certutil - Online in the Cloud

PROGRAM:

NAME

certutil - Manage keys and certificate in both NSS databases and other NSS tokens

SYNOPSIS

certutil [options] [[arguments]]

STATUS

This documentation is still work in progress. Please contribute to the initial review in
Mozilla NSS bug 836477[1]

DESCRIPTION

The Certificate Database Tool, certutil, is a command-line utility that can create and
modify certificate and key databases. It can specifically list, generate, modify, or
delete certificates, create or change the password, generate new public and private key
pairs, display the contents of the key database, or delete key pairs within the key
database.

Certificate issuance, part of the key and certificate management process, requires that
keys and certificates be created in the key database. This document discusses certificate
and key database management. For information on the security module database management,
see the modutil manpage.

COMMAND OPTIONS AND ARGUMENTS

Running certutil always requires one and only one command option to specify the type of
certificate operation. Each command option may take zero or more arguments. The command
option -H will list all the command options and their relevant arguments.

Command Options

-A
Add an existing certificate to a certificate database. The certificate database should
already exist; if one is not present, this command option will initialize one by
default.

-B
Run a series of commands from the specified batch file. This requires the -i argument.

-C
Create a new binary certificate file from a binary certificate request file. Use the
-i argument to specify the certificate request file. If this argument is not used,
certutil prompts for a filename.

-D
Delete a certificate from the certificate database.

--rename
Change the database nickname of a certificate.

-E
Add an email certificate to the certificate database.

-F
Delete a private key from a key database. Specify the key to delete with the -n
argument. Specify the database from which to delete the key with the -d argument. Use
the -k argument to specify explicitly whether to delete a DSA, RSA, or ECC key. If you
don't use the -k argument, the option looks for an RSA key matching the specified
nickname.

When you delete keys, be sure to also remove any certificates associated with those
keys from the certificate database, by using -D. Some smart cards do not let you
remove a public key you have generated. In such a case, only the private key is
deleted from the key pair. You can display the public key with the command certutil -K
-h tokenname.

-G
Generate a new public and private key pair within a key database. The key database
should already exist; if one is not present, this command option will initialize one
by default. Some smart cards can store only one key pair. If you create a new key pair
for such a card, the previous pair is overwritten.

-H
Display a list of the command options and arguments.

-K
List the key ID of keys in the key database. A key ID is the modulus of the RSA key or
the publicValue of the DSA key. IDs are displayed in hexadecimal ("0x" is not shown).

-L
List all the certificates, or display information about a named certificate, in a
certificate database. Use the -h tokenname argument to specify the certificate
database on a particular hardware or software token.

-M
Modify a certificate's trust attributes using the values of the -t argument.

-N
Create new certificate and key databases.

-O
Print the certificate chain.

-R
Create a certificate request file that can be submitted to a Certificate Authority
(CA) for processing into a finished certificate. Output defaults to standard out
unless you use -o output-file argument. Use the -a argument to specify ASCII output.

-S
Create an individual certificate and add it to a certificate database.

-T
Reset the key database or token.

-U
List all available modules or print a single named module.

-V
Check the validity of a certificate and its attributes.

-W
Change the password to a key database.

--merge
Merge two databases into one.

--upgrade-merge
Upgrade an old database and merge it into a new database. This is used to migrate
legacy NSS databases (cert8.db and key3.db) into the newer SQLite databases (cert9.db
and key4.db).

Arguments

Arguments modify a command option and are usually lower case, numbers, or symbols.

-a
Use ASCII format or allow the use of ASCII format for input or output. This formatting
follows RFC 1113. For certificate requests, ASCII output defaults to standard output
unless redirected.

-b validity-time
Specify a time at which a certificate is required to be valid. Use when checking
certificate validity with the -V option. The format of the validity-time argument is
YYMMDDHHMMSS[+HHMM|-HHMM|Z], which allows offsets to be set relative to the validity
end time. Specifying seconds (SS) is optional. When specifying an explicit time, use a
Z at the end of the term, YYMMDDHHMMSSZ, to close it. When specifying an offset time,
use YYMMDDHHMMSS+HHMM or YYMMDDHHMMSS-HHMM for adding or subtracting time,
respectively.

