Encryption libraries in Ubuntu

This table contains a list of encryption libraries supported in main as well as 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/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, e.g. 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) (or openssl enc -ciphers) (or 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 (eg, gcrypt20)	bulk encryption	src/gcrypt.h gcry_cipher_algos		compare src/gcrypt.h for changes
gcrypt (eg, gcrypt20)	digital signatures	src/gcrypt.h gcry_pk_algos		compare src/gcrypt.h for changes
gcrypt (eg, gcrypt20)	authentication/integrity	src/gcrypt.h gcry_pk_algos		compare src/gcrypt.h for changes
gnutls (eg, gnutls28)	bulk encryption	gnutls-cli -l | grep Ciphers:	interpret output/research	compare sorted output in diff for changes
gnutls (eg, gnutls28)	digital signatures	gnutls-cli -l | grep 'Public Key'	interpret output/research	compare sorted output in diff for changes
gnutls (eg, 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 collection of core cryptographic primitives such a symmetric, asymmetric, hashing, signing.

gcrypt

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

gnutls

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

nettle

https://www.lysator.liu.se/~nisse/nettle/ is a low-level library designed to be easy to integrate into higher-level libraries.

NSS

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

Kernel

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