Annotation of src/usr.bin/ssh/sshbuf.h, Revision 1.12
1.12 ! djm 1: /* $OpenBSD: sshbuf.h,v 1.11 2018/07/09 21:56:06 markus Exp $ */
1.1 djm 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:
18: #ifndef _SSHBUF_H
19: #define _SSHBUF_H
20:
21: #include <sys/types.h>
22: #include <stdarg.h>
23: #include <stdio.h>
24: #include <openssl/bn.h>
25: #include <openssl/ec.h>
26:
27: #define SSHBUF_SIZE_MAX 0x8000000 /* Hard maximum size */
28: #define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */
29: #define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */
30: #define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */
31:
32: /*
33: * NB. do not depend on the internals of this. It will be made opaque
34: * one day.
35: */
36: struct sshbuf {
37: u_char *d; /* Data */
38: const u_char *cd; /* Const data */
39: size_t off; /* First available byte is buf->d + buf->off */
40: size_t size; /* Last byte is buf->d + buf->size - 1 */
41: size_t max_size; /* Maximum size of buffer */
42: size_t alloc; /* Total bytes allocated to buf->d */
43: int readonly; /* Refers to external, const data */
44: int dont_free; /* Kludge to support sshbuf_init */
45: u_int refcount; /* Tracks self and number of child buffers */
46: struct sshbuf *parent; /* If child, pointer to parent */
47: };
48:
49: /*
50: * Create a new sshbuf buffer.
51: * Returns pointer to buffer on success, or NULL on allocation failure.
52: */
53: struct sshbuf *sshbuf_new(void);
54:
55: /*
56: * Create a new, read-only sshbuf buffer from existing data.
57: * Returns pointer to buffer on success, or NULL on allocation failure.
58: */
59: struct sshbuf *sshbuf_from(const void *blob, size_t len);
60:
61: /*
62: * Create a new, read-only sshbuf buffer from the contents of an existing
63: * buffer. The contents of "buf" must not change in the lifetime of the
64: * resultant buffer.
65: * Returns pointer to buffer on success, or NULL on allocation failure.
66: */
67: struct sshbuf *sshbuf_fromb(struct sshbuf *buf);
68:
69: /*
70: * Create a new, read-only sshbuf buffer from the contents of a string in
71: * an existing buffer (the string is consumed in the process).
72: * The contents of "buf" must not change in the lifetime of the resultant
73: * buffer.
74: * Returns pointer to buffer on success, or NULL on allocation failure.
75: */
76: int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp);
77:
78: /*
79: * Clear and free buf
80: */
81: void sshbuf_free(struct sshbuf *buf);
82:
83: /*
84: * Reset buf, clearing its contents. NB. max_size is preserved.
85: */
86: void sshbuf_reset(struct sshbuf *buf);
87:
88: /*
89: * Return the maximum size of buf
90: */
91: size_t sshbuf_max_size(const struct sshbuf *buf);
92:
93: /*
94: * Set the maximum size of buf
95: * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
96: */
97: int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size);
98:
99: /*
100: * Returns the length of data in buf
101: */
102: size_t sshbuf_len(const struct sshbuf *buf);
103:
104: /*
105: * Returns number of bytes left in buffer before hitting max_size.
106: */
107: size_t sshbuf_avail(const struct sshbuf *buf);
108:
109: /*
1.6 mmcc 110: * Returns a read-only pointer to the start of the data in buf
1.1 djm 111: */
112: const u_char *sshbuf_ptr(const struct sshbuf *buf);
113:
114: /*
1.6 mmcc 115: * Returns a mutable pointer to the start of the data in buf, or
1.1 djm 116: * NULL if the buffer is read-only.
117: */
118: u_char *sshbuf_mutable_ptr(const struct sshbuf *buf);
119:
120: /*
121: * Check whether a reservation of size len will succeed in buf
122: * Safer to use than direct comparisons again sshbuf_avail as it copes
123: * with unsigned overflows correctly.
124: * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
125: */
126: int sshbuf_check_reserve(const struct sshbuf *buf, size_t len);
1.8 djm 127:
128: /*
129: * Preallocates len additional bytes in buf.
130: * Useful for cases where the caller knows how many bytes will ultimately be
131: * required to avoid realloc in the buffer code.
132: * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
133: */
134: int sshbuf_allocate(struct sshbuf *buf, size_t len);
1.1 djm 135:
136: /*
137: * Reserve len bytes in buf.
138: * Returns 0 on success and a pointer to the first reserved byte via the
139: * optional dpp parameter or a negative * SSH_ERR_* error code on failure.
