Implement high-quality random number generation using AES-CTR mode wi…

…th OpenSSL and AES-NI support This commit introduces significant improvements to `nwipe`'s random number generation by implementing AES-CTR mode using OpenSSL with AES-NI hardware acceleration. The changes include: - **AES-CTR PRNG Implementation**: A new pseudo-random number generator (PRNG) based on AES-128 in counter (CTR) mode has been added. This PRNG uses OpenSSL’s EVP API for cryptographic operations, ensuring strong random number generation. - **AES-NI Hardware Support**: The PRNG now detects if the system supports AES-NI and uses hardware acceleration when available for improved performance, particularly on 64-bit systems. A new function `has_aes_ni()` checks for AES-NI support, ensuring that the fastest available option is used. - **Default PRNG Selection**: For 64-bit systems, AES-CTR is now the default PRNG due to its higher performance and security. On 32-bit systems, the XORoshiro-256 PRNG remains the default due to performance considerations. - **Improved Error Handling**: Error handling has been extensively revised. The AES-CTR PRNG now provides detailed error messages, including the detection of potential OpenSSL failures, and uses structured logging (`NWIPE_LOG_DEBUG` and `NWIPE_LOG_NOTICE`) to report PRNG initialization and errors. - **Memory Management**: Smart pointers have been introduced to manage memory automatically within the AES-CTR PRNG, preventing memory leaks. All memory used by the OpenSSL contexts (EVP_MD_CTX and EVP_CIPHER_CTX) is now properly cleaned up after use. - **Performance Enhancements**: The PRNG’s performance has been optimized, especially for 64-bit systems. Additionally, the code now checks for edge cases when reading remaining bytes, and memset is used to handle uninitialized memory areas. - **Formatting and Code Cleanup**: Deprecated SHA256 calls have been replaced with OpenSSL’s EVP API. Multiple formatting issues in various source files (`pass.c`, `options.c`, `gui.c`, etc.) have been fixed, improving code readability and compliance with the coding standards. - **Regression Fixes**: Several small regressions from previous changes have been fixed, including uninitialized variables, implicit function declarations, and incorrect function calls that previously led to warnings and potential crashes (e.g., segfaults in `pass.c`). - **Logging and Debugging**: Improved logging messages and detailed debug information have been added, particularly around the AES-CTR initialization and error handling paths. This implementation significantly improves the security, performance, and reliability of random number generation in `nwipe` and ensures that the tool is better equipped for modern cryptographic standards. Squashed commit of the following: commit 03284d7 Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri Aug 23 19:17:05 2024 +0200 Fixed formatting commit 31df3eb Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri Aug 23 19:15:01 2024 +0200 Fixed type error on i686 - uint64_t for AES-CTR commit e56a47c Merge: 3465260 d1edd05 Author: Fabian Druschke <fdruschke@outlook.com> Date: Tue Aug 20 10:39:26 2024 +0100 Merge branch 'master' into aes-ctr commit 3465260 Merge: 1bf5ff1 5140f92 Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri May 10 01:41:09 2024 +0200 Merge branch 'master' into aes-ctr commit 1bf5ff1 Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri May 10 01:14:11 2024 +0200 Added check for return value in prng.c and nwipe_log accordingly. commit 9015a32 Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri May 10 00:11:59 2024 +0200 Removed error handling using goto, now returning instead. Changed from void to int functions, removed cleanup(); on error , instead relying on cleanup routine on exit. commit 10ea2bb Author: Fabian Druschke <fdruschke@outlook.com> Date: Mon Apr 15 13:47:05 2024 +0200 Adapted the aes-ctr-prng accordingly, to report SANITY level errors, in case of failure. commit 71e7f8f Author: Fabian Druschke <fdruschke@outlook.com> Date: Mon Apr 15 13:46:35 2024 +0200 Added case handling for NWIPE_LOG_LEVEL_SANITY, providing the github issue link, if a SANITY level error occurs. commit 0f3e7f5 Author: Fabian Druschke <fdruschke@outlook.com> Date: Mon Apr 15 00:40:22 2024 +0200 Added check in pass.c wether nwipe_aes_ctr_prng is being used or not, if not a segfault was the result. Now fixed. commit ce09d8e Author: Fabian Druschke <fdruschke@outlook.com> Date: Sat Apr 13 00:58:34 2024 +0200 Missing