Apache HTTP Server Version 2.4

Apache > HTTP Server > Documentation > Version 2.4 > Miscellaneous Documentation

# Password Formats

Notes about the password encryption formats generated and understood by Apache.

## Basic Authentication

There are five formats that Apache recognizes for basic-authentication passwords. Note that not all formats work on every platform:

bcrypt
  "$2y$" + the result of the crypt_blowfish algorithm. See the APR source file crypt_blowfish.c for the details of the algorithm.
MD5
  "$apr1$" + the result of an Apache-specific algorithm using an iterated (1,000 times) MD5 digest of various combinations of a random 32-bit salt and the password. See the APR source file apr_md5.c for the details of the algorithm.
SHA1
  "{SHA}" + Base64-encoded SHA-1 digest of the password. Insecure.
CRYPT
  Unix only. Uses the traditional Unix `crypt(3)` function with a randomly-generated 32-bit salt (only 12 bits used) and the first 8 characters of the password. Insecure.
PLAIN TEXT (i.e. unencrypted)
  Windows & Netware only. Insecure.

### Generating values with htpasswd

### bcrypt

`$ htpasswd -nbB myName myPassword
myName:$2y$05$c4WoMPo3SXsafkva.HHa6uXQZWr7oboPiC2bT/r7q1BB8I2s0BRqC`

### MD5

`$ htpasswd -nbm myName myPassword
myName:$apr1$r31.....$HqJZimcKQFAMYayBlzkrA/`

### SHA1

`$ htpasswd -nbs myName myPassword
myName:{SHA}VBPuJHI7uixaa6LQGWx4s+5GKNE=`

### CRYPT

`$ htpasswd -nbd myName myPassword
myName:rqXexS6ZhobKA`

### Generating CRYPT and MD5 values with the OpenSSL command-line program

OpenSSL knows the Apache-specific MD5 algorithm.

### MD5

`$ openssl passwd -apr1 myPassword
$apr1$qHDFfhPC$nITSVHgYbDAK1Y0acGRnY0`

### CRYPT

`openssl passwd -crypt myPassword
qQ5vTYO3c8dsU`

### Validating CRYPT or MD5 passwords with the OpenSSL command line program

The salt for a CRYPT password is the first two characters (converted to a binary value). To validate `myPassword` against `rqXexS6ZhobKA`

### CRYPT

`$ openssl passwd -crypt -salt rq myPassword
Warning: truncating password to 8 characters
rqXexS6ZhobKA`

Note that using `myPasswo` instead of `myPassword` will produce the same result because only the first 8 characters of CRYPT passwords are considered.

The salt for an MD5 password is between `$apr1$` and the following `$` (as a Base64-encoded binary value - max 8 chars). To validate `myPassword` against `$apr1$r31.....$HqJZimcKQFAMYayBlzkrA/`

### MD5

`$ openssl passwd -apr1 -salt r31..... myPassword
$apr1$r31.....$HqJZimcKQFAMYayBlzkrA/`

### Database password fields for mod_dbd

The SHA1 variant is probably the most useful format for DBD authentication. Since the SHA1 and Base64 functions are commonly available, other software can populate a database with encrypted passwords that are usable by Apache basic authentication.

To create Apache SHA1-variant basic-authentication passwords in various languages:

### PHP

`'{SHA}' . base64_encode(sha1($password, TRUE))`

### Java

`"{SHA}" + new sun.misc.BASE64Encoder().encode(java.security.MessageDigest.getInstance("SHA1").digest(password.getBytes()))`

### ColdFusion

`"{SHA}" & ToBase64(BinaryDecode(Hash(password, "SHA1"), "Hex"))`

### Ruby

`require 'digest/sha1'
require 'base64'
'{SHA}' + Base64.encode64(Digest::SHA1.digest(password))`

### C or C++

`Use the APR function: apr_sha1_base64`

### Python

`import base64
import hashlib
"{SHA}" + format(base64.b64encode(hashlib.sha1(password).digest()))`

### PostgreSQL (with the contrib/pgcrypto functions installed)

`'{SHA}'||encode(digest(password,'sha1'),'base64')`

## Digest Authentication

Apache recognizes one format for digest-authentication passwords - the MD5 hash of the string `user:realm:password` as a 32-character string of hexadecimal digits. `realm` is the Authorization Realm argument to the `AuthName` directive in httpd.conf.

### Database password fields for mod_dbd

Since the MD5 function is commonly available, other software can populate a database with encrypted passwords that are usable by Apache digest authentication.

To create Apache digest-authentication passwords in various languages:

### PHP

`md5($user . ':' . $realm . ':' .$password)`

### Java

`byte b[] = java.security.MessageDigest.getInstance("MD5").digest( (user + ":" + realm + ":" + password ).getBytes());
java.math.BigInteger bi = new java.math.BigInteger(1, b);
String s = bi.toString(16);
while (s.length() < 32)
s = "0" + s; // String s is the encrypted password`

### ColdFusion

`LCase(Hash( (user & ":" & realm & ":" & password) , "MD5"))`

### Ruby

`require 'digest/md5'
Digest::MD5.hexdigest(user + ':' + realm + ':' + password)`

### PostgreSQL (with the contrib/pgcrypto functions installed)

`encode(digest( user || ':' || realm || ':' || password , 'md5'), 'hex')`