_tee_sec_storage_key_cfg_t *cfg, const uint8_t *hash, size_t hlen, esp_tee_sec_storage_ecdsa_sign_t *out_sign)
 {
-    bool valid_arg = (esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t)) &&
-                      esp_tee_buf_in_ree(hash, hlen) &&
+    if (!esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    esp_tee_sec_storage_key_cfg_t cfg_local = *cfg;
+    char id_buf[NVS_KEY_NAME_MAX_SIZE];
+    tee_snapshot_ree_str(&cfg_local.id, id_buf, sizeof(id_buf));
+
+    bool valid_arg = (esp_tee_buf_in_ree(hash, hlen) &&
                       esp_tee_buf_in_ree(out_sign, sizeof(esp_tee_sec_storage_ecdsa_sign_t)) &&
-                      !esp_tee_sec_storage_is_key_tee_owned(cfg->id));
+                      !esp_tee_sec_storage_is_key_tee_owned(cfg_local.id));
     if (!valid_arg) {
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(valid_arg);
 
-    return esp_tee_sec_storage_ecdsa_sign(cfg, hash, hlen, out_sign);
+    return esp_tee_sec_storage_ecdsa_sign(&cfg_local, hash, hlen, out_sign);
 }
 
 esp_err_t _ss_esp_tee_sec_storage_ecdsa_get_pubkey(const esp_tee_sec_storage_key_cfg_t *cfg, esp_tee_sec_storage_ecdsa_pubkey_t *out_pubkey)
 {
-    bool valid_arg = (esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t)) &&
-                      esp_tee_buf_in_ree(out_pubkey, sizeof(esp_tee_sec_storage_ecdsa_pubkey_t)) &&
-                      !esp_tee_sec_storage_is_key_tee_owned(cfg->id));
+    if (!esp_tee_buf_in_ree(cfg, sizeof(esp_tee_sec_storage_key_cfg_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    esp_tee_sec_storage_key_cfg_t cfg_local = *cfg;
+    char id_buf[NVS_KEY_NAME_MAX_SIZE];
+    tee_snapshot_ree_str(&cfg_local.id, id_buf, sizeof(id_buf));
+
+    bool valid_arg = (esp_tee_buf_in_ree(out_pubkey, sizeof(esp_tee_sec_storage_ecdsa_pubkey_t)) &&
+                      !esp_tee_sec_storage_is_key_tee_owned(cfg_local.id));
     if (!valid_arg) {
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(valid_arg);
 
-    return esp_tee_sec_storage_ecdsa_get_pubkey(cfg, out_pubkey);
+    return esp_tee_sec_storage_ecdsa_get_pubkey(&cfg_local, out_pubkey);
 }
 
 esp_err_t _ss_esp_tee_sec_storage_aead_encrypt(esp_tee_sec_storage_aead_ctx_t *ctx, uint8_t *tag, size_t tag_len, uint8_t *output)
@@ -240,14 +254,21 @@ esp_err_t _ss_esp_tee_sec_storage_aead_encrypt(esp_tee_sec_storage_aead_ctx_t *c
 
 esp_err_t _ss_esp_tee_sec_storage_aead_decrypt(const esp_tee_sec_storage_aead_ctx_t *ctx, const uint8_t *tag, size_t tag_len, uint8_t *output)
 {
-    bool valid_arg = (esp_tee_buf_in_ree(ctx, sizeof(esp_tee_sec_storage_aead_ctx_t)) &&
-                      esp_tee_buf_in_ree(ctx->input, ctx->input_len) &&
-                      esp_tee_buf_in_ree(tag, tag_len) &&
-                      esp_tee_buf_in_ree(output, ctx->input_len) &&
-                      !esp_tee_sec_storage_is_key_tee_owned(ctx->key_id));
+    if (!esp_tee_buf_in_ree(ctx, sizeof(esp_tee_sec_storage_aead_ctx_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
 
