internal.h

00001 /* internal.h
00002  *
00003  * Copyright (C) 2014-2016 wolfSSL Inc.
00004  *
00005  * This file is part of wolfSSH.
00006  *
00007  * wolfSSH is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * wolfSSH is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with wolfSSH.  If not, see <http://www.gnu.org/licenses/>.
00019  */
00020 
00021 
00022 /*
00023  * The internal module contains the private data and functions. The public
00024  * API calls into this module to do the work of processing the connections.
00025  */
00026 
00027 
00028 #pragma once
00029 
00030 #include <wolfssh/ssh.h>
00031 #include <wolfcrypt/hash.h>
00032 #include <wolfcrypt/random.h>
00033 #include <wolfcrypt/aes.h>
00034 #include <wolfcrypt/dh.h>
00035 #include <wolfcrypt/ecc.h>
00036 
00037 
00038 #if !defined (ALIGN16)
00039     #if defined (__GNUC__)
00040         #define ALIGN16 __attribute__ ( (aligned (16)))
00041     #elif defined(_MSC_VER)
00042         /* disable align warning, we want alignment ! */
00043         #pragma warning(disable: 4324)
00044         #define ALIGN16 __declspec (align (16))
00045     #else
00046         #define ALIGN16
00047     #endif
00048 #endif
00049 
00050 
00051 #ifdef __cplusplus
00052 extern "C" {
00053 #endif
00054 
00055 
00056 WOLFSSH_LOCAL const char* GetErrorString(int);
00057 
00058 
00059 enum {
00060     /* Any of the items can be none. */
00061     ID_NONE,
00062 
00063     /* Encryption IDs */
00064     ID_AES128_CBC,
00065     ID_AES128_GCM,
00066 
00067     /* Integrity IDs */
00068     ID_HMAC_SHA1,
00069     ID_HMAC_SHA1_96,
00070     ID_HMAC_SHA2_256,
00071 
00072     /* Key Exchange IDs */
00073     ID_DH_GROUP1_SHA1,
00074     ID_DH_GROUP14_SHA1,
00075     ID_DH_GEX_SHA256,
00076     ID_ECDH_SHA2_NISTP256,
00077     ID_ECDH_SHA2_NISTP384,
00078     ID_ECDH_SHA2_NISTP521,
00079 
00080     /* Public Key IDs */
00081     ID_SSH_RSA,
00082     ID_ECDSA_SHA2_NISTP256,
00083     ID_ECDSA_SHA2_NISTP384,
00084     ID_ECDSA_SHA2_NISTP521,
00085 
00086     /* Service IDs */
00087     ID_SERVICE_USERAUTH,
00088     ID_SERVICE_CONNECTION,
00089 
00090     /* UserAuth IDs */
00091     ID_USERAUTH_PASSWORD,
00092     ID_USERAUTH_PUBLICKEY,
00093 
00094     /* Channel Type IDs */
00095     ID_CHANTYPE_SESSION,
00096 
00097     ID_UNKNOWN
00098 };
00099 
00100 
00101 #define MAX_ENCRYPTION 3
00102 #define MAX_INTEGRITY 2
00103 #define MAX_KEY_EXCHANGE 2
00104 #define MAX_PUBLIC_KEY 1
00105 #define MAX_HMAC_SZ SHA256_DIGEST_SIZE
00106 #define MIN_BLOCK_SZ 8
00107 #define COOKIE_SZ 16
00108 #define LENGTH_SZ 4
00109 #define PAD_LENGTH_SZ 1
00110 #define MIN_PAD_LENGTH 4
00111 #define BOOLEAN_SZ 1
00112 #define MSG_ID_SZ 1
00113 #define SHA1_96_SZ 12