If this option is not used, the validity check defaults to the current system time.

-c issuer
Identify the certificate of the CA from which a new certificate will derive its
authenticity. Use the exact nickname or alias of the CA certificate, or use the CA's
email address. Bracket the issuer string with quotation marks if it contains spaces.

-d [prefix]directory
Specify the database directory containing the certificate and key database files.

certutil supports two types of databases: the legacy security databases (cert8.db,
key3.db, and secmod.db) and new SQLite databases (cert9.db, key4.db, and pkcs11.txt).

NSS recognizes the following prefixes:

· sql: requests the newer database

· dbm: requests the legacy database

If no prefix is specified the default type is retrieved from NSS_DEFAULT_DB_TYPE. If
NSS_DEFAULT_DB_TYPE is not set then dbm: is the default.

--dump-ext-val OID
For single cert, print binary DER encoding of extension OID.

-e
Check a certificate's signature during the process of validating a certificate.

--email email-address
Specify the email address of a certificate to list. Used with the -L command option.

--extGeneric OID:critical-flag:filename[,OID:critical-flag:filename]...
Add one or multiple extensions that certutil cannot encode yet, by loading their
encodings from external files.

· OID (example): 1.2.3.4

· critical-flag: critical or not-critical

· filename: full path to a file containing an encoded extension

-f password-file
Specify a file that will automatically supply the password to include in a certificate
or to access a certificate database. This is a plain-text file containing one
password. Be sure to prevent unauthorized access to this file.

-g keysize
Set a key size to use when generating new public and private key pairs. The minimum is
512 bits and the maximum is 16384 bits. The default is 2048 bits. Any size between the
minimum and maximum is allowed.

-h tokenname
Specify the name of a token to use or act on. If not specified the default token is
the internal database slot.

-i input_file
Pass an input file to the command. Depending on the command option, an input file can
be a specific certificate, a certificate request file, or a batch file of commands.

-k key-type-or-id
Specify the type or specific ID of a key.

The valid key type options are rsa, dsa, ec, or all. The default value is rsa.
Specifying the type of key can avoid mistakes caused by duplicate nicknames. Giving a
key type generates a new key pair; giving the ID of an existing key reuses that key
pair (which is required to renew certificates).

-l
Display detailed information when validating a certificate with the -V option.

-m serial-number
Assign a unique serial number to a certificate being created. This operation should be
performed by a CA. If no serial number is provided a default serial number is made
from the current time. Serial numbers are limited to integers

-n nickname
Specify the nickname of a certificate or key to list, create, add to a database,
modify, or validate. Bracket the nickname string with quotation marks if it contains
spaces.

-o output-file
Specify the output file name for new certificates or binary certificate requests.
Bracket the output-file string with quotation marks if it contains spaces. If this
argument is not used the output destination defaults to standard output.

-P dbPrefix
Specify the prefix used on the certificate and key database file. This argument is
provided to support legacy servers. Most applications do not use a database prefix.

-p phone
Specify a contact telephone number to include in new certificates or certificate
requests. Bracket this string with quotation marks if it contains spaces.

-q pqgfile or curve-name
Read an alternate PQG value from the specified file when generating DSA key pairs. If
this argument is not used, certutil generates its own PQG value. PQG files are created
with a separate DSA utility.

