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1
19
20 package com.maverick.crypto.publickey;
21
22 import java.io.IOException  ;
23 import com.maverick.crypto.digests.SHA1Digest;
24 import java.math.BigInteger ;
25
26
27 public class RsaPublicKey
28 extends RsaKey implements PublicKey {
29
30 protected BigInteger publicExponent;
31
32 protected final static byte[] ASN_SHA1 = {
33 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e,
34 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
35 };
36
37 public RsaPublicKey() {
38 }
39
40 public RsaPublicKey(BigInteger modulus, BigInteger publicExponent) {
41 super(modulus);
42 this.publicExponent = publicExponent;
43 }
44
45 public BigInteger getPublicExponent() {
46 return publicExponent;
47 }
48
49 protected void setPublicExponent(BigInteger publicExponent) {
50 this.publicExponent = publicExponent;
51 }
52
53 public boolean verifySignature(byte[] signature, byte[] msg) {
54
55 BigInteger signatureInt = new BigInteger (1, signature);
56
57 signatureInt = Rsa.doPublic(signatureInt,
58 getModulus(), publicExponent);
59
60 signatureInt = Rsa.removePKCS1(signatureInt, 1);
61
62 signature = signatureInt.toByteArray();
63
64 SHA1Digest h = new SHA1Digest();
65 h.update(msg, 0, msg.length);
66 byte[] data = new byte[h.getDigestSize()];
67 h.doFinal(data, 0);
68
69 if(data.length != (signature.length - ASN_SHA1.length)) {
70 return false;
71 }
72
73 byte[] cmp = ASN_SHA1;
74 for(int i = 0, j = 0; i < signature.length; i++, j++) {
75 if(i == ASN_SHA1.length) {
76 cmp = data;
77 j = 0;
78 }
79 if(signature[i] != cmp[j]) {
80 return false;
81 }
82 }
83 return true;
84
85 }
86
87 public int hashCode() {
88
89 int hashCode = getModulus().hashCode();
90
91 hashCode ^= publicExponent.hashCode();
92
93 return hashCode;
94 }
95
96
97 }
98 |
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