00114 #define UINT32_SZ 4
00115 #define SSH_PROTO_SZ 7 /* "SSH-2.0" */
00116 #define SSH_PROTO_EOL_SZ 2 /* Just the CRLF */
00117 #define AEAD_IMP_IV_SZ 4
00118 #define AEAD_EXP_IV_SZ 8
00119 #define AEAD_NONCE_SZ (AEAD_IMP_IV_SZ+AEAD_EXP_IV_SZ)
00120 #ifndef DEFAULT_HIGHWATER_MARK
00121     #define DEFAULT_HIGHWATER_MARK ((1024 * 1024 * 1024) - (32 * 1024))
00122 #endif
00123 #ifndef DEFAULT_WINDOW_SZ
00124     //#define DEFAULT_WINDOW_SZ (1024 * 1024)
00125     #define DEFAULT_WINDOW_SZ (8 * 1024) // ESP32 Doesn't have that much RAM
00126 #endif
00127 #ifndef DEFAULT_MAX_PACKET_SZ
00128     //#define DEFAULT_MAX_PACKET_SZ (16 * 1024)
00129     #define DEFAULT_MAX_PACKET_SZ (2 * 1024) // ESP32 Doesn't have that much RAM
00130 #endif
00131 #ifndef DEFAULT_NEXT_CHANNEL
00132     #define DEFAULT_NEXT_CHANNEL 0
00133 #endif
00134 
00135 
00136 WOLFSSH_LOCAL byte NameToId(const char*, word32);
00137 WOLFSSH_LOCAL const char* IdToName(byte);
00138 
00139 
00140 #define STATIC_BUFFER_LEN AES_BLOCK_SIZE
00141 /* This is one AES block size. We always grab one
00142  * block size first to decrypt to find the size of
00143  * the rest of the data. */
00144 
00145 
00146 typedef struct Buffer {
00147     void* heap;       /* Heap for allocations */
00148     word32 length;    /* total buffer length used */
00149     word32 idx;       /* idx to part of length already consumed */
00150     byte* buffer;     /* place holder for actual buffer */
00151     word32 bufferSz;  /* current buffer size */
00152     ALIGN16 byte staticBuffer[STATIC_BUFFER_LEN];
00153     byte dynamicFlag; /* dynamic memory currently in use */
00154 } Buffer;
00155 
00156 
00157 WOLFSSH_LOCAL int BufferInit(Buffer*, word32, void*);
00158 WOLFSSH_LOCAL int GrowBuffer(Buffer*, word32, word32);
00159 WOLFSSH_LOCAL void ShrinkBuffer(Buffer* buf, int);
00160 
00161 
00162 /* our wolfSSH Context */
00163 struct WOLFSSH_CTX {
00164     void* heap;                       /* heap hint */
00165     WS_CallbackIORecv ioRecvCb;       /* I/O Receive Callback */
00166     WS_CallbackIOSend ioSendCb;       /* I/O Send Callback */
00167     WS_CallbackUserAuth userAuthCb;   /* User Authentication Callback */
00168     WS_CallbackHighwater highwaterCb; /* Data Highwater Mark Callback */
00169 
00170     byte* privateKey;                 /* Owned by CTX */
00171     word32 privateKeySz;
00172     byte useEcc;                      /* Depends on the private key */
00173     word32 highwaterMark;
00174     const char* banner;
00175     word32 bannerSz;
00176     byte side;                        /* client or server */
00177     byte showBanner;
00178 };
00179 
00180 
00181 typedef struct Ciphers {
00182     Aes aes;
00183 } Ciphers;