Elliptic curve name is one of the ones from SUITE B: nistp256, nistp384, nistp521

If NSS has been compiled with support curves outside of SUITE B: sect163k1, nistk163,
sect163r1, sect163r2, nistb163, sect193r1, sect193r2, sect233k1, nistk233, sect233r1,
nistb233, sect239k1, sect283k1, nistk283, sect283r1, nistb283, sect409k1, nistk409,
sect409r1, nistb409, sect571k1, nistk571, sect571r1, nistb571, secp160k1, secp160r1,
secp160r2, secp192k1, secp192r1, nistp192, secp224k1, secp224r1, nistp224, secp256k1,
secp256r1, secp384r1, secp521r1, prime192v1, prime192v2, prime192v3, prime239v1,
prime239v2, prime239v3, c2pnb163v1, c2pnb163v2, c2pnb163v3, c2pnb176v1, c2tnb191v1,
c2tnb191v2, c2tnb191v3, c2pnb208w1, c2tnb239v1, c2tnb239v2, c2tnb239v3, c2pnb272w1,
c2pnb304w1, c2tnb359w1, c2pnb368w1, c2tnb431r1, secp112r1, secp112r2, secp128r1,
secp128r2, sect113r1, sect113r2 sect131r1, sect131r2

-r
Display a certificate's binary DER encoding when listing information about that
certificate with the -L option.

-s subject
Identify a particular certificate owner for new certificates or certificate requests.
Bracket this string with quotation marks if it contains spaces. The subject
identification format follows RFC #1485.

-t trustargs
Specify the trust attributes to modify in an existing certificate or to apply to a
certificate when creating it or adding it to a database. There are three available
trust categories for each certificate, expressed in the order SSL, email, object
signing for each trust setting. In each category position, use none, any, or all of
the attribute codes:

· p - Valid peer

· P - Trusted peer (implies p)

· c - Valid CA

· T - Trusted CA (implies c)

· C - trusted CA for client authentication (ssl server only)

· u - user

The attribute codes for the categories are separated by commas, and the entire set of
attributes enclosed by quotation marks. For example:

-t "TCu,Cu,Tu"

Use the -L option to see a list of the current certificates and trust attributes in a
certificate database.

-u certusage
Specify a usage context to apply when validating a certificate with the -V option.

The contexts are the following:

· C (as an SSL client)

· V (as an SSL server)

· L (as an SSL CA)

· A (as Any CA)

· Y (Verify CA)

· S (as an email signer)

· R (as an email recipient)

· O (as an OCSP status responder)

· J (as an object signer)

-v valid-months
Set the number of months a new certificate will be valid. The validity period begins
at the current system time unless an offset is added or subtracted with the -w option.
If this argument is not used, the default validity period is three months.

-w offset-months
Set an offset from the current system time, in months, for the beginning of a
certificate's validity period. Use when creating the certificate or adding it to a
database. Express the offset in integers, using a minus sign (-) to indicate a
negative offset. If this argument is not used, the validity period begins at the
current system time. The length of the validity period is set with the -v argument.

-X
Force the key and certificate database to open in read-write mode. This is used with
the -U and -L command options.

-x
Use certutil to generate the signature for a certificate being created or added to a
database, rather than obtaining a signature from a separate CA.

-y exp
Set an alternate exponent value to use in generating a new RSA public key for the
database, instead of the default value of 65537. The available alternate values are 3
and 17.

-z noise-file
Read a seed value from the specified file to generate a new private and public key
pair. This argument makes it possible to use hardware-generated seed values or
manually create a value from the keyboard. The minimum file size is 20 bytes.

-Z hashAlg
Specify the hash algorithm to use with the -C, -S or -R command options. Possible
keywords:

· MD2

· MD4

· MD5

· SHA1

· SHA224

· SHA256

· SHA384

· SHA512

-0 SSO_password
Set a site security officer password on a token.

-1 | --keyUsage keyword,keyword
Set an X.509 V3 Certificate Type Extension in the certificate. There are several
available keywords:

· digitalSignature

· nonRepudiation

· keyEncipherment

· dataEncipherment

· keyAgreement

· certSigning

· crlSigning

· critical

-2
Add a basic constraint extension to a certificate that is being created or added to a
database. This extension supports the certificate chain verification process.
certutil prompts for the certificate constraint extension to select.

X.509 certificate extensions are described in RFC 5280.