-    if (ctx->aad_len != 0) {
-        valid_arg &= esp_tee_buf_in_ree(ctx->aad, ctx->aad_len);
+    esp_tee_sec_storage_aead_ctx_t ctx_local = *ctx;
+    char id_buf[NVS_KEY_NAME_MAX_SIZE];
+    tee_snapshot_ree_str(&ctx_local.key_id, id_buf, sizeof(id_buf));
+
+    bool valid_arg = (esp_tee_buf_in_ree(ctx_local.input, ctx_local.input_len) &&
+                      esp_tee_buf_in_ree(tag, tag_len) &&
+                      esp_tee_buf_in_ree(output, ctx_local.input_len) &&
+                      !esp_tee_sec_storage_is_key_tee_owned(ctx_local.key_id));
+
+    if (ctx_local.aad_len != 0) {
+        valid_arg &= esp_tee_buf_in_ree(ctx_local.aad, ctx_local.aad_len);
     }
 
     if (!valid_arg) {
@@ -255,23 +276,28 @@ esp_err_t _ss_esp_tee_sec_storage_aead_decrypt(const esp_tee_sec_storage_aead_ct
     }
     ESP_FAULT_ASSERT(valid_arg);
 
-    return esp_tee_sec_storage_aead_decrypt(ctx, tag, tag_len, output);
+    return esp_tee_sec_storage_aead_decrypt(&ctx_local, tag, tag_len, output);
 }
 
 esp_err_t _ss_esp_tee_sec_storage_ecdsa_sign_pbkdf2(const esp_tee_sec_storage_pbkdf2_ctx_t *ctx, const uint8_t *hash, size_t hlen, esp_tee_sec_storage_ecdsa_sign_t *out_sign, esp_tee_sec_storage_ecdsa_pubkey_t *out_pubkey)
 {
-    bool valid_addr = (esp_tee_buf_in_ree(ctx, sizeof(esp_tee_sec_storage_pbkdf2_ctx_t)) &&
-                       esp_tee_buf_in_ree(hash, hlen) &&
+    if (!esp_tee_buf_in_ree(ctx, sizeof(esp_tee_sec_storage_pbkdf2_ctx_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    const esp_tee_sec_storage_pbkdf2_ctx_t ctx_local = *ctx;
+
+    bool valid_addr = (esp_tee_buf_in_ree(hash, hlen) &&
                        esp_tee_buf_in_ree(out_sign, sizeof(esp_tee_sec_storage_ecdsa_sign_t)) &&
                        esp_tee_buf_in_ree(out_pubkey, sizeof(esp_tee_sec_storage_ecdsa_pubkey_t)) &&
-                       esp_tee_buf_in_ree(ctx->salt, ctx->salt_len));
+                       esp_tee_buf_in_ree(ctx_local.salt, ctx_local.salt_len));
 
     if (!valid_addr) {
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    return esp_tee_sec_storage_ecdsa_sign_pbkdf2(ctx, hash, hlen, out_sign, out_pubkey);
+    return esp_tee_sec_storage_ecdsa_sign_pbkdf2(&ctx_local, hash, hlen, out_sign, out_pubkey);
 }
 
 /* ---------------------------------------------- MMU HAL ------------------------------------------------- */
@@ -378,30 +404,6 @@ static bool is_flash_addr_readable(uint32_t paddr, uint32_t len)
     return !esp_tee_flash_check_prange_in_tee_region(paddr, len);
 }
 
-static bool is_spi_host_in_ree(spi_flash_host_inst_t *host)
-{
-    const spi_flash_hal_context_t *ctx = (const spi_flash_hal_context_t *)host;
-
-    return (esp_tee_buf_in_ree(host, sizeof(spi_flash_hal_context_t)) &&
-            ctx->spi == spi_flash_ll_get_hw(SPI1_HOST));
-}
-
-static bool is_spi_trans_valid(spi_flash_host_inst_t *host, spi_flash_trans_t *trans)
-{
-    if (!is_spi_host_in_ree(host) || !esp_tee_buf_in_ree(trans, sizeof(spi_flash_trans_t))) {
-        return false;
-    }
-
-    bool valid_addr = true;
-    if (trans->mosi_len != 0) {
-        valid_addr &= esp_tee_buf_in_ree(trans->mosi_data, trans->mosi_len);
-    }
-    if (trans->miso_len != 0) {
-        valid_addr &= esp_tee_buf_in_ree(trans->miso_data, trans->miso_len);
-    }
-    return valid_addr;
-}
-
 static bool is_spi_cmd_addr_ok(uint32_t addr_bitlen, uint32_t address, uint32_t mosi_len, uint32_t miso_len)
 {
     if (addr_bitlen == 0) {
@@ -426,206 +428,246 @@ static const spi_flash_host_driver_t tee_host_driver = {
     .configure_host_io_mode = spi_flash_hal_configure_host_io_mode,
 };
 
