From 6c290c09f3a7224f6a76baf048f55a32260e3706 Mon Sep 17 00:00:00 2001
From: "nilesh.kale" <nilesh.kale@espressif.com>
Date: Tue, 13 May 2025 17:01:07 +0530
Subject: [PATCH] feat: enabled ECDSA-P192 support for ESP32H2

---
 .../src/esp32h2/secure_boot_secure_features.c |  9 ++-
 .../bootloader_support/src/secure_boot.c      | 23 +++++-
 components/efuse/include/esp_efuse.h          | 45 +++++++++++-
 components/efuse/src/esp_efuse_fields.c       | 72 ++++++++++++++++++-
 components/esp_hw_support/Kconfig             |  7 ++
 components/esp_system/startup.c               |  5 ++
 components/hal/esp32h2/efuse_hal.c            | 13 +++-
 components/hal/esp32h2/include/hal/ecdsa_ll.h | 10 +++
 .../hal/esp32h2/include/hal/efuse_hal.h       |  9 ++-
 components/hal/esp32h2/include/hal/efuse_ll.h |  7 +-
 components/mbedtls/port/ecdsa/ecdsa_alt.c     |  4 +-
 .../test_apps/main/test_mbedtls_ecdsa.c       |  8 ++-
 .../esp32h2/include/soc/Kconfig.soc_caps.in   |  4 ++
 components/soc/esp32h2/include/soc/soc_caps.h |  2 +
 docs/en/api-reference/peripherals/ecdsa.rst   | 16 +++++
 15 files changed, 223 insertions(+), 11 deletions(-)

diff --git a/components/bootloader_support/src/esp32h2/secure_boot_secure_features.c b/components/bootloader_support/src/esp32h2/secure_boot_secure_features.c
index 9ea0f69e4b..da7f84df5c 100644
--- a/components/bootloader_support/src/esp32h2/secure_boot_secure_features.c
+++ b/components/bootloader_support/src/esp32h2/secure_boot_secure_features.c
@@ -1,10 +1,11 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
 #include <strings.h>
+#include "hal/ecdsa_ll.h"
 #include "esp_flash_encrypt.h"
 #include "esp_secure_boot.h"
 #include "esp_efuse.h"
@@ -36,6 +37,12 @@ esp_err_t esp_secure_boot_enable_secure_features(void)
     ESP_LOGW(TAG, "UART ROM Download mode kept enabled - SECURITY COMPROMISED");
 #endif
 
+#ifdef SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+    if (ecdsa_ll_is_configurable_curve_supported()) {
+        esp_efuse_write_field_bit(ESP_EFUSE_WR_DIS_ECDSA_CURVE_MODE);
+    }
+#endif
+
 #ifndef CONFIG_SECURE_BOOT_ALLOW_JTAG
     ESP_LOGI(TAG, "Disable hardware & software JTAG...");
     esp_efuse_write_field_bit(ESP_EFUSE_DIS_PAD_JTAG);
diff --git a/components/bootloader_support/src/secure_boot.c b/components/bootloader_support/src/secure_boot.c
index 9015bdfd5a..164a629934 100644
--- a/components/bootloader_support/src/secure_boot.c
+++ b/components/bootloader_support/src/secure_boot.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -12,6 +12,10 @@
 #include "esp_secure_boot.h"
 #include "hal/efuse_hal.h"
 
+#ifdef SOC_ECDSA_SUPPORTED
+#include "hal/ecdsa_ll.h"
+#endif
+
 #ifndef BOOTLOADER_BUILD
 static __attribute__((unused)) const char *TAG = "secure_boot";
 
@@ -331,6 +335,23 @@ bool esp_secure_boot_cfg_verify_release_mode(void)
     }
 #endif
 