00184 
00185 
00186 typedef struct Keys {
00187     byte iv[AES_BLOCK_SIZE];
00188     byte ivSz;
00189     byte encKey[AES_BLOCK_SIZE];
00190     byte encKeySz;
00191     byte macKey[MAX_HMAC_SZ];
00192     byte macKeySz;
00193 } Keys;
00194 
00195 
00196 typedef struct HandshakeInfo {
00197     byte kexId;
00198     byte pubKeyId;
00199     byte encryptId;
00200     byte macId;
00201     byte hashId;
00202     byte kexPacketFollows;
00203     byte aeadMode;
00204 
00205     byte blockSz;
00206     byte macSz;
00207 
00208     Keys keys;
00209     Keys peerKeys;
00210     wc_HashAlg hash;
00211     byte e[257]; /* May have a leading zero for unsigned or is a Q_S value. */
00212     word32 eSz;
00213     byte x[257]; /* May have a leading zero, for unsigned. */
00214     word32 xSz;
00215     byte* kexInit;
00216     word32 kexInitSz;
00217 
00218     word32 dhGexMinSz;
00219     word32 dhGexPreferredSz;
00220     word32 dhGexMaxSz;
00221     byte* primeGroup;
00222     word32 primeGroupSz;
00223     byte* generator;
00224     word32 generatorSz;
00225 
00226     byte useEcc;
00227     union {
00228         DhKey dh;
00229         ecc_key ecc;
00230     } privKey;
00231 } HandshakeInfo;
00232 
00233 
00234 /* our wolfSSH session */
00235 struct WOLFSSH {
00236     WOLFSSH_CTX* ctx;      /* owner context */
00237     int error;
00238     int rfd;
00239     int wfd;
00240     void* ioReadCtx;       /* I/O Read  Context handle */
00241     void* ioWriteCtx;      /* I/O Write Context handle */
00242     int rflags;            /* optional read  flags */
00243     int wflags;            /* optional write flags */
00244     word32 txCount;
00245     word32 rxCount;
00246     word32 highwaterMark;
00247     byte highwaterFlag;    /* Set when highwater CB called */
00248     void* highwaterCtx;
00249     word32 curSz;
00250     word32 seq;
00251     word32 peerSeq;
00252     word32 packetStartIdx; /* Current send packet start index */
00253     byte paddingSz;        /* Current send packet padding size */
00254     byte acceptState;
00255     byte connectState;
00256     byte clientState;
00257     byte serverState;
00258     byte processReplyState;
00259     byte isKeying;
00260 
00261     byte connReset;
00262     byte isClosed;
00263 
00264     byte blockSz;
00265     byte encryptId;
00266     byte macId;
00267     byte macSz;
00268     byte aeadMode;
00269     byte peerBlockSz;
00270     byte peerEncryptId;
00271     byte peerMacId;
00272     byte peerMacSz;
00273     byte peerAeadMode;
00274 
00275     Ciphers encryptCipher;
00276     Ciphers decryptCipher;
00277 
00278     word32 nextChannel;
00279     WOLFSSH_CHANNEL* channelList;
00280     word32 channelListSz;
00281     word32 defaultPeerChannelId;
