This is a text-only version of the following page on https://raymii.org:
---
Title       : 	Use the Nitrokey HSM or SmartCard-HSM with sc-hsm-embedded, mod_nss and Apache (read only module)
Author      : 	Remy van Elst
Date        : 	15-07-2016
URL         : 	https://raymii.org/s/articles/Use_the_Nitrokey_HSM_or_SmartCard-HSM_with_sc-hsm-embedded_mod_nss_and_Apache_read_only_module.html
Format      : 	Markdown/HTML
---



![][1]

> The NitroKey HSM in a sealed package

This is a guide on using the Nitrokey HSM with sc-hsm-embedded module instead of
the PC/SC daemon and OpenSC, mod_nss and the Apache webserver. This is an
extension on the earlier guide, with new benchmarks. The sc-hsm-embedded module
is not using a global lock like OpenSC, therefore providing better performance.
The sc-hsm-embedded module is also a read only module, suitable for embedded
systems. Read only also makes it more secure when deployed, even when the user
pin leaks out an attacker cannot create new keypairs or delete the current ones.

The HSM allows you to store the private key for a SSL certificate inside the HSM
(instead of on the filesystem), so that it can never leave the device and thus
never be stolen.

The guide covers the installation of the sc-hsm-embedded module, configuration
of and benchmarks from Apache with the HSM and different key sizes.

### Introduction

![][2]

> The SmartCard-HSM

The [Nitrokey HSM][3] is an open hardware and open software device. It is a USB
version of the [SmartCard-HSM][4]. Both the [SmartCard-HSM][5] as the [Nitrokey
HSM][6] have sources available and are fully supported by the [OpenSC][7]
project.

If you are new to the NitroKey HSM/SmartCard HSM, please also [read my getting
started][8] article. It explains what the HSM is, how to set it up and how to
use it with OpenSSH for example.

I have [multiple articles][9] on this nice device, so make sure to read the
others as well.

To follow this article, I recommend you first read the [article on the Nitrokey
HSM with mod_nss and Apache][10] I wrote earlier. The other article has more
explanation and examples, this article will focus on the installation of the
module and the benchmarks.

In a recent conversation I had with Andreas Schwier, one of the people behind
the [SmardCard-HSM][4] project, I was informed about the `sc-hsm-embedded`
module. Andreas told me that they, in [their load tests][11], experienced bad
performance with OpenSC because of a global lock. Their benchmarks were done
with their own PKCS#11 module, which we are covering here in this article.

The `sc-hsm-embedded` is described as:

    
    
    Light-weight, read-only PKCS#11 library for using the SmartCard-HSM in embedded systems.
    

So you will not be able to create keypairs with this module or write
certificates to the HSM.

This guide was tested on Ubuntu 14.04 and Arch Linux with a NitroKey HSM.

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### Installation of the sc-hsm-embedded module

For Arch Linux [I made an AUR package][13] of the module [and an AUR
package][14] for the OpenSSL Engine.

Do note that you can install this module next to the OpenSC package. They don't
conflict with one another.

On Ubuntu, install the development tools and pcsclite packages:

    
    
    apt-get install automake build-essential pkg-config libtool libusb-1.0-0-dev libpcsclite-dev checkinstall
    

Clone the git repository:

    
    
    git clone https://github.com/CardContact/sc-hsm-embedded.git sc-hsm-embedded-2.9
    cd sc-hsm-embedded-2.9
    

Execute the following commands to generate a `/.configure` file using the
`autotools`:

    
    
    libtoolize --force
    aclocal
    autoheader
    automake --force-missing --add-missing
    autoconf
    

Continue the compilation:

    
    
    ./configure
    make
    

I like to create a debian package with `checkinstall` instead of a `make
install`. It's certainly not the official way to create debian packages, but it
does allow you to keep a system clean and allows for easier upgrading. Also, a
package is much more convinient if you are distributing it in a repo or with
Ansible. Create the package:

    
    
    checkinstall
    

The default settings should be OK, but change them as you like. The final output
should be along the lines of:

    
    
    **********************************************************************
    
     Done. The new package has been installed and saved to
    
     /root/repo/sc-hsm-embedded-2.9/sc-hsm-embedded_2.9-1_amd64.deb
    
     You can remove it from your system anytime using: 
    
          dpkg -r sc-hsm-embedded
    
    **********************************************************************
    

On any other distro, use their native way to build a package (hi `PKGBUILD`) or
just do a plain simple `make install`.

