CERTUTIL(1) NSS Security Tools CERTUTIL(1)
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 and the associated certificate from a
database. Specify the key to delete with the -n argument or the -k
argument. Specify the database from which to delete the key with
the -d argument.
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.
-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.
--simple-self-signed
When printing the certificate chain, don't search for a chain if
issuer name equals to subject name.
-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:
o sql: requests the newer database
o 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.
o OID (example): 1.2.3.4
o critical-flag: critical or not-critical
o 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.
The name can also be a PKCS #11 URI. For example, the NSS internal
certificate store can be unambiguously specified as
"pkcs11:token=NSS%20Certificate%20DB". For details about the
format, see RFC 7512.
-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.
The nickname can also be a PKCS #11 URI. For example, if you have a
certificate named "my-server-cert" on the internal certificate
store, it can be unambiguously specified as
"pkcs11:token=NSS%20Certificate%20DB;object=my-server-cert". For
details about the format, see RFC 7512.
-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 nistp256, nistp384,
nistp521, curve25519.
If a token is available that supports more curves, the foolowing
curves are supported as well: 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:
o p - Valid peer
o P - Trusted peer (implies p)
o c - Valid CA
o C - Trusted CA (implies c)
o T - trusted CA for client authentication (ssl server only)
The attribute codes for the categories are separated by commas, and
the entire set of attributes enclosed by quotation marks. For
example:
-t "TC,C,T"
Use the -L option to see a list of the current certificates and
trust attributes in a certificate database.
Note that the output of the -L option may include "u" flag, which
means that there is a private key associated with the certificate.
It is a dynamic flag and you cannot set it with certutil.
-u certusage
Specify a usage context to apply when validating a certificate with
the -V option.
The contexts are the following:
o C (as an SSL client)
o V (as an SSL server)
o L (as an SSL CA)
o A (as Any CA)
o Y (Verify CA)
o S (as an email signer)
o R (as an email recipient)
o O (as an OCSP status responder)
o J (as an object signer)
o I (as an IPSEC user)
-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.
--pss
Restrict the generated certificate (with the -S option) or
certificate request (with the -R option) to be used with the
RSA-PSS signature scheme. This only works when the private key of
the certificate or certificate request is RSA.
--pss-sign
Sign the generated certificate with the RSA-PSS signature scheme
(with the -C or -S option). This only works when the private key of
the signer's certificate is RSA. If the signer's certificate is
restricted to RSA-PSS, it is not necessary to specify this option.
-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:
o MD2
o MD4
o MD5
o SHA1
o SHA224
o SHA256
o SHA384
o 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:
o digitalSignature
o nonRepudiation
o keyEncipherment
o dataEncipherment
o keyAgreement
o certSigning
o crlSigning
o 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:
o sslClient
o sslServer
o smime
o objectSigning
o sslCA
o smimeCA
o objectSigningCA
o 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:
o serverAuth
o clientAuth
o codeSigning
o emailProtection
o timeStamp
o ocspResponder
o stepUp
o msTrustListSign
o critical
o x509Any
o ipsecIKE
o ipsecIKEEnd
o ipsecIKEIntermediate
o ipsecEnd
o ipsecTunnel
o ipsecUser
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:
o cert8.db or cert9.db
o key3.db or key4.db
o 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:
o -k to specify either the key type to generate or, when renewing a
certificate, the existing key pair to use
o -g to set the keysize of the key to generate
o -s to set the subject name of the certificate
o -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 ",," -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 jsmith AT example.com
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:
o To return a specific key, use the -nname argument with the name of
the key.
o If there are multiple security devices loaded, then the -htokenname
argument can search a specific token or all tokens.
o 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
uri: pkcs11:token=NSS%20Certificate%20DB;manufacturer=Mozilla%20Foundation;serial=0000000000000000;model=NSS%203
slot: NSS Internal Cryptographic Services
token: NSS Generic Crypto Services
uri: pkcs11:token=NSS%20Generic%20Crypto%20Services;manufacturer=Mozilla%20Foundation;serial=0000000000000000;model=NSS%203
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 ",," -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 ",P," -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 "CT,CT,CT"
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 "jsmith AT example.com"
"Builtin Object Token:Thawte Personal Freemail CA" [E=personal-freemail AT thawte.com,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=jsmith AT example.com,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:
o cert8.db for certificates
o key3.db for keys
o 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:
o cert9.db for certificates
o key4.db for keys
o 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:
o 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:
o https://wiki.mozilla.org/NSS_Shared_DB
SEE ALSO
pk12util (1)
modutil (1)
certutil has arguments or operations that use features defined in
several IETF RFCs.
o http://tools.ietf.org/html/rfc5280
o http://tools.ietf.org/html/rfc1113
o http://tools.ietf.org/html/rfc1485
The NSS wiki has information on the new database design and how to
configure applications to use it.
o https://wiki.mozilla.org/NSS_Shared_DB_Howto
o https://wiki.mozilla.org/NSS_Shared_DB
ADDITIONAL RESOURCES
For information about NSS and other tools related to NSS (like JSS),
check out the NSS project wiki at
http://www.mozilla.org/projects/security/pki/nss/. The NSS site relates
directly to NSS code changes and releases.
Mailing lists: https://lists.mozilla.org/listinfo/dev-tech-crypto
IRC: Freenode at #dogtag-pki
AUTHORS
The NSS tools were written and maintained by developers with Netscape,
Red Hat, Sun, Oracle, Mozilla, and Google.
Authors: Elio Maldonado <emaldona AT redhat.com>, Deon Lackey
<dlackey AT redhat.com>.
LICENSE
Licensed under the Mozilla Public License, v. 2.0. If a copy of the MPL
was not distributed with this file, You can obtain one at
http://mozilla.org/MPL/2.0/.
NOTES
1. Mozilla NSS bug 836477
https://bugzilla.mozilla.org/show_bug.cgi?id=836477
nss-tools 3.90.0 Nov 13 2013 CERTUTIL(1)
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