feat(core/prodtest): Check for device S/N in device certificates.

diff --git a/core/embed/projects/prodtest/README.md b/core/embed/projects/prodtest/README.md
index db9c09b4..4f091fc7 100644
--- a/core/embed/projects/prodtest/README.md
+++ b/core/embed/projects/prodtest/README.md
@@ -700,7 +700,8 @@ OK 638c8a83ddc8fd84cddf5a0a4fa3d9615146cd341685dca942bab1132c2bc99b
 ```
 
 ### secrets-certdev-write
-Writes the X.509 device attestation certificate issued by the Trezor Company for the attestation key stored in MCU.
+Writes the X.509 device attestation certificate issued by the Trezor Company for the attestation key stored in the MCU.
+The `otp-device-sn-write` command must be executed before calling this command.
 
 Example:
 ```
@@ -709,7 +710,7 @@ OK
 ```
 
 ### secrets-certdev-read
-Retrieves the X.509 device attestation certificate issued by the Trezor Company for the attestation key stored in MCU.
+Retrieves the X.509 device attestation certificate issued by the Trezor Company for the attestation key stored in the MCU.
 
 Example:
 ```
@@ -746,6 +747,7 @@ OK <hexadecimal string>
 
 ### optiga-certdev-write
 Writes the X.509 certificate issued by the Trezor Company for the device attestation key stored in Optiga.
+The `otp-device-sn-write` command must be executed before calling this command.
 
 Example:
 ```
@@ -1008,7 +1010,7 @@ OK 00000300
 
 ### tropic-get-chip-id
 
-Reads the Tropic chip ID. The command returns `OK` followed by the chip ID.
+Reads the Tropic chip ID. The command returns `OK` followed by the 128-byte serialization of `lt_chip_id_t`.
 
 Example:
 ```
@@ -1119,6 +1121,7 @@ OK <hexadecimal string>
 ### tropic-certdev-write
 
 Writes the X.509 certificate issued by the Trezor Company for the device attestation key stored in Tropic.
+The `otp-device-sn-write` command must be executed before calling this command.
 