There should now be a new library on your system:

    
    
    file /usr/local/lib/libsc-hsm-pkcs11.so
    /usr/local/lib/libsc-hsm-pkcs11.so: ELF 64-bit LSB  shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=1ede3f07f0094711931f5e25d9716622742356da, stripped
    

On Arch:

    
    
    file /usr/lib/libsc-hsm-pkcs11.so
    /usr/lib/libsc-hsm-pkcs11.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=3854bdd3a096b19c927817a486140bc2750555f8, stripped
    

Later in the article, place the correct path to this `.so` file in the
configuration. Or, if you want to be able to copy and paste the commands, create
a symlink:

    
    
    ln -s /usr/lib/libsc-hsm-pkcs11.so /usr/local/lib/libsc-hsm-pkcs11.so
    

You can test the new module with their own test tool or `pkcs11-tool`:

    
    
    pkcs11-tool --module libsc-hsm-pkcs11.so --login --pin 648219 --show-info
    

Output:

    
    
    Cryptoki version 2.20
    Manufacturer     CardContact (www.cardcontact.de)
    Library          SmartCard-HSM R/O with PC/SC (ver 2.8)
    Using slot 1 with a present token (0x5)
    

Compared with the `opensc-pkcs11` module:

    
    
     pkcs11-tool --module opensc-pkcs11.so --login --show-info --pin 648219
    

Output:

    
    
    Cryptoki version 2.20
    Manufacturer     OpenSC Project
    Library          OpenSC smartcard framework (ver 0.16)
    Using slot 1 with a present token (0x4)
    

You will notice that most operations with `pkcs11-tool`, like creating a
keypair, will fail:

    
    
    pkcs11-tool --module libsc-hsm-pkcs11.so --login --pin 648219 --keypairgen --key-type rsa:1024 --id 1 --label "HSM RSA Key Remy"
    

Output:

    
    
    Using slot 1 with a present token (0x5)
    error: Generate RSA mechanism not supported
    
    Aborting.
    

This is expected since it's a read only module. Read only also makes it more
secure when deployed, even when the user pin leaks out an attacker cannot create
new keypairs or delete the current ones.

A delete operation will not give any error messages:

    
    
    pkcs11-tool --module libsc-hsm-pkcs11.so --login --pin 648219 --delete-object --type privkey --id 3
    

Output:

    
    
    Using slot 1 with a present token (0x5)
    

But, if you list the objects before and after you will see that the key you
tried to delete is still there.

Just listing data does work:

    
    
    pkcs11-tool --module libsc-hsm-pkcs11.so --login --pin 648219 --list-objects --id 01
    

Output:

    
    
    Using slot 1 with a present token (0x5)
    Public Key Object; RSA 2048 bits
      label:      1024cert
      ID:         03
      Usage:      encrypt, verify
    Certificate Object, type = X.509 cert
      label:      1024cert
      ID:         03
    

Reading the data does work as well:

    
    
    pkcs11-tool --module libsc-hsm-pkcs11.so --login --pin 648219 --read-object --id 1 --type cert | base64
    

Output:

    
    
    Using slot 1 with a present token (0x5)
    MIIDcjCCAloCCQDIi8zcoGtnejANBgkqhkiG9w0BAQsFADB7MQswCQYDVQQGEwJOTDEVMBMGA1UE
    [...]
    qJ49qqLd5I24yKXxh9qTYrXDxHPAExqXHnwydXiDRQ==
    

### Creating the keys and certificates

We will now start with creating the keypairs in the HSM and generating the
certificates.

