Namespace rsa

RSA Public Key cryptography
Defined in: rsa.js.

Namespace Summary
Constructor Attributes	Constructor Name and Description
	rsa An implementation of PKCS#1 v2.1.

Field Summary
Field Attributes	Field Name and Description
<static>	rsa.encryption_hash Hash function to use for OAEP label (hashing.sha256 by default)
<static>	rsa.error_code If something fails, this code provides information about the error.
<static>	rsa.label Label of OAEP encryption, an ASCII string empty by default.
<static>	rsa.mgf_hash Hash function to use for MGF function (hashing.sha256 by default)
<static>	rsa.salt Salt of PSS signature, an ASCII string empty by default.
<static>	rsa.signature_hash Hash function to use for PSS signature (hashing.sha256 by default)

Method Summary
Method Attributes	Method Name and Description
<private> <static>	rsa._pkcs1_sig_pad(m, n) EMSA-PKCS1-v1_5-ENCODE
<private> <static>	rsa._private(message, priv) RSADP/RSASP1 - Computes m^d mod n using CRT coefficients.
<static>	rsa.decrypt(message, priv) RSAES-OAEP-DECRYPT decryption.
<static>	rsa.encrypt(m, pub) RSAES-OAEP-ENCRYPT encryption.
<static>	rsa.MGF(seed, length) MGF1 message generating function.
<static>	rsa.sign(message, priv) RSASSA-PSS-SIGN signature using rsa.signature_hash.
<static>	rsa.sign_pkcs1_v1_5(message, priv) RSASSA-PKCS1-V1_5-SIGN signature using rsa.signature_hash.
<static>	rsa.verify(data, signature, pub) RSASSA-PSS-VERIFY signature verification using rsa.signature_hash.
<static>	rsa.verify_pkcs1_v1_5(data, signature, pub) RSASSA-PKCS1-V1_5-VERIFY signature verification using rsa.signature_hash.

Namespace Detail

rsa

An implementation of PKCS#1 v2.1.

The main difference with other PKCS#1 implementations is the format of the keys. Instead of using ASN.1 for encoding, the keys are stored in an equivalent JSON object. For a public key, the fields are 'n' for the modulus and 'e' for the public exponent. In addition, a private key must contain the CRT values 'dmp1', 'dmq1', 'p', 'q' and 'iqmp' (the private exponent 'd' is not required because it is not used for decryption; using BigInteger it is easy to compute 'dmp1', 'dmq1' and 'iqmp' from 'd', 'p' and 'q').

Use the following PHP script (requires the openssl extension) to convert a PKCS#1 key to JSON:

#!/usr/bin/env php
<?
if(count($argv)<2) die("Usage: {$argv[0]} file.pem\n");
$f = "file://{$argv[1]}";
if(!($k = openssl_pkey_get_private($f)))
 dir("Failed to import private key {$argv[1]}.\n");
$d = openssl_pkey_get_details($k);
$pk = $d['rsa'];
foreach($pk as $p=>$v) $pk[$p] = bin2hex($v);
echo json_encode($pk)."\n";

Author: Anonymized.

Requires:: BigInteger; encoding; hashing

Field Detail

<static> rsa.encryption_hash

Hash function to use for OAEP label (hashing.sha256 by default)

<static> rsa.error_code

If something fails, this code provides information about the error.

Code	Description
0	No error.
1	Message is too long for the modulus.
2	Invalid length of the input to decrypt or verify.
3	Top byte/bit is not zero after decryption/verification.
4	Incorrect padding of encrypted/signature data.
5	Bad label of OAEP encryption.
6	PSS salt is too long for modulus.
7	Invalid PSS padding byte in PSS signature.

<static> rsa.label

Label of OAEP encryption, an ASCII string empty by default. Can be of any length since it will be hash using rsa.encryption_hash

<static> rsa.mgf_hash

Hash function to use for MGF function (hashing.sha256 by default)

<static> rsa.salt

Salt of PSS signature, an ASCII string empty by default. The max length is n-h-2 where n is the modulus size in bytes and h the size in bytes of the output of the hash function.

<static> rsa.signature_hash

Hash function to use for PSS signature (hashing.sha256 by default)

Method Detail

<private> <static> rsa._pkcs1_sig_pad(m, n)

EMSA-PKCS1-v1_5-ENCODE

Parameters:
m
n

<private> <static> {string} rsa._private(message, priv)

RSADP/RSASP1 - Computes m^d mod n using CRT coefficients.

Parameters:
{string} message: Hex-encoded message
{privateKey} priv: Private key object

Returns:: {string} Hex string representing m^d mod n

<static> {string} rsa.decrypt(message, priv)

RSAES-OAEP-DECRYPT decryption.

Parameters:
{string} message: Hex string containing the encrypted data
{privateKey} priv: Private Key

Returns:: {string} ASCII string representing the original message, or an empty string if decryption failed.

<static> {string} rsa.encrypt(m, pub)

RSAES-OAEP-ENCRYPT encryption.

Parameters:
{string} m: Message to encode, an ASCII string
{publicKey} pub: Public key

Returns:: {string} Hex string representing the encrypted message

<static> {string} rsa.MGF(seed, length)

MGF1 message generating function. Underlying hash function is rsa.mgf_hash

Parameters:
{string} seed: Hex string containing the seed for message generation
{number} length: Length n of the requested message in bytes

Returns:: {string} Hex string of the desired length

<static> {string} rsa.sign(message, priv)

RSASSA-PSS-SIGN signature using rsa.signature_hash.

Parameters:
{string} message: ASCII string containing the data to sign
{privateKey} priv: Private Key

Returns:: {string} Hex string representing a PSS signature for the data

<static> {string} rsa.sign_pkcs1_v1_5(message, priv)

RSASSA-PKCS1-V1_5-SIGN signature using rsa.signature_hash.

Parameters:
{string} message: ASCII string containing the data to sign
{privateKey} priv: Private Key

Returns:: {string} Hex string representing a PKCS1v1.5 signature for the data

<static> {boolean} rsa.verify(data, signature, pub)

RSASSA-PSS-VERIFY signature verification using rsa.signature_hash.

Parameters:
{string} data: ASCII string containing the signed data
{string} signature: Hex string containing the signature of the data
{publicKey} pub: Public key of the expected sender

Returns:: {boolean} whether s is a valid signature for m from pub

<static> {boolean} rsa.verify_pkcs1_v1_5(data, signature, pub)

RSASSA-PKCS1-V1_5-VERIFY signature verification using rsa.signature_hash.

Parameters:
{string} data: ASCII string containing the signed data
{string} signature: Hex string containing the signature of the data
{publicKey} pub: Public key of the expected sender

Returns:: {boolean} whether s is a valid signature for m from pub

Classes

Namespace rsa