00282 
00283     Buffer inputBuffer;
00284     Buffer outputBuffer;
00285     WC_RNG* rng;
00286 
00287     byte h[WC_MAX_DIGEST_SIZE];
00288     word32 hSz;
00289     byte k[257];           /* May have a leading zero, for unsigned. */
00290     word32 kSz;
00291     byte sessionId[WC_MAX_DIGEST_SIZE];
00292     word32 sessionIdSz;
00293 
00294     Keys keys;
00295     Keys peerKeys;
00296     HandshakeInfo* handshake;
00297 
00298     void* userAuthCtx;
00299     char* userName;
00300     word32 userNameSz;
00301     char* password;
00302     word32 passwordSz;
00303     byte* pkBlob;
00304     word32 pkBlobSz;
00305     byte* peerProtoId;     /* Save for rekey */
00306     word32 peerProtoIdSz;
00307 };
00308 
00309 
00310 struct WOLFSSH_CHANNEL {
00311     byte channelType;
00312     word32 channel;
00313     word32 windowSz;
00314     word32 maxPacketSz;
00315     word32 peerChannel;
00316     word32 peerWindowSz;
00317     word32 peerMaxPacketSz;
00318     Buffer inputBuffer;
00319     struct WOLFSSH* ssh;
00320     struct WOLFSSH_CHANNEL* next;
00321 };
00322 
00323 
00324 WOLFSSH_LOCAL WOLFSSH_CTX* CtxInit(WOLFSSH_CTX*, byte, void*);
00325 WOLFSSH_LOCAL void CtxResourceFree(WOLFSSH_CTX*);
00326 WOLFSSH_LOCAL WOLFSSH* SshInit(WOLFSSH*, WOLFSSH_CTX*);
00327 WOLFSSH_LOCAL void SshResourceFree(WOLFSSH*, void*);
00328 
00329 WOLFSSH_LOCAL WOLFSSH_CHANNEL* ChannelNew(WOLFSSH*, byte, word32, word32);
00330 WOLFSSH_LOCAL int ChannelUpdate(WOLFSSH_CHANNEL*, word32, word32, word32);
00331 WOLFSSH_LOCAL void ChannelDelete(WOLFSSH_CHANNEL*, void*);
00332 WOLFSSH_LOCAL WOLFSSH_CHANNEL* ChannelFind(WOLFSSH*, word32, byte);
00333 WOLFSSH_LOCAL int ChannelRemove(WOLFSSH*, word32, byte);
00334 WOLFSSH_LOCAL int ChannelPutData(WOLFSSH_CHANNEL*, byte*, word32);
00335 WOLFSSH_LOCAL int wolfSSH_ProcessBuffer(WOLFSSH_CTX*,
00336                                         const byte*, word32,
00337                                         int, int);
00338 
00339 
00340 #ifndef WOLFSSH_USER_IO
00341 
00342 /* default I/O handlers */
00343 WOLFSSH_LOCAL int wsEmbedRecv(WOLFSSH*, void*, word32, void*);
00344 WOLFSSH_LOCAL int wsEmbedSend(WOLFSSH*, void*, word32, void*);
00345 
00346 #endif /* WOLFSSH_USER_IO */
00347 
00348 
00349 WOLFSSH_LOCAL int DoReceive(WOLFSSH*);
00350 WOLFSSH_LOCAL int DoProtoId(WOLFSSH*);
00351 WOLFSSH_LOCAL int SendProtoId(WOLFSSH*);
00352 WOLFSSH_LOCAL int SendKexInit(WOLFSSH*);
00353 WOLFSSH_LOCAL int SendKexDhInit(WOLFSSH*);
00354 WOLFSSH_LOCAL int SendKexDhReply(WOLFSSH*);
00355 WOLFSSH_LOCAL int SendKexDhGexRequest(WOLFSSH*);
00356 WOLFSSH_LOCAL int SendKexDhGexGroup(WOLFSSH*);
00357 WOLFSSH_LOCAL int SendNewKeys(WOLFSSH*);
00358 WOLFSSH_LOCAL int SendUnimplemented(WOLFSSH*);