+#ifdef SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+    if (ecdsa_ll_is_configurable_curve_supported()) {
+        secure = esp_efuse_read_field_bit(ESP_EFUSE_WR_DIS_ECDSA_CURVE_MODE);
+        if (!secure) {
+            uint8_t current_curve;
+            esp_err_t err = esp_efuse_read_field_blob(ESP_EFUSE_ECDSA_CURVE_MODE, &current_curve, ESP_EFUSE_ECDSA_CURVE_MODE[0]->bit_count);
+            if (err == ESP_OK) {
+                if (current_curve != ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P256_BIT_LOCKED) {
+                    // If not P256 mode
+                    result &= secure;
+                    ESP_LOGW(TAG, "Not write disabled ECDSA curve mode (set WR_DIS_ECDSA_CURVE_MODE->1)");
+                }
+            }
+        }
+    }
+#endif
+
 #ifdef CONFIG_SECURE_BOOT_ENABLE_AGGRESSIVE_KEY_REVOKE
     secure = esp_efuse_read_field_bit(ESP_EFUSE_SECURE_BOOT_AGGRESSIVE_REVOKE);
     result &= secure;
diff --git a/components/efuse/include/esp_efuse.h b/components/efuse/include/esp_efuse.h
index fa075f91ac..460e69bd6b 100644
--- a/components/efuse/include/esp_efuse.h
+++ b/components/efuse/include/esp_efuse.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2017-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2017-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -159,7 +159,7 @@ esp_err_t esp_efuse_write_field_cnt(const esp_efuse_desc_t* field[], size_t cnt)
  *
  * @return
  * - ESP_OK: The operation was successfully completed, or the bit was already set to value 1.
- * - ESP_ERR_INVALID_ARG: Error in the passed arugments, including if the efuse field is not 1 bit wide.
+ * - ESP_ERR_INVALID_ARG: Error in the passed arguments, including if the efuse field is not 1 bit wide.
  */
 esp_err_t esp_efuse_write_field_bit(const esp_efuse_desc_t* field[]);
 
@@ -468,7 +468,7 @@ esp_err_t esp_efuse_batch_write_begin(void);
  *
  * @return
  *          - ESP_OK: Successful.
- *          - ESP_ERR_INVALID_STATE: Tha batch mode was not set.
+ *          - ESP_ERR_INVALID_STATE: The batch mode was not set.
  */
 esp_err_t esp_efuse_batch_write_cancel(void);
 
@@ -783,6 +783,45 @@ esp_err_t esp_secure_boot_read_key_digests(esp_secure_boot_key_digests_t *truste
  */
 esp_err_t esp_efuse_check_errors(void);
 
+#if SOC_ECDSA_SUPPORTED
+/**
+ * @brief Checks if 192-bit ECDSA curve operations are supported.
+ *
+ * This function checks if the current eFuse configuration supports 192-bit ECDSA curve operations.
+*/
+bool esp_efuse_is_ecdsa_p192_curve_supported(void);
+
+/**
+ * @brief Checks if 256-bit ECDSA curve operations are supported.
+ *
+ * This function checks if the current eFuse configuration supports 256-bit ECDSA curve operations.
+*/
+bool esp_efuse_is_ecdsa_p256_curve_supported(void);
+#endif /* SOC_ECDSA_SUPPORTED*/
+
+#if SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+typedef enum {
+    ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P256_BIT = 0,
+    ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P192_BIT = 1,
+    ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_BOTH_P192_P256_BIT = 2,
+    ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P256_BIT_LOCKED = 3,
+} esp_efuse_ecdsa_curve_mode_t;
+
+/**
+ * @brief Enables 192-bit ECDSA curve operations by setting the appropriate eFuse value.
+ *
+ * This function enables support for 192-bit ECDSA curve operations by configuring the
+ * ECDSA curve mode eFuse. It checks the current curve mode and attempts to set it to
+ * allow both P192 and P256 operations if not already set.
+ *
+ * @return
+ *    - ESP_OK: Successfully enabled 192-bit ECDSA operations or already enabled
+ *    - ESP_FAIL: Failed to enable operations due to write protection
+ *    - Other error codes: Failed to read/write eFuse
+ */
+esp_err_t esp_efuse_enable_ecdsa_p192_curve_mode(void);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/efuse/src/esp_efuse_fields.c b/components/efuse/src/esp_efuse_fields.c
index a73ed03915..9a13be8f44 100644
--- a/components/efuse/src/esp_efuse_fields.c
+++ b/components/efuse/src/esp_efuse_fields.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2017-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2017-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -16,6 +16,13 @@
 #include "esp_log.h"
 #include "soc/efuse_periph.h"
 #include "sys/param.h"
+#include "soc/soc_caps.h"
+#include "hal/efuse_ll.h"
+#include "hal/efuse_hal.h"
+
+#ifdef SOC_ECDSA_SUPPORTED
+#include "hal/ecdsa_ll.h"
+#endif /* SOC_ECDSA_SUPPORTED */
 
 static __attribute__((unused)) const char *TAG = "efuse";
 
