1 /* 2 * Dropbear - a SSH2 server 3 * 4 * Copyright (c) 2002,2003 Matt Johnston 5 * All rights reserved. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 * SOFTWARE. */ 24 25 #ifndef DROPBEAR_ALGO_H_ 26 27 #define DROPBEAR_ALGO_H_ 28 29 #include "includes.h" 30 #include "buffer.h" 31 32 #define DROPBEAR_MODE_UNUSED 0 33 #define DROPBEAR_MODE_CBC 1 34 #define DROPBEAR_MODE_CTR 2 35 36 struct Algo_Type { 37 38 const char *name; /* identifying name */ 39 char val; /* a value for this cipher, or -1 for invalid */ 40 const void *data; /* algorithm specific data */ 41 char usable; /* whether we can use this algorithm */ 42 const void *mode; /* the mode, currently only used for ciphers, 43 points to a 'struct dropbear_cipher_mode' */ 44 }; 45 46 typedef struct Algo_Type algo_type; 47 48 /* lists mapping ssh types of algorithms to internal values */ 49 extern algo_type sshkex[]; 50 extern algo_type sigalgs[]; 51 extern algo_type sshciphers[]; 52 extern algo_type sshhashes[]; 53 extern algo_type ssh_compress[]; 54 extern algo_type ssh_delaycompress[]; 55 extern algo_type ssh_nocompress[]; 56 57 extern const struct dropbear_cipher dropbear_nocipher; 58 extern const struct dropbear_cipher_mode dropbear_mode_none; 59 extern const struct dropbear_hash dropbear_nohash; 60 61 struct dropbear_cipher { 62 const struct ltc_cipher_descriptor *cipherdesc; 63 const unsigned long keysize; 64 const unsigned char blocksize; 65 }; 66 67 struct dropbear_cipher_mode { 68 int (*start)(int cipher, const unsigned char *IV, 69 const unsigned char *key, 70 int keylen, int num_rounds, void *cipher_state); 71 int (*encrypt)(const unsigned char *pt, unsigned char *ct, 72 unsigned long len, void *cipher_state); 73 int (*decrypt)(const unsigned char *ct, unsigned char *pt, 74 unsigned long len, void *cipher_state); 75 int (*aead_crypt)(unsigned int seq, 76 const unsigned char *in, unsigned char *out, 77 unsigned long len, unsigned long taglen, 78 void *cipher_state, int direction); 79 int (*aead_getlength)(unsigned int seq, 80 const unsigned char *in, unsigned int *outlen, 81 unsigned long len, void *cipher_state); 82 const struct dropbear_hash *aead_mac; 83 }; 84 85 struct dropbear_hash { 86 const struct ltc_hash_descriptor *hash_desc; 87 const unsigned long keysize; 88 /* hashsize may be truncated from the size returned by hash_desc, 89 eg sha1-96 */ 90 const unsigned char hashsize; 91 }; 92 93 enum dropbear_kex_mode { 94 #if DROPBEAR_NORMAL_DH 95 DROPBEAR_KEX_NORMAL_DH, 96 #endif 97 #if DROPBEAR_ECDH 98 DROPBEAR_KEX_ECDH, 99 #endif 100 #if DROPBEAR_CURVE25519 101 DROPBEAR_KEX_CURVE25519, 102 #endif 103 }; 104 105 struct dropbear_kex { 106 enum dropbear_kex_mode mode; 107 108 /* "normal" DH KEX */ 109 const unsigned char *dh_p_bytes; 110 const int dh_p_len; 111 112 /* elliptic curve DH KEX */ 113 #if DROPBEAR_ECDH 114 const struct dropbear_ecc_curve *ecc_curve; 115 #else 116 const void* dummy; 117 #endif 118 119 /* both */ 120 const struct ltc_hash_descriptor *hash_desc; 121 }; 122 123 /* Includes all algorithms is useall is set */ 124 void buf_put_algolist_all(buffer * buf, const algo_type localalgos[], int useall); 125 /* Includes "usable" algorithms */ 126 void buf_put_algolist(buffer * buf, const algo_type localalgos[]); 127 128 #define KEXGUESS2_ALGO_NAME "kexguess2@matt.ucc.asn.au" 129 130 int buf_has_algo(buffer *buf, const char *algo); 131 algo_type * first_usable_algo(algo_type algos[]); 132 algo_type * buf_match_algo(buffer* buf, algo_type localalgos[], 133 int kexguess2, int *goodguess); 134 135 #if DROPBEAR_USER_ALGO_LIST 136 int check_user_algos(const char* user_algo_list, algo_type * algos, 137 const char *algo_desc); 138 char * algolist_string(const algo_type algos[]); 139 #endif 140 141 enum { 142 DROPBEAR_COMP_NONE, 143 DROPBEAR_COMP_ZLIB, 144 DROPBEAR_COMP_ZLIB_DELAY, 145 }; 146 147 #endif /* DROPBEAR_ALGO_H_ */ 148