The PKCS #12 utility, pk12util, enables sharing certificates among any server that supports PKCS #12. The tool can import certificates and keys from PKCS #12 files into security databases, export certificates, and list certificates and keys.
pk12util 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). If the prefix sql: is not used, then the tool assumes that the given databases are in the old format.
-m | --key-len keyLength
-n | --cert-key-len certKeyLength
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.
Importing Keys and Certificates
The most basic usage of pk12util for importing a certificate or key is the PKCS #12 input file (-i) and some way to specify the security database being accessed (either -d for a directory or -h for a token).
pk12util -i p12File [-h tokenname] [-v] [-d [sql:]directory] [-P dbprefix] [-k slotPasswordFile|-K slotPassword] [-w p12filePasswordFile|-W p12filePassword]
# pk12util -i /tmp/cert-files/users.p12 -d sql:/home/my/sharednssdb Enter a password which will be used to encrypt your keys. The password should be at least 8 characters long, and should contain at least one non-alphabetic character. Enter new password: Re-enter password: Enter password for PKCS12 file: pk12util: PKCS12 IMPORT SUCCESSFUL
Exporting Keys and Certificates
Using the pk12util command to export certificates and keys requires both the name of the certificate to extract from the database (-n) and the PKCS #12-formatted output file to write to. There are optional parameters that can be used to encrypt the file to protect the certificate material.
pk12util -o p12File -n certname [-c keyCipher] [-C certCipher] [-m|--key_len keyLen] [-n|--cert_key_len certKeyLen] [-d [sql:]directory] [-P dbprefix] [-k slotPasswordFile|-K slotPassword] [-w p12filePasswordFile|-W p12filePassword]
# pk12util -o certs.p12 -n Server-Cert -d sql:/home/my/sharednssdb Enter password for PKCS12 file: Re-enter password:
Listing Keys and Certificates
The information in a .p12 file are not human-readable. The certificates and keys in the file can be printed (listed) in a human-readable pretty-print format that shows information for every certificate and any public keys in the .p12 file.
pk12util -l p12File [-h tokenname] [-r] [-d [sql:]directory] [-P dbprefix] [-k slotPasswordFile|-K slotPassword] [-w p12filePasswordFile|-W p12filePassword]
For example, this prints the default ASCII output:
# pk12util -l certs.p12 Enter password for PKCS12 file: Key(shrouded): Friendly Name: Thawte Freemail Member's Thawte Consulting (Pty) Ltd. ID Encryption algorithm: PKCS #12 V2 PBE With SHA-1 And 3KEY Triple DES-CBC Parameters: Salt: 45:2e:6a:a0:03:4d:7b:a1:63:3c:15:ea:67:37:62:1f Iteration Count: 1 (0x1) Certificate: Data: Version: 3 (0x2) Serial Number: 13 (0xd) Signature Algorithm: PKCS #1 SHA-1 With RSA Encryption Issuer: "Efirstname.lastname@example.org,CN=Thawte Personal Freemail C A,OU=Certification Services Division,O=Thawte Consulting,L=Cape T own,ST=Western Cape,C=ZA"
Alternatively, the -r prints the certificates and then exports them into separate DER binary files. This allows the certificates to be fed to another application that supports .p12 files. Each certificate is written to a sequentially-number file, beginning with file0001.der and continuing through file000N.der, incrementing the number for every certificate:
pk12util -l test.p12 -r Enter password for PKCS12 file: Key(shrouded): Friendly Name: Thawte Freemail Member's Thawte Consulting (Pty) Ltd. ID Encryption algorithm: PKCS #12 V2 PBE With SHA-1 And 3KEY Triple DES-CBC Parameters: Salt: 45:2e:6a:a0:03:4d:7b:a1:63:3c:15:ea:67:37:62:1f Iteration Count: 1 (0x1) Certificate Friendly Name: Thawte Personal Freemail Issuing CA - Thawte Consulting Certificate Friendly Name: Thawte Freemail Member's Thawte Consulting (Pty) Ltd. ID
PKCS #12 provides for not only the protection of the private keys but also the certificate and meta-data associated with the keys. Password-based encryption is used to protect private keys on export to a PKCS #12 file and, optionally, the associated certificates. If no algorithm is specified, the tool defaults to using PKCS #12 SHA-1 and 3-key triple DES for private key encryption. When not in FIPS mode, PKCS #12 SHA-1 and 40-bit RC4 is used for certificate encryption. When in FIPS mode, there is no certificate encryption. If certificate encryption is not wanted, specify "NONE" as the argument of the -C option.
The private key is always protected with strong encryption by default.
Several types of ciphers are supported.
PKCS #5 password-based encryption
PKCS #12 password-based encryption
With PKCS #12, the crypto provider may be the soft token module or an external hardware module. If the cryptographic module does not support the requested algorithm, then the next best fit will be selected (usually the default). If no suitable replacement for the desired algorithm can be found, the tool returns the error no security module can perform the requested operation.
NSS originally used BerkeleyDB databases to store security information. The last versions of these legacy databases are:
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 BerkleyDB. These new databases provide more accessibility and performance:
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:
# pk12util -i /tmp/cert-files/users.p12 -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:
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:
For an engineering draft on the changes in the shared NSS databases, see the NSS project wiki:
The exporting behavior of pk12util has changed over time, while importing files exported with older versions of NSS is still supported.
Until the 3.30 release, pk12util used the UTF-16 encoding for the PKCS #5 password-based encryption schemes, while the recommendation is to encode passwords in UTF-8 if the used encryption scheme is defined outside of the PKCS #12 standard.
Until the 3.31 release, even when "AES-128-CBC" or "AES-192-CBC" is given from the command line, pk12util always used 256-bit AES as the underlying encryption scheme.
For historical reasons, pk12util accepts password-based encryption schemes not listed in this document. However, those schemes are not officially supported and may have issues in interoperability with other tools.
The NSS wiki has information on the new database design and how to configure applications to use it.
For information about NSS and other tools related to NSS (like JSS), check out the NSS project wiki at m[blue]http://www.mozilla.org/projects/security/pki/nss/m. The NSS site relates directly to NSS code changes and releases.
Mailing lists: https://lists.mozilla.org/listinfo/dev-tech-crypto
The NSS tools were written and maintained by developers with Netscape, Red Hat, Sun, Oracle, Mozilla, and Google.
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/.