-3
Add an authority key ID extension to a certificate that is being created or added to a
database. This extension supports the identification of a particular certificate, from
among multiple certificates associated with one subject name, as the correct issuer of
a certificate. The Certificate Database Tool will prompt you to select the authority
key ID extension.

X.509 certificate extensions are described in RFC 5280.

-4
Add a CRL distribution point extension to a certificate that is being created or added
to a database. This extension identifies the URL of a certificate's associated
certificate revocation list (CRL). certutil prompts for the URL.

X.509 certificate extensions are described in RFC 5280.

-5 | --nsCertType keyword,keyword
Add an X.509 V3 certificate type extension to a certificate that is being created or
added to the database. There are several available keywords:

· sslClient

· sslServer

· smime

· objectSigning

· sslCA

· smimeCA

· objectSigningCA

· critical

X.509 certificate extensions are described in RFC 5280.

-6 | --extKeyUsage keyword,keyword
Add an extended key usage extension to a certificate that is being created or added to
the database. Several keywords are available:

· serverAuth

· clientAuth

· codeSigning

· emailProtection

· timeStamp

· ocspResponder

· stepUp

· msTrustListSign

· critical

X.509 certificate extensions are described in RFC 5280.

-7 emailAddrs
Add a comma-separated list of email addresses to the subject alternative name
extension of a certificate or certificate request that is being created or added to
the database. Subject alternative name extensions are described in Section 4.2.1.7 of
RFC 3280.

-8 dns-names
Add a comma-separated list of DNS names to the subject alternative name extension of a
certificate or certificate request that is being created or added to the database.
Subject alternative name extensions are described in Section 4.2.1.7 of RFC 3280.

--extAIA
Add the Authority Information Access extension to the certificate. X.509 certificate
extensions are described in RFC 5280.

--extSIA
Add the Subject Information Access extension to the certificate. X.509 certificate
extensions are described in RFC 5280.

--extCP
Add the Certificate Policies extension to the certificate. X.509 certificate
extensions are described in RFC 5280.

--extPM
Add the Policy Mappings extension to the certificate. X.509 certificate extensions are
described in RFC 5280.

--extPC
Add the Policy Constraints extension to the certificate. X.509 certificate extensions
are described in RFC 5280.

--extIA
Add the Inhibit Any Policy Access extension to the certificate. X.509 certificate
extensions are described in RFC 5280.

--extSKID
Add the Subject Key ID extension to the certificate. X.509 certificate extensions are
described in RFC 5280.

--extNC
Add a Name Constraint extension to the certificate. X.509 certificate extensions are
described in RFC 5280.

--extSAN type:name[,type:name]...
Create a Subject Alt Name extension with one or multiple names.

-type: directory, dn, dns, edi, ediparty, email, ip, ipaddr, other, registerid,
rfc822, uri, x400, x400addr

--empty-password
Use empty password when creating new certificate database with -N.

--keyAttrFlags attrflags
PKCS #11 key Attributes. Comma separated list of key attribute flags, selected from
the following list of choices: {token | session} {public | private} {sensitive |
insensitive} {modifiable | unmodifiable} {extractable | unextractable}

--keyOpFlagsOn opflags, --keyOpFlagsOff opflags
PKCS #11 key Operation Flags. Comma separated list of one or more of the following:
{token | session} {public | private} {sensitive | insensitive} {modifiable |
unmodifiable} {extractable | unextractable}

--new-n nickname
A new nickname, used when renaming a certificate.

--source-dir certdir
Identify the certificate database directory to upgrade.

--source-prefix certdir
Give the prefix of the certificate and key databases to upgrade.

--upgrade-id uniqueID
Give the unique ID of the database to upgrade.

--upgrade-token-name name
Set the name of the token to use while it is being upgraded.

-@ pwfile
Give the name of a password file to use for the database being upgraded.

