src/libstrongswan/plugins/pkcs1/pkcs1_encoder.c

   1 /*
   2  * Copyright (C) 2009 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 #include "pkcs1_encoder.h"
  17
  18 #include <utils/debug.h>
  19 #include <asn1/asn1.h>
  20 #include <asn1/oid.h>
  21
  22 /**
  23  * Encode a public key in PKCS#1/ASN.1 DER
  24  */
  25 static bool build_pub(chunk_t *encoding, va_list args)
  26 {
  27         chunk_t n, e;
  28
  29         if (cred_encoding_args(args, CRED_PART_RSA_MODULUS, &n,
  30                                                    CRED_PART_RSA_PUB_EXP, &e, CRED_PART_END))
  31         {
  32                 *encoding = asn1_wrap(ASN1_SEQUENCE, "mm",
  33                                                 asn1_wrap(ASN1_INTEGER, "c", n),
  34                                                 asn1_wrap(ASN1_INTEGER, "c", e));
  35                 return TRUE;
  36         }
  37         return FALSE;
  38 }
  39
  40 /**
  41  * Encode a public key in PKCS#1/ASN.1 DER, contained in subjectPublicKeyInfo
  42  */
  43 static bool build_pub_info(chunk_t *encoding, va_list args)
  44 {
  45         chunk_t n, e;
  46
  47         if (cred_encoding_args(args, CRED_PART_RSA_MODULUS, &n,
  48                                                    CRED_PART_RSA_PUB_EXP, &e, CRED_PART_END))
  49         {
  50                 *encoding = asn1_wrap(ASN1_SEQUENCE, "mm",
  51                                                 asn1_algorithmIdentifier(OID_RSA_ENCRYPTION),
  52                                                 asn1_bitstring("m",
  53                                                         asn1_wrap(ASN1_SEQUENCE, "mm",
  54                                                                 asn1_wrap(ASN1_INTEGER, "c", n),
  55                                                                 asn1_wrap(ASN1_INTEGER, "c", e))));
  56                 return TRUE;
  57         }
  58         return FALSE;
  59 }
  60
  61 /**
  62  * Encode a private key in PKCS#1/ASN.1 DER
  63  */
  64 static bool build_priv(chunk_t *encoding, va_list args)
  65 {
  66         chunk_t n, e, d, p, q, exp1, exp2, coeff;
  67
  68         if (cred_encoding_args(args, CRED_PART_RSA_MODULUS, &n,
  69                                         CRED_PART_RSA_PUB_EXP, &e, CRED_PART_RSA_PRIV_EXP, &d,
  70                                         CRED_PART_RSA_PRIME1, &p, CRED_PART_RSA_PRIME2, &q,
  71                                         CRED_PART_RSA_EXP1, &exp1, CRED_PART_RSA_EXP2, &exp2,
  72                                         CRED_PART_RSA_COEFF, &coeff, CRED_PART_END))
  73         {
  74                 *encoding = asn1_wrap(ASN1_SEQUENCE, "cmmssssss",
  75                                                 ASN1_INTEGER_0,
  76                                                 asn1_wrap(ASN1_INTEGER, "c", n),
  77                                                 asn1_wrap(ASN1_INTEGER, "c", e),
  78                                                 asn1_wrap(ASN1_INTEGER, "c", d),
  79                                                 asn1_wrap(ASN1_INTEGER, "c", p),
  80                                                 asn1_wrap(ASN1_INTEGER, "c", q),
  81                                                 asn1_wrap(ASN1_INTEGER, "c", exp1),
  82                                                 asn1_wrap(ASN1_INTEGER, "c", exp2),
  83                                                 asn1_wrap(ASN1_INTEGER, "c", coeff));
  84                 return TRUE;
  85         }
  86         return FALSE;
  87 }
  88
  89 /**
  90  * Build the SHA1 hash of pubkey(info) ASN.1 data
  91  */
  92 static bool hash_pubkey(chunk_t pubkey, chunk_t *hash)
  93 {
  94         hasher_t *hasher;
  95
  96         hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
  97         if (!hasher || !hasher->allocate_hash(hasher, pubkey, hash))
  98         {
  99                 DESTROY_IF(hasher);
 100                 chunk_free(&pubkey);
 101                 DBG1(DBG_LIB, "SHA1 hash algorithm not supported, "
 102                          "fingerprinting failed");
 103                 return FALSE;
 104         }
 105         hasher->destroy(hasher);
 106         chunk_free(&pubkey);
 107         return TRUE;
 108 }
 109
 110 /**
 111  * build the fingerprint of the subjectPublicKeyInfo object
 112  */
 113 static bool build_info_sha1(chunk_t *encoding, va_list args)
 114 {
 115         chunk_t pubkey;
 116
 117         if (build_pub_info(&pubkey, args))
 118         {
 119                 return hash_pubkey(pubkey, encoding);
 120         }
 121         return FALSE;
 122 }
 123
 124 /**
 125  * build the fingerprint of the subjectPublicKey object
 126  */
 127 static bool build_sha1(chunk_t *encoding, va_list args)
 128 {
 129         chunk_t pubkey;
 130
 131         if (build_pub(&pubkey, args))
 132         {
 133                 return hash_pubkey(pubkey, encoding);
 134         }
 135         return FALSE;
 136 }
 137
 138 /**
 139  * See header.
 140  */
 141 bool pkcs1_encoder_encode(cred_encoding_type_t type, chunk_t *encoding,
 142                                                   va_list args)
 143 {
 144         switch (type)
 145         {
 146                 case KEYID_PUBKEY_INFO_SHA1:
 147                         return build_info_sha1(encoding, args);
 148                 case KEYID_PUBKEY_SHA1:
 149                         return build_sha1(encoding, args);
 150                 case PUBKEY_ASN1_DER:
 151                         return build_pub(encoding, args);
 152                 case PUBKEY_SPKI_ASN1_DER:
 153                         return build_pub_info(encoding, args);
 154                 case PRIVKEY_ASN1_DER:
 155                         return build_priv(encoding, args);
 156                 default:
 157                         return FALSE;
 158         }
 159 }
 160
 161