Création d’une autorité de certification#

Nitrokey 3	Nitrokey Passkey	Nitrokey FIDO2	Nitrokey U2F	Nitrokey HSM 2	Nitrokey Pro 2	Nitrokey Start	Nitrokey Storage 2
✓	⨯	⨯	⨯	✓	✓	✓	✓

Cet article vous montre comment configurer votre propre autorité de certification privée soutenue par un HSM Nitrokey. Cette autorité de certification n’est pas automatisée et n’est pas vraiment évolutive. D’autres projets open source peuvent être référencés pour l’automatisation et l’évolutivité.

Choisir les algorithmes cryptographiques #

Je vais supposer que vous êtes aussi paranoïaque que moi, donc je vais utiliser la commande suivante pour générer des clés privées :

pkcs11-tool -l --keypairgen --key-type EC:secp384r1 --label root

Mais, si vous êtes moins paranoïaque que moi, vous pouvez choisir sans risque les options suivantes :

pkcs11-tool -l --keypairgen --key-type EC:secp256r1 --label root
pkcs11-tool -l --keypairgen --key-type rsa:4096 --label root

De même, j’utiliserai l’algorithme sha512 tout au long de cet article, mais sha256 peut être utilisé en toute sécurité.

Préparation du démarrage #

Pour commencer, vous devez choisir un répertoire pour stocker votre AC.

pki_dir=/opt/certificate-authority
mkdir $pki_dir
cd $pki_dir
mkdir certs config crl newcerts intermediate intermediate/certs intermediate/crl intermediate/csr intermediate/newcerts
touch index.txt intermediate/index.txt
cd config

Installez les outils nécessaires :

# Arch Linux
pacman -S community/opensc community/libp11

# Ubuntu
sudo apt-get install opensc gnutls-bin

Pour Windows, téléchargez les versions officielles OpenSC et assurez-vous d’installer p11tool comme décrit. En utilisant le PowerShell, la plupart des commandes devraient être identiques tant que les deux outils et leurs binaires se trouvent dans votre PATH.

Création de l’autorité de certification racine #

Nous commençons par générer la clé privée de l’autorité de certification directement sur le Nitrokey HSM. Cela nous permet d’utiliser la clé privée à l’avenir, mais pas d’y accéder.

# Generate private key on HSM
$ pkcs11-tool -l --keypairgen --key-type EC:secp384r1 --label root
Using slot 0 with a present token (0x0)
Logging in to "SmartCard-HSM (UserPIN)".
Please enter User PIN:
Key pair generated:
Private Key Object; EC
  label:      root
  ID:         e0161cc8b6f5d66ac6835ecdecb623fc0506a675
  Usage:      sign, derive
  Access:     none
Public Key Object; EC  EC_POINT 384 bits
  EC_POINT:   046104c1e7b40e1ef9e5d47399aeeda695026c9eb626462059eb696e8f2b647b42d64ac3b7fc7a5b31aa3edf9bce46b2cdcf8e5d190b13601d3d14ffb119c8cf60033c6b78ba579b85113ca536eef1cf85ba418ff0110a56ec881b329e0562e090a3e7
  EC_PARAMS:  06052b81040022
  label:      root
  ID:         e0161cc8b6f5d66ac6835ecdecb623fc0506a675
  Usage:      verify, derive
  Access:     none

Notez le numéro d’identification (e0161cc8b6f5d66ac6835ecdecb623fc0506a675), nous en aurons besoin plus tard.

Si vous avez besoin de l’ID à l’avenir, vous pouvez répertorier les clés sur le HSM de Nitrokey :

pkcs11-tool -O

Nous devons créer un fichier de configuration pour générer un certificat public auto-signé.

vim create_root_cert.ini

Remplissez la demande d’informations entre <angle brackets> avec les informations relatives à votre CA.

