1package org.bouncycastle.asn1; 2 3import java.io.ByteArrayInputStream; 4import java.io.IOException; 5import java.io.InputStream; 6 7import org.bouncycastle.util.Arrays; 8import org.bouncycastle.util.Strings; 9import org.bouncycastle.util.encoders.Hex; 10 11/** 12 * Abstract base for the ASN.1 OCTET STRING data type 13 * <p> 14 * This supports BER, and DER forms of the data. 15 * </p><p> 16 * DER form is always primitive single OCTET STRING, while 17 * BER support includes the constructed forms. 18 * </p> 19 * <hr> 20 * <p><b>X.690</b></p> 21 * <p><b>8: Basic encoding rules</b></p> 22 * <p><b>8.7 Encoding of an octetstring value</b></p> 23 * <p> 24 * <b>8.7.1</b> The encoding of an octetstring value shall be 25 * either primitive or constructed at the option of the sender. 26 * <blockquote> 27 * NOTE — Where it is necessary to transfer part of an octet string 28 * before the entire OCTET STRING is available, the constructed encoding 29 * is used. 30 * </blockquote> 31 * <p> 32 * <b>8.7.2</b> The primitive encoding contains zero, 33 * one or more contents octets equal in value to the octets 34 * in the data value, in the order they appear in the data value, 35 * and with the most significant bit of an octet of the data value 36 * aligned with the most significant bit of an octet of the contents octets. 37 * </p> 38 * <p> 39 * <b>8.7.3</b> The contents octets for the constructed encoding shall consist 40 * of zero, one, or more encodings. 41 * <blockquote> 42 * NOTE — Each such encoding includes identifier, length, and contents octets, 43 * and may include end-of-contents octets if it is constructed. 44 * </blockquote> 45 * </p> 46 * <p> 47 * <b>8.7.3.1</b> To encode an octetstring value in this way, 48 * it is segmented. Each segment shall consist of a series of 49 * consecutive octets of the value. There shall be no significance 50 * placed on the segment boundaries. 51 * <blockquote> 52 * NOTE — A segment may be of size zero, i.e. contain no octets. 53 * </blockquote> 54 * </p> 55 * <p> 56 * <b>8.7.3.2</b> Each encoding in the contents octets shall represent 57 * a segment of the overall octetstring, the encoding arising from 58 * a recursive application of this subclause. 59 * In this recursive application, each segment is treated as if it were 60 * a octetstring value. The encodings of the segments shall appear in the contents 61 * octets in the order in which their octets appear in the overall value. 62 * <blockquote> 63 * NOTE 1 — As a consequence of this recursion, 64 * each encoding in the contents octets may itself 65 * be primitive or constructed. 66 * However, such encodings will usually be primitive. 67 * <br /> 68 * NOTE 2 — In particular, the tags in the contents octets are always universal class, number 4. 69 * </blockquote> 70 * </p> 71 * <p><b>9: Canonical encoding rules</b></p> 72 * <p><b>9.1 Length forms</b></p> 73 * <p> 74 * If the encoding is constructed, it shall employ the indefinite-length form. 75 * If the encoding is primitive, it shall include the fewest length octets necessary. 76 * [Contrast with 8.1.3.2 b).] 77 * </p> 78 * <p><b>9.2 String encoding forms</b></p> 79 * <p> 80 * BIT STRING, OCTET STRING,and restricted character string 81 * values shall be encoded with a primitive encoding if they would 82 * require no more than 1000 contents octets, and as a constructed 83 * encoding otherwise. The string fragments contained in 84 * the constructed encoding shall be encoded with a primitive encoding. 85 * The encoding of each fragment, except possibly 86 * the last, shall have 1000 contents octets. (Contrast with 8.21.6.) 87 * </p><p> 88 * <b>10: Distinguished encoding rules</b> 89 * </p><p> 90 * <b>10.1 Length forms</b> 91 * The definite form of length encoding shall be used, 92 * encoded in the minimum number of octets. 