NWIPE_LOG_NOTICE for AES-CTR init changed to DEBUG level. commit 8b284f3 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sat Apr 13 00:50:25 2024 +0200 Changed notification for successful PRNG init for AES-CTR to NWIPE_LOG_DEBUG. commit 8702cc3 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sat Apr 13 00:13:51 2024 +0200 Added missing cleanup routine in prior commit in aes_ctr_prng.c and header definitions. commit 35cd055 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sat Apr 13 00:12:01 2024 +0200 Fixed formatting in pass.c commit beff746 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sat Apr 13 00:11:28 2024 +0200 Added cleanup routine aes_ctr_prng_general_cleanup() after nwipe_random_pass and nwipe_random_verify in order to cleanup PRNG state. commit 1a95202 Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri Apr 12 23:25:04 2024 +0200 Part of the comments were missing, fixed. commit a65410a Author: Fabian Druschke <fdruschke@outlook.com> Date: Fri Apr 12 23:20:41 2024 +0200 Added extensive error handling, in order to check for OpenSSL library malfunction. commit 6518963 Author: Fabian Druschke <fdruschke@outlook.com> Date: Thu Apr 11 00:20:54 2024 +0200 Improved PRNG description for AES-CTR-256 in gui.c commit fe493cf Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 23:51:12 2024 +0200 Added function has_aes_ni() in order to check for AES-Ni support, and set the PRNG accordingly. commit adcd442 Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 15:40:24 2024 +0200 Handle edge case for remaining bytes in nwipe_aes_ctr_prng_read using memset. commit ce2db63 Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 15:08:25 2024 +0200 Fixed comments, indicating AES-CTR-128 instead of 256 bit commit da53ee0 Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 14:53:45 2024 +0200 Reverted by mistake nwipe_random back to nwipe_dodshort, now compliant with master commit e479239 Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 13:23:36 2024 +0200 Fixed formatting commit e0d9584 Author: Fabian Druschke <fdruschke@outlook.com> Date: Wed Apr 10 13:22:25 2024 +0200 Minor changes, added comments for further explanation. commit 7410d21 Author: Fabian Druschke <fdruschke@outlook.com> Date: Tue Apr 9 12:49:02 2024 +0200 Fixed uninitialized temp_buffer in aes_ctr_prng_genrand_uint256_to_buf commit cd5f071 Merge: 3cb78ca 2809580 Author: PartialVolume <22084881+PartialVolume@users.noreply.github.com> Date: Sun Apr 7 22:22:55 2024 +0100 Merge branch 'master' into aes-ctr commit 3cb78ca Author: Fabian Druschke <fdruschke@outlook.com> Date: Sun Mar 31 14:03:38 2024 +0200 Added error checking and nwipe_log to aes_ctr_prng.c commit 20fea0d Author: Fabian Druschke <fdruschke@outlook.com> Date: Sun Mar 31 13:54:54 2024 +0200 Only C implementation, removed CPP here. commit d5b39f6 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sun Mar 31 00:43:58 2024 +0100 Introduced smart pointers to manage memory for EVP_MD_CTX and EVP_CIPHER_CTX within the AES CTR PRNG C++ implementation. This ensures automatic resource release, preventing memory leaks and enhancing code safety. commit f6aeae3 Author: Fabian Druschke <fdruschke@outlook.com> Date: Sun Mar 31 00:34:15 2024 +0100 Created seamless integrated .cpp AES-CTR-PRNG in order to avoid memory issues. commit eecddb2 Author: Knogle <fdruschke@outlook.com> Date: Sun Mar 24 22:48:06 2024 +0000 aes_ctr_prng_init was missing in header, causing implicit declaration warnings. commit 8fe4db4 Author: Knogle <fdruschke@outlook.com> Date: Sun Mar 24 18:30:52 2024 +0000 Replaced traditional deprecated SHA256 declarations with EVP-API infrastructure commit 55472fb Author: Knogle <fdruschke@outlook.com> Date: Sun Mar 24 03:43:36 2024 +0000 To consider, AES-128-CTR as default option for 64-Bit, and Xoroshiro-256 as default option for 32-Bit due to performance and quality reasons. commit 1a964bc Author: Fabian Druschke <fabian@knogle.industries> Date: Sat Mar 23 19:12:24 2024 -0300 Fixed missing XORoshiro-256 in options.c bottom section. Added AES-128-CTR OpenSSL descriptions. commit cf9822a Author: Fabian Druschke <fabian@knogle.industries> Date: Sat Mar 23 18:48:38 2024 -0300 Several changes, adding AES-128 using libssl in CTR mode as new PRNG, in experimental state. Fixed formatting, fixed AES PRNG header.
Knogle · Sep 8, 2024 · 25693a9 · 25693a9
1 parent f250aee
commit 25693a9
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diff --git a/configure.ac b/configure.ac
@@ -50,6 +50,24 @@ PKG_CHECK_MODULES(
 	)]
 )
 