USAGE AND EXAMPLES

Most of the command options in the examples listed here have more arguments available. The
arguments included in these examples are the most common ones or are used to illustrate a
specific scenario. Use the -H option to show the complete list of arguments for each
command option.

Creating New Security Databases

Certificates, keys, and security modules related to managing certificates are stored in
three related databases:

· cert8.db or cert9.db

· key3.db or key4.db

· secmod.db or pkcs11.txt

These databases must be created before certificates or keys can be generated.

certutil -N -d [sql:]directory

Creating a Certificate Request

A certificate request contains most or all of the information that is used to generate the
final certificate. This request is submitted separately to a certificate authority and is
then approved by some mechanism (automatically or by human review). Once the request is
approved, then the certificate is generated.

$ certutil -R -k key-type-or-id [-q pqgfile|curve-name] -g key-size -s subject [-h tokenname] -d [sql:]directory [-p phone] [-o output-file] [-a]

The -R command options requires four arguments:

· -k to specify either the key type to generate or, when renewing a certificate, the
existing key pair to use

· -g to set the keysize of the key to generate

· -s to set the subject name of the certificate

· -d to give the security database directory

The new certificate request can be output in ASCII format (-a) or can be written to a
specified file (-o).

For example:

$ certutil -R -k rsa -g 1024 -s "CN=John Smith,O=Example Corp,L=Mountain View,ST=California,C=US" -d sql:$HOME/nssdb -p 650-555-0123 -a -o cert.cer

Generating key. This may take a few moments...

Creating a Certificate

A valid certificate must be issued by a trusted CA. This can be done by specifying a CA
certificate (-c) that is stored in the certificate database. If a CA key pair is not
available, you can create a self-signed certificate using the -x argument with the -S
command option.

$ certutil -S -k rsa|dsa|ec -n certname -s subject [-c issuer |-x] -t trustargs -d [sql:]directory [-m serial-number] [-v valid-months] [-w offset-months] [-p phone] [-1] [-2] [-3] [-4] [-5 keyword] [-6 keyword] [-7 emailAddress] [-8 dns-names] [--extAIA] [--extSIA] [--extCP] [--extPM] [--extPC] [--extIA] [--extSKID]

The series of numbers and --ext* options set certificate extensions that can be added to
the certificate when it is generated by the CA. Interactive prompts will result.

For example, this creates a self-signed certificate:

$ certutil -S -s "CN=Example CA" -n my-ca-cert -x -t "C,C,C" -1 -2 -5 -m 3650

The interative prompts for key usage and whether any extensions are critical and responses
have been ommitted for brevity.

From there, new certificates can reference the self-signed certificate:

$ certutil -S -s "CN=My Server Cert" -n my-server-cert -c "my-ca-cert" -t "u,u,u" -1 -5 -6 -8 -m 730

Generating a Certificate from a Certificate Request

When a certificate request is created, a certificate can be generated by using the request
and then referencing a certificate authority signing certificate (the issuer specified in
the -c argument). The issuing certificate must be in the certificate database in the
specified directory.

certutil -C -c issuer -i cert-request-file -o output-file [-m serial-number] [-v valid-months] [-w offset-months] -d [sql:]directory [-1] [-2] [-3] [-4] [-5 keyword] [-6 keyword] [-7 emailAddress] [-8 dns-names]

For example:

$ certutil -C -c "my-ca-cert" -i /home/certs/cert.req -o cert.cer -m 010 -v 12 -w 1 -d sql:$HOME/nssdb -1 nonRepudiation,dataEncipherment -5 sslClient -6 clientAuth -7 [email protected]

Listing Certificates

The -L command option lists all of the certificates listed in the certificate database.
The path to the directory (-d) is required.