Please do read the [article on the Nitrokey HSM with mod_nss and Apache][10] to
find out how to fully configure the NitroKey HSM/SmartCard HSM with `mod_nss`.
This is a more compact version without all the explanation.

I did create three test keypairs, one `RSA 1024` bit, one `RSA 2048` bit and one
`EC` pair. They have ID 1, 2 and, suprisingly, 3. If you want to follow along,
also create the keys. Start with the 1024 bit key:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --keypairgen --key-type rsa:1024 --id 1 --label "httpd1024" 
    

Output:

    
    
    Key pair generated:
    Private Key Object; RSA 
      label:      httpd1024
      ID:         01
      Usage:      decrypt, sign, unwrap
    Public Key Object; RSA 1024 bits
      label:      httpd1024
      ID:         01
      Usage:      encrypt, verify, wrap
    

2048 bit key:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --keypairgen --key-type rsa:2048 --id 2 --label "httpd2048" 
    

Output:

    
    
    Key pair generated:
    Private Key Object; RSA 
      label:      httpd2048
      ID:         02
      Usage:      decrypt, sign, unwrap
    Public Key Object; RSA 2048 bits
      label:      httpd2048
      ID:         02
      Usage:      encrypt, verify, wrap
    

And the EC key:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --keypairgen --key-type EC:prime256v1 --id 3 --label "httpdECprime256v1"
    

Output:

    
    
    Private Key Object; EC
      label:      httpdECprime256v1
      ID:         03
      Usage:      sign, derive
    Public Key Object; EC  EC_POINT 256 bits
      EC_POINT:   044104ca3ff52e48bd85f3878ef8e1b59498c9fcc7741a1e547f2849ff4a5f716d96ea49ab8f25c61e7b4ad899fd3df8996767e70672ceb9297758695810fbc30ba660
      EC_PARAMS:  06082a8648ce3d030107
      label:      httpdECprime256v1
      ID:         03
      Usage:      verify
    

We need to generate (self signed) certificates for all of these keypairs. We
will use OpenSSL with a configfile do to that. See [my tutorial on the Nitrokey
if you want to generate a CSR and what to put in][15] `hsm.conf`.

I did have some issues when providing the slot and ID, OpenSSL gave errors like
these:

    
    
    engine "pkcs11" set.
    Invalid slot number: 1
    PKCS11_get_private_key returned NULL
    cannot load Private Key from engine
    140378622912152:error:26096080:engine routines:ENGINE_load_private_key:failed loading private key:eng_pkey.c:124:
    unable to load Private Key
    

Turns out, I was using the wrong slot number:

    
    
    pkcs11-tool --list-slots
    

Output:

    
    
    Available slots:
    Slot 0 (0x0): Lenovo Integrated Smart Card Reader 00 00
      (empty)
    Slot 1 (0x4): Nitrokey Nitrokey HSM (010000000000000000000000) 01 00
      token label        : SmartCard-HSM (UserPIN)
      token manufacturer : www.CardContact.de
      token model        : PKCS#15 emulated
      token flags        : rng, login required, PIN initialized, token initialized
      hardware version   : 24.13
      firmware version   : 2.0
      serial num         : DENK0100186
    

I was using slot 1, but that did not work. Slot 4 (`0x4`) did work. You can
provide the slot and ID to OpenSSL in multiple formats:

    
    
    supported formats: <id>, <slot>:<id>, id_<id>, slot_<slot>-id_<id>, label_<label>, slot_<slot>-label_<label>
    where <slot> is the slot number as normal integer,
    and <id> is the id number as hex string.
    and <label> is the textual key label string.
    

