Encryption libraries in Ubuntu

This table lists encryption libraries supported in main, along with instructions on how to find relevant information about algorithms from a specific library.

Overview of the libraries

Source package

The package that contains the library.

Algorithm application

• Bulk encryption: Encrypting large amounts of data such as network

  traffic or storage.

• Digital signature: Authenticating messages or documents.

• Authentication/integrity: Verifying that the data’s integrity is

  intact via message authentication codes, hashes, TLS handshake, and so on.

Name of encryption algorithm/hash function

A command to list all encryption algorithms or hash functions that this library provides.

Max key length/hash value (in bits)

• Filter: If the command that lists algorithms displays too many

  algorithms (including deprecated or experimental ones), you must filter only the relevant ones.

• Interpret: Derive the max key length/hash value from the name of

  the displayed algorithm.

• Research: Consult the documentation for that specific algorithm

  implementation in the library.

Notes

Additional instructions on how to find more information about a specific library, for example, changes between releases.

Source package	Algorithm application	Name of encryption algorithm/hash function	Max key length/hash value (in bits)	Notes
OpenSSL	Bulk encryption	openssl ciphers | sed 's/:/\n/g' | sort -u (or openssl enc -help, openssl enc -ciphers, openssl list -cipher-algorithms)	Interpret output/research	Compare sorted output in diff for changes
OpenSSL	Digital signature	Research (or openssl list -signature-algorithms)	Research
OpenSSL	Authentication/integrity	openssl dgst -help (or openssl list -mac-algorithms and openssl list -digest-algorithms)	Interpret output/research	Compare sorted output in diff for changes
gcrypt (for example, gcrypt20)	Bulk encryption	src/gcrypt.h gcry_cipher_algos		Compare src/gcrypt.h for changes
gcrypt (for example, gcrypt20)	Digital signatures	src/gcrypt.h gcry_pk_algos		Compare src/gcrypt.h for changes
gcrypt (for example, gcrypt20)	Authentication/integrity	src/gcrypt.h gcry_pk_algos		Compare src/gcrypt.h for changes
gnutls (for example, gnutls28)	Bulk encryption	gnutls-cli -l | grep Ciphers:	Interpret output/research	Compare sorted output in diff for changes
gnutls (for example, gnutls28)	Digital signatures	gnutls-cli -l | grep 'Public Key'	Interpret output/research	Compare sorted output in diff for changes
gnutls (for example, gnutls28)	Authentication/integrity	gnutls-cli -l | grep MACs:	Interpret output/research	Compare sorted output in diff for changes
nettle	Bulk encryption	nettle.html documentation (use w3m -dump path/to/nettle.html for text file)	Interpret output/research
nettle	Digital signatures	nettle.html documentation (use w3m -dump path/to/nettle.html for text file)	Interpret output/research
nettle	Authentication/integrity	nettle.html documentation (use w3m -dump path/to/nettle.html for text file)	Interpret output/research
NSS	Bulk encryption	modutil -rawlist (this may not be complete)	Interpret output/research	Compare output between releases
NSS	Digital signatures	modutil -rawlist (this may not be complete)	Interpret output/research	Compare output between releases
NSS	Authentication/integrity	modutil -rawlist (this may not be complete)	Interpret output/research	Compare output between releases
Kernel	Bulk encryption	grep CRYPTO_ /boot/config...	Filter/interpret output/research
Kernel	Digital signatures	grep CRYPTO_ /boot/config...	Filter/interpret output/research
Kernel	Authentication/integrity	grep CRYPTO_ /boot/config...	Filter/interpret output/research

OpenSSL

OpenSSL is a library that provides secure communications over computer networks, such as TLS/SSL protocols, and a collection of core cryptographic primitives such as symmetric, asymmetric, hashing, and signing.

gcrypt

GNU libgcrypt is a library that provides core primitives such as block ciphers, public-key algorithms, and digests.

gnutls

GnuTLS is a library that provides TLS/SSL protocols similar to OpenSSL but with a GNU licensing model.

nettle

Nettle is a low-level library designed to be easy to integrate into higher-level libraries and applications.

NSS

Network Security Services (NSS) is a set of libraries that provide TLS/SSL, PKI, and cryptographic functions.

Kernel

The Linux kernel provides a cryptographic API and implementations of primitives (AES, SHA, RNG, etc.).