$ certutil -L -d sql:/home/my/sharednssdb

Certificate Nickname Trust Attributes
SSL,S/MIME,JAR/XPI

CA Administrator of Instance pki-ca1's Example Domain ID u,u,u
TPS Administrator's Example Domain ID u,u,u
Google Internet Authority ,,
Certificate Authority - Example Domain CT,C,C

Using additional arguments with -L can return and print the information for a single,
specific certificate. For example, the -n argument passes the certificate name, while the
-a argument prints the certificate in ASCII format:

$ certutil -L -d sql:$HOME/nssdb -a -n my-ca-cert
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
For a human-readable display

$ certutil -L -d sql:$HOME/nssdb -n my-ca-cert
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 3650 (0xe42)
Signature Algorithm: PKCS #1 SHA-1 With RSA Encryption
Issuer: "CN=Example CA"
Validity:
Not Before: Wed Mar 13 19:10:29 2013
Not After : Thu Jun 13 19:10:29 2013
Subject: "CN=Example CA"
Subject Public Key Info:
Public Key Algorithm: PKCS #1 RSA Encryption
RSA Public Key:
Modulus:
9e:0a:ce:ab:f3:27:20:55:80:5a:83:5d:16:12:c9:30:
4d:c3:50:eb:c5:45:3f:dc:6b:d6:03:f9:e0:8c:0c:07:
12:fd:02:ba:5f:fa:b0:ef:e0:b0:2b:e7:00:11:e2:1f:
ab:a7:9e:ce:b1:5d:1c:cf:39:19:42:d9:66:37:82:49:
3b:be:69:6c:2e:f6:29:c9:e7:0d:6b:30:22:fc:d0:30:
56:75:3f:eb:a1:ce:b1:aa:15:15:61:3e:80:14:28:f7:
d5:2b:37:6c:a4:d0:18:8a:fc:63:05:94:b9:b9:75:74:
11:3a:00:3d:64:a2:b2:15:d2:34:2c:85:ed:7f:a4:9b
Exponent: 65537 (0x10001)
Signed Extensions:
Name: Certificate Type
Data: none

Name: Certificate Basic Constraints
Data: Is a CA with no maximum path length.

Name: Certificate Key Usage
Critical: True
Usages: Certificate Signing

Signature Algorithm: PKCS #1 SHA-1 With RSA Encryption
Signature:
3a:72:19:33:90:00:8d:db:cd:5d:d6:32:8c:ad:cf:91:
1c:6d:94:31:a4:32:c6:2b:5e:68:b5:59:3b:e4:68:d6:
79:d1:52:fb:1e:0d:fd:3d:5c:a6:05:c0:f3:09:8d:60:
a2:85:59:2e:e9:bc:3f:8a:16:5f:b8:c1:e1:c4:ad:b6:
36:e7:ba:8a:73:50:e9:e0:ee:ed:69:ab:a8:bf:33:de:
25:2b:43:0c:6c:f9:68:85:a1:bd:ab:6f:c5:d1:55:52:
64:cd:77:57:c6:59:38:ba:8d:d4:b4:db:f0:f2:c0:33:
ee:c5:83:ef:5a:b1:29:a2:07:53:9a:b8:f7:38:a3:7e
Fingerprint (MD5):
86:D8:A5:8B:8A:26:BE:9E:17:A8:7B:66:10:6B:27:80
Fingerprint (SHA1):
48:78:09:EF:C5:D4:0C:BD:D2:64:45:59:EB:03:13:15:F7:A9:D6:F7

Certificate Trust Flags:
SSL Flags:
Valid CA
Trusted CA
User
Email Flags:
Valid CA
Trusted CA
User
Object Signing Flags:
Valid CA
Trusted CA
User

Listing Keys

Keys are the original material used to encrypt certificate data. The keys generated for
certificates are stored separately, in the key database.

To list all keys in the database, use the -K command option and the (required) -d argument
to give the path to the directory.

