src/misc/update.h

   1 /*****************************************************************************
   2  * update.h: VLC PGP update private API
   3  *****************************************************************************
   4  * Copyright © 2007-2008 VLC authors and VideoLAN
   5  *
   6  * Authors: Rafaël Carré <funman@videolanorg>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either release 2 of the License, or
  11  * (at your option) any later release.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #include <vlc_update.h>
  24 #include <vlc_atomic.h>
  25
  26 enum    /* Packet types */
  27 {
  28     SIGNATURE_PACKET    = 0x02,
  29     PUBLIC_KEY_PACKET   = 0x06,
  30     USER_ID_PACKET      = 0x0d
  31 };
  32
  33 enum    /* Signature types */
  34 {
  35     BINARY_SIGNATURE        = 0x00,
  36     TEXT_SIGNATURE          = 0x01,
  37
  38     /* Public keys signatures */
  39     GENERIC_KEY_SIGNATURE   = 0x10, /* No assumption of verification */
  40     PERSONA_KEY_SIGNATURE   = 0x11, /* No verification has been made */
  41     CASUAL_KEY_SIGNATURE    = 0x12, /* Some casual verification */
  42     POSITIVE_KEY_SIGNATURE  = 0x13  /* Substantial verification */
  43 };
  44
  45 enum    /* Signature subpacket types */
  46 {
  47     ISSUER_SUBPACKET    = 0x10
  48 };
  49
  50 struct public_key_packet_t
  51 {
  52
  53     uint8_t version;      /* we use only version 4 */
  54     uint8_t timestamp[4]; /* creation time of the key */
  55     uint8_t algo;         /* we only use DSA */
  56     /* the multi precision integers, with their 2 bytes length header */
  57     uint8_t p[2+3072/8];
  58     uint8_t q[2+256/8];
  59     uint8_t g[2+3072/8];
  60     uint8_t y[2+3072/8];
  61 };
  62
  63 /* used for public key and file signatures */
  64 struct signature_packet_t
  65 {
  66     uint8_t version; /* 3 or 4 */
  67
  68     uint8_t type;
  69     uint8_t public_key_algo;    /* DSA only */
  70     uint8_t digest_algo;
  71
  72     uint8_t hash_verification[2];
  73     uint8_t issuer_longid[8];
  74
  75     union   /* version specific data */
  76     {
  77         struct
  78         {
  79             uint8_t hashed_data_len[2];     /* scalar number */
  80             uint8_t *hashed_data;           /* hashed_data_len bytes */
  81             uint8_t unhashed_data_len[2];   /* scalar number */
  82             uint8_t *unhashed_data;         /* unhashed_data_len bytes */
  83         } v4;
  84         struct
  85         {
  86             uint8_t hashed_data_len;    /* MUST be 5 */
  87             uint8_t timestamp[4];       /* 4 bytes scalar number */
  88         } v3;
  89     } specific;
  90
  91 /* The part below is made of consecutive MPIs, their number and size being
  92  * public-key-algorithm dependent.
  93  *
  94  * Since we use DSA signatures only, there is 2 integers, r & s.
  95  * They range from 160 for 1k keys to 256 bits for 3k keys.
  96  */
  97     uint8_t r[2+256/8];
  98     uint8_t s[2+256/8];
  99 };
 100
 101 typedef struct public_key_packet_t public_key_packet_t;
 102 typedef struct signature_packet_t signature_packet_t;
 103
 104 struct public_key_t
 105 {
 106     uint8_t longid[8];       /* Long id */
 107     uint8_t *psz_username;    /* USER ID */
 108
 109     public_key_packet_t key;       /* Public key packet */
 110
 111     signature_packet_t sig;     /* Signature packet, by the embedded key */
 112 };
 113
 114 typedef struct public_key_t public_key_t;
 115
 116 /**
 117  * Non blocking binary download
 118  */
 119 typedef struct
 120 {
 121     VLC_COMMON_MEMBERS
 122
 123     vlc_thread_t thread;
 124     atomic_bool aborted;
 125     update_t *p_update;
 126     char *psz_destdir;
 127 } update_download_thread_t;
 128
 129 /**
 130  * Non blocking update availability verification
 131  */
 132 typedef struct
 133 {
 134     vlc_thread_t thread;
 135
 136     update_t *p_update;
 137     void (*pf_callback)( void *, bool );
 138     void *p_data;
 139 } update_check_thread_t;
 140
 141 /**
 142  * The update object. Stores (and caches) all information relative to updates
 143  */
 144 struct update_t
 145 {
 146     libvlc_int_t *p_libvlc;
 147     vlc_mutex_t lock;
 148     struct update_release_t release;    ///< Release (version)
 149     public_key_t *p_pkey;
 150     update_download_thread_t *p_download;
 151     update_check_thread_t *p_check;
 152 };
 153
 154 /*
 155  * download a public key (the last one) from videolan server, and parse it
 156  */
 157 public_key_t *
 158 download_key(
 159         vlc_object_t *p_this, const uint8_t *p_longid,
 160         const uint8_t *p_signature_issuer );
 161
 162 /*
 163  * fill a public_key_t with public key data, including:
 164  *   * public key packet
 165  *   * signature packet issued by key which long id is p_sig_issuer
 166  *   * user id packet
 167  */
 168 int
 169 parse_public_key(
 170         const uint8_t *p_key_data, size_t i_key_len, public_key_t *p_key,
 171         const uint8_t *p_sig_issuer );
 172
 173 /*
 174  * Verify an OpenPGP signature made on some hash, with some DSA public key
 175  */
 176 int
 177 verify_signature(signature_packet_t *sign, public_key_packet_t *p_key,
 178         uint8_t *p_hash );
 179
 180 /*
 181  * Download the signature associated to a document or a binary file.
 182  * We're given the file's url, we just append ".asc" to it and download
 183  */
 184 int
 185 download_signature(
 186         vlc_object_t *p_this, signature_packet_t *p_sig, const char *psz_url );
 187
 188 /*
 189  * return a hash of a text
 190  */
 191 uint8_t *
 192 hash_from_text(
 193         const char *psz_text, signature_packet_t *p_sig );
 194
 195 /*
 196  * return a hash of a file
 197  */
 198 uint8_t *
 199 hash_from_file(
 200         const char *psz_file, signature_packet_t *p_sig );
 201
 202 /*
 203  * return a hash of a public key
 204  */
 205 uint8_t *
 206 hash_from_public_key( public_key_t *p_pkey );