Autorité de certification

EN CHANTIER

Article en cours d'écriture et/ou de test. Certains éléments peuvent être incomplets et mener à un résultat non fonctionnel.
Merci de ne pas rager.

Je ne travail actuellement pas sur ce sujet. Je ne sais pas si cette documentation sera un jour terminée.

Préparation

Création de l'arborescence

mkdir -p AC/{private,certs,newcerts,crl}

Création du catalogue d'information sur les certificats

touch AC/index.txt

Création du fichier serial

echo "01" > AC/serial

Chaque certificat possède un numéro de série. Ce fichier contient le numéro de série du prochain certificat. La valeur est incrémentée automatiquement.

Fichier de configuration OpenSSL

cp /etc/ssl/openssl.cnf AC/ca-config

<syntaxhighlight lang="bash">

2. OpenSSL example configuration file.
3. This is mostly being used for generation of certificate requests.

1. This definition stops the following lines choking if HOME isn't
2. defined.

HOME = . RANDFILE = $ENV::HOME/.rnd

1. Extra OBJECT IDENTIFIER info:
2. oid_file = $ENV::HOME/.oid

oid_section = new_oids

1. To use this configuration file with the "-extfile" option of the
2. "openssl x509" utility, name here the section containing the
3. X.509v3 extensions to use:
4. extensions =
5. (Alternatively, use a configuration file that has only
6. X.509v3 extensions in its main [= default] section.)

[ new_oids ]

1. We can add new OIDs in here for use by 'ca', 'req' and 'ts'.
2. Add a simple OID like this:
3. testoid1=1.2.3.4
4. Or use config file substitution like this:
5. testoid2=${testoid1}.5.6

1. Policies used by the TSA examples.

tsa_policy1 = 1.2.3.4.1 tsa_policy2 = 1.2.3.4.5.6 tsa_policy3 = 1.2.3.4.5.7

1. Section pour certificats EV (source : http://www.michellesullivan.org/blog/366)
2. businessCategory=2.5.4.15
3. streetAddress=2.5.4.9
4. stateOrProvinceName=2.5.4.8
5. countryName=2.5.4.6
6. jurisdictionOfIncorporationStateOrProvinceName=1.3.6.1.4.1.311.60.2.1.2
7. jurisdictionOfIncorporationLocalityName=1.3.6.1.4.1.311.60.2.1.1
8. jurisdictionOfIncorporationCountryName=1.3.6.1.4.1.311.60.2.1.3

[ ca ] default_ca = CA_default # The default ca section

[ CA_default ]

dir = . # Where everything is kept certs = $dir/certs # Where the issued certs are kept crl_dir = $dir/crl # Where the issued crl are kept database = $dir/index.txt # database index file.

1. unique_subject = no # Set to 'no' to allow creation of

# several ctificates with same subject. new_certs_dir = $dir/newcerts # default place for new certs.

certificate = $dir/certs/ca.crt # The CA certificate serial = $dir/serial # The current serial number crlnumber = $dir/crlnumber # the current crl number # must be commented out to leave a V1 CRL crl = $dir/crl.pem # The current CRL private_key = $dir/private/ca.key # The private key RANDFILE = /dev/random # private random number file

x509_extensions = usr_cert # The extentions to add to the cert

1. Comment out the following two lines for the "traditional"
2. (and highly broken) format.

name_opt = ca_default # Subject Name options cert_opt = ca_default # Certificate field options

1. Extension copying option: use with caution.
2. copy_extensions = copy

1. Extensions to add to a CRL. Note: Netscape communicator chokes on V2 CRLs
2. so this is commented out by default to leave a V1 CRL.
3. crlnumber must also be commented out to leave a V1 CRL.
4. crl_extensions = crl_ext

default_days = 5000 # how long to certify for default_crl_days= 30 # how long before next CRL default_md = default # use public key default MD preserve = no # keep passed DN ordering

1. A few difference way of specifying how similar the request should look
2. For type CA, the listed attributes must be the same, and the optional
3. and supplied fields are just that :-)

policy = policy_match

1. For the CA policy

[ policy_match ] countryName = match stateOrProvinceName = match organizationName = match organizationalUnitName = optional commonName = supplied emailAddress = optional

1. For the 'anything' policy
2. At this point in time, you must list all acceptable 'object'
3. types.

[ policy_anything ] countryName = optional stateOrProvinceName = optional localityName = optional organizationName = optional organizationalUnitName = optional commonName = supplied emailAddress = optional