93 * [Contrast with 8.1.3.2 b).] 94 * </p><p> 95 * <b>10.2 String encoding forms</b> 96 * For BIT STRING, OCTET STRING and restricted character string types, 97 * the constructed form of encoding shall not be used. 98 * (Contrast with 8.21.6.) 99 * </p> 100 */ 101public abstract class ASN1OctetString 102 extends ASN1Primitive 103 implements ASN1OctetStringParser 104{ 105 byte[] string; 106 107 /** 108 * return an Octet String from a tagged object. 109 * 110 * @param obj the tagged object holding the object we want. 111 * @param explicit true if the object is meant to be explicitly 112 * tagged false otherwise. 113 * @exception IllegalArgumentException if the tagged object cannot 114 * be converted. 115 */ 116 public static ASN1OctetString getInstance( 117 ASN1TaggedObject obj, 118 boolean explicit) 119 { 120 ASN1Primitive o = obj.getObject(); 121 122 if (explicit || o instanceof ASN1OctetString) 123 { 124 return getInstance(o); 125 } 126 else 127 { 128 return BEROctetString.fromSequence(ASN1Sequence.getInstance(o)); 129 } 130 } 131 132 /** 133 * return an Octet String from the given object. 134 * 135 * @param obj the object we want converted. 136 * @exception IllegalArgumentException if the object cannot be converted. 137 */ 138 public static ASN1OctetString getInstance( 139 Object obj) 140 { 141 if (obj == null || obj instanceof ASN1OctetString) 142 { 143 return (ASN1OctetString)obj; 144 } 145 else if (obj instanceof byte[]) 146 { 147 try 148 { 149 return ASN1OctetString.getInstance(ASN1Primitive.fromByteArray((byte[])obj)); 150 } 151 catch (IOException e) 152 { 153 throw new IllegalArgumentException("failed to construct OCTET STRING from byte[]: " + e.getMessage()); 154 } 155 } 156 else if (obj instanceof ASN1Encodable) 157 { 158 ASN1Primitive primitive = ((ASN1Encodable)obj).toASN1Primitive(); 159 160 if (primitive instanceof ASN1OctetString) 161 { 162 return (ASN1OctetString)primitive; 163 } 164 } 165 166 throw new IllegalArgumentException("illegal object in getInstance: " + obj.getClass().getName()); 167 } 168 169 /** 170 * Base constructor. 171 * 172 * @param string the octets making up the octet string. 173 */ 174 public ASN1OctetString( 175 byte[] string) 176 { 177 if (string == null) 178 { 179 throw new NullPointerException("string cannot be null"); 180 } 181 this.string = string; 182 } 183 184 /** 185 * Return the content of the OCTET STRING as an InputStream. 186 * 187 * @return an InputStream representing the OCTET STRING's content. 188 */ 189 public InputStream getOctetStream() 190 { 191 return new ByteArrayInputStream(string); 192 } 193 194 /** 195 * Return the parser associated with this object. 196 * 197 * @return a parser based on this OCTET STRING 198 */ 199 public ASN1OctetStringParser parser() 200 { 201 return this; 202 } 203 204 /** 205 * Return the content of the OCTET STRING as a byte array. 206 * 207 * @return the byte[] representing the OCTET STRING's content. 208 */ 209 public byte[] getOctets() 210 { 211 return string; 212 } 213 214 public int hashCode() 215 { 216 return Arrays.hashCode(this.getOctets()); 217 } 218 219 boolean asn1Equals( 220 ASN1Primitive o) 221 { 222 if (!(o instanceof ASN1OctetString)) 223 { 224 return false; 225 } 226 227 ASN1OctetString other = (ASN1OctetString)o; 228 229 return Arrays.areEqual(string, other.string); 230 } 231 232 public ASN1Primitive getLoadedObject() 233 { 234 return this.toASN1Primitive(); 235 } 236 237 ASN1Primitive toDERObject() 238 { 239 return new DEROctetString(string); 240 } 241 242 ASN1Primitive toDLObject() 243 { 244 return new DEROctetString(string); 245 } 246 247 abstract void encode(ASN1OutputStream out) 248 throws IOException; 249 250 public String toString() 251 { 252 return "#"+ Strings.fromByteArray(Hex.encode(string)); 253 } 254} 255