-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIA4OVgB4FRq4l5zjEmd4r/jswRcHlZQ
kg10p9rzG3VyXCPpa/ZkwOYy+kGq7a7BjAKTpic2cUNRim4m8HKTdc8CAwEAAQ==
-----END PUBLIC KEY-----

/**
...省略...
 *This method accepts public key
 * in the rsaencryption pkcs #1 format (oid: 1.2.840.113549.1.1.1).
 * The format is defined as:
 * PublicKeyInfo ::= SEQUENCE {
 *   algorithm       AlgorithmIdentifier,
 *   PublicKey       BIT STRING
 * }
 * Where AlgorithmIdentifier is:
 * AlgorithmIdentifier ::= SEQUENCE {
 *   algorithm       OBJECT IDENTIFIER,     the OID of the enc algorithm
 *   parameters      ANY DEFINED BY algorithm OPTIONAL (NULL for PKCS #1)
 * }
 * and PublicKey is a SEQUENCE encapsulated in a BIT STRING
 * RSAPublicKey ::= SEQUENCE {
 *   modulus           INTEGER,  -- n
 *   publicExponent    INTEGER   -- e
 * }
 */

 1 RSAKey.prototype.parseKey = function (pem) {
 2   try {
 3 ...
 4     var der = reHex.test(pem) ? Hex.decode(pem) : Base64.unarmor(pem);
 5     var asn1 = ASN1.decode(der);
 6 ...
 7     if (asn1.sub.length === 9) {
 8       // Parse the private key.
 9     }
10     else if (asn1.sub.length === 2) {
11       // Parse the public key.
12       var bit_string = asn1.sub[1];
13       var sequence = bit_string.sub[0];
14       modulus = sequence.sub[0].getHexStringValue();
15       this.n = parseBigInt(modulus, 16);
16       public_exponent = sequence.sub[1].getHexStringValue();
17       this.e = parseInt(public_exponent, 16);
18     }
19     else {
20       return false;
21     }
22     return true;
23   }
24   catch (ex) {
25     return false;
26   }
27 };