-static inline const spi_flash_host_driver_t *tee_substitute_host_driver(spi_flash_host_inst_t *host)
+static spi_flash_host_inst_t *tee_own_host(const spi_flash_host_inst_t *host, spi_flash_hal_context_t *snap)
 {
-    const spi_flash_host_driver_t *orig = host->driver;
-    host->driver = &tee_host_driver;
-    return orig;
+    if (!esp_tee_buf_in_ree(host, sizeof(spi_flash_hal_context_t))) {
+        return NULL;
+    }
+
+    *snap = *(const spi_flash_hal_context_t *)host;
+
+    /* Reject a host aimed at another peripheral rather than silently retargeting it */
+    if (snap->spi != spi_flash_ll_get_hw(SPI1_HOST)) {
+        return NULL;
+    }
+
+    snap->inst.driver = &tee_host_driver;
+    snap->spi         = spi_flash_ll_get_hw(SPI1_HOST);
+
+    return &snap->inst;
 }
 
 uint32_t _ss_spi_flash_hal_check_status(spi_flash_host_inst_t *host)
 {
-    bool valid_addr = is_spi_host_in_ree(host);
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return 0;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return spi_flash_hal_check_status(host);
+    return spi_flash_hal_check_status(tee_host);
 }
 
 esp_err_t _ss_spi_flash_hal_common_command(spi_flash_host_inst_t *host, spi_flash_trans_t *trans)
 {
-    bool trans_valid = is_spi_trans_valid(host, trans);
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
+
+    if (!esp_tee_buf_in_ree(trans, sizeof(spi_flash_trans_t))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    spi_flash_trans_t trans_snap = *trans;
+
+    bool trans_valid = true;
+    if (trans_snap.mosi_len != 0) {
+        trans_valid &= esp_tee_buf_in_ree(trans_snap.mosi_data, trans_snap.mosi_len);
+    }
+    if (trans_snap.miso_len != 0) {
+        trans_valid &= esp_tee_buf_in_ree(trans_snap.miso_data, trans_snap.miso_len);
+    }
+    trans_valid &= is_spi_cmd_addr_ok(trans_snap.address_bitlen, trans_snap.address,
+                                      trans_snap.mosi_len, trans_snap.miso_len);
     if (!trans_valid) {
+        ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, trans_snap.address);
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(trans_valid);
 
-    bool addr_ok = is_spi_cmd_addr_ok(trans->address_bitlen, trans->address, trans->mosi_len, trans->miso_len);
-    if (!addr_ok) {
-        ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, trans->address);
-        return ESP_ERR_INVALID_ARG;
-    }
-    ESP_FAULT_ASSERT(addr_ok);
-
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    esp_err_t r = spi_flash_hal_common_command(host, trans);
-    host->driver = orig;
-    return r;
+    return spi_flash_hal_common_command(tee_host, &trans_snap);
 }
 
 esp_err_t _ss_spi_flash_hal_device_config(spi_flash_host_inst_t *host)
 {
-    bool valid_addr = is_spi_host_in_ree(host);
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return ESP_ERR_INVALID_ARG;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return spi_flash_hal_device_config(host);
+    return spi_flash_hal_device_config(tee_host);
 }
 
 void _ss_spi_flash_hal_erase_block(spi_flash_host_inst_t *host, uint32_t start_address)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       start_address <= FLASH_ADDR_MAX_24BIT &&
-                       is_flash_addr_writable(start_address, FLASH_BLOCK_SIZE));
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
+    bool valid_addr = (start_address <= FLASH_ADDR_MAX_24BIT &&
+                       is_flash_addr_writable(start_address, FLASH_BLOCK_SIZE));
     if (!valid_addr) {
         ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, start_address);
         return;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    spi_flash_hal_erase_block(host, start_address);
-    host->driver = orig;
+    spi_flash_hal_erase_block(tee_host, start_address);
 }
 
 void _ss_spi_flash_hal_erase_sector(spi_flash_host_inst_t *host, uint32_t start_address)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       start_address <= FLASH_ADDR_MAX_24BIT &&
-                       is_flash_addr_writable(start_address, FLASH_SECTOR_SIZE));
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
+    bool valid_addr = (start_address <= FLASH_ADDR_MAX_24BIT &&
+                       is_flash_addr_writable(start_address, FLASH_SECTOR_SIZE));
     if (!valid_addr) {
         ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, start_address);
         return;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    spi_flash_hal_erase_sector(host, start_address);
-    host->driver = orig;
+    spi_flash_hal_erase_sector(tee_host, start_address);
 }
 