+PKG_CHECK_MODULES(
+    [OPENSSL],
+    [openssl],
+    [
+            CFLAGS="${CFLAGS} ${OPENSSL_CFLAGS}"
+            LIBS="${LIBS} ${OPENSSL_LIBS}"
+    ],
+    [AC_CHECK_LIB([ssl], [SSL_library_init], [
+            LIBS="-lssl -lcrypto $LIBS"
+            AC_CHECK_HEADERS(openssl/ssl.h,, [
+                AC_CHECK_HEADERS(openssl/crypto.h, [
+                    AC_DEFINE([OPENSSL_IN_SUBDIR], [openssl/], [Look for openssl headers in subdir])
+                    ], [AC_MSG_ERROR([openssl headers not found])])
+            ])
+        ], [AC_MSG_ERROR([OpenSSL development library not found])]
+    )]
+)
+
 PKG_CHECK_MODULES(
 	[LIBCONFIG],
 	[libconfig],

diff --git a/src/Makefile.am b/src/Makefile.am
@@ -6,5 +6,5 @@ AM_LDFLAGS =
 # this lists the binaries to produce, the (non-PHONY, binary) targets in
 # the previous manual Makefile
 bin_PROGRAMS = nwipe
-nwipe_SOURCES = context.h logging.h options.h prng.h version.h temperature.h nwipe.c gui.c method.h pass.c device.c gui.h isaac_rand/isaac_standard.h isaac_rand/isaac_rand.h isaac_rand/isaac_rand.c isaac_rand/isaac64.h isaac_rand/isaac64.c mt19937ar-cok/mt19937ar-cok.c nwipe.h mt19937ar-cok/mt19937ar-cok.h alfg/add_lagg_fibonacci_prng.h alfg/add_lagg_fibonacci_prng.c xor/xoroshiro256_prng.h xor/xoroshiro256_prng.c pass.h device.h logging.c method.c options.c prng.c version.c temperature.c PDFGen/pdfgen.h PDFGen/pdfgen.c create_pdf.c create_pdf.h embedded_images/shred_db.jpg.c embedded_images/shred_db.jpg.h  embedded_images/tick_erased.jpg.c embedded_images/tick_erased.jpg.h embedded_images/redcross.c embedded_images/redcross.h hpa_dco.h hpa_dco.c miscellaneous.h miscellaneous.c embedded_images/nwipe_exclamation.jpg.h embedded_images/nwipe_exclamation.jpg.c conf.h conf.c customers.h customers.c hddtemp_scsi/hddtemp.h hddtemp_scsi/scsi.h hddtemp_scsi/scsicmds.h hddtemp_scsi/get_scsi_temp.c hddtemp_scsi/scsi.c hddtemp_scsi/scsicmds.c
+nwipe_SOURCES = context.h logging.h options.h prng.h version.h temperature.h nwipe.c gui.c method.h pass.c device.c gui.h isaac_rand/isaac_standard.h isaac_rand/isaac_rand.h isaac_rand/isaac_rand.c isaac_rand/isaac64.h isaac_rand/isaac64.c mt19937ar-cok/mt19937ar-cok.c nwipe.h mt19937ar-cok/mt19937ar-cok.h alfg/add_lagg_fibonacci_prng.h alfg/add_lagg_fibonacci_prng.c xor/xoroshiro256_prng.h xor/xoroshiro256_prng.c aes/aes_ctr_prng.h aes/aes_ctr_prng.c pass.h device.h logging.c method.c options.c prng.c version.c temperature.c PDFGen/pdfgen.h PDFGen/pdfgen.c create_pdf.c create_pdf.h embedded_images/shred_db.jpg.c embedded_images/shred_db.jpg.h  embedded_images/tick_erased.jpg.c embedded_images/tick_erased.jpg.h embedded_images/redcross.c embedded_images/redcross.h hpa_dco.h hpa_dco.c miscellaneous.h miscellaneous.c embedded_images/nwipe_exclamation.jpg.h embedded_images/nwipe_exclamation.jpg.c conf.h conf.c customers.h customers.c hddtemp_scsi/hddtemp.h hddtemp_scsi/scsi.h hddtemp_scsi/scsicmds.h hddtemp_scsi/get_scsi_temp.c hddtemp_scsi/scsi.c hddtemp_scsi/scsicmds.c
 nwipe_LDADD = $(PARTED_LIBS) $(LIBCONFIG)
diff --git a/src/aes/aes_ctr_prng.c b/src/aes/aes_ctr_prng.c
@@ -0,0 +1,160 @@
+/*
+ * AES CTR PRNG Implementation