[ ca ]
# `man ca`
default_ca = CA_default

[ CA_default ]
# Directory and file locations.
dir               = /opt/certificate-authority
certs             = $dir/certs
crl_dir           = $dir/crl
new_certs_dir     = $dir/newcerts
database          = $dir/index.txt
serial            = $dir/serial

# SHA-1 is deprecated, so use SHA-2 instead.
default_md        = sha512

name_opt          = ca_default
cert_opt          = ca_default
default_days      = 375
preserve          = no
policy            = policy_strict

[ policy_strict ]
# The root CA should only sign intermediate certificates that match.
# See the POLICY FORMAT section of `man ca`.
countryName             = match
stateOrProvinceName     = match
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ req ]
# Options for the `req` tool (`man req`).
default_bits        = 4096
distinguished_name  = req_distinguished_name
string_mask         = utf8only
prompt              = no

# SHA-1 is deprecated, so use SHA-2 instead.
default_md          = sha512

[ req_distinguished_name ]
C                   = <two lettter country>
ST                  = <full state name>
O                   = <your company>
OU                  = <your company> Certificate Authority
CN                  = <your company> Root CA

[ v3_ca ]
# Extensions for a typical CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

Générez le certificat public auto-signé à partir de la clé privée. Utilisez la valeur d’identification de la clé privée obtenue précédemment.

$ openssl req -config create_root_cert.ini -engine pkcs11 -keyform engine -key e0161cc8b6f5d66ac6835ecdecb623fc0506a675 -new -x509 -days 3650 -sha512 -extensions v3_ca -out ../certs/root.crt
engine "pkcs11" set.
Enter PKCS#11 token PIN for SmartCard-HSM (UserPIN):

Vérifier que le certificat racine a été généré correctement. Vérifiez que l’algorithme de signature correspond à celui du haut et du bas. Vérifiez que Issuer et Subject correspondent, tous les certificats racine sont auto-signés. Vérifiez que l’utilisation de la clé correspond à ce qui était dans les informations v3_ca dans notre fichier de configuration.

$ openssl x509 -noout -text -in ../certs/root.crt
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            25:ac:e1:36:75:67:26:1d:bb:96:4b:84:c2:2d:83:25:7b:cc:e0:e5
        Signature Algorithm: ecdsa-with-SHA512
        Issuer: C = US, ST = My State, O = My Company, OU = My Company Certificate Authority, CN = My Company Root CA
        Validity
            Not Before: Aug 18 20:13:20 2020 GMT
            Not After : Aug 16 20:13:20 2030 GMT
        Subject: C = US, ST = My State, O = My Company, OU = My Company Certificate Authority, CN = My Company Root CA
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (384 bit)
                pub:
                    04:c1:e7:b4:0e:1e:f9:e5:d4:73:99:ae:ed:a6:95:
                    02:6c:9e:b6:26:46:20:59:eb:69:6e:8f:2b:64:7b:
                    42:d6:4a:c3:b7:fc:7a:5b:31:aa:3e:df:9b:ce:46:
                    b2:cd:cf:8e:5d:19:0b:13:60:1d:3d:14:ff:b1:19:
                    c8:cf:60:03:3c:6b:78:ba:57:9b:85:11:3c:a5:36:
                    ee:f1:cf:85:ba:41:8f:f0:11:0a:56:ec:88:1b:32:
                    9e:05:62:e0:90:a3:e7
                ASN1 OID: secp384r1
                NIST CURVE: P-384
        X509v3 extensions:
            X509v3 Subject Key Identifier:
                F1:FA:61:75:0B:AC:3C:95:97:EF:73:3C:3F:38:22:B1:DB:D9:BF:41
            X509v3 Authority Key Identifier:
                keyid:F1:FA:61:75:0B:AC:3C:95:97:EF:73:3C:3F:38:22:B1:DB:D9:BF:41

            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage: critical
                Digital Signature, Certificate Sign, CRL Sign
    Signature Algorithm: ecdsa-with-SHA512
         30:64:02:30:53:b8:b6:5a:41:4b:4f:6a:d1:a6:76:88:df:13:
         d6:da:c7:48:aa:8b:aa:ff:13:6c:d1:00:53:90:92:b5:71:57:
         eb:d0:bf:3e:5d:2e:62:c0:3e:40:0f:64:25:a5:92:0f:02:30:
         15:0a:19:d5:a2:09:86:d8:9d:07:67:71:c3:84:f2:6b:90:20:
         2d:29:10:9e:4c:73:7a:55:56:4b:dc:fe:8d:3f:f0:9c:20:e1:
         5a:74:fb:41:86:ad:a4:66:61:74:d7:fd

Création de l’autorité de certification intermédiaire #

Nous continuons en générant la clé privée de l’autorité de certification intermédiaire directement sur le Nitrokey HSM. Cela nous permet d’utiliser la clé privée à l’avenir, mais pas d’y accéder.

