NAME
Crypt::OpenSSL::RSA - RSA encoding and decoding, using the openSSL libraries
SYNOPSIS
use Crypt::OpenSSL::Random;
use Crypt::OpenSSL::RSA;
# not necessary if we have /dev/random:
Crypt::OpenSSL::Random::random_seed($good_entropy);
Crypt::OpenSSL::RSA->import_random_seed();
$rsa_pub = Crypt::OpenSSL::RSA->new_public_key($key_string);
$rsa_pub->use_sslv23_padding(); # use_pkcs1_oaep_padding is the default
$ciphertext = $rsa->encrypt($plaintext);
$rsa_priv = Crypt::OpenSSL::RSA->new_private_key($key_string);
$plaintext = $rsa->encrypt($ciphertext);
$rsa = Crypt::OpenSSL::RSA->generate_key( 1024 ); # or
$rsa = Crypt::OpenSSL::RSA->generate_key( 1024, $prime );
print "private key is:\n", $rsa->get_private_key_string();
print "public key is:\n", $rsa->get_public_key_string();
$rsa_priv->use_md5_hash(); # use_sha1_hash is the default
$signature = $rsa_priv->sign($plaintext);
print "Signed correctly\n" if ( $rsa->verify($plaintext, $signature) );DESCRIPTION
Crypt::OpenSSL::RSA provides the ability to RSA encrypt strings which are somewhat shorter than the block size of a key. It also allows for decryption, signatures and signature verification.
NOTE: Many of the methods in this package can croak, so use eval, or Error.pm's try/catch mechanism to capture errors. Also, while some methods from earlier versions of this package return true on success, this (never documented) behavior is no longer the case.
Class Methods
- new_public_key
-
Create a new Crypt::OpenSSL::RSA object by loading a public key in from an X509 encoded string. The string should include the -----BEGIN...----- and -----END...----- lines. The padding is set to PKCS1_OAEP, but can be changed with the use_xxx_padding methods
- new_private_key
-
Create a new Crypt::OpenSSL::RSA object by loading a private key in from an X509 encoded string. The string should include the -----BEGIN...----- and -----END...----- lines. The padding is set to PKCS1_OAEP, but can be changed with use_xxx_padding.
- generate_key
-
Create a new Crypt::OpenSSL::RSA object by constructing a private/public key pair. The first (mandetory) argument is the key size, while the second optional argument specifies the public exponent (the default public exponent is 65535). The padding is set to PKCS1_OAEP, but can be changed with use_xxx_padding methods.
NOTE - using generate_key as an instance method on an rsa object created by the deprecated new method is itself deprecated.
- new_key_from_parameters
-
Given Crypt::OpenSSL::Bignum objects for n, e, and optionally d, p, and q, where p and q are the prime factors of n, e is the public exponent and d is the private exponent, create a new Crypt::OpenSSL::RSA object using these values. If p and q are provided and d is undef, d is computed. Note that while p and q are not necessary for a private key, their presence will speed up computation.
- import_random_seed
-
Import a random seed from Crypt::OpenSSL::Random, since the OpenSSL libraries won't allow sharing of random structures across perl XS modules.
- new
-
The no-arg new constructor is DEPRECATED - use generate_key, new_public_key or new_private_key instead.
Instance Methods
- DESTROY
-
Clean up after ourselves. In particular, erase and free the memory occupied by the RSA key structure.
- load_public_key
-
DEPRECATED - use new_public_key instead
- load_private_key
-
DEPRECATED - use new_public_key instead
- get_public_key_string
-
Return the public portion of the key as an X509 encoded string.
- get_private_key_string
-
Return the X509 encoding of the private key.
- encrypt
-
Encrypt a string using the public (portion of the) key
- sign
-
Sign a string using the secret (portion of the) key
- verify
-
Check the signature on a text.
- decrypt
-
Decrypt a binary "string". Croaks if the key is public only.
- set_padding_mode
-
DEPRECATED Use the use_xxx_padding methods instead
- use_no_padding
-
Use raw RSA encryption. This mode should only be used to implement cryptographically sound padding modes in the application code. Encrypting user data directly with RSA is insecure.
- use_pkcs1_padding
-
Use PKCS #1 v1.5 padding. This currently is the most widely used mode of padding.
- use_pkcs1_oaep_padding
-
Use EME-OAEP padding as defined in PKCS #1 v2.0 with SHA-1, MGF1 and an empty encoding parameter. This mode of padding is recommended for all new applications. It is the default mode used by Crypt::OpenSSL::RSA.
- use_sslv23_padding
-
Use PKCS #1 v1.5 padding with an SSL-specific modification that denotes that the server is SSL3 capable.
- get_padding_mode
-
DEPRECATED
- use_md5_hash
-
Use the RFC 1321 MD5 hashing algorithm by Ron Rivest when signing and verifying messages.
- use_sha1_hash
-
Use the RFC 3174 Secure Hashing Algorithm (FIPS 180-1) when signing and verifying messages. This is the default.
- use_ripemd160_hash
-
Dobbertin, Bosselaers and Preneel's RIPEMD hashing algorithm when signing and verifying messages.
- size
-
Returns the size, in bytes, of the key. All encrypted text will be of this size, and depending on the padding mode used, the length of the text to be encrypted should be:
- check_key
-
This function validates the RSA key, returning a true value if the key is valid, and a false value otherwise.
- get_key_parameters
-
Return Crypt::OpenSSL::Bignum objects representing the values of n, e, d, p, q, d mod (p-1), d mod (q-1), and 1/q mod p, where p and q are the prime factors of n, e is the public exponent and d is the private exponent. Some of these values may return as undef; only n and e will be defined for a public key. The Crypt::OpenSSL::Bignum module must be installed for this to work.
BUGS
There is a small memory leak when generating new keys of more than 512 bits.
AUTHOR
Ian Robertson, iroberts@cpan.org
SEE ALSO
perl(1), Crypt::OpenSSL::Random(3), Crypt::OpenSSL::Bignum(3), rsa(3), RSA_new(3), RSA_public_encrypt(3), RSA_size(3), RSA_generate_key(3), RSA_check_key(3)