argon2_pass($type, $password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

This function processes the $password with the given $salt and parameters. It encodes the resulting tag and the parameters as a password string (e.g. "$argon2id$v=19$m=65536,t=2,p=1$c29tZXNhbHQ$wWKIMhR9lyDFvRz9YTZweHKfbftvj+qf+YFY4NeBbtA").

• $type

  The argon2 type that is used. This must be one of 'argon2id', 'argon2i' or 'argon2d'.

• $password

  This is the password that is to be turned into a cryptographic key.

• $salt

  This is the salt that is used. It must be long enough to be unique.

• $t_cost

  This is the time-cost factor, typically a small integer that can be derived as explained above.

• $m_factor

  This is the memory costs factor. This must be given as a integer followed by an order of magnitude ("k", "M" or "G" for kilobytes, megabytes or gigabytes respectively), e.g. '64M'.

• $parallelism

  This is the number of threads that are used in computing it.

• $tag_size

  This is the size of the raw result in bytes. Typical values are 16 or 32.

argon2_verify($encoded, $password)

This verifies that the $password matches $encoded. All parameters and the tag value are extracted from $encoded, so no further arguments are necessary.

argon2_raw($type, $password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

This function processes the $password with the given $salt and parameters much like "argon2_pass", but returns the binary tag instead of a formatted string.

argon2id_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

argon2i_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

argon2d_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

This function processes the $password much like "argon2_pass" does, but the $type argument is set like the function name.

argon2id_verify($encoded, $password)

argon2i_verify($encoded, $password)

argon2d_verify($encoded, $password)

This verifies that the $password matches $encoded and the given type. All parameters and the tag value are extracted from $encoded, so no further arguments are necessary.

argon2id_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

argon2i_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

argon2d_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

This function processes the $password much like "argon2_raw" does, but the $type argument is set like the function name.

argon2_needs_rehash($encoded, $type, $t_cost, $m_cost, $parallelism, $output_length, $salt_length)

This function checks if a password-encoded string needs a rehash. It will return true if the $type (valid values are "argon2i", "argon2id" or "argon2d"), $t_cost, $m_cost, $parallelism, $output_length or $salt_length arguments mismatches any of the parameters of the password-encoded hash.

argon2_types

This returns all supported argon2 subtypes. Currently that's 'argon2id', 'argon2i' and 'argon2d'.

ACKNOWLEDGEMENTS

This module is based on the reference implementation as can be found at <https://github.com/P-H-C/phc-winner-argon2>.

SEE ALSO

You will also need a good source of randomness to generate good salts. Some possible solutions include:

• Net::SSLeay

  Its RAND_bytes function is OpenSSL's pseudo-randomness source.

• Crypt::URandom

  A minimalistic abstraction around OS-provided non-blocking (pseudo-)randomness.

• "/dev/random" / "/dev/urandom"

  A Linux/BSD specific pseudo-file that will allow you to read random bytes.

Implementations of other similar algorithms include:

• Crypt::Bcrypt

  An implementation of bcrypt, a battle-tested algorithm that tries to be CPU but not particularly memory intensive.

• Crypt::ScryptKDF

  An implementation of scrypt, a older scheme that also tries to be memory hard.