# Generate private key on HSM
$ pkcs11-tool -l --keypairgen --key-type EC:secp384r1 --label intermediate
Using slot 0 with a present token (0x0)
Logging in to "SmartCard-HSM (UserPIN)".
Please enter User PIN:
Key pair generated:
Private Key Object; EC
  label:      intermediate
  ID:         bcb48fe9b566ae61891aabbfde6a23d4ff3ab639
  Usage:      sign, derive
  Access:     none
Public Key Object; EC  EC_POINT 384 bits
  EC_POINT:   046104d0fb5c0cd10c0b6e4d0f6986755824b624ec9fcd8ff9ae5f0109fe6ff3ad887ca760717da894f3ff84dc8c24fe8c93b0cd840a6aa941bb2866c061cef60e47b893d71852b50d6762af10c951426e55ec8925a6cd83aeae1730311108afdbcdee
  EC_PARAMS:  06052b81040022
  label:      intermediate
  ID:         bcb48fe9b566ae61891aabbfde6a23d4ff3ab639
  Usage:      verify, derive
  Access:     none

Notez le numéro d’identification (bcb48fe9b566ae61891aabbfde6a23d4ff3ab639), nous en aurons besoin plus tard.

Si vous avez besoin de l’ID à l’avenir, vous pouvez répertorier les clés sur le HSM de Nitrokey :

pkcs11-tool -O

Nous devons créer un fichier de configuration pour générer un certificat public auto-signé.

vim create_intermediate_csr.ini

Remplissez la demande d’informations entre <angle brackets> avec les informations relatives à votre CA.

[ req ]
# Options for the `req` tool (`man req`).
default_bits        = 4096
distinguished_name  = req_distinguished_name
string_mask         = utf8only
prompt              = no

# SHA-1 is deprecated, so use SHA-2 instead.
[ v3_ca ]
# Extensions for a typical CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true
keyUsage = critical, digitalSignature, cRLSign, keyCertSign
default_md          = sha512

[ req_distinguished_name ]
C                   = <two lettter country>
ST                  = <full state name>
O                   = <your company>
OU                  = <your company> Certificate Authority
CN                  = <your company> Intermediate CA

Générez la demande de signature de certificat pour l’AC intermédiaire à partir de la clé privée de l’AC intermédiaire. Utilisez la valeur d’identification de la clé privée obtenue précédemment.

$ openssl req -config create_intermediate_csr.ini -engine pkcs11 -keyform engine -key bcb48fe9b566ae61891aabbfde6a23d4ff3ab639 -new -sha512 -out ../intermediate/csr/intermediate.csr
engine "pkcs11" set.
Enter PKCS#11 token PIN for SmartCard-HSM (UserPIN):

Vérifiez que le CSR a été créé correctement. Vérifiez que votre objet est correct. Vérifiez que votre clé publique et votre algorithme de signature sont corrects.