Generate the 1024 bit RSA certificate with ID 1:

    
    
    OPENSSL_CONF=./hsm.conf openssl req -engine pkcs11 -keyform engine -new -key slot_4-id_1 -nodes -days 3560 -x509 -sha256 -out "rsa1024.tst.raymii.org.pem" -subj "/C=NL/ST=Zuid Holland/L=Rotterdam/O=Sparkling Network/OU=IT Dept/CN=rsa1024.tst.raymii.org"
    

The 2048 bit RSA certificate with ID 2:

    
    
    OPENSSL_CONF=./hsm.conf openssl req -engine pkcs11 -keyform engine -new -key slot_4-id_2 -nodes -days 3560 -x509 -sha256 -out "rsa2048.tst.raymii.org.pem" -subj "/C=NL/ST=Zuid Holland/L=Rotterdam/O=Sparkling Network/OU=IT Dept/CN=rsa2048.tst.raymii.org"
    

The EC certificate:

    
    
    OPENSSL_CONF=./hsm.conf openssl req -engine pkcs11 -keyform engine -new -key slot_4-id_3 -nodes -days 3560 -x509 -sha256 -out "httpdECprime256v1.tst.raymii.org.pem" -subj "/C=NL/ST=Zuid Holland/L=Rotterdam/O=Sparkling Network/OU=IT Dept/CN=httpdECprime256v1.tst.raymii.org"
    

Do note that you can also generate a CSR and submit that to your certificate
provider The getting started article covers that as well.

Convert the PEM certificates into DER format, since DER is what the HSM uses:

    
    
    openssl x509 -in rsa1024.tst.raymii.org.pem -out rsa1024.tst.raymii.org.der -outform der
    
    openssl x509 -in rsa2048.tst.raymii.org.pem -out rsa2048.tst.raymii.org.der -outform der
    
    openssl x509 -in httpdECprime256v1.tst.raymii.org.pem -out httpdECprime256v1.tst.raymii.org.der -outform der
    

Load the DER certificates into the HSM together with the keys:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --write-object rsa1024.tst.raymii.org.der --type cert --id 1 --label 'rsa1024'
    

Output:

    
    
    Using slot 1 with a present token (0x4)
    Created certificate:
    Certificate Object, type = X.509 cert
      label:      rsa1024
      ID:         01
    

THe 2048 bit RSA key:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --write-object rsa2048.tst.raymii.org.der --type cert --id 2 --label 'rsa2048'
    

Output:

    
    
    Created certificate:
    Certificate Object, type = X.509 cert
      label:      rsa2048
      ID:         02
    

The EC key:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --write-object httpdECprime256v1.tst.raymii.org.der --type cert --id 3 --label 'ECprime256v1'
    

Output:

    
    
    Created certificate:
    Certificate Object, type = X.509 cert
      label:      ECprime256v1
      ID:         03
    

My HSM now has the following configuration:

    
    
    pkcs11-tool --module opensc-pkcs11.so --login --pin 648219 --list-objects 
    

Output:

    
    
    Using slot 1 with a present token (0x4)
    Private Key Object; RSA 
      label:      rsa1024
      ID:         01
      Usage:      decrypt, sign, unwrap
    Certificate Object, type = X.509 cert
      label:      rsa1024
      ID:         01
    Public Key Object; RSA 1024 bits
      label:      rsa1024
      ID:         01
      Usage:      encrypt, verify
    Certificate Object, type = X.509 cert
      label:      rsa2048
      ID:         02
    Public Key Object; RSA 1024 bits
      label:      rsa2048
      ID:         02
      Usage:      encrypt, verify
    Private Key Object; RSA 
      label:      rsa2048
      ID:         02
      Usage:      decrypt, sign, unwrap
    Private Key Object; EC
      label:      ECprime256v1
      ID:         03
      Usage:      sign, derive
    Certificate Object, type = X.509 cert
      label:      ECprime256v1
      ID:         03
    Public Key Object; RSA 1024 bits
      label:      ECprime256v1
      ID:         03
      Usage:      encrypt, verify
    

### Configuring Apache and mod_nss

Make sure that you have Apache and `mod_nss` installed:

    
    
    apt-get install apache2 libapache2-mod-nss
    

Enable mod_nss with the following command:

    
    
    a2enmod nss
    

Disable `mod_ssl`:

    
    
    a2dismod ssl
    

On other Linux distro's you might need to manually change config files. On my
Arch installation I had to add the following to `/etc/http/conf/http.conf`:

    
    
    Include conf/extra/nss.conf
    

#### Configuring the NSS certificate database

NSS requires a certificate database. We also need to tell NSS to load the
`pkcs11` module.