[ req ] default_bits = 4096 default_keyfile = privkey.pem distinguished_name = req_distinguished_name attributes = req_attributes x509_extensions = v3_ca # The extentions to add to the self signed cert

1. Passwords for private keys if not present they will be prompted for
2. input_password = secret
3. output_password = secret

1. This sets a mask for permitted string types. There are several options.
2. default: PrintableString, T61String, BMPString.
3. pkix  : PrintableString, BMPString (PKIX recommendation before 2004)
4. utf8only: only UTF8Strings (PKIX recommendation after 2004).
5. nombstr : PrintableString, T61String (no BMPStrings or UTF8Strings).
6. MASK:XXXX a literal mask value.
7. WARNING: ancient versions of Netscape crash on BMPStrings or UTF8Strings.

string_mask = utf8only

1. req_extensions = v3_req # The extensions to add to a certificate request

[ req_distinguished_name ] countryName = Country Name (2 letter code) countryName_default = FR countryName_min = 2 countryName_max = 2

stateOrProvinceName = State or Province Name (full name) stateOrProvinceName_default = Seine et Marne

localityName = Locality Name (eg, city) localityName_default = Melun

0.organizationName = Organization Name (eg, company) 0.organizationName_default =

1. we can do this but it is not needed normally :-)
2. 1.organizationName = Second Organization Name (eg, company)
3. 1.organizationName_default = World Wide Web Pty Ltd

organizationalUnitName = Organizational Unit Name (eg, section) organizationalUnitName_default =

commonName = Common Name (e.g. server FQDN or YOUR name) commonName_default = ca.jmador.yo commonName_max = 256

emailAddress = Email Address emailAddress_default = contact@jmador.yo emailAddress_max = 256

1. SET-ex3 = SET extension number 3

[ req_attributes ] challengePassword = A challenge password challengePassword_min = 4 challengePassword_max = 20

unstructuredName = An optional company name

[ usr_cert ]

1. These extensions are added when 'ca' signs a request.

1. This goes against PKIX guidelines but some CAs do it and some software
2. requires this to avoid interpreting an end user certificate as a CA.

basicConstraints=CA:FALSE

1. Here are some examples of the usage of nsCertType. If it is omitted
2. the certificate can be used for anything *except* object signing.

1. This is OK for an SSL server.
2. nsCertType = server

1. For an object signing certificate this would be used.
2. nsCertType = objsign

1. For normal client use this is typical
2. nsCertType = client, email

1. and for everything including object signing:
2. nsCertType = client, email, objsign

1. This is typical in keyUsage for a client certificate.
2. keyUsage = nonRepudiation, digitalSignature, keyEncipherment

1. This will be displayed in Netscape's comment listbox.

nsComment = "OpenSSL Generated Certificate"

1. PKIX recommendations harmless if included in all certificates.

subjectKeyIdentifier=hash authorityKeyIdentifier=keyid,issuer

1. This stuff is for subjectAltName and issuerAltname.
2. Import the email address.
3. subjectAltName=email:copy
4. An alternative to produce certificates that aren't
5. deprecated according to PKIX.
6. subjectAltName=email:move

1. Copy subject details
2. issuerAltName=issuer:copy

1. nsCaRevocationUrl = http://www.domain.dom/ca-crl.pem
2. nsBaseUrl
3. nsRevocationUrl
4. nsRenewalUrl
5. nsCaPolicyUrl
6. nsSslServerName

1. This is required for TSA certificates.
2. extendedKeyUsage = critical,timeStamping

[ v3_req ]

1. Extensions to add to a certificate request

basicConstraints = CA:FALSE keyUsage = nonRepudiation, digitalSignature, keyEncipherment

[ v3_ca ]

1. Extensions for a typical CA

1. PKIX recommendation.

subjectKeyIdentifier=hash

authorityKeyIdentifier=keyid:always,issuer

1. This is what PKIX recommends but some broken software chokes on critical
2. extensions.
3. basicConstraints = critical,CA:true
4. So we do this instead.

basicConstraints = CA:true

1. Key usage: this is typical for a CA certificate. However since it will
2. prevent it being used as an test self-signed certificate it is best
3. left out by default.
4. keyUsage = cRLSign, keyCertSign

1. Some might want this also
2. nsCertType = sslCA, emailCA

1. Include email address in subject alt name: another PKIX recommendation
2. subjectAltName=email:copy
3. Copy issuer details
4. issuerAltName=issuer:copy