$ openssl req -text -noout -verify -in ../intermediate/csr/intermediate.csr
verify OK
Certificate Request:
    Data:
        Version: 1 (0x0)
        Subject: C = US, ST = My State, O = My Company, OU = My Company Certificate Authority, CN = My Company Intermediate CA
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (384 bit)
                pub:
                    04:d0:fb:5c:0c:d1:0c:0b:6e:4d:0f:69:86:75:58:
                    24:b6:24:ec:9f:cd:8f:f9:ae:5f:01:09:fe:6f:f3:
                    ad:88:7c:a7:60:71:7d:a8:94:f3:ff:84:dc:8c:24:
                    fe:8c:93:b0:cd:84:0a:6a:a9:41:bb:28:66:c0:61:
                    ce:f6:0e:47:b8:93:d7:18:52:b5:0d:67:62:af:10:
                    c9:51:42:6e:55:ec:89:25:a6:cd:83:ae:ae:17:30:
                    31:11:08:af:db:cd:ee
                ASN1 OID: secp384r1
                NIST CURVE: P-384
        Attributes:
            a0:00
    Signature Algorithm: ecdsa-with-SHA512
         30:64:02:30:6a:1d:75:8b:59:99:2c:a8:5d:a0:7f:02:7d:9a:
         aa:40:74:7a:65:20:03:6b:bc:65:fb:7d:d1:7f:5b:24:ae:6f:
         40:16:ac:82:0b:80:9b:81:f9:d9:64:ea:0f:41:4c:d7:02:30:
         4d:28:7f:e3:76:52:c7:10:e1:bd:b7:2e:ea:65:78:41:0c:96:
         50:5f:e9:1f:be:18:ac:14:ba:65:3f:b0:2a:f4:0f:d0:56:ab:
         d0:8c:bf:d0:92:9e:f6:e5:f6:8a:af:a5

Nous devons trouver l’URI PKCS#11 entièrement qualifié pour votre clé privée :

$ p11tool --list-all
warning: no token URL was provided for this operation; the available tokens are:

pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00

$ p11tool --login --list-all pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00
Token 'SmartCard-HSM (UserPIN)' with URL 'pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00' requires user PIN
Enter PIN:
Object 0:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=private
        Type: Private key (EC/ECDSA-SECP384R1)
        Label: root
        Flags: CKA_PRIVATE; CKA_NEVER_EXTRACTABLE; CKA_SENSITIVE;
        ID: e0:16:1c:c8:b6:f5:d6:6a:c6:83:5e:cd:ec:b6:23:fc:05:06:a6:75

Object 1:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=public
        Type: Public key (EC/ECDSA-SECP384R1)
        Label: root
        ID: e0:16:1c:c8:b6:f5:d6:6a:c6:83:5e:cd:ec:b6:23:fc:05:06:a6:75

Object 2:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=private
        Type: Private key (EC/ECDSA-SECP384R1)
        Label: intermediate
        Flags: CKA_PRIVATE; CKA_NEVER_EXTRACTABLE; CKA_SENSITIVE;
        ID: bc:b4:8f:e9:b5:66:ae:61:89:1a:ab:bf:de:6a:23:d4:ff:3a:b6:39

Object 3:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=public
        Type: Public key (EC/ECDSA-SECP384R1)
        Label: intermediate
        ID: bc:b4:8f:e9:b5:66:ae:61:89:1a:ab:bf:de:6a:23:d4:ff:3a:b6:39

Dans ce cas, l’URI PKCS#11 entièrement qualifié est :

pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=private

Maintenant, nous devons créer un fichier de configuration pour utiliser la clé privée du certificat racine pour signer le csr du certificat intermédiaire.

vim sign_intermediate_csr.ini

[ ca ]
# `man ca`
default_ca = CA_default

[ CA_default ]
# Directory and file locations.
dir               = /opt/certificate-authority
certs             = $dir/certs
crl_dir           = $dir/crl
new_certs_dir     = $dir/newcerts
database          = $dir/index.txt
serial            = $dir/serial

# The root key and root certificate.
private_key       = pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=private
certificate       = ../certs/root.crt

# SHA-1 is deprecated, so use SHA-2 instead.
default_md        = sha512

name_opt          = ca_default
cert_opt          = ca_default
default_days      = 375
preserve          = no
policy            = policy_loose

[ policy_loose ]
# Allow the intermediate CA to sign a more diverse range of certificates.
# See the POLICY FORMAT section of the `ca` man page.
countryName             = optional
stateOrProvinceName     = optional
localityName            = optional
organizationName        = optional
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ v3_intermediate_ca ]
# Extensions for a typical intermediate CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true, pathlen:0
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

Ensuite, signez le certificat intermédiaire avec le certificat racine.

