| Key |
|
typedict |
| |
A
Key
is a cryptographic key generator object.
It can generate symmetric (a.k.a., secure) and asymmetric (a.k.a.,
public/private key pair) keys using a variety of cryptographic
algorithms.
Access to certain algorithms may require loading additional
class files through a provider such as
BouncyCastle.org.
Yoix programs interact with these key generators
by reading, writing or executing the following
Key
fields:
| algorithm |
A read-only
String
that provides the name of the algorithm, as defined by the provider, used to generate the key.
| | key |
A read-only
Dictionary
that contains representations of the key's bytes.
For a symmetric key, the
Dictionary
will contain fields called
secret_bytes,
which is an
Array
of
int
values representing the encoded bytes of the key,
and
secret_text,
which is a
String
of the key bytes in hex-encoded format using two hex characters per byte.
For an asymmetric key, the
Dictionary
contains fields that describe both the public key component and the
private key component in a manner similar to that used for a symmetric key.
In this case, the fields are called
public_bytes,
private_bytes,
public_text
and
private_text.
| | keystring([int type]) |
A
Builtin
that returns a
String
that can be used by other Yoix operations requiring a key.
Although the string is both hex-encoded and encrypted, it should be considered as insecure as
clear text and merely serves to hide pertinent information from only the most
casual and incurious of observers.
In addition to the key bytes, the string also encodes the key type and the name of the
key algorithm.
An
int
argument can be used to specify for which key type a string should be genreated.
For a symmetric key, there is one choice for key type and supplying no argument
is equivalent to specifying
SECRET_KEY.
For an asymmetric key pair, supplying no argument is equivalent to specifying
PUBLIC_KEY.
The private key component must be specifically requested by specifying
PRIVATE_KEY.
| | parameters |
A read-only
Dictionary
summarizing the algorithm parameters used for generating the key.
| | provider |
A read-only
Dictionary
summarizing all the information related to the provider of this key algorithm.
| | specification |
A
Dictionary
used to specify the key generation algorithm.
Common component fields are:
| keysize |
An
int
specifying the size of a generated key in bytes.
| | provider |
A
String
specifying the algorithm provider to use when generating keys.
| | random |
A secure
Random
that will be used when generating keys.
| | transformation |
A
String
giving the name of the algorithm to use for key generation or the
algorithm name, mode and padding to be used for key generation in the form
This value must be present and non-null within the dictionary.
algorithm/mode/padding.
| | type |
An
int
representing the key type, which would be either
ASYMMETRIC_KEY
or
SYMMETRIC_KEY.
This value must be present and non-null within the dictionary.
|
|
Several permanent fields have not been documented and should not be
used in Yoix applications.
| |
| Example: |
The program,
import yoix.*.*;
Key k = {
Dictionary specification = {
int type = SYMMETRIC_KEY;
String transformation = "DES";
};
};
Cipher c = {
String specification = "DES";
int opmode = ENCRYPT_MODE;
String initializer = k.keystring();
};
c.text = "Try encrypting this text.";
Array encrypted = c.text;
c.opmode = DECRYPT_MODE;
c.text = encrypted;
fprintf(stdout, "Encrypted text:\n%s\n\n", btoh(encrypted));
fprintf(stdout, "Decrypted text:\n%s\n\n", c.text);
creates a symmetric key that is used by a
Cipher
object to encrypt and decrypt some text.
This next example is much the same except that it creates an asymmetric key pair.
Its public key is used by a
Cipher
to encrypt some text and its private key is used by another
Cipher
to decrypt it.
Since the standard Java distribution does not include the algorithms for constructing
asymmetric keys, the example uses the BouncyCastle package available at
bouncycastle.org as the provider.
import yoix.*.*;
String bcjarfile = "Data/bcprov-jdk14-129.jar";
String fullpath = yoixPath(argv[0]);
int last = lastIndexOf(fullpath, '/');
String jarpath = substring(fullpath, 0, last+1) + bcjarfile;
adjustSecurity(ADDPROVIDER,
"org.bouncycastle.jce.provider.BouncyCastleProvider",
jarpath);
Key k = {
Dictionary specification = {
int type = ASYMMETRIC_KEY;
String transformation = "RSA";
String provider = "BC";
};
};
Cipher c1 = {
String specification = "RSA";
int opmode = ENCRYPT_MODE;
String initializer = k.keystring(PUBLIC_KEY);
};
Cipher c2 = {
String specification = "RSA";
int opmode = DECRYPT_MODE;
String initializer = k.keystring(PRIVATE_KEY);
};
c1.text = "Try encrypting this text.";
Array encrypted = c1.text;
c2.text = encrypted;
fprintf(stdout, "Encrypted text:\n%s\n\n", btoh(encrypted));
fprintf(stdout, "Decrypted text:\n%s\n\n", c2.text);
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| See Also: |
adjustSecurity,
Certificate,
Cipher,
KeyStore,
Random
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Yoix is a registered trademark of AT&T Inc.
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