Create the database folder:

    
    
    mkdir -p /etc/nss/db/
    

Create a new NSS database:

    
    
    certutil -N -d /etc/nss/db/
    

It will ask you for a password. Enter a secure one, or, when testing, just pres
RETURN twice. Output:

    
    
    Enter a password which will be used to encrypt your keys.
    The password should be at least 8 characters long,
    and should contain at least one non-alphabetic character.
    
    Enter new password: 
    Re-enter password: 
    

Add the HSM module to NSS. This is where things differ from the other tutorial.
We add the `sc-hsm-embedded` module here and give it a different name:

    
    
    modutil -add hsm -libfile /usr/lib/libsc-hsm-pkcs11.so -dbdir /etc/nss/db/
    

Enable the module:

    
    
    modutil -enable hsm -dbdir /etc/nss/db/
    

The other module we named `pkcs11`. If you want to, you could add them both and
switch if needed.

We need the `Token Name` to put in the `mod_nss` configuration. Find it:

    
    
    modutil -dbdir /etc/nss/db/ -list 
    

Output, snipped:

    
    
      2. hsm
      library name: /usr/lib/libsc-hsm-pkcs11.so
       slots: 2 slots attached
      status: loaded
    
       slot: Nitrokey Nitrokey HSM (010000000000000000000000) 01 00
      token: SmartCard-HSM
    -----------------------------------------------------------
    

The name in this case is `SmartCard-HSM`. List all the certificates with the
`certutil` command:

    
    
    certutil -d /etc/nss/db/ -h 'SmartCard-HSM' -L 
    

Output:

    
    
    SmartCard-HSM:ECprime256v1                                   u,u,u
    SmartCard-HSM:rsa2048                                        u,u,u
    SmartCard-HSM:rsa1024                                        u,u,u
    

You can view the certificates with the following command:

    
    
    certutil -d /etc/nss/db -h 'SmartCard-HSM' -L -n "SmartCard-HSM:rsa1024" 
    

Output:

    
    
    Enter Password or Pin for "SmartCard-HSM": 648219
    Certificate:
        Data:
            Version: 1 (0x0)
            Serial Number:
                00:ab:93:b2:05:d0:f7:70:6e
            Signature Algorithm: PKCS #1 SHA-256 With RSA Encryption
            Issuer: "CN=rsa1024.tst.raymii.org,OU=IT Dept,O=Sparkling Network,L=R
                otterdam,ST=Zuid Holland,C=NL"
            Validity:
                Not Before: Fri Jul 15 07:38:14 2016
                Not After : Tue Apr 14 07:38:14 2026
            Subject: "CN=rsa1024.tst.raymii.org,OU=IT Dept,O=Sparkling Network,L=
                Rotterdam,ST=Zuid Holland,C=NL"
    

(`-n` names the specific certificate we want to list/show. `-a` enables ASCII
output.)

Place the PIN for the slot in this file:

    
    
    cat /etc/nss/db/pin.txt
    SmartCard-HSM:648219
    

The format is: `tokenname:pin`.