$ openssl ca -config sign_intermediate_csr.ini -engine pkcs11 -keyform engine -extensions v3_intermediate_ca -days 1825 -notext -md sha512 -create_serial -in ../intermediate/csr/intermediate.csr -out ../intermediate/certs/intermediate.crt
engine "pkcs11" set.
Using configuration from sign_intermediate_csr.ini
Enter PKCS#11 token PIN for SmartCard-HSM (UserPIN):
Check that the request matches the signature
Signature ok
Certificate Details:
        Serial Number:
            35:47:4d:05:12:cc:e1:a8:b6:bf:dd:3e:c8:29:7b:18:c0:a1:5c:68
        Validity
            Not Before: Aug 18 20:44:17 2020 GMT
            Not After : Aug 17 20:44:17 2025 GMT
        Subject:
            countryName               = US
            stateOrProvinceName       = My State
            organizationName          = My Company
            organizationalUnitName    = My Company Certificate Authority
            commonName                = My Company Intermediate CA
        X509v3 extensions:
            X509v3 Subject Key Identifier:
                1D:4F:E5:ED:11:42:9A:AC:25:E4:51:A3:42:67:97:39:A0:10:AE:82
            X509v3 Authority Key Identifier:
                keyid:F1:FA:61:75:0B:AC:3C:95:97:EF:73:3C:3F:38:22:B1:DB:D9:BF:41

            X509v3 Basic Constraints: critical
                CA:TRUE, pathlen:0
            X509v3 Key Usage: critical
                Digital Signature, Certificate Sign, CRL Sign
Certificate is to be certified until Aug 17 20:44:17 2025 GMT (1825 days)
Sign the certificate? [y/n]:y


1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated

Vérifiez que le certificat racine a été généré correctement. Vérifiez que l’émetteur et le sujet sont différents et corrects. Vérifier que l’utilisation de la clé correspond au fichier de configuration. Vérifiez que l’algorithme de signature est correct en haut et en bas.

$ openssl x509 -noout -text -in ../intermediate/certs/intermediate.crt
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            35:47:4d:05:12:cc:e1:a8:b6:bf:dd:3e:c8:29:7b:18:c0:a1:5c:68
        Signature Algorithm: ecdsa-with-SHA512
        Issuer: C = US, ST = My State, O = My Company, OU = My Company Certificate Authority, CN = My Company Root CA
        Validity
            Not Before: Aug 18 20:44:17 2020 GMT
            Not After : Aug 17 20:44:17 2025 GMT
        Subject: C = US, ST = My State, O = My Company, OU = My Company Certificate Authority, CN = My Company Intermediate CA
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (384 bit)
                pub:
                    04:d0:fb:5c:0c:d1:0c:0b:6e:4d:0f:69:86:75:58:
                    24:b6:24:ec:9f:cd:8f:f9:ae:5f:01:09:fe:6f:f3:
                    ad:88:7c:a7:60:71:7d:a8:94:f3:ff:84:dc:8c:24:
                    fe:8c:93:b0:cd:84:0a:6a:a9:41:bb:28:66:c0:61:
                    ce:f6:0e:47:b8:93:d7:18:52:b5:0d:67:62:af:10:
                    c9:51:42:6e:55:ec:89:25:a6:cd:83:ae:ae:17:30:
                    31:11:08:af:db:cd:ee
                ASN1 OID: secp384r1
                NIST CURVE: P-384
        X509v3 extensions:
            X509v3 Subject Key Identifier:
                1D:4F:E5:ED:11:42:9A:AC:25:E4:51:A3:42:67:97:39:A0:10:AE:82
            X509v3 Authority Key Identifier:
                keyid:F1:FA:61:75:0B:AC:3C:95:97:EF:73:3C:3F:38:22:B1:DB:D9:BF:41