$ certutil -K -d sql:$HOME/nssdb
certutil: Checking token "NSS Certificate DB" in slot "NSS User Private Key and Certificate Services "
< 0> rsa 455a6673bde9375c2887ec8bf8016b3f9f35861d Thawte Freemail Member's Thawte Consulting (Pty) Ltd. ID
< 1> rsa 40defeeb522ade11090eacebaaf1196a172127df Example Domain Administrator Cert
< 2> rsa 1d0b06f44f6c03842f7d4f4a1dc78b3bcd1b85a5 John Smith user cert

There are ways to narrow the keys listed in the search results:

· To return a specific key, use the -nname argument with the name of the key.

· If there are multiple security devices loaded, then the -htokenname argument can
search a specific token or all tokens.

· If there are multiple key types available, then the -kkey-type argument can search a
specific type of key, like RSA, DSA, or ECC.

Listing Security Modules

The devices that can be used to store certificates -- both internal databases and external
devices like smart cards -- are recognized and used by loading security modules. The -U
command option lists all of the security modules listed in the secmod.db database. The
path to the directory (-d) is required.

$ certutil -U -d sql:/home/my/sharednssdb

slot: NSS User Private Key and Certificate Services
token: NSS Certificate DB

slot: NSS Internal Cryptographic Services
token: NSS Generic Crypto Services

Adding Certificates to the Database

Existing certificates or certificate requests can be added manually to the certificate
database, even if they were generated elsewhere. This uses the -A command option.

certutil -A -n certname -t trustargs -d [sql:]directory [-a] [-i input-file]

For example:

$ certutil -A -n "CN=My SSL Certificate" -t "u,u,u" -d sql:/home/my/sharednssdb -i /home/example-certs/cert.cer

A related command option, -E, is used specifically to add email certificates to the
certificate database. The -E command has the same arguments as the -A command. The trust
arguments for certificates have the format SSL,S/MIME,Code-signing, so the middle trust
settings relate most to email certificates (though the others can be set). For example:

$ certutil -E -n "CN=John Smith Email Cert" -t ",Pu," -d sql:/home/my/sharednssdb -i /home/example-certs/email.cer

Deleting Certificates to the Database

Certificates can be deleted from a database using the -D option. The only required options
are to give the security database directory and to identify the certificate nickname.

certutil -D -d [sql:]directory -n "nickname"

For example:

$ certutil -D -d sql:/home/my/sharednssdb -n "my-ssl-cert"

Validating Certificates

A certificate contains an expiration date in itself, and expired certificates are easily
rejected. However, certificates can also be revoked before they hit their expiration date.
Checking whether a certificate has been revoked requires validating the certificate.
Validation can also be used to ensure that the certificate is only used for the purposes
it was initially issued for. Validation is carried out by the -V command option.

certutil -V -n certificate-name [-b time] [-e] [-u cert-usage] -d [sql:]directory

For example, to validate an email certificate:

$ certutil -V -n "John Smith's Email Cert" -e -u S,R -d sql:/home/my/sharednssdb

Modifying Certificate Trust Settings

The trust settings (which relate to the operations that a certificate is allowed to be
used for) can be changed after a certificate is created or added to the database. This is
especially useful for CA certificates, but it can be performed for any type of
certificate.

certutil -M -n certificate-name -t trust-args -d [sql:]directory

For example:

$ certutil -M -n "My CA Certificate" -d sql:/home/my/sharednssdb -t "CTu,CTu,CTu"

Printing the Certificate Chain

Certificates can be issued in chains because every certificate authority itself has a
certificate; when a CA issues a certificate, it essentially stamps that certificate with
its own fingerprint. The -O prints the full chain of a certificate, going from the initial
CA (the root CA) through ever intermediary CA to the actual certificate. For example, for
an email certificate with two CAs in the chain:

$ certutil -d sql:/home/my/sharednssdb -O -n "[email protected]"
"Builtin Object Token:Thawte Personal Freemail CA" [E=[email protected],CN=Thawte Personal Freemail CA,OU=Certification Services Division,O=Thawte Consulting,L=Cape Town,ST=Western Cape,C=ZA]

"Thawte Personal Freemail Issuing CA - Thawte Consulting" [CN=Thawte Personal Freemail Issuing CA,O=Thawte Consulting (Pty) Ltd.,C=ZA]