 Example:
 ```
diff --git a/core/embed/projects/prodtest/cmd/common.c b/core/embed/projects/prodtest/cmd/common.c
index 4d0186f5..ed772708 100644
--- a/core/embed/projects/prodtest/cmd/common.c
+++ b/core/embed/projects/prodtest/cmd/common.c
@@ -19,6 +19,7 @@
 
 #include <trezor_model.h>
 #include <trezor_rtl.h>
+#include <util/unit_properties.h>
 
 #include "common.h"
 
@@ -63,6 +64,13 @@ static const uint8_t OID_COMMON_NAME[] = {
     0x55, 0x04, 0x03, // corresponds to commonName in X.509
 };
 
+#if !(defined TREZOR_MODEL_T3B1 || defined TREZOR_MODEL_T3T1)
+static const uint8_t OID_SERIAL_NUMBER[] = {
+  0x06, 0x03, // an OID of 3 bytes
+    0x55, 0x04, 0x05, // corresponds to serialNumber in X.509
+};
+#endif
+
 static const uint8_t SUBJECT_COMMON_NAME[] = {
 #ifdef TREZOR_MODEL_T2B1
   'T', '2', 'B', '1', ' ', 'T', 'r', 'e', 'z', 'o', 'r', ' ', 'S', 'a', 'f', 'e', ' ', '3',
@@ -184,44 +192,51 @@ static bool get_authority_key_digest(cli_t* cli, DER_ITEM* tbs_cert,
   return true;
 }
 
-static bool get_common_name(DER_ITEM* name, const uint8_t** common_name,
-                            size_t* common_name_size) {
+static bool get_name_attribute(DER_ITEM* name, const uint8_t* type,
+                               size_t type_size, const uint8_t** value,
+                               size_t* value_size) {
   if (name->id != DER_SEQUENCE) {
     return false;
   }
 
-  DER_ITEM distinguished_name = {0};
-  if (!der_read_item(&name->buf, &distinguished_name) ||
-      distinguished_name.id != DER_SET) {
-    return false;
-  }
+  DER_ITEM relative_distinguished_name = {0};
+  while (der_read_item(&name->buf, &relative_distinguished_name)) {
+    if (relative_distinguished_name.id != DER_SET) {
+      return false;
+    }
 
-  DER_ITEM attribute = {0};
-  if (!der_read_item(&distinguished_name.buf, &attribute) ||
-      attribute.id != DER_SEQUENCE) {
-    return false;
-  }
+    DER_ITEM attribute = {0};
+    if (!der_read_item(&relative_distinguished_name.buf, &attribute) ||
+        attribute.id != DER_SEQUENCE) {
+      return false;
+    }
 
-  DER_ITEM attribute_type = {0};
-  if (!der_read_item(&attribute.buf, &attribute_type) ||
-      attribute_type.buf.size != sizeof(OID_COMMON_NAME) ||
-      memcmp(attribute_type.buf.data, OID_COMMON_NAME,
-             sizeof(OID_COMMON_NAME)) != 0) {
-    return false;
-  }
+    DER_ITEM attribute_type = {0};
+    if (!der_read_item(&attribute.buf, &attribute_type)) {
+      return false;
+    }
 
-  DER_ITEM attribute_value = {0};
-  if (!der_read_item(&attribute.buf, &attribute_value) ||
-      attribute_value.id != DER_UTF8_STRING) {
-    return false;
-  }
+    if (attribute_type.buf.size != type_size ||
+        memcmp(attribute_type.buf.data, type, type_size) != 0) {
+      continue;
+    }
 
-  if (!buffer_ptr(&attribute_value.buf, common_name)) {
-    return false;
+    DER_ITEM attribute_value = {0};
+    if (!der_read_item(&attribute.buf, &attribute_value) ||
+        (attribute_value.id != DER_UTF8_STRING &&
+         attribute_value.id != DER_PRINTABLE_STRING)) {
+      return false;
+    }
+
+    if (!buffer_ptr(&attribute_value.buf, value)) {
+      return false;
+    }
+    *value_size = buffer_remaining(&attribute_value.buf);
+    return true;
   }
-  *common_name_size = buffer_remaining(&attribute_value.buf);
 
-  return true;
+  // Attribute not found.
+  return false;
 }
 
 static bool verify_signature(alg_id_t alg_id, const uint8_t* pub_key,
@@ -333,7 +348,9 @@ bool check_cert_chain(cli_t* cli, const uint8_t* chain, size_t chain_size,
       // Check the common name of the subject of the device certificate.
       const uint8_t* common_name = NULL;
       size_t common_name_size = 0;
-      if (!get_common_name(&subject, &common_name, &common_name_size) ||
+      if (!get_name_attribute(&subject, OID_COMMON_NAME,
+                              sizeof(OID_COMMON_NAME), &common_name,
+                              &common_name_size) ||
           common_name_size != sizeof(SUBJECT_COMMON_NAME) ||
           memcmp(common_name, SUBJECT_COMMON_NAME,
                  sizeof(SUBJECT_COMMON_NAME)) != 0) {
@@ -341,6 +358,33 @@ bool check_cert_chain(cli_t* cli, const uint8_t* chain, size_t chain_size,
                   "check_device_cert_chain, invalid common name.");
         return false;
       }
+
+#if !(defined TREZOR_MODEL_T3B1 || defined TREZOR_MODEL_T3T1)
+      // Check that the serial number of the subject, matches the device.
+      uint8_t device_sn[MAX_DEVICE_SN_SIZE] = {0};
+      size_t device_sn_size = 0;
+      if (!get_device_sn(device_sn, sizeof(device_sn), &device_sn_size) ||
