NAME

       Crypt::AuthEnc::ChaCha20Poly1305 - Authenticated encryption in ChaCha20-Poly1305 mode

SYNOPSIS

        ### OO interface
        use Crypt::AuthEnc::ChaCha20Poly1305;

        # encrypt and authenticate
        my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
        $ae->adata_add('additional_authenticated_data1');
        $ae->adata_add('additional_authenticated_data2');
        my $ct = $ae->encrypt_add('data1');
        $ct .= $ae->encrypt_add('data2');
        $ct .= $ae->encrypt_add('data3');
        my $tag = $ae->encrypt_done();

        # decrypt and verify
        my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
        $ae->adata_add('additional_authenticated_data1');
        $ae->adata_add('additional_authenticated_data2');
        my $pt = $ae->decrypt_add('ciphertext1');
        $pt .= $ae->decrypt_add('ciphertext2');
        $pt .= $ae->decrypt_add('ciphertext3');
        my $tag = $ae->decrypt_done();
        die "decrypt failed" unless $tag eq $expected_tag;

        #or
        my $result = $ae->decrypt_done($expected_tag); # 0 or 1

        ### functional interface
        use Crypt::AuthEnc::ChaCha20Poly1305 qw(chacha20poly1305_encrypt_authenticate chacha20poly1305_decrypt_verify);

        my ($ciphertext, $tag) = chacha20poly1305_encrypt_authenticate($key, $iv, $adata, $plaintext);
        my $plaintext = chacha20poly1305_decrypt_verify($key, $iv, $adata, $ciphertext, $tag);

DESCRIPTION

       Provides encryption and authentication based on ChaCha20 + Poly1305 as defined in RFC 7539
       - <https://tools.ietf.org/html/rfc7539>

EXPORT

       Nothing is exported by default.

       You can export selected functions:

         use Crypt::AuthEnc::ChaCha20Poly1305 qw(chacha20poly1305_encrypt_authenticate chacha20poly1305_decrypt_verify);

FUNCTIONS

   chacha20poly1305_encrypt_authenticate
        my ($ciphertext, $tag) = chacha20poly1305_encrypt_authenticate($key, $iv, $adata, $plaintext);

        # $key ..... key of proper length (128 or 256 bits / 16 or 32 bytes)
        # $iv ...... initialization vector (64 or 96 bits / 8 or 12 bytes)
        # $adata ... additional authenticated data (optional)

   chacha20poly1305_decrypt_verify
        my $plaintext = chacha20poly1305_decrypt_verify($key, $iv, $adata, $ciphertext, $tag);
        # on error returns undef

METHODS

   new
        my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);

        # $key ..... encryption key of proper length (128 or 256 bits / 16 or 32 bytes)
        # $iv ...... initialization vector (64 or 96 bits / 8 or 12 bytes)

   adata_add
       Add additional authenticated data.  Can be called before the first "encrypt_add" or
       "decrypt_add";

        $ae->adata_add($aad_data);                     # can be called multiple times

   encrypt_add
        $ciphertext = $ae->encrypt_add($data);         # can be called multiple times

   encrypt_done
        $tag = $ae->encrypt_done();                    # returns $tag value

   decrypt_add
        $plaintext = $ae->decrypt_add($ciphertext);    # can be called multiple times

   decrypt_done
        my $tag = $ae->decrypt_done;           # returns $tag value
        #or
        my $result = $ae->decrypt_done($tag);  # returns 1 (success) or 0 (failure)

   set_iv
        my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key)->set_iv($iv);
        # $iv ...... initialization vector (64 or 96 bits / 8 or 12 bytes)

   set_iv_rfc7905
       See <https://tools.ietf.org/html/rfc7905>

        my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key)->set_iv_rfc7905($iv, $seqnum);
        # $iv ...... initialization vector (96 bits / 12 bytes)
        # $seqnum .. 64bit integer (sequence number)

   clone
        my $ae_new = $ae->clone;

SEE ALSO

       •   CryptX, Crypt::AuthEnc::GCM, Crypt::AuthEnc::CCM, Crypt::AuthEnc::EAX,
           Crypt::AuthEnc::OCB

       •   <https://tools.ietf.org/html/rfc7539>