Unix crypt(3)

E721424

Unix crypt(3) is a traditional Unix library function and algorithm used to hash and verify passwords, historically based on modified DES and later extended to support stronger schemes.

All labels observed (1)

Label Occurrences
Unix crypt(3) canonical 1

How this entity was disambiguated

Statements (53)

Predicate Object
instanceOf C library function ⓘ
Unix library function ⓘ
authentication mechanism ⓘ
password hashing function ⓘ
basedOn Data Encryption Standard ⓘ
modified DES cipher ⓘ
category Unix security ⓘ
cryptographic software ⓘ
definedIn crypt.h ⓘ
unistd.h ⓘ
extendedToSupport Blowfish-based password hashes ⓘ
MD5-based password hashes ⓘ
SHA-256-based password hashes ⓘ
SHA-512-based password hashes ⓘ
modular crypt format ⓘ
identifierPrefix $1$ for MD5-based hashes ⓘ
$2$ or $2a$ or $2y$ for Blowfish-based hashes ⓘ
$5$ for SHA-256-based hashes ⓘ
$6$ for SHA-512-based hashes ⓘ
implementedIn BSD C libraries ⓘ
linked to: BSD userland

glibc ⓘ
linked to: GNU C Library

musl libc ⓘ
linked to: musl
implements one-way hash function ⓘ
influenced design of modern password hashing schemes ⓘ
input salt value ⓘ
user password ⓘ
introducedIn Unix Version 7 ⓘ
linked to: V7 UNIX
introducedInYear 1979 ⓘ
nameOrigin crypt function in section 3 of Unix manual ⓘ
operatingSystemFamily Unix ⓘ
originalAlgorithm DES-based password hash ⓘ
originalIterationCount 25 DES iterations ⓘ
originalKeySpace 56-bit DES key ⓘ
originalPasswordLengthLimit 8 characters ⓘ
originalSaltEncoding 2-character string ⓘ
originalSaltLength 12 bits ⓘ
output encoded password hash ⓘ
outputFormat printable ASCII string ⓘ
parameter const char *key ⓘ
const char *salt ⓘ
primaryUse password hashing ⓘ
password verification ⓘ
returnType char * ⓘ
standardizedIn POSIX ⓘ
Single UNIX Specification ⓘ
status legacy for DES-based variant ⓘ
stillUsedFor backward compatibility ⓘ
usedBy /etc/passwd ⓘ
/etc/shadow ⓘ
PAM authentication modules ⓘ
login programs ⓘ
vulnerability limited password length in original DES variant ⓘ
susceptible to brute-force attacks for DES-based hashes ⓘ

How these facts were elicited

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

John the Ripper → supportsHashType → Unix crypt(3) ⓘ