@@ -81,3 +88,66 @@ esp_err_t esp_efuse_update_secure_version(uint32_t secure_version)
     }
     return ESP_OK;
 }
+
+#if SOC_ECDSA_SUPPORTED
+bool esp_efuse_is_ecdsa_p192_curve_supported(void)
+{
+#if SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+    if (ecdsa_ll_is_configurable_curve_supported()) {
+        uint32_t current_curve = efuse_hal_get_ecdsa_curve_mode();
+        return (current_curve == ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_BOTH_P192_P256_BIT || current_curve == ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P192_BIT);
+    } else {
+        return true;
+    }
+#else
+    return true;
+#endif /* SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED */
+}
+
+bool esp_efuse_is_ecdsa_p256_curve_supported(void)
+{
+#if SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+    if (ecdsa_ll_is_configurable_curve_supported()) {
+        uint32_t current_curve = efuse_hal_get_ecdsa_curve_mode();
+        return (current_curve != ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P192_BIT);
+    } else {
+        return true;
+    }
+#else
+    return true;
+#endif /* SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED */
+}
+#endif /* SOC_ECDSA_SUPPORTED */
+
+#if SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+esp_err_t esp_efuse_enable_ecdsa_p192_curve_mode(void)
+{
+
+    if (ecdsa_ll_is_configurable_curve_supported()) {
+        esp_err_t err;
+        uint8_t current_curve, next_curve;
+
+        current_curve = efuse_hal_get_ecdsa_curve_mode();
+        // Check if already in desired state
+        if (current_curve == ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_BOTH_P192_P256_BIT || current_curve == ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P192_BIT) {
+            ESP_EARLY_LOGD(TAG, "ECDSA P-192 curve mode is already enabled");
+            return ESP_OK;
+        }
+
+        // Check if write is disabled or already locked to P256
+        if (esp_efuse_read_field_bit(ESP_EFUSE_WR_DIS_ECDSA_CURVE_MODE) || current_curve == ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_ONLY_P256_BIT_LOCKED) {
+            ESP_EARLY_LOGE(TAG, "ECDSA curve mode is locked, cannot enable P-192 curve");
+            return ESP_FAIL;
+        }
+
+        // Attempt to write new curve mode
+        next_curve = ESP_EFUSE_ECDSA_CURVE_MODE_ALLOW_BOTH_P192_P256_BIT;
+        err = esp_efuse_write_field_blob(ESP_EFUSE_ECDSA_CURVE_MODE, &next_curve, ESP_EFUSE_ECDSA_CURVE_MODE[0]->bit_count);
+        if (err != ESP_OK) {
+            ESP_EARLY_LOGE(TAG, "Failed to enable ECDSA P-192 curve %d", err);
+            return err;
+        }
+    }
+    return ESP_OK;
+}
+#endif /* SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED */
diff --git a/components/esp_hw_support/Kconfig b/components/esp_hw_support/Kconfig
index 418fbbe87b..8ef4337d5f 100644
--- a/components/esp_hw_support/Kconfig
+++ b/components/esp_hw_support/Kconfig
@@ -346,4 +346,11 @@ menu "Hardware Settings"
             time point multiplication operations by changing the default ESP-IDF configurations.
             Performing constant time operations protect the ECC multiplication operations from timing attacks.
 
+    config ESP_ECDSA_ENABLE_P192_CURVE
+        bool "Enable ECDSA 192-curve operations"
+        depends on SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+        default N
+        help
+            By default, only the 256-bit curve operations are allowed. If this configuration is enabled,
+            it will set the eFuse to allow ECDSA operations using both the 192-bit and 256-bit curves
 endmenu
diff --git a/components/esp_system/startup.c b/components/esp_system/startup.c
index a1076ff224..0c19da28db 100644
--- a/components/esp_system/startup.c
+++ b/components/esp_system/startup.c
@@ -428,6 +428,11 @@ static void do_core_init(void)
     esp_efuse_set_rom_log_scheme(ROM_LOG_MODE);
 #endif
 
+#if CONFIG_ESP_ECDSA_ENABLE_P192_CURVE
+    err = esp_efuse_enable_ecdsa_p192_curve_mode();
+    assert(err == ESP_OK && "Failed to enable ECDSA 192-curve operations");
+#endif
+
 #if CONFIG_ESP_XT_WDT
     esp_xt_wdt_config_t cfg = {
         .timeout                = CONFIG_ESP_XT_WDT_TIMEOUT,
diff --git a/components/hal/esp32h2/efuse_hal.c b/components/hal/esp32h2/efuse_hal.c
index 697f581e5f..4b09fb854d 100644
--- a/components/hal/esp32h2/efuse_hal.c
+++ b/components/hal/esp32h2/efuse_hal.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -7,6 +7,7 @@
 #include "sdkconfig.h"
 #include <sys/param.h>
 #include "soc/soc_caps.h"
+#include "soc/chip_revision.h"
 #include "hal/assert.h"
 #include "hal/efuse_hal.h"
 #include "hal/efuse_ll.h"
@@ -78,6 +79,16 @@ void efuse_hal_rs_calculate(const void *data, void *rs_values)
     ets_efuse_rs_calculate(data, rs_values);
 }
 