+ * Author: Fabian Druschke
+ * Date: 2024-03-13
+ *
+ * This header file contains definitions for the AES (Advanced Encryption Standard)
+ * implementation in CTR (Counter) mode for pseudorandom number generation, utilizing
+ * OpenSSL for cryptographic functions.
+ *
+ * As the author of this work, I, Fabian Druschke, hereby release this work into the public
+ * domain. I dedicate any and all copyright interest in this work to the public domain,
+ * making it free to use for anyone for any purpose without any conditions, unless such
+ * conditions are required by law.
+ *
+ * This software is provided "as is", without warranty of any kind, express or implied,
+ * including but not limited to the warranties of merchantability, fitness for a particular
+ * purpose and noninfringement. In no event shall the authors be liable for any claim,
+ * damages or other liability, whether in an action of contract, tort or otherwise, arising
+ * from, out of or in connection with the software or the use or other dealings in the software.
+ *
+ * USAGE OF OPENSSL IN THIS SOFTWARE:
+ * This software uses OpenSSL for cryptographic operations. Users are responsible for
+ * ensuring compliance with OpenSSL's licensing terms.
+ */
+
+#include "aes_ctr_prng.h"
+#include <openssl/evp.h>
+#include <openssl/sha.h>
+#include <openssl/err.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+typedef enum {
+    NWIPE_LOG_NONE = 0,
+    NWIPE_LOG_DEBUG,  // Debugging messages, detailed for troubleshooting
+    NWIPE_LOG_INFO,  // Informative logs, for regular operation insights
+    NWIPE_LOG_NOTICE,  // Notices for significant but non-critical events
+    NWIPE_LOG_WARNING,  // Warnings about potential errors
+    NWIPE_LOG_ERROR,  // Error messages, significant issues that affect operation
+    NWIPE_LOG_FATAL,  // Fatal errors, require immediate termination of the program
+    NWIPE_LOG_SANITY,  // Sanity checks, used primarily in debugging phases
+    NWIPE_LOG_NOTIMESTAMP  // Log entries without timestamp information
+} nwipe_log_t;
+
+extern void nwipe_log( nwipe_log_t level, const char* format, ... );
+
+/* Initializes the AES CTR pseudorandom number generator state.
+   This function sets up the cryptographic context necessary for generating
+   pseudorandom numbers using AES in CTR mode. It utilizes SHA-256 to derive
+   a key from the provided seed, ensuring that the PRNG output is unpredictable
+   and secure, provided the seed is kept secret and is sufficiently random.
+   - state: Pointer to the AES CTR PRNG state structure.
+   - init_key: Array containing the seed for key generation.
+   - key_length: Length of the seed array. */
+int aes_ctr_prng_init( aes_ctr_state_t* state, unsigned long init_key[], unsigned long key_length )
+{
+    assert( state != NULL && init_key != NULL && key_length > 0 );  // Validate inputs
+
+    unsigned char key[32];  // Storage for the 256-bit key
+    memset( state->ivec, 0, AES_BLOCK_SIZE );  // Clear IV buffer
+    state->num = 0;  // Reset the block counter
+    memset( state->ecount, 0, AES_BLOCK_SIZE );  // Clear encryption count buffer
+
+    nwipe_log( NWIPE_LOG_DEBUG, "Initializing AES CTR PRNG with provided seed." );  // Log initialization