"(null)" [E=[email protected],CN=Thawte Freemail Member]

Resetting a Token

The device which stores certificates -- both external hardware devices and internal
software databases -- can be blanked and reused. This operation is performed on the device
which stores the data, not directly on the security databases, so the location must be
referenced through the token name (-h) as well as any directory path. If there is no
external token used, the default value is internal.

certutil -T -d [sql:]directory -h token-name -0 security-officer-password

Many networks have dedicated personnel who handle changes to security tokens (the security
officer). This person must supply the password to access the specified token. For example:

$ certutil -T -d sql:/home/my/sharednssdb -h nethsm -0 secret

Upgrading or Merging the Security Databases

Many networks or applications may be using older BerkeleyDB versions of the certificate
database (cert8.db). Databases can be upgraded to the new SQLite version of the database
(cert9.db) using the --upgrade-merge command option or existing databases can be merged
with the new cert9.db databases using the ---merge command.

The --upgrade-merge command must give information about the original database and then use
the standard arguments (like -d) to give the information about the new databases. The
command also requires information that the tool uses for the process to upgrade and write
over the original database.

certutil --upgrade-merge -d [sql:]directory [-P dbprefix] --source-dir directory --source-prefix dbprefix --upgrade-id id --upgrade-token-name name [-@ password-file]

For example:

$ certutil --upgrade-merge -d sql:/home/my/sharednssdb --source-dir /opt/my-app/alias/ --source-prefix serverapp- --upgrade-id 1 --upgrade-token-name internal

The --merge command only requires information about the location of the original database;
since it doesn't change the format of the database, it can write over information without
performing interim step.

certutil --merge -d [sql:]directory [-P dbprefix] --source-dir directory --source-prefix dbprefix [-@ password-file]

For example:
$ certutil --merge -d sql:/home/my/sharednssdb --source-dir /opt/my-app/alias/ --source-prefix serverapp-
Running certutil Commands from a Batch File

A series of commands can be run sequentially from a text file with the -B command option.
The only argument for this specifies the input file.

$ certutil -B -i /path/to/batch-file

NSS DATABASE TYPES

NSS originally used BerkeleyDB databases to store security information. The last versions
of these legacy databases are:

· cert8.db for certificates

· key3.db for keys

· secmod.db for PKCS #11 module information

BerkeleyDB has performance limitations, though, which prevent it from being easily used by
multiple applications simultaneously. NSS has some flexibility that allows applications to
use their own, independent database engine while keeping a shared database and working
around the access issues. Still, NSS requires more flexibility to provide a truly shared
security database.

In 2009, NSS introduced a new set of databases that are SQLite databases rather than
BerkeleyDB. These new databases provide more accessibility and performance:

· cert9.db for certificates

· key4.db for keys

· pkcs11.txt, a listing of all of the PKCS #11 modules, contained in a new subdirectory
in the security databases directory

Because the SQLite databases are designed to be shared, these are the shared database
type. The shared database type is preferred; the legacy format is included for backward
compatibility.

By default, the tools (certutil, pk12util, modutil) assume that the given security
databases follow the more common legacy type. Using the SQLite databases must be manually
specified by using the sql: prefix with the given security directory. For example:

$ certutil -L -d sql:/home/my/sharednssdb

To set the shared database type as the default type for the tools, set the
NSS_DEFAULT_DB_TYPE environment variable to sql:

export NSS_DEFAULT_DB_TYPE="sql"

This line can be set added to the ~/.bashrc file to make the change permanent.

Most applications do not use the shared database by default, but they can be configured to
use them. For example, this how-to article covers how to configure Firefox and Thunderbird
to use the new shared NSS databases:

· https://wiki.mozilla.org/NSS_Shared_DB_Howto

For an engineering draft on the changes in the shared NSS databases, see the NSS project
wiki:

· https://wiki.mozilla.org/NSS_Shared_DB

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