            X509v3 Basic Constraints: critical
                CA:TRUE, pathlen:0
            X509v3 Key Usage: critical
                Digital Signature, Certificate Sign, CRL Sign
    Signature Algorithm: ecdsa-with-SHA512
         30:66:02:31:00:9a:6e:08:d2:d6:3a:29:f6:ba:0c:4c:3a:f4:
         af:40:5e:e0:71:f2:bc:e4:47:f5:b4:ee:10:d7:27:b1:25:0b:
         4b:09:78:a1:b8:f2:b8:71:c5:4e:41:33:8e:64:db:ec:eb:02:
         31:00:fc:39:26:c2:ad:7b:3c:ab:75:06:34:02:47:79:40:31:
         1d:eb:17:ad:32:10:67:97:37:6f:7f:3c:ce:3e:12:3c:e9:7c:
         fa:43:3e:34:5d:5e:f4:f3:2f:fd:6a:2f:14:da

Vérifiez que le certificat intermédiaire est vérifié par rapport au certificat racine.

$ openssl verify -CAfile ../certs/root.crt ../intermediate/certs/intermediate.crt
../intermediate/certs/intermediate.crt: OK

Créez un fichier de chaîne de certificats :

cat ../intermediate/certs/intermediate.crt ../certs/root.crt > ../intermediate/certs/chain.crt

Vous avez maintenant une autorité de certification soutenue par un HSM.

Signer un certificat de serveur #

Maintenant que vous disposez d’une autorité de certification, vous souhaitez probablement savoir comment l’utiliser.

Créez un CSR selon la méthode normale pour votre application. La création correcte de votre certificat, y compris le SAN, pour votre application particulière sort du cadre de ce document.

Nous devons trouver l’URI PKCS#11 entièrement qualifié pour votre clé privée :

$ p11tool --list-all
warning: no token URL was provided for this operation; the available tokens are:

*pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00*

$ p11tool --login --list-all pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00
Token 'SmartCard-HSM (UserPIN)' with URL 'pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00' requires user PIN
Enter PIN:
Object 0:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=private
        Type: Private key (EC/ECDSA-SECP384R1)
        Label: root
        Flags: CKA_PRIVATE; CKA_NEVER_EXTRACTABLE; CKA_SENSITIVE;
        ID: e0:16:1c:c8:b6:f5:d6:6a:c6:83:5e:cd:ec:b6:23:fc:05:06:a6:75

Object 1:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%E0%16%1C%C8%B6%F5%D6%6A%C6%83%5E%CD%EC%B6%23%FC%05%06%A6%75;object=root;type=public
        Type: Public key (EC/ECDSA-SECP384R1)
        Label: root
        ID: e0:16:1c:c8:b6:f5:d6:6a:c6:83:5e:cd:ec:b6:23:fc:05:06:a6:75

Object 2:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=private
        Type: Private key (EC/ECDSA-SECP384R1)
        Label: intermediate
        Flags: CKA_PRIVATE; CKA_NEVER_EXTRACTABLE; CKA_SENSITIVE;
        ID: bc:b4:8f:e9:b5:66:ae:61:89:1a:ab:bf:de:6a:23:d4:ff:3a:b6:39

Object 3:
        URL: pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=public
        Type: Public key (EC/ECDSA-SECP384R1)
        Label: intermediate
        ID: bc:b4:8f:e9:b5:66:ae:61:89:1a:ab:bf:de:6a:23:d4:ff:3a:b6:39

Dans ce cas, l’URI PKCS#11 entièrement qualifié est :

pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=private

Créez un fichier de configuration pour utiliser la clé privée du certificat intermédiaire pour signer les CSRs de vos serveurs.

vim sign_server_csrs.ini

[ ca ]
# `man ca`
default_ca = CA_default

[ CA_default ]
# Directory and file locations.
dir               = /opt/certificate-authority/intermediate
certs             = $dir/certs
crl_dir           = $dir/crl
new_certs_dir     = $dir/newcerts
database          = $dir/index.txt
serial            = $dir/serial