+
+    EVP_MD_CTX* mdctx = EVP_MD_CTX_new();  // Create new SHA-256 context
+    if( !mdctx )
+    {
+        nwipe_log( NWIPE_LOG_FATAL,
+                   "Failed to allocate EVP_MD_CTX for SHA-256, return code: %d.",
+                   ERR_get_error() );  // Log context allocation failure
+        return -1;  // Handle error
+    }
+
+    if( EVP_DigestInit_ex( mdctx, EVP_sha256(), NULL ) != 1 )
+    {
+        nwipe_log( NWIPE_LOG_FATAL,
+                   "SHA-256 context initialization failed, return code: %d.",
+                   ERR_get_error() );  // Log init failure
+        return -1;  // Handle error
+    }
+
+    EVP_DigestUpdate(
+        mdctx, (const unsigned char*) init_key, key_length * sizeof( unsigned long ) );  // Process the seed
+
+    if( EVP_DigestFinal_ex( mdctx, key, NULL ) != 1 )
+    {
+        nwipe_log( NWIPE_LOG_FATAL,
+                   "SHA-256 hash finalization failed, return code: %d.",
+                   ERR_get_error() );  // Log finalization failure
+        return -1;  // Handle error
+    }
+    EVP_MD_CTX_free( mdctx );
+    mdctx = NULL;  // Clean up SHA-256 context
+
+    state->ctx = EVP_CIPHER_CTX_new();  // Create new AES-256-CTR context
+    if( !state->ctx )
+    {
+        nwipe_log( NWIPE_LOG_FATAL,
+                   "Failed to allocate EVP_CIPHER_CTX, return code: %d.",
+                   ERR_get_error() );  // Log cipher context failure
+        return -1;  // Handle error
+    }
+
+    if( EVP_EncryptInit_ex( state->ctx, EVP_aes_256_ctr(), NULL, key, state->ivec ) != 1 )
+    {
+        nwipe_log( NWIPE_LOG_FATAL,
+                   "AES-256-CTR encryption context initialization failed, return code: %d.",
+                   ERR_get_error() );  // Log encryption init failure
+        return -1;  // Handle error
+    }
+
+    nwipe_log( NWIPE_LOG_DEBUG, "AES CTR PRNG successfully initialized." );  // Log successful initialization
+    return 0;  // Exit successfully
+}
+/* Generates pseudorandom numbers and writes them to a buffer.
+   This function performs the core operation of producing pseudorandom data.
+   It directly updates the buffer provided, filling it with pseudorandom bytes
+   generated using the AES-256-CTR mode of operation.
+   - state: Pointer to the initialized AES CTR PRNG state.
+   - bufpos: Target buffer where the pseudorandom numbers will be written. */
+int aes_ctr_prng_genrand_uint256_to_buf( aes_ctr_state_t* state, unsigned char* bufpos )
+{
+    assert( state != NULL && bufpos != NULL );  // Validate inputs
+
+    unsigned char temp_buffer[32];  // Temporary storage for pseudorandom bytes
+    memset( temp_buffer, 0, sizeof( temp_buffer ) );  // Zero out temporary buffer
+    int outlen;  // Length of data produced by encryption
+
+    if( EVP_EncryptUpdate( state->ctx, temp_buffer, &outlen, temp_buffer, sizeof( temp_buffer ) ) != 1 )
+    {
+        nwipe_log( NWIPE_LOG_ERROR,
+                   "Failed to generate pseudorandom numbers, return code: %d.",
+                   ERR_get_error() );  // Log generation failure
+        return -1;  // Handle error
+    }
+
