Botan: src/asn1/asn1_str.cpp Source File

00001 /*
00002 * Simple ASN.1 String Types
00003 * (C) 1999-2007 Jack Lloyd
00004 *
00005 * Distributed under the terms of the Botan license
00006 */
00007 
00008 #include <botan/asn1_obj.h>
00009 #include <botan/der_enc.h>
00010 #include <botan/ber_dec.h>
00011 #include <botan/charset.h>
00012 #include <botan/parsing.h>
00013 
00014 namespace Botan {
00015 
00016 namespace {
00017 
00018 /*
00019 * Choose an encoding for the string
00020 */
00021 ASN1_Tag choose_encoding(const std::string& str,
00022                          const std::string& type)
00023    {
00024    static const byte IS_PRINTABLE[256] = {
00025       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00026       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00027       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
00028       0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01,
00029       0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00,
00030       0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
00031       0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
00032       0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
00033       0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
00034       0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
00035       0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00036       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00037       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00038       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00039       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00040       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00041       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00042       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00043       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00044       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00045       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00046       0x00, 0x00, 0x00, 0x00 };
00047 
00048    for(u32bit j = 0; j != str.size(); ++j)
00049       {
00050       if(!IS_PRINTABLE[static_cast<byte>(str[j])])
00051          {
00052          if(type == "utf8")   return UTF8_STRING;
00053          if(type == "latin1") return T61_STRING;
00054          throw Invalid_Argument("choose_encoding: Bad string type " + type);
00055          }
00056       }
00057    return PRINTABLE_STRING;
00058    }
00059 
00060 }
00061 
00062 /*
00063 * Check if type is a known ASN.1 string type
00064 */
00065 bool is_string_type(ASN1_Tag tag)
00066    {
00067    if(tag == NUMERIC_STRING || tag == PRINTABLE_STRING ||
00068       tag == VISIBLE_STRING || tag == T61_STRING || tag == IA5_STRING ||
00069       tag == UTF8_STRING || tag == BMP_STRING)
00070       return true;
00071    return false;
00072    }
00073 
00074 /*
00075 * Create an ASN1_String
00076 */
00077 ASN1_String::ASN1_String(const std::string& str, ASN1_Tag t) : tag(t)
00078    {
00079    iso_8859_str = Charset::transcode(str, LOCAL_CHARSET, LATIN1_CHARSET);
00080 
00081    if(tag == DIRECTORY_STRING)
00082       tag = choose_encoding(iso_8859_str, "latin1");
00083 
00084    if(tag != NUMERIC_STRING &&
00085       tag != PRINTABLE_STRING &&
00086       tag != VISIBLE_STRING &&
00087       tag != T61_STRING &&
00088       tag != IA5_STRING &&
00089       tag != UTF8_STRING &&
00090       tag != BMP_STRING)
00091       throw Invalid_Argument("ASN1_String: Unknown string type " +
00092                              to_string(tag));
00093    }
00094 
00095 /*
00096 * Create an ASN1_String
00097 */
00098 ASN1_String::ASN1_String(const std::string& str)
00099    {
00100    iso_8859_str = Charset::transcode(str, LOCAL_CHARSET, LATIN1_CHARSET);
00101    tag = choose_encoding(iso_8859_str, "latin1");
00102    }
00103 
00104 /*
00105 * Return this string in ISO 8859-1 encoding
00106 */
00107 std::string ASN1_String::iso_8859() const
00108    {
00109    return iso_8859_str;
00110    }
00111 
00112 /*
00113 * Return this string in local encoding
00114 */
00115 std::string ASN1_String::value() const
00116    {
00117    return Charset::transcode(iso_8859_str, LATIN1_CHARSET, LOCAL_CHARSET);
00118    }
00119 
00120 /*
00121 * Return the type of this string object
00122 */
00123 ASN1_Tag ASN1_String::tagging() const
00124    {
00125    return tag;
00126    }
00127 
00128 /*
00129 * DER encode an ASN1_String
00130 */
00131 void ASN1_String::encode_into(DER_Encoder& encoder) const
00132    {
00133    std::string value = iso_8859();
00134    if(tagging() == UTF8_STRING)
00135       value = Charset::transcode(value, LATIN1_CHARSET, UTF8_CHARSET);
00136    encoder.add_object(tagging(), UNIVERSAL, value);
00137    }
00138 
00139 /*
00140 * Decode a BER encoded ASN1_String
00141 */
00142 void ASN1_String::decode_from(BER_Decoder& source)
00143    {
00144    BER_Object obj = source.get_next_object();
00145 
00146    Character_Set charset_is;
00147 
00148    if(obj.type_tag == BMP_STRING)
00149       charset_is = UCS2_CHARSET;
00150    else if(obj.type_tag == UTF8_STRING)
00151       charset_is = UTF8_CHARSET;
00152    else
00153       charset_is = LATIN1_CHARSET;
00154 
00155    *this = ASN1_String(
00156       Charset::transcode(ASN1::to_string(obj), charset_is, LOCAL_CHARSET),
00157       obj.type_tag);
00158    }
00159 
00160 }