1 /* $OpenBSD: sshbuf-misc.c,v 1.13 2020/01/25 23:28:06 djm Exp $ */ 2 /* 3 * Copyright (c) 2011 Damien Miller 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 #include "includes.h" 18 __RCSID("$NetBSD: sshbuf-misc.c,v 1.10 2020/02/27 00:24:40 christos Exp $"); 19 20 #include <sys/types.h> 21 #include <sys/socket.h> 22 #include <netinet/in.h> 23 #include <errno.h> 24 #include <stdlib.h> 25 #include <stdint.h> 26 #include <stdio.h> 27 #include <limits.h> 28 #include <string.h> 29 #include <resolv.h> 30 #include <ctype.h> 31 32 #include "ssherr.h" 33 #define SSHBUF_INTERNAL 34 #include "sshbuf.h" 35 36 void 37 sshbuf_dump_data(const void *s, size_t len, FILE *f) 38 { 39 size_t i, j; 40 const u_char *p = (const u_char *)s; 41 42 for (i = 0; i < len; i += 16) { 43 fprintf(f, "%.4zu: ", i); 44 for (j = i; j < i + 16; j++) { 45 if (j < len) 46 fprintf(f, "%02x ", p[j]); 47 else 48 fprintf(f, " "); 49 } 50 fprintf(f, " "); 51 for (j = i; j < i + 16; j++) { 52 if (j < len) { 53 if (isascii(p[j]) && isprint(p[j])) 54 fprintf(f, "%c", p[j]); 55 else 56 fprintf(f, "."); 57 } 58 } 59 fprintf(f, "\n"); 60 } 61 } 62 63 void 64 sshbuf_dump(struct sshbuf *buf, FILE *f) 65 { 66 fprintf(f, "buffer %p len = %zu\n", buf, sshbuf_len(buf)); 67 sshbuf_dump_data(sshbuf_ptr(buf), sshbuf_len(buf), f); 68 } 69 70 char * 71 sshbuf_dtob16(struct sshbuf *buf) 72 { 73 size_t i, j, len = sshbuf_len(buf); 74 const u_char *p = sshbuf_ptr(buf); 75 char *ret; 76 const char hex[] = "0123456789abcdef"; 77 78 if (len == 0) 79 return strdup(""); 80 if (SIZE_MAX / 2 <= len || (ret = malloc(len * 2 + 1)) == NULL) 81 return NULL; 82 for (i = j = 0; i < len; i++) { 83 ret[j++] = hex[(p[i] >> 4) & 0xf]; 84 ret[j++] = hex[p[i] & 0xf]; 85 } 86 ret[j] = '\0'; 87 return ret; 88 } 89 90 int 91 sshbuf_dtob64(const struct sshbuf *d, struct sshbuf *b64, int wrap) 92 { 93 size_t i, slen = 0; 94 char *s = NULL; 95 int r; 96 97 if (d == NULL || b64 == NULL || sshbuf_len(d) >= SIZE_MAX / 2) 98 return SSH_ERR_INVALID_ARGUMENT; 99 if (sshbuf_len(d) == 0) 100 return 0; 101 slen = ((sshbuf_len(d) + 2) / 3) * 4 + 1; 102 if ((s = malloc(slen)) == NULL) 103 return SSH_ERR_ALLOC_FAIL; 104 if (b64_ntop(sshbuf_ptr(d), sshbuf_len(d), s, slen) == -1) { 105 r = SSH_ERR_INTERNAL_ERROR; 106 goto fail; 107 } 108 if (wrap) { 109 for (i = 0; s[i] != '\0'; i++) { 110 if ((r = sshbuf_put_u8(b64, s[i])) != 0) 111 goto fail; 112 if (i % 70 == 69 && (r = sshbuf_put_u8(b64, '\n')) != 0) 113 goto fail; 114 } 115 if ((i - 1) % 70 != 69 && (r = sshbuf_put_u8(b64, '\n')) != 0) 116 goto fail; 117 } else { 118 if ((r = sshbuf_put(b64, s, strlen(s))) != 0) 119 goto fail; 120 } 121 /* Success */ 122 r = 0; 