+    memcpy( bufpos, temp_buffer, sizeof( temp_buffer ) );  // Copy pseudorandom bytes to buffer
+    return 0;  // Exit successfully
+}
+// General cleanup function for AES CTR PRNG
+int aes_ctr_prng_general_cleanup( aes_ctr_state_t* state )
+{
+    if( state != NULL )
+    {
+        // Free the EVP_CIPHER_CTX if it has been allocated
+        if( state->ctx )
+        {
+            EVP_CIPHER_CTX_free( state->ctx );
+            state->ctx = NULL;  // Nullify the pointer after free
+        }
+
+        // Clear sensitive information from the state
+        memset( state->ivec, 0, AES_BLOCK_SIZE );
+        memset( state->ecount, 0, AES_BLOCK_SIZE );
+        state->num = 0;
+    }
+    return 0;
+}
diff --git a/src/aes/aes_ctr_prng.h b/src/aes/aes_ctr_prng.h
@@ -0,0 +1,51 @@
+/*
+ * AES CTR PRNG Definitions
+ * Author: Fabian Druschke
+ * Date: 2024-03-13
+ *
+ * This header file contains definitions for the AES (Advanced Encryption Standard)
+ * implementation in CTR (Counter) mode for pseudorandom number generation, utilizing
+ * OpenSSL for cryptographic functions.
+ *
+ * As the author of this work, I, Fabian Druschke, hereby release this work into the public
+ * domain. I dedicate any and all copyright interest in this work to the public domain,
+ * making it free to use for anyone for any purpose without any conditions, unless such
+ * conditions are required by law.
+ *
+ * This software is provided "as is", without warranty of any kind, express or implied,
+ * including but not limited to the warranties of merchantability, fitness for a particular
+ * purpose and noninfringement. In no event shall the authors be liable for any claim,
+ * damages or other liability, whether in an action of contract, tort or otherwise, arising
+ * from, out of or in connection with the software or the use or other dealings in the software.
+ *
+ * USAGE OF OPENSSL IN THIS SOFTWARE:
+ * This software uses OpenSSL for cryptographic operations. Users are responsible for
+ * ensuring compliance with OpenSSL's licensing terms.
+ */
+
+#ifndef AES_CTR_RNG_H
+#define AES_CTR_RNG_H
+
+#include <stdint.h>
+#include <openssl/aes.h>
+#include <openssl/evp.h>
+
+// Structure to store the state of the AES-CTR random number generator
+typedef struct
+{
+    EVP_CIPHER_CTX* ctx;
+    unsigned char ivec[AES_BLOCK_SIZE];
+    unsigned int num;
+    unsigned char ecount[AES_BLOCK_SIZE];
+} aes_ctr_state_t;
+
+// Initializes the AES-CTR random number generator
+int aes_ctr_prng_init( aes_ctr_state_t* state, unsigned long init_key[], unsigned long key_length );
+
+// Generates a 256-bit random number using AES-CTR and stores it directly in the output buffer
+int aes_ctr_prng_genrand_uint256_to_buf( aes_ctr_state_t* state, unsigned char* bufpos );
+
+// General cleanup function for AES CTR PRNG
+int aes_ctr_prng_general_cleanup( aes_ctr_state_t* state );
+
+#endif  // AES_CTR_RNG_H
diff --git a/src/gui.c b/src/gui.c
@@ -1616,11 +1616,12 @@ void nwipe_gui_prng( void )
     extern nwipe_prng_t nwipe_aes_ctr_prng;
     extern nwipe_prng_t nwipe_xoroshiro256_prng;
     extern nwipe_prng_t nwipe_add_lagg_fibonacci_prng;
+    extern nwipe_prng_t nwipe_aes_ctr_prng;
 