+uint32_t efuse_hal_get_ecdsa_curve_mode(void)
+{
+     if (ESP_CHIP_REV_ABOVE(efuse_hal_chip_revision(), 102)) {
+        return efuse_ll_get_ecdsa_curve_mode();
+    } else {
+        // Curve mode is not configurable for previous versions
+        return 0;
+    }
+}
+
 /******************* eFuse control functions *************************/
 
 bool efuse_hal_is_coding_error_in_block(unsigned block)
diff --git a/components/hal/esp32h2/include/hal/ecdsa_ll.h b/components/hal/esp32h2/include/hal/ecdsa_ll.h
index bd352b2e95..8c99171fdb 100644
--- a/components/hal/esp32h2/include/hal/ecdsa_ll.h
+++ b/components/hal/esp32h2/include/hal/ecdsa_ll.h
@@ -357,6 +357,16 @@ static inline int ecdsa_ll_get_operation_result(void)
     return REG_GET_BIT(ECDSA_RESULT_REG, ECDSA_OPERATION_RESULT);
 }
 
+/**
+ * @brief Check if the ECDSA curves configuration is supported
+ * The ECDSA curves configuration is only avliable in chip version
+ * above 1.2 in ESP32-H2
+ */
+static inline bool ecdsa_ll_is_configurable_curve_supported(void)
+{
+    return ESP_CHIP_REV_ABOVE(efuse_hal_chip_revision(), 102);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/hal/esp32h2/include/hal/efuse_hal.h b/components/hal/esp32h2/include/hal/efuse_hal.h
index b6c83d6da6..37c4f72cd9 100644
--- a/components/hal/esp32h2/include/hal/efuse_hal.h
+++ b/components/hal/esp32h2/include/hal/efuse_hal.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -54,6 +54,13 @@ void efuse_hal_program(uint32_t block);
  */
 void efuse_hal_rs_calculate(const void *data, void *rs_values);
 
+/**
+ * @brief Get ECDSA curve mode
+ *
+ * @return ECDSA curve mode
+ */
+uint32_t efuse_hal_get_ecdsa_curve_mode(void);
+
 /**
  * @brief Checks coding error in a block
  *
diff --git a/components/hal/esp32h2/include/hal/efuse_ll.h b/components/hal/esp32h2/include/hal/efuse_ll.h
index d2aa40fcb3..c099c4db97 100644
--- a/components/hal/esp32h2/include/hal/efuse_ll.h
+++ b/components/hal/esp32h2/include/hal/efuse_ll.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -20,6 +20,11 @@ extern "C" {
 
 /******************* eFuse fields *************************/
 
+__attribute__((always_inline)) static inline uint32_t efuse_ll_get_ecdsa_curve_mode(void)
+{
+    return EFUSE.rd_repeat_data0.ecdsa_curve_mode;
+}
+
 __attribute__((always_inline)) static inline uint32_t efuse_ll_get_flash_crypt_cnt(void)
 {
     return EFUSE.rd_repeat_data1.spi_boot_crypt_cnt;
diff --git a/components/mbedtls/port/ecdsa/ecdsa_alt.c b/components/mbedtls/port/ecdsa/ecdsa_alt.c
index c8b396cf00..a562d2bdc5 100644
--- a/components/mbedtls/port/ecdsa/ecdsa_alt.c
+++ b/components/mbedtls/port/ecdsa/ecdsa_alt.c
@@ -446,7 +446,9 @@ int __wrap_mbedtls_ecdsa_verify_restartable(mbedtls_ecp_group *grp,
                          const mbedtls_mpi *s,
                          mbedtls_ecdsa_restart_ctx *rs_ctx)
 {
-    if ((grp->id == MBEDTLS_ECP_DP_SECP192R1 || grp->id == MBEDTLS_ECP_DP_SECP256R1) && blen == ECDSA_SHA_LEN) {
+    if (((grp->id == MBEDTLS_ECP_DP_SECP192R1 && esp_efuse_is_ecdsa_p192_curve_supported())
+        || (grp->id == MBEDTLS_ECP_DP_SECP256R1 && esp_efuse_is_ecdsa_p256_curve_supported()))
+        && blen == ECDSA_SHA_LEN) {
         return esp_ecdsa_verify(grp, buf, blen, Q, r, s);
     } else {
         return __real_mbedtls_ecdsa_verify_restartable(grp, buf, blen, Q, r, s, rs_ctx);
diff --git a/components/mbedtls/test_apps/main/test_mbedtls_ecdsa.c b/components/mbedtls/test_apps/main/test_mbedtls_ecdsa.c
index aeb830f0b2..46ab27d04f 100644
--- a/components/mbedtls/test_apps/main/test_mbedtls_ecdsa.c
+++ b/components/mbedtls/test_apps/main/test_mbedtls_ecdsa.c
@@ -1,6 +1,6 @@
 /* mbedTLS Elliptic Curve Digital Signature performance tests
  *
- * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -22,6 +22,10 @@
 