123 fail: 124 freezero(s, slen); 125 return r; 126 } 127 128 char * 129 sshbuf_dtob64_string(const struct sshbuf *buf, int wrap) 130 { 131 struct sshbuf *tmp; 132 char *ret; 133 134 if ((tmp = sshbuf_new()) == NULL) 135 return NULL; 136 if (sshbuf_dtob64(buf, tmp, wrap) != 0) { 137 sshbuf_free(tmp); 138 return NULL; 139 } 140 ret = sshbuf_dup_string(tmp); 141 sshbuf_free(tmp); 142 return ret; 143 } 144 145 int 146 sshbuf_b64tod(struct sshbuf *buf, const char *b64) 147 { 148 size_t plen = strlen(b64); 149 int nlen, r; 150 u_char *p; 151 152 if (plen == 0) 153 return 0; 154 if ((p = malloc(plen)) == NULL) 155 return SSH_ERR_ALLOC_FAIL; 156 if ((nlen = b64_pton(b64, p, plen)) < 0) { 157 explicit_bzero(p, plen); 158 free(p); 159 return SSH_ERR_INVALID_FORMAT; 160 } 161 if ((r = sshbuf_put(buf, p, nlen)) < 0) { 162 explicit_bzero(p, plen); 163 free(p); 164 return r; 165 } 166 explicit_bzero(p, plen); 167 free(p); 168 return 0; 169 } 170 171 char * 172 sshbuf_dup_string(struct sshbuf *buf) 173 { 174 const u_char *p = NULL, *s = sshbuf_ptr(buf); 175 size_t l = sshbuf_len(buf); 176 char *r; 177 178 if (s == NULL || l > SIZE_MAX) 179 return NULL; 180 /* accept a nul only as the last character in the buffer */ 181 if (l > 0 && (p = memchr(s, '\0', l)) != NULL) { 182 if (p != s + l - 1) 183 return NULL; 184 l--; /* the nul is put back below */ 185 } 186 if ((r = malloc(l + 1)) == NULL) 187 return NULL; 188 if (l > 0) 189 memcpy(r, s, l); 190 r[l] = '\0'; 191 return r; 192 } 193 194 int 195 sshbuf_cmp(const struct sshbuf *b, size_t offset, 196 const void *s, size_t len) 197 { 198 if (sshbuf_ptr(b) == NULL) 199 return SSH_ERR_INTERNAL_ERROR; 200 if (offset > SSHBUF_SIZE_MAX || len > SSHBUF_SIZE_MAX || len == 0) 201 return SSH_ERR_INVALID_ARGUMENT; 202 if (offset + len > sshbuf_len(b)) 203 return SSH_ERR_MESSAGE_INCOMPLETE; 204 if (timingsafe_bcmp(sshbuf_ptr(b) + offset, s, len) != 0) 205 return SSH_ERR_INVALID_FORMAT; 206 return 0; 207 } 208 209 int 210 sshbuf_find(const struct sshbuf *b, size_t start_offset, 211 const void *s, size_t len, size_t *offsetp) 212 { 213 void *p; 214 215 if (offsetp != NULL) 216 *offsetp = 0; 217 if (sshbuf_ptr(b) == NULL) 218 return SSH_ERR_INTERNAL_ERROR; 219 if (start_offset > SSHBUF_SIZE_MAX || len > SSHBUF_SIZE_MAX || len == 0) 220 return SSH_ERR_INVALID_ARGUMENT; 221 if (start_offset > sshbuf_len(b) || start_offset + len > sshbuf_len(b)) 222 return SSH_ERR_MESSAGE_INCOMPLETE; 223 if ((p = memmem(sshbuf_ptr(b) + start_offset, 224 sshbuf_len(b) - start_offset, s, len)) == NULL) 225 return SSH_ERR_INVALID_FORMAT; 226 if (offsetp != NULL) 227 *offsetp = (const u_char *)p - sshbuf_ptr(b); 228 return 0; 229 } 230