summaryrefslogtreecommitdiffstats
path: root/bcprov/src/main/java/org/bouncycastle/asn1/x509/SubjectKeyIdentifier.java
blob: 1a9400dd52b50db8048ebbdb2dc199ae5a5546d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
package org.bouncycastle.asn1.x509;

import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.crypto.Digest;
// BEGIN android-changed
import org.bouncycastle.crypto.digests.AndroidDigestFactory;
// END android-changed

/**
 * The SubjectKeyIdentifier object.
 * <pre>
 * SubjectKeyIdentifier::= OCTET STRING
 * </pre>
 */
public class SubjectKeyIdentifier
    extends ASN1Object
{
    private byte[] keyidentifier;

    public static SubjectKeyIdentifier getInstance(
        ASN1TaggedObject obj,
        boolean          explicit)
    {
        return getInstance(ASN1OctetString.getInstance(obj, explicit));
    }

    public static SubjectKeyIdentifier getInstance(
        Object obj)
    {
        if (obj instanceof SubjectKeyIdentifier)
        {
            return (SubjectKeyIdentifier)obj;
        }
        else if (obj != null)
        {
            return new SubjectKeyIdentifier(ASN1OctetString.getInstance(obj));
        }

        return null;
    }

    public static SubjectKeyIdentifier fromExtensions(Extensions extensions)
    {
        return SubjectKeyIdentifier.getInstance(extensions.getExtensionParsedValue(Extension.subjectKeyIdentifier));
    }

    public SubjectKeyIdentifier(
        byte[] keyid)
    {
        this.keyidentifier = keyid;
    }

    protected SubjectKeyIdentifier(
        ASN1OctetString keyid)
    {
        this.keyidentifier = keyid.getOctets();
    }

    public byte[] getKeyIdentifier()
    {
        return keyidentifier;
    }

    public ASN1Primitive toASN1Primitive()
    {
        return new DEROctetString(keyidentifier);
    }


    /**
     * Calculates the keyidentifier using a SHA1 hash over the BIT STRING
     * from SubjectPublicKeyInfo as defined in RFC3280.
     *
     * @param spki the subject public key info.
     * @deprecated
     */
    public SubjectKeyIdentifier(
        SubjectPublicKeyInfo    spki)
    {
        this.keyidentifier = getDigest(spki);
    }

    /**
     * Return a RFC 3280 type 1 key identifier. As in:
     * <pre>
     * (1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the
     * value of the BIT STRING subjectPublicKey (excluding the tag,
     * length, and number of unused bits).
     * </pre>
     * @param keyInfo the key info object containing the subjectPublicKey field.
     * @return the key identifier.
     * @deprecated use org.bouncycastle.cert.X509ExtensionUtils.createSubjectKeyIdentifier
     */
    public static SubjectKeyIdentifier createSHA1KeyIdentifier(SubjectPublicKeyInfo keyInfo)
    {
        return new SubjectKeyIdentifier(keyInfo);
    }

    /**
     * Return a RFC 3280 type 2 key identifier. As in:
     * <pre>
     * (2) The keyIdentifier is composed of a four bit type field with
     * the value 0100 followed by the least significant 60 bits of the
     * SHA-1 hash of the value of the BIT STRING subjectPublicKey.
     * </pre>
     * @param keyInfo the key info object containing the subjectPublicKey field.
     * @return the key identifier.
     * @deprecated use org.bouncycastle.cert.X509ExtensionUtils.createTruncatedSubjectKeyIdentifier
     */
    public static SubjectKeyIdentifier createTruncatedSHA1KeyIdentifier(SubjectPublicKeyInfo keyInfo)
    {
        byte[] dig = getDigest(keyInfo);
        byte[] id = new byte[8];

        System.arraycopy(dig, dig.length - 8, id, 0, id.length);

        id[0] &= 0x0f;
        id[0] |= 0x40;
        
        return new SubjectKeyIdentifier(id);
    }

    private static byte[] getDigest(SubjectPublicKeyInfo spki)
    {
        // BEGIN android-changed
        Digest digest = AndroidDigestFactory.getSHA1();
        // END android-changed
        byte[]  resBuf = new byte[digest.getDigestSize()];

        byte[] bytes = spki.getPublicKeyData().getBytes();
        digest.update(bytes, 0, bytes.length);
        digest.doFinal(resBuf, 0);
        return resBuf;
    }
}