+          device_sn_size == 0) {
+        cli_error(cli, CLI_ERROR,
+                  "check_device_cert_chain, device_sn not set.");
+      }
+
+      const uint8_t* subject_sn = NULL;
+      size_t subject_sn_size = 0;
+      if (!get_name_attribute(&subject, OID_SERIAL_NUMBER,
+                              sizeof(OID_SERIAL_NUMBER), &subject_sn,
+                              &subject_sn_size)) {
+        cli_error(cli, CLI_ERROR,
+                  "check_device_cert_chain, device_sn not set.");
+      }
+
+      if (subject_sn_size != device_sn_size ||
+          memcmp(subject_sn, device_sn, device_sn_size) != 0) {
+        cli_error(cli, CLI_ERROR,
+                  "check_device_cert_chain, serial number mismatch.");
+        return false;
+      }
+#endif
     }
 
     // Read the Subject Public Key Info.
diff --git a/core/embed/projects/prodtest/main.c b/core/embed/projects/prodtest/main.c
index 5488b441..d03f2413 100644
--- a/core/embed/projects/prodtest/main.c
+++ b/core/embed/projects/prodtest/main.c
@@ -197,13 +197,11 @@ void prodtest_show_homescreen(void) {
   memset(&g_layout, 0, sizeof(g_layout));
   g_layout.set = true;
 
-  static char device_sn[FLASH_OTP_BLOCK_SIZE] = {0};
-
-  if (sectrue == flash_otp_read(FLASH_OTP_BLOCK_DEVICE_SN, 0,
-                                (uint8_t *)device_sn, sizeof(device_sn)) &&
-      (device_sn[0] != 0xFF)) {
-    screen_prodtest_welcome(&g_layout.layout, device_sn,
-                            strnlen(device_sn, sizeof(device_sn) - 1));
+  static char device_sn[MAX_DEVICE_SN_SIZE] = {0};
+  size_t device_sn_size = 0;
+  if (get_device_sn((uint8_t *)device_sn, sizeof(device_sn) - 1,
+                    &device_sn_size)) {
+    screen_prodtest_welcome(&g_layout.layout, device_sn, device_sn_size);
   } else {
     screen_prodtest_welcome(&g_layout.layout, NULL, 0);
   }
diff --git a/core/embed/util/unit_properties/inc/util/unit_properties.h b/core/embed/util/unit_properties/inc/util/unit_properties.h
index be813ff1..163302b9 100644
--- a/core/embed/util/unit_properties/inc/util/unit_properties.h
+++ b/core/embed/util/unit_properties/inc/util/unit_properties.h
@@ -21,6 +21,8 @@
 
 #include <trezor_types.h>
 
+#define MAX_DEVICE_SN_SIZE 31
+
 #ifdef SECURE_MODE
 
 // Initializes module a detects the unit properties
@@ -64,3 +66,6 @@ void unit_properties_get(unit_properties_t* props);
 
 // Gets a pointer to the static unit properties structure
 const unit_properties_t* unit_properties(void);
+
+bool get_device_sn(uint8_t* device_sn, size_t max_device_sn_size,
+                   size_t* device_sn_size);
diff --git a/core/embed/util/unit_properties/stm32/unit_properties.c b/core/embed/util/unit_properties/stm32/unit_properties.c
index d7716472..37712732 100644
--- a/core/embed/util/unit_properties/stm32/unit_properties.c
+++ b/core/embed/util/unit_properties/stm32/unit_properties.c
@@ -160,6 +160,26 @@ void unit_properties_get(unit_properties_t* props) {
   *props = drv->cache;
 }
 
+bool get_device_sn(uint8_t* device_sn, size_t max_device_sn_size,
+                   size_t* device_sn_size) {
+  uint8_t block[FLASH_OTP_BLOCK_SIZE] = {0};
+  // The OTP block should contain a null-terminated string when set.
+  if (sectrue !=
+          flash_otp_read(FLASH_OTP_BLOCK_DEVICE_SN, 0, block, sizeof(block)) ||
+      block[0] == 0xFF) {
+    return false;
+  }
+
+  size_t len = strnlen((char*)block, sizeof(block));
+  if (len > max_device_sn_size) {
+    return false;
+  }
+
+  memcpy(device_sn, block, len);
+  *device_sn_size = len;
+  return true;
+}
+
 #endif  // SECURE_MODE
 
 const unit_properties_t* unit_properties(void) {
diff --git a/core/embed/util/unit_properties/unix/unit_properties.c b/core/embed/util/unit_properties/unix/unit_properties.c
index c6585d2b..f161a269 100644
--- a/core/embed/util/unit_properties/unix/unit_properties.c
+++ b/core/embed/util/unit_properties/unix/unit_properties.c
@@ -78,3 +78,15 @@ const unit_properties_t* unit_properties(void) {
 
   return &cache;
 }
+
+bool get_device_sn(uint8_t* device_sn, size_t max_device_sn_size,
+                   size_t* device_sn_size) {
+  uint8_t sn[] = "12345678901234";
+  if (max_device_sn_size < sizeof(sn) - 1) {
+    return false;
+  }
+
+  memcpy(device_sn, sn, sizeof(sn) - 1);
+  *device_sn_size = sizeof(sn) - 1;
+  return true;
+}
diff --git a/crypto/der.h b/crypto/der.h
index 1888d8a7..2836a3c6 100644
--- a/crypto/der.h
+++ b/crypto/der.h
@@ -33,6 +33,7 @@
 #define DER_SEQUENCE 0x30
 #define DER_SET 0x31
 #define DER_UTF8_STRING 0x0c
+#define DER_PRINTABLE_STRING 0x13
 #define DER_INTEGER 0x02
 #define DER_BIT_STRING 0x03
 #define DER_OCTET_STRING 0x04