 void _ss_spi_flash_hal_program_page(spi_flash_host_inst_t *host, const void *buffer, uint32_t address, uint32_t length)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       address <= FLASH_ADDR_MAX_24BIT &&
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
+
+    bool valid_addr = (address <= FLASH_ADDR_MAX_24BIT &&
                        is_flash_addr_writable(address, length) &&
                        esp_tee_buf_in_ree(buffer, length));
-
     if (!valid_addr) {
         ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, address);
         return;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    spi_flash_hal_program_page(host, buffer, address, length);
-    host->driver = orig;
+    spi_flash_hal_program_page(tee_host, buffer, address, length);
 }
 
 esp_err_t _ss_spi_flash_hal_read(spi_flash_host_inst_t *host, void *buffer, uint32_t address, uint32_t read_len)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       is_flash_addr_readable(address, read_len) &&
-                       esp_tee_buf_in_ree(buffer, read_len));
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
+    bool valid_addr = (is_flash_addr_readable(address, read_len) &&
+                       esp_tee_buf_in_ree(buffer, read_len));
     if (!valid_addr) {
         ESP_LOGD(TAG, "[%s] Illegal flash access at 0x%08x", __func__, address);
         return ESP_ERR_INVALID_ARG;
     }
     ESP_FAULT_ASSERT(valid_addr);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    esp_err_t r = spi_flash_hal_read(host, buffer, address, read_len);
-    host->driver = orig;
-    return r;
+    return spi_flash_hal_read(tee_host, buffer, address, read_len);
 }
 
 void _ss_spi_flash_hal_resume(spi_flash_host_inst_t *host)
 {
-    bool valid_addr = is_spi_host_in_ree(host);
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    spi_flash_hal_resume(host);
-    host->driver = orig;
+    spi_flash_hal_resume(tee_host);
 }
 
 esp_err_t _ss_spi_flash_hal_set_write_protect(spi_flash_host_inst_t *host, bool wp)
 {
-    bool valid_addr = is_spi_host_in_ree(host);
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return ESP_ERR_INVALID_ARG;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    esp_err_t r = spi_flash_hal_set_write_protect(host, wp);
-    host->driver = orig;
-    return r;
+    return spi_flash_hal_set_write_protect(tee_host, wp);
 }
 
 esp_err_t _ss_spi_flash_hal_setup_read_suspend(spi_flash_host_inst_t *host, const spi_flash_sus_cmd_conf *sus_conf)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       esp_tee_buf_in_ree(sus_conf, sizeof(spi_flash_sus_cmd_conf)));
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return ESP_ERR_INVALID_ARG;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return spi_flash_hal_setup_read_suspend(host, sus_conf);
+    if (!esp_tee_buf_in_ree(sus_conf, sizeof(spi_flash_sus_cmd_conf))) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    const spi_flash_sus_cmd_conf sus_snap = *sus_conf;
+    return spi_flash_hal_setup_read_suspend(tee_host, &sus_snap);
 }
 
 bool _ss_spi_flash_hal_supports_direct_read(spi_flash_host_inst_t *host, const void *p)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) && esp_tee_ptr_in_ree(p));
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return false;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return spi_flash_hal_supports_direct_read(host, p);
+    if (!esp_tee_ptr_in_ree(p)) {
+        return false;
+    }
+
+    return spi_flash_hal_supports_direct_read(tee_host, p);
 }
 
 bool _ss_spi_flash_hal_supports_direct_write(spi_flash_host_inst_t *host, const void *p)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) && esp_tee_ptr_in_ree(p));
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return false;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return spi_flash_hal_supports_direct_write(host, p);
+    if (!esp_tee_ptr_in_ree(p)) {
+        return false;
+    }
+
+    return spi_flash_hal_supports_direct_write(tee_host, p);
 }
 
 void _ss_spi_flash_hal_suspend(spi_flash_host_inst_t *host)
 {
-    bool valid_addr = is_spi_host_in_ree(host);
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    spi_flash_hal_suspend(host);
-    host->driver = orig;
+    spi_flash_hal_suspend(tee_host);
 }
 