1. DER hex encoding of an extension: beware experts only!
2. obj=DER:02:03
3. Where 'obj' is a standard or added object
4. You can even override a supported extension:
5. basicConstraints= critical, DER:30:03:01:01:FF

[ crl_ext ]

1. CRL extensions.
2. Only issuerAltName and authorityKeyIdentifier make any sense in a CRL.

1. issuerAltName=issuer:copy

authorityKeyIdentifier=keyid:always

[ proxy_cert_ext ]

1. These extensions should be added when creating a proxy certificate

1. This goes against PKIX guidelines but some CAs do it and some software
2. requires this to avoid interpreting an end user certificate as a CA.

basicConstraints=CA:FALSE

1. Here are some examples of the usage of nsCertType. If it is omitted
2. the certificate can be used for anything *except* object signing.

1. This is OK for an SSL server.
2. nsCertType = server

1. For an object signing certificate this would be used.
2. nsCertType = objsign

1. For normal client use this is typical
2. nsCertType = client, email

1. and for everything including object signing:
2. nsCertType = client, email, objsign

1. This is typical in keyUsage for a client certificate.
2. keyUsage = nonRepudiation, digitalSignature, keyEncipherment

1. This will be displayed in Netscape's comment listbox.

nsComment = "OpenSSL Generated Certificate"

1. PKIX recommendations harmless if included in all certificates.

subjectKeyIdentifier=hash authorityKeyIdentifier=keyid,issuer

1. This stuff is for subjectAltName and issuerAltname.
2. Import the email address.
3. subjectAltName=email:copy
4. An alternative to produce certificates that aren't
5. deprecated according to PKIX.
6. subjectAltName=email:move

1. Copy subject details
2. issuerAltName=issuer:copy

1. nsCaRevocationUrl = http://www.domain.dom/ca-crl.pem
2. nsBaseUrl
3. nsRevocationUrl
4. nsRenewalUrl
5. nsCaPolicyUrl
6. nsSslServerName

1. This really needs to be in place for it to be a proxy certificate.

proxyCertInfo=critical,language:id-ppl-anyLanguage,pathlen:3,policy:foo

[ tsa ]

default_tsa = tsa_config1 # the default TSA section

[ tsa_config1 ]

1. These are used by the TSA reply generation only.

dir = ./demoCA # TSA root directory serial = $dir/tsaserial # The current serial number (mandatory) crypto_device = builtin # OpenSSL engine to use for signing signer_cert = $dir/tsacert.pem # The TSA signing certificate # (optional) certs = $dir/cacert.pem # Certificate chain to include in reply # (optional) signer_key = $dir/private/tsakey.pem # The TSA private key (optional)

default_policy = tsa_policy1 # Policy if request did not specify it # (optional) other_policies = tsa_policy2, tsa_policy3 # acceptable policies (optional) digests = md5, sha1 # Acceptable message digests (mandatory) accuracy = secs:1, millisecs:500, microsecs:100 # (optional) clock_precision_digits = 0 # number of digits after dot. (optional) ordering = yes # Is ordering defined for timestamps? # (optional, default: no) tsa_name = yes # Must the TSA name be included in the reply? # (optional, default: no) ess_cert_id_chain = no # Must the ESS cert id chain be included? # (optional, default: no) </syntaxhighlight>

cd AC

Création du certificat racine

openssl req -new -x509 -extensions v3_ca -newkey rsa:4096 -keyout private/ca.key -out certs/ca.crt -config ca-config

• req : utilitaire de génération de certificats et de demandes de certificat PKCS#10.
• -new : nouvelle demande de certificat.
• -x509 : cette option génère un certificat auto-signé à la place d'une demande de certificat. Elle est utilisée typiquement pour générer des certificats de test ou le certificat auto-signé racine d'une CA.
• -extensions v3_ca : permet de générer un certificat SSL v3, en se référant à la section v3_ca du fichier de configuration d'OpenSSL.
• -newkey rsa:4096 : Génération d'une clé privée RSA de 4096 bits.
• -keyout private/ca.key : donne le nom de fichier où la clé privée créée sera écrite.
• -out certs/ca.crt : spécifie le nom du fichier (le certificat) de sortie.
• -config ca-config : permet d'utiliser un fichier de configuration alternatif, à la place d'openssl.cnf.

Si vous ne voulez pas chiffrer la clé privée, ajoutez l'option -nodes (déconseillé).