Also make sure to give the correct permissions to the NSS db:

    
    
    chown -R http:root /etc/nss/db/
    

#### Apache mod_nss configuration

Make sure you have disabled `mod_ssl` in the Apache configuration and have
enabled `mod_nss`. This is my `nss.conf` file:

    
    
    # grep -v -e "#" -e '^$' /etc/httpd/conf/extra/nss.conf
    LoadModule nss_module modules/libmodnss.so
    Listen 8443
    AddType application/x-x509-ca-cert .crt
    AddType application/x-pkcs7-crl    .crl
    NSSPassPhraseDialog file:/etc/nss/db/pin.txt
    NSSPassPhraseHelper /usr/bin/nss_pcache
    NSSEnforceValidCerts off
    NSSSessionCacheTimeout 100
    NSSSession3CacheTimeout 86400
    NSSRandomSeed startup builtin
    NSSRenegotiation off
    NSSRequireSafeNegotiation off
    <VirtualHost _default_:8443>
      DocumentRoot "/etc/httpd/htdocs"
      ServerName rsa1024.tst.raymii.org:8443
      ErrorLog /etc/httpd/logs/error_log
      TransferLog /etc/httpd/logs/access_log
      LogLevel info
      NSSEngine on
      NSSCipherSuite ALL
      NSSProtocol TLSv1.0,TLSv1.1,TLSv1.2
      NSSNickname "SmartCard-HSM:rsa1024"
      NSSCertificateDatabase /etc/nss/db
      <Files ~ "\.(cgi|shtml|phtml|php3?)$">
          NSSOptions +StdEnvVars
      </Files>
      <Directory "/var/www/cgi-bin">
          NSSOptions +StdEnvVars
      </Directory>
    </VirtualHost>  
    

On Arch I had to comment out `NSSSessionCacheSize` and replace
`NSSPassPhraseHelper /usr/libexec/nss_pcache` with `NSSPassPhraseHelper
/usr/bin/nss_pcache`. For the testing certificate I also had to add
`NSSEnforceValidCerts off`. The rest is just the example config.

Make sure the certificate name is correct here:

    
    
    NSSNickname "SmartCard-HSM (UserPIN):httpdcert"
    

For the two other keys, change the two variables when testing the different keys

    
    
      ServerName rsa1024.tst.raymii.org:8443
      NSSNickname "SmartCard-HSM:rsa1024"
    

Respectively to their other names.

Restart the webserver to make the configuration active.

### Benchmarking 2048 bit RSA

The Nitrokey HSM is not a fast HSM. I've worked with HSM's that are capable of
multiple hundreds of signs per second, and this HSM is not one that can do that.
But, as we know, that's not the intended target for the device. It's meant for
safe and secure key storage, for example to encrypt files or protect SSH or
S/MIME keys. I did a few `siege` benchmarks, and as you can see it is quite
slow.

The page that was being loaded is a plain text file containing only the text
`Jeej it works!`.

Remember to update your httpd config if needed:

    
    
    ServerName rsa2048.tst.raymii.org:8443
    NSSNickname "SmartCard-HSM:rsa2048"
    

A siege test with 5 concurrent users, 30 seconds:

    
    
    siege -c5 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             36 hits
    Availability:             100.00 %
    Elapsed time:             29.10 secs
    Data transferred:         0.00 MB
    Response time:            1.63 secs
    Transaction rate:         1.24 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              2.02
    Successful transactions:  36
    Failed transactions:      0
    Longest transaction:      5.13
    Shortest transaction:     0.73
    

10 concurrent users:

    
    
    siege -c10 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             38 hits
    Availability:             100.00 %
    Elapsed time:             29.97 secs
    Data transferred:         0.00 MB
    Response time:            4.57 secs
    Transaction rate:         1.27 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              5.80
    Successful transactions:  38
    Failed transactions:      0
    Longest transaction:      11.15
    Shortest transaction:     0.74
    

20 concurrent users:

    
    
    siege -c20 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             37 hits
    Availability:             100.00 %
    Elapsed time:             29.22 secs
    Data transferred:         0.00 MB
    Response time:            9.62 secs
    Transaction rate:         1.27 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              12.18
    Successful transactions:  37
    Failed transactions:      0
    Longest transaction:      20.47
    Shortest transaction:     1.65
    

60 benchmark mode:

    
    
    siege -c60 -b -t30S https://127.0.0.1:8443
    

Result:

This specific test failed, where the NSS log has the following errors:

    
    
    Broken pipe: SSL library error -5992 writing data
    SSL input filter read failed.
    SSL Library Error: -8023 Unknown
    AH01382: Request header read timeout
    

### Benchmarking 1024 bit RSA

A [product folder][16] mentions that the HSM should be a bit faster with smaller
keys. Now do note that it's not recommended to use a 1024 bit key in production.
But, this is just a benchmark test.