 /* ---------------------------------------------- SPI Flash Extras ------------------------------------------------- */
@@ -676,38 +718,41 @@ uint32_t _ss_bootloader_flash_execute_command_common(
 
 esp_err_t _ss_memspi_host_flush_cache(spi_flash_host_inst_t *host, uint32_t addr, uint32_t size)
 {
-    bool valid_addr = (is_spi_host_in_ree(host) &&
-                       is_flash_addr_readable(addr, size));
-
-    if (!valid_addr) {
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
         return ESP_ERR_INVALID_ARG;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
-    return memspi_host_flush_cache(host, addr, size);
+    if (!is_flash_addr_readable(addr, size)) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    return memspi_host_flush_cache(tee_host, addr, size);
 }
 
 esp_err_t _ss_spi_flash_chip_generic_config_host_io_mode(esp_flash_t *chip, uint32_t flags)
 {
-    spi_flash_host_inst_t *host = NULL;
-    bool valid_addr = (esp_tee_buf_in_ree(chip, sizeof(struct esp_flash_t)) &&
-                       is_spi_host_in_ree((host = chip->host)));
-
-    if (!valid_addr) {
+    if (!esp_tee_buf_in_ree(chip, sizeof(struct esp_flash_t))) {
         return ESP_ERR_INVALID_ARG;
     }
-    ESP_FAULT_ASSERT(valid_addr);
+
+    spi_flash_host_inst_t *const host = chip->host;
+    spi_flash_hal_context_t host_snap;
+    spi_flash_host_inst_t *tee_host = tee_own_host(host, &host_snap);
+    if (tee_host == NULL) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    ESP_FAULT_ASSERT(tee_host != NULL);
 
     esp_flash_t chip_snap = {
-        .host          = host,
+        .host          = tee_host,
         .read_mode     = chip->read_mode,
         .hpm_dummy_ena = chip->hpm_dummy_ena,
     };
 
-    const spi_flash_host_driver_t *orig = tee_substitute_host_driver(host);
-    esp_err_t r = spi_flash_chip_generic_config_host_io_mode(&chip_snap, flags);
-    host->driver = orig;
-    return r;
+    return spi_flash_chip_generic_config_host_io_mode(&chip_snap, flags);
 }
 
 #if CONFIG_IDF_TARGET_ESP32C5

components/esp_tee/subproject/main/include/esp_tee_memory_utils.h

@@ -7,6 +7,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <string.h>
 #include "esp_attr.h"
 #include "soc/soc.h"
 #include "soc/ext_mem_defs.h"
@@ -42,6 +43,20 @@ FORCE_INLINE_ATTR bool esp_tee_ptr_in_ree(const void *p)
     return esp_tee_buf_in_ree(p, 4);
 }
 
+/* NOTE: re-points a REE string argument at a TEE-resident copy */
+FORCE_INLINE_ATTR void tee_snapshot_ree_str(const char **name, char *buf, size_t buf_len)
+{
+    const char *src = *name;
+    if (src == NULL || buf_len == 0) {
+        return;
+    }
+
+    memcpy(buf, src, buf_len);
+    buf[buf_len - 1] = '\0';
+
+    *name = buf;
+}
+
 #ifdef __cplusplus
 }
 #endif

components/mbedtls/port/ecc/esp_ecc.c

@@ -75,21 +75,18 @@ int esp_ecc_point_multiply(const ecc_point_t *point, const uint8_t *scalar, ecc_
 int esp_ecc_point_verify(const ecc_point_t *point)
 {
     int result;
+    const unsigned len = point->len;
 
-    /* point->len drives a fixed-stride MMIO write loop in the HAL; an unvalidated oversized
-     * value (attacker-controlled via the TEE secure service) walks past the ECC register block
-     * and can reach other peripheral registers (CWE-787). Reject non-curve lengths up front and
-     * return 0 (point not verified) -- the fail-safe value for this routine. */
-    if (point->len != P192_LEN && point->len != P256_LEN
+    if (len != P192_LEN && len != P256_LEN
 #if SOC_ECC_SUPPORT_CURVE_P384
-            && point->len != P384_LEN
+            && len != P384_LEN
 #endif
        ) {
         return 0;
     }
 
     esp_ecc_acquire_hardware();
-    ecc_hal_write_verify_param(point->x, point->y, point->len);
+    ecc_hal_write_verify_param(point->x, point->y, len);
     ecc_hal_set_mode(ECC_MODE_VERIFY);
     ecc_hal_start_calc();