Add a buffer_size parameter to random byte generating function

Author: Andrzej Kurek

atecc608a_utils.c

@@ -62,7 +62,7 @@ psa_status_t atecc608a_check_config_locked()
     return status;
 }
 
-psa_status_t atecc608a_random(uint8_t *rand_out)
+psa_status_t atecc608a_random_32_bytes(uint8_t *rand_out, size_t buffer_size)
 {
     psa_status_t status = PSA_ERROR_GENERIC_ERROR;
 
@@ -71,6 +71,11 @@ psa_status_t atecc608a_random(uint8_t *rand_out)
         return PSA_ERROR_INVALID_ARGUMENT;
     }
 
+    if (buffer_size < 32)
+    {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
     ASSERT_SUCCESS_PSA(atecc608a_init());
     ASSERT_SUCCESS(atcab_random(rand_out));
 

atecc608a_utils.h

@@ -62,6 +62,6 @@ psa_status_t atecc608a_get_serial_number(uint8_t *buffer, size_t buffer_size,
 psa_status_t atecc608a_check_config_locked();
 
 /** Generate a 32 byte random number from the CryptoAuth device. */
-psa_status_t atecc608a_random(uint8_t *rand_out);
+psa_status_t atecc608a_random_32_bytes(uint8_t *rand_out, size_t buffer_size);
 
 #endif /* ATECC608A_SE_H */

main.c

@@ -124,7 +124,7 @@ psa_status_t test_write_read_slot(uint16_t slot)
     uint8_t data_write[TEST_WRITE_READ_SIZE] = {};
     uint8_t data_read[TEST_WRITE_READ_SIZE] = {};
 
-    ASSERT_SUCCESS_PSA(atecc608a_random(data_write));
+    ASSERT_SUCCESS_PSA(atecc608a_random_32_bytes(data_write, TEST_WRITE_READ_SIZE));
     ASSERT_SUCCESS_PSA(atecc608a_write(slot, 0, data_write, TEST_WRITE_READ_SIZE));
     ASSERT_SUCCESS_PSA(atecc608a_read(slot, 0, data_read, TEST_WRITE_READ_SIZE));
     ASSERT_STATUS(memcmp(data_write, data_read, TEST_WRITE_READ_SIZE),