A siege test with 5 concurrent users, 30 seconds:

    
    
    siege -c5 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Lifting the server siege...
    Transactions:             49 hits
    Availability:             100.00 %
    Elapsed time:             29.38 secs
    Data transferred:         0.00 MB
    Response time:            0.30 secs
    Transaction rate:         1.67 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              0.50
    Successful transactions:  49
    Failed transactions:      0
    Longest transaction:      1.09
    Shortest transaction:     0.22
    

10 concurrent users:

    
    
    siege -c10 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             109 hits
    Availability:             100.00 %
    Elapsed time:             29.57 secs
    Data transferred:         0.00 MB
    Response time:            0.56 secs
    Transaction rate:         3.69 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              2.06
    Successful transactions:  109
    Failed transactions:      0
    Longest transaction:      2.39
    Shortest transaction:     0.22
    

20 concurrent users:

    
    
    siege -c20 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             134 hits
    Availability:             100.00 %
    Elapsed time:             29.41 secs
    Data transferred:         0.00 MB
    Response time:            2.02 secs
    Transaction rate:         4.56 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              9.19
    Successful transactions:  134
    Failed transactions:      0
    Longest transaction:      8.12
    Shortest transaction:     0.23
    

60 benchmark mode:

    
    
    siege -c60 -b -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             86 hits
    Availability:             66.15 %
    Elapsed time:             29.09 secs
    Data transferred:         0.00 MB
    Response time:            11.14 secs
    Transaction rate:         2.96 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              32.94
    Successful transactions:  86
    Failed transactions:      44
    Longest transaction:      22.15
    Shortest transaction:     0.87
    

### Benchmarking the EC prime256v1 key

A siege test with 5 concurrent users, 30 seconds:

    
    
    siege -c5 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:                     55 hits
    Availability:                 100.00 %
    Elapsed time:                  29.26 secs
    Data transferred:               0.00 MB
    Response time:                  0.32 secs
    Transaction rate:               1.88 trans/sec
    Throughput:                     0.00 MB/sec
    Concurrency:                    0.60
    Successful transactions:          55
    Failed transactions:               0
    Longest transaction:            1.18
    Shortest transaction:           0.22
    

10 concurrent users:

    
    
    siege -c10 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             96 hits
    Availability:             100.00 %
    Elapsed time:             29.04 secs
    Data transferred:         0.00 MB
    Response time:            0.76 secs
    Transaction rate:         3.31 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              2.52
    Successful transactions:  96
    Failed transactions:      0
    Longest transaction:      3.15
    Shortest transaction:     0.25
    

20 concurrent users:

    
    
    siege -c20 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             117 hits
    Availability:             100.00 %
    Elapsed time:             29.98 secs
    Data transferred:         0.00 MB
    Response time:            2.57 secs
    Transaction rate:         3.90 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              10.02
    Successful transactions:  117
    Failed transactions:      0
    Longest transaction:      7.42
    Shortest transaction:     0.49
    

30 concurrent users:

    
    
    siege -c30 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             108 hits
    Availability:             91.53 %
    Elapsed time:             29.09 secs
    Data transferred:         0.00 MB
    Response time:            5.09 secs
    Transaction rate:         3.71 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              18.90
    Successful transactions:  108
    Failed transactions:      10
    Longest transaction:      19.20
    Shortest transaction:     0.51
    

40 concurrent users:

    
    
    siege -c40 -d5 -t30S https://127.0.0.1:8443
    

Result:

    
    
    Transactions:             105 hits
    Availability:             98.13 %
    Elapsed time:             29.52 secs
    Data transferred:         0.00 MB
    Response time:            6.43 secs
    Transaction rate:         3.56 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              22.86
    Successful transactions:  105
    Failed transactions:      2
    Longest transaction:      20.14
    Shortest transaction:     0.50
    