00359 WOLFSSH_LOCAL int SendDisconnect(WOLFSSH*, word32);
00360 WOLFSSH_LOCAL int SendIgnore(WOLFSSH*, const unsigned char*, word32);
00361 WOLFSSH_LOCAL int SendDebug(WOLFSSH*, byte, const char*);
00362 WOLFSSH_LOCAL int SendServiceRequest(WOLFSSH*, byte);
00363 WOLFSSH_LOCAL int SendServiceAccept(WOLFSSH*, byte);
00364 WOLFSSH_LOCAL int SendUserAuthRequest(WOLFSSH*, byte);
00365 WOLFSSH_LOCAL int SendUserAuthSuccess(WOLFSSH*);
00366 WOLFSSH_LOCAL int SendUserAuthFailure(WOLFSSH*, byte);
00367 WOLFSSH_LOCAL int SendUserAuthBanner(WOLFSSH*);
00368 WOLFSSH_LOCAL int SendUserAuthPkOk(WOLFSSH*, const byte*, word32,
00369                                    const byte*, word32);
00370 WOLFSSH_LOCAL int SendRequestSuccess(WOLFSSH*, int);
00371 WOLFSSH_LOCAL int SendChannelOpenSession(WOLFSSH*, word32, word32);
00372 WOLFSSH_LOCAL int SendChannelOpenConf(WOLFSSH*);
00373 WOLFSSH_LOCAL int SendChannelEof(WOLFSSH*, word32);
00374 WOLFSSH_LOCAL int SendChannelClose(WOLFSSH*, word32);
00375 WOLFSSH_LOCAL int SendChannelData(WOLFSSH*, word32, byte*, word32);
00376 WOLFSSH_LOCAL int SendChannelWindowAdjust(WOLFSSH*, word32, word32);
00377 WOLFSSH_LOCAL int SendChannelRequestShell(WOLFSSH*);
00378 WOLFSSH_LOCAL int SendChannelSuccess(WOLFSSH*, word32, int);
00379 WOLFSSH_LOCAL int GenerateKey(byte, byte, byte*, word32, const byte*, word32,
00380                               const byte*, word32, const byte*, word32);
00381 
00382 
00383 enum AcceptStates {
00384     ACCEPT_BEGIN = 0,
00385     ACCEPT_SERVER_VERSION_SENT,
00386     ACCEPT_CLIENT_VERSION_DONE,
00387     ACCEPT_SERVER_KEXINIT_SENT,
00388     ACCEPT_KEYED,
00389     ACCEPT_CLIENT_USERAUTH_REQUEST_DONE,
00390     ACCEPT_SERVER_USERAUTH_ACCEPT_SENT,
00391     ACCEPT_CLIENT_USERAUTH_DONE,
00392     ACCEPT_SERVER_USERAUTH_SENT,
00393     ACCEPT_CLIENT_CHANNEL_REQUEST_DONE,
00394     ACCEPT_SERVER_CHANNEL_ACCEPT_SENT
00395 };
00396 
00397 
00398 enum ConnectStates {
00399     CONNECT_BEGIN = 0,
00400     CONNECT_CLIENT_VERSION_SENT,
00401     CONNECT_SERVER_VERSION_DONE,
00402     CONNECT_CLIENT_KEXINIT_SENT,
00403     CONNECT_SERVER_KEXINIT_DONE,
00404     CONNECT_CLIENT_KEXDH_INIT_SENT,
00405     CONNECT_KEYED,
00406     CONNECT_CLIENT_USERAUTH_REQUEST_SENT,
00407     CONNECT_SERVER_USERAUTH_REQUEST_DONE,
00408     CONNECT_CLIENT_USERAUTH_SENT,
00409     CONNECT_SERVER_USERAUTH_ACCEPT_DONE,
00410     CONNECT_CLIENT_CHANNEL_OPEN_SESSION_SENT,
00411     CONNECT_SERVER_CHANNEL_OPEN_SESSION_DONE,
00412     CONNECT_CLIENT_CHANNEL_REQUEST_SHELL_SENT,
00413     CONNECT_SERVER_CHANNEL_REQUEST_SHELL_DONE
00414 };
00415 
00416 
00417 enum ClientStates {
00418     CLIENT_BEGIN = 0,
00419     CLIENT_VERSION_DONE,
