1 /* $OpenBSD: ssh_api.h,v 1.2 2018/04/10 00:10:49 djm Exp $ */ 2 /* 3 * Copyright (c) 2012 Markus Friedl. All rights reserved. 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #ifndef API_H 19 #define API_H 20 21 #include <sys/types.h> 22 #include <signal.h> 23 24 #include "openbsd-compat/sys-queue.h" 25 26 #include "cipher.h" 27 #include "sshkey.h" 28 #include "kex.h" 29 #include "ssh.h" 30 #include "ssh2.h" 31 #include "packet.h" 32 33 struct kex_params { 34 char *proposal[PROPOSAL_MAX]; 35 }; 36 37 /* public SSH API functions */ 38 39 /* 40 * ssh_init() create a ssh connection object with given (optional) 41 * key exchange parameters. 42 */ 43 int ssh_init(struct ssh **, int is_server, struct kex_params *kex_params); 44 45 /* 46 * release ssh connection state. 47 */ 48 void ssh_free(struct ssh *); 49 50 /* 51 * attach application specific data to the connection state 52 */ 53 void ssh_set_app_data(struct ssh *, void *); 54 void *ssh_get_app_data(struct ssh *); 55 56 /* 57 * ssh_add_hostkey() registers a private/public hostkey for an ssh 58 * connection. 59 * ssh_add_hostkey() needs to be called before a key exchange is 60 * initiated with ssh_packet_next(). 61 * private hostkeys are required if we need to act as a server. 62 * public hostkeys are used to verify the servers hostkey. 63 */ 64 int ssh_add_hostkey(struct ssh *ssh, struct sshkey *key); 65 66 /* 67 * ssh_set_verify_host_key_callback() registers a callback function 68 * which should be called instead of the default verification. The 69 * function given must return 0 if the hostkey is ok, -1 if the 70 * verification has failed. 71 */ 72 int ssh_set_verify_host_key_callback(struct ssh *ssh, 73 int (*cb)(struct sshkey *, struct ssh *)); 74 75 /* 76 * ssh_packet_next() advances to the next input packet and returns 77 * the packet type in typep. 78 * ssh_packet_next() works by processing an input byte-stream, 79 * decrypting the received data and hiding the key-exchange from 80 * the caller. 81 * ssh_packet_next() sets typep if there is no new packet available. 82 * in this case the caller must fill the input byte-stream by passing 83 * the data received over network to ssh_input_append(). 84 * additionally, the caller needs to send the resulting output 85 * byte-stream back over the network. otherwise the key exchange 86 * would not proceed. the output byte-stream is accessed through 87 * ssh_output_ptr(). 88 */ 89 int ssh_packet_next(struct ssh *ssh, u_char *typep); 90 91 /* 92 * ssh_packet_payload() returns a pointer to the raw payload data of 93 * the current input packet and the length of this payload. 94 * the payload is accessible until ssh_packet_next() is called again. 95 */ 96 const u_char *ssh_packet_payload(struct ssh *ssh, size_t *lenp); 97 98 /* 99 * ssh_packet_put() creates an encrypted packet with the given type 100 * and payload. 101 * the encrypted packet is appended to the output byte-stream. 102 */ 103 int ssh_packet_put(struct ssh *ssh, int type, const u_char *data, 104 size_t len); 105 106 /* 107 * ssh_input_space() checks if 'len' bytes can be appended to the 108 * input byte-stream. 109 */ 110 int ssh_input_space(struct ssh *ssh, size_t len); 111 112 /* 113 * ssh_input_append() appends data to the input byte-stream. 114 */ 115 int ssh_input_append(struct ssh *ssh, const u_char *data, size_t len); 116 117 /* 118 * ssh_output_space() checks if 'len' bytes can be appended to the 119 * output byte-stream. XXX 120 */ 121 int ssh_output_space(struct ssh *ssh, size_t len); 122 123 /* 124 * ssh_output_ptr() retrieves both a pointer and the length of the 125 * current output byte-stream. the bytes need to be sent over the 126 * network. the number of bytes that have been successfully sent can 127 * be removed from the output byte-stream with ssh_output_consume(). 128 */ 129 const u_char *ssh_output_ptr(struct ssh *ssh, size_t *len); 130 131 /* 132 * ssh_output_consume() removes the given number of bytes from 133 * the output byte-stream. 134 */ 135 int ssh_output_consume(struct ssh *ssh, size_t len); 136 137 #endif 138