# The root key and root certificate.
private_key       = pkcs11:model=PKCS%2315%20emulated;manufacturer=www.CardContact.de;serial=DENK0104068;token=SmartCard-HSM%20%28UserPIN%29%00%00%00%00%00%00%00%00%00;id=%BC%B4%8F%E9%B5%66%AE%61%89%1A%AB%BF%DE%6A%23%D4%FF%3A%B6%39;object=intermediate;type=private
certificate       = $dir/certs/intermediate.crt

# SHA-1 is deprecated, so use SHA-2 instead.
default_md        = sha512

name_opt          = ca_default
cert_opt          = ca_default
default_days      = 375
preserve          = no
policy            = policy_loose

[ policy_loose ]
# Allow the intermediate CA to sign a more diverse range of certificates.
# See the POLICY FORMAT section of the `ca` man page.
countryName             = optional
stateOrProvinceName     = optional
localityName            = optional
organizationName        = optional
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ server_cert ]
# Extensions for server certificates (`man x509v3_config`).
basicConstraints = CA:FALSE
nsCertType = server
nsComment = "OpenSSL Generated Server Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer:always
keyUsage = critical, digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth

Ensuite, exécutez openssl pour signer le CSR du serveur.

$ openssl ca -config sign_server_csrs.ini -engine pkcs11 -keyform engine -extensions server_cert -days 375 -notext -md sha512 -create_serial -in server_cert.csr -out server_cert.crt
engine "pkcs11" set.
Using configuration from sign_server_csrs.ini
Enter PKCS#11 token PIN for SmartCard-HSM (UserPIN):
Check that the request matches the signature
Signature ok
Certificate Details:
        Serial Number:
            40:7f:dc:90:b0:3a:1b:fb:d3:e2:74:8d:40:28:a8:12:f7:7e:c3:74
        Validity
            Not Before: Aug 18 21:32:42 2020 GMT
            Not After : Aug 28 21:32:42 2021 GMT
        Subject:
            countryName               = US
            stateOrProvinceName       = My State
            organizationName          = My Company
            organizationalUnitName    = media
            commonName                = media
        X509v3 extensions:
            X509v3 Basic Constraints:
                CA:FALSE
            Netscape Cert Type:
                SSL Server
            Netscape Comment:
                OpenSSL Generated Server Certificate
            X509v3 Subject Key Identifier:
                26:89:19:95:6C:93:8C:DD:6E:AA:61:D5:C0:E6:78:CC:F1:47:64:FC
            X509v3 Authority Key Identifier:
                keyid:1D:4F:E5:ED:11:42:9A:AC:25:E4:51:A3:42:67:97:39:A0:10:AE:82
                DirName:/C=US/ST=My State/O=My Company/OU=My Company Certificate Authority/CN=My Company Root CA
                serial:35:47:4D:05:12:CC:E1:A8:B6:BF:DD:3E:C8:29:7B:18:C0:A1:5C:68

            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment
            X509v3 Extended Key Usage:
                TLS Web Server Authentication
Certificate is to be certified until Aug 28 21:32:42 2021 GMT (375 days)
Sign the certificate? [y/n]:y


1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated

Références #

J’ai utilisé les ressources suivantes pour aider à la compilation de ce document.

Comment initialiser votre HSM Nitrokey
`Comment créer une AC racine et intermédiaire <https://jamielinux.com/docs/openssl-certificate-authority/create-the-root-pair.html>`___.
Comment s’assurer que les numéros de série de vos certs intermédiaires d’AC et de serveur sont conformes aux spécifications.
`Comment générer des clés privées ECC <https://dev.to/benjaminblack/obtaining-an-elliptic-curve-dsa-certificate-with-lets-encrypt-51bc>`___.
`Comment trouver l’URI de PCKS11 à partir de votre HSM <https://www.infradead.org/openconnect/pkcs11.html>`___.
`Dépannage (forum) <https://support.nitrokey.com/t/pki-ca-nitrokey-hsm-does-not-support-signing/2598/14>`___.

Ce document a été initialement écrit par lyntux.

Création d’une autorité de certification#

Choisir les algorithmes cryptographiques#

Préparation du démarrage#

Création de l’autorité de certification racine#

Création de l’autorité de certification intermédiaire#

Signer un certificat de serveur#

Références#