00420     CLIENT_KEXINIT_DONE,
00421     CLIENT_KEXDH_INIT_DONE,
00422     CLIENT_USERAUTH_REQUEST_DONE,
00423     CLIENT_USERAUTH_DONE,
00424     CLIENT_DONE
00425 };
00426 
00427 
00428 enum ServerStates {
00429     SERVER_BEGIN = 0,
00430     SERVER_VERSION_DONE,
00431     SERVER_KEXINIT_DONE,
00432     SERVER_USERAUTH_REQUEST_DONE,
00433     SERVER_USERAUTH_ACCEPT_DONE,
00434     SERVER_CHANNEL_OPEN_DONE,
00435     SERVER_DONE
00436 };
00437 
00438 
00439 enum ProcessReplyStates {
00440     PROCESS_INIT,
00441     PROCESS_PACKET_LENGTH,
00442     PROCESS_PACKET_FINISH,
00443     PROCESS_PACKET
00444 };
00445 
00446 
00447 enum WS_MessageIds {
00448     MSGID_DISCONNECT = 1,
00449     MSGID_IGNORE = 2,
00450     MSGID_UNIMPLEMENTED = 3,
00451     MSGID_DEBUG = 4,
00452     MSGID_SERVICE_REQUEST = 5,
00453     MSGID_SERVICE_ACCEPT = 6,
00454 
00455     MSGID_KEXINIT = 20,
00456     MSGID_NEWKEYS = 21,
00457 
00458     MSGID_KEXDH_INIT = 30,
00459     MSGID_KEXECDH_INIT = 30,
00460 
00461     MSGID_KEXDH_REPLY = 31,
00462     MSGID_KEXECDH_REPLY = 31,
00463     MSGID_KEXDH_GEX_GROUP = 31,
00464     MSGID_KEXDH_GEX_INIT = 32,
00465     MSGID_KEXDH_GEX_REPLY = 33,
00466     MSGID_KEXDH_GEX_REQUEST = 34,
00467 
00468     MSGID_USERAUTH_REQUEST = 50,
00469     MSGID_USERAUTH_FAILURE = 51,
00470     MSGID_USERAUTH_SUCCESS = 52,
00471     MSGID_USERAUTH_BANNER = 53,
00472     MSGID_USERAUTH_PK_OK = 60, /* Public Key OK */
00473     MSGID_USERAUTH_PW_CHRQ = 60, /* Password Change Request */
00474 
00475     MSGID_GLOBAL_REQUEST = 80,
00476     MSGID_REQUEST_SUCCESS = 81,
00477     MSGID_REQUEST_FAILURE = 82,
00478 
00479     MSGID_CHANNEL_OPEN = 90,
00480     MSGID_CHANNEL_OPEN_CONF = 91,
00481     MSGID_CHANNEL_OPEN_FAIL = 92,
00482     MSGID_CHANNEL_WINDOW_ADJUST = 93,
00483     MSGID_CHANNEL_DATA = 94,
00484     MSGID_CHANNEL_EOF = 96,
00485     MSGID_CHANNEL_CLOSE = 97,
00486     MSGID_CHANNEL_REQUEST = 98,
00487     MSGID_CHANNEL_SUCCESS = 99,
00488     MSGID_CHANNEL_FAILURE = 100
00489 };
00490 
00491 
00492 /* dynamic memory types */
00493 enum WS_DynamicTypes {
00494     DYNTYPE_CTX,
00495     DYNTYPE_SSH,
00496     DYNTYPE_CHANNEL,
00497     DYNTYPE_BUFFER,
00498     DYNTYPE_ID,
00499     DYNTYPE_HS,
00500     DYNTYPE_CA,
00501     DYNTYPE_CERT,
00502     DYNTYPE_PRIVKEY,
00503     DYNTYPE_PUBKEY,
00504     DYNTYPE_DH,
00505     DYNTYPE_RNG,
00506     DYNTYPE_STRING,
00507     DYNTYPE_MPINT
00508 };
00509 
00510 
00511 enum WS_BufferTypes {
00512     BUFTYPE_CA,
00513     BUFTYPE_CERT,
00514     BUFTYPE_PRIVKEY,
00515     BUFTYPE_PUBKEY
00516 };
00517 
00518 
00519 WOLFSSH_LOCAL void DumpOctetString(const byte*, word32);
00520 
00521 
00522 #ifdef __cplusplus
00523 }
00524 #endif
00525