60 benchmark mode:

    
    
    siege -c60 -b -t30S https://127.0.0.1:8443
    

Result:

    
    
    Lifting the server siege...
    Transactions:             58 hits
    Availability:             56.31 %
    Elapsed time:             29.42 secs
    Data transferred:         0.00 MB
    Response time:            10.78 secs
    Transaction rate:         1.97 trans/sec
    Throughput:               0.00 MB/sec
    Concurrency:              21.25
    Successful transactions:  58
    Failed transactions:      45
    Longest transaction:      19.18
    Shortest transaction:     2.12
    

### Benchmarking with PHP and Wordpress

I setup a default PHP (7), MariaDB and Wordpress install with this mod_nss
Apache and ran the some benchmarks on that as well to show how a 'real' site
performs. This with the EC key we also used above. Just using the site, browsing
with firefox/chrome and updating/editing posts also works fine, feels snappy
enough.

20 concurrent users:

    
    
    siege -c20 -d5 -t30S 'https://127.0.0.1:8443/wordpress/'
    

Result:

    
    
    Transactions:             132 hits
    Availability:             92.96 %
    Elapsed time:             29.64 secs
    Data transferred:         1.13 MB
    Response time:            3.83 secs
    Transaction rate:         4.45 trans/sec
    Throughput:               0.04 MB/sec
    Concurrency:              17.05
    Successful transactions:  132
    Failed transactions:      10
    Longest transaction:      8.15
    Shortest transaction:     0.44
    

### Comparing and conclusion

Most of the benchmarks are comparable to the benchmarks with the OpenSC module.
Except for the EC keypair, since that failed with the OpenSC module. I did try
to switch to the other NSS certificate DB (with the opensc module) but that
failed. So, if you want to use an EC keypair, you need to use this module.

As said in the other article, the HSM is not a fast HSM, but that is not the
target. It's target is to enable everyone to have secure key storage for a
reasonable price, instead of thousands of dollars for a big-company-name HSM.

This read only module is very nice if you are deploying this HSM in untrusted
places, for example at a client or in a datacenter. It also seperates the HSM
management from the actual usage by the webserver. If you need to renew the
certificate or generate a new keypair, you need to take the device to a machine
with OpenSC and all the tools installed (which can be an offline machine),
instead of the webserver being able to do this. If the webserver ever gets
compromised, they will not be able to edit/delete or otherwise write to the HSM.

One of the next articles will be about a HSM cluster with multiple HSM's, which
will result in a speed increase.

   [1]: https://raymii.org/s/inc/img/nitrokey1.jpg
   [2]: https://raymii.org/s/inc/img/sc-hsm.jpg
   [3]: http://nitrokey.com
   [4]: http://www.smartcard-hsm.com/
   [5]: http://www.smartcard-hsm.com/opensource.html
   [6]: https://github.com/nitrokey
   [7]: https://github.com/OpenSC/OpenSC/wiki/SmartCardHSM
   [8]: https://raymii.org/s/articles/Get_Started_With_The_Nitrokey_HSM.html
   [9]: https://raymii.org/s/tags/nitrokey.html
   [10]: https://raymii.org/s/articles/Nitrokey_HSM_in_Apache_with_mod_nss.html
   [11]: http://www.smartcard-hsm.com/2015/11/20/Building-a-SmartCard-HSM-Cluster.html
   [12]: https://www.digitalocean.com/?refcode=7435ae6b8212
   [13]: https://aur.archlinux.org/packages/sc-hsm-embedded-git/
   [14]: https://aur.archlinux.org/packages/engine_pkcs11_alternative/
   [15]: https://raymii.org/s/articles/Get_Started_With_The_Nitrokey_HSM.html#Using_the_keys
   [16]: http://www.cardcontact.de/products/SmartCard-HSM_V1.1.pdf

---

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