     extern int terminate_signal;
 
     /* The number of implemented PRNGs. */
-    const int count = 5;
+    const int count = 6;
 
     /* The first tabstop. */
     const int tab1 = 2;
@@ -1662,6 +1663,10 @@ void nwipe_gui_prng( void )
     {
         focus = 4;
     }
+    if( nwipe_options.prng == &nwipe_aes_ctr_prng )
+    {
+        focus = 5;
+    }
     do
     {
         /* Clear the main window. */
@@ -1678,6 +1683,7 @@ void nwipe_gui_prng( void )
         mvwprintw( main_window, yy++, tab1, "  %s", nwipe_isaac64.label );
         mvwprintw( main_window, yy++, tab1, "  %s", nwipe_add_lagg_fibonacci_prng.label );
         mvwprintw( main_window, yy++, tab1, "  %s", nwipe_xoroshiro256_prng.label );
+        mvwprintw( main_window, yy++, tab1, "  %s", nwipe_aes_ctr_prng.label );
         yy++;
 
         /* Print the cursor. */
@@ -1852,6 +1858,49 @@ void nwipe_gui_prng( void )
                            tab1,
                            "especially for legacy systems, due to its efficiency and minimal demands.  " );
                 break;
+            case 5:
+
+                mvwprintw(
+                    main_window, yy++, tab1, "AES-256 in Counter Mode (CTR), securely implemented by Fabian Druschke" );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "within nwipe using OpenSSL, leverages the cryptographic robustness and " );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "efficiency of AES for generating high-quality pseudo-random numbers.   " );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "                                                                            " );
+                mvwprintw(
+                    main_window, yy++, tab1, "This adaptation emphasizes the utilization of AES New Instructions    " );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "(AES-NI) starting from the Westmere-EP microarchitecture, enhancing the" );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "performance and security for data wiping applications. The integration " );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "of AES-NI accelerates cryptographic computations, making AES-256 CTR an" );
+                mvwprintw( main_window, yy++, tab1, "ideal choice for efficient and secure data erasure in nwipe." );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "                                                                            " );
+                mvwprintw( main_window,
+                           yy++,
+                           tab1,
+                           "Compliant with NIST SP 800-38A for cryptographic standards, AES-256 CTR" );
+                mvwprintw(
+                    main_window, yy++, tab1, "stands as the world gold standard for data encryption techniques." );
+                mvwprintw( main_window, yy++, tab1, "Intended to be used only with 64-Bit CPUs, supporting AES-Ni." );
+                break;
         }
 
         /* switch */
@@ -1922,6 +1971,10 @@ void nwipe_gui_prng( void )
                 {
                     nwipe_options.prng = &nwipe_xoroshiro256_prng;
                 }
+                if( focus == 5 )
+                {
+                    nwipe_options.prng = &nwipe_aes_ctr_prng;
+                }
                 return;
 
             case KEY_BACKSPACE:

diff --git a/src/logging.c b/src/logging.c
@@ -411,6 +411,10 @@ void nwipe_log( nwipe_log_t level, const char* format, ... )
     {
         fprintf( stderr, "nwipe_log: pthread_mutex_unlock failed. Code %i \n", r );
     }
+    if( level == NWIPE_LOG_SANITY )
+    {
+        nwipe_log( NWIPE_LOG_NOTICE, "Please report this bug to %s." NWIPE_GITHUB_ISSUE_URL );
+    }
     return;
 
 } /* nwipe_log */

diff --git a/src/nwipe.h b/src/nwipe.h
@@ -108,6 +108,8 @@ typedef unsigned char u8;
 
 #define THREAD_CANCELLATION_TIMEOUT 10
 
+#define NWIPE_GITHUB_ISSUE_URL "https://github.com/martijnvanbrummelen/nwipe/issues"
+
 /* This is required for ioctl FDFLUSH. */
 #include <linux/fd.h>