 #include "ecdsa/ecdsa_alt.h"
 
+#if SOC_ECDSA_SUPPORTED
+#include "hal/ecdsa_ll.h"
+#endif
+
 #define TEST_ASSERT_MBEDTLS_OK(X) TEST_ASSERT_EQUAL_HEX32(0, -(X))
 
 #if CONFIG_NEWLIB_NANO_FORMAT
@@ -32,6 +36,8 @@
 #define NEWLIB_NANO_COMPAT_CAST(int64_t_var)  int64_t_var
 #endif
 
+__attribute__((unused)) static const char * TAG = "mbedtls_test";
+
 /*
  * All the following values are in big endian format, as required by the mbedTLS APIs
  */
diff --git a/components/soc/esp32h2/include/soc/Kconfig.soc_caps.in b/components/soc/esp32h2/include/soc/Kconfig.soc_caps.in
index 91cbc33d46..6009686a44 100644
--- a/components/soc/esp32h2/include/soc/Kconfig.soc_caps.in
+++ b/components/soc/esp32h2/include/soc/Kconfig.soc_caps.in
@@ -1075,6 +1075,10 @@ config SOC_ECDSA_USES_MPI
     bool
     default y
 
+config SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+    bool
+    default y
+
 config SOC_UART_NUM
     int
     default 2
diff --git a/components/soc/esp32h2/include/soc/soc_caps.h b/components/soc/esp32h2/include/soc/soc_caps.h
index 233c66c2b7..932888c9fe 100644
--- a/components/soc/esp32h2/include/soc/soc_caps.h
+++ b/components/soc/esp32h2/include/soc/soc_caps.h
@@ -462,6 +462,8 @@
 
 /*------------------------- ECDSA CAPS -------------------------*/
 #define SOC_ECDSA_USES_MPI                  (1)
+#define SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED   (1)
+
 /*-------------------------- UART CAPS ---------------------------------------*/
 // ESP32-H2 has 2 UARTs
 #define SOC_UART_NUM                (2)
diff --git a/docs/en/api-reference/peripherals/ecdsa.rst b/docs/en/api-reference/peripherals/ecdsa.rst
index d6e19cf5bc..ef96098b5a 100644
--- a/docs/en/api-reference/peripherals/ecdsa.rst
+++ b/docs/en/api-reference/peripherals/ecdsa.rst
@@ -60,6 +60,22 @@ Following code snippet uses :cpp:func:`esp_efuse_write_key` to set physical key
     }
 
 
+.. only:: SOC_ECDSA_P192_CURVE_DEFAULT_DISABLED
+
+    ECDSA Curve Configuration
+    -------------------------
+
+    .. only:: esp32h2
+
+        The ECDSA peripheral of the ESP32-H2 supports both ECDSA-P192 and ECDSA-P256 operations. However, starting with ESP32-H2 revision 1.2, only ECDSA-P256 operations are enabled by default. You can enable ECDSA-P192 operations using the following configuration options:
+
+    - :ref:`CONFIG_ESP_ECDSA_ENABLE_P192_CURVE` enables support for ECDSA-P192 curve operations, allowing the device to perform ECDSA operations with both 192-bit and 256-bit curves. However, if ECDSA-P192 operations have already been permanently disabled during eFuse write protection, enabling this option can not re-enable ECDSA-P192 curve operations.
+
+    - :cpp:func:`esp_efuse_enable_ecdsa_p192_curve_mode()` enables ECDSA-P192 curve operations programmatically by writing the appropriate value to the eFuse, allowing both P-192 and P-256 curve operations. Note that this API will fail if the eFuse is already write-protected.
+
+Non-Determinisitic Signature Generation
+---------------------------------------
+
 Dependency on TRNG
 ------------------