140: */
141: int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp);
142:
143: /*
144: * Consume len bytes from the start of buf
145: * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
146: */
147: int sshbuf_consume(struct sshbuf *buf, size_t len);
148:
149: /*
150: * Consume len bytes from the end of buf
151: * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
152: */
153: int sshbuf_consume_end(struct sshbuf *buf, size_t len);
154:
155: /* Extract or deposit some bytes */
156: int sshbuf_get(struct sshbuf *buf, void *v, size_t len);
157: int sshbuf_put(struct sshbuf *buf, const void *v, size_t len);
158: int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v);
159:
160: /* Append using a printf(3) format */
161: int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
162: __attribute__((format(printf, 2, 3)));
163: int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap);
164:
165: /* Functions to extract or store big-endian words of various sizes */
166: int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp);
167: int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp);
168: int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp);
169: int sshbuf_get_u8(struct sshbuf *buf, u_char *valp);
170: int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val);
171: int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val);
172: int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val);
173: int sshbuf_put_u8(struct sshbuf *buf, u_char val);
174:
175: /*
176: * Functions to extract or store SSH wire encoded strings (u32 len || data)
177: * The "cstring" variants admit no \0 characters in the string contents.
178: * Caller must free *valp.
179: */
180: int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp);
181: int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp);
182: int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v);
183: int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len);
184: int sshbuf_put_cstring(struct sshbuf *buf, const char *v);
185: int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v);
186:
187: /*
188: * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to
189: * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the
190: * next sshbuf-modifying function call. Caller does not free.
191: */
192: int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp,
193: size_t *lenp);
194:
195: /* Skip past a string */
196: #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL)
197:
198: /* Another variant: "peeks" into the buffer without modifying it */
199: int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
200: size_t *lenp);
1.9 djm 201: /* XXX peek_u8 / peek_u32 */
1.1 djm 202:
203: /*
204: * Functions to extract or store SSH wire encoded bignums and elliptic
205: * curve points.
206: */
207: int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v);
1.4 djm 208: int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
209: const u_char **valp, size_t *lenp);
1.2 dtucker 210: int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v);
211: int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len);
1.1 djm 212: int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g);
213: int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v);
214: int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g);
215: int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v);
216:
1.3 djm 217: /* Dump the contents of the buffer in a human-readable format */
1.1 djm 218: void sshbuf_dump(struct sshbuf *buf, FILE *f);
1.3 djm 219:
220: /* Dump specified memory in a human-readable format */
221: void sshbuf_dump_data(const void *s, size_t len, FILE *f);
1.1 djm 222:
223: /* Return the hexadecimal representation of the contents of the buffer */
224: char *sshbuf_dtob16(struct sshbuf *buf);
225:
226: /* Encode the contents of the buffer as base64 */
227: char *sshbuf_dtob64(struct sshbuf *buf);
228:
229: /* Decode base64 data and append it to the buffer */
230: int sshbuf_b64tod(struct sshbuf *buf, const char *b64);
1.7 djm 231:
232: /*
233: * Duplicate the contents of a buffer to a string (caller to free).
234: * Returns NULL on buffer error, or if the buffer contains a premature
235: * nul character.
236: */
237: char *sshbuf_dup_string(struct sshbuf *buf);
1.1 djm 238:
239: /* Macros for decoding/encoding integers */
240: #define PEEK_U64(p) \
1.5 djm 241: (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \
242: ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \
243: ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \
244: ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \
245: ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \
246: ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \
247: ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \
248: (u_int64_t)(((const u_char *)(p))[7]))
1.1 djm 249: #define PEEK_U32(p) \
1.5 djm 250: (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \
251: ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \
252: ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \
253: (u_int32_t)(((const u_char *)(p))[3]))
1.1 djm 254: #define PEEK_U16(p) \
1.5 djm 255: (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \
256: (u_int16_t)(((const u_char *)(p))[1]))
1.1 djm 257:
258: #define POKE_U64(p, v) \
259: do { \
1.5 djm 260: const u_int64_t __v = (v); \
261: ((u_char *)(p))[0] = (__v >> 56) & 0xff; \
262: ((u_char *)(p))[1] = (__v >> 48) & 0xff; \
263: ((u_char *)(p))[2] = (__v >> 40) & 0xff; \
264: ((u_char *)(p))[3] = (__v >> 32) & 0xff; \
265: ((u_char *)(p))[4] = (__v >> 24) & 0xff; \
266: ((u_char *)(p))[5] = (__v >> 16) & 0xff; \
267: ((u_char *)(p))[6] = (__v >> 8) & 0xff; \
268: ((u_char *)(p))[7] = __v & 0xff; \
1.1 djm 269: } while (0)
270: #define POKE_U32(p, v) \
271: do { \
1.5 djm 272: const u_int32_t __v = (v); \
273: ((u_char *)(p))[0] = (__v >> 24) & 0xff; \
274: ((u_char *)(p))[1] = (__v >> 16) & 0xff; \
275: ((u_char *)(p))[2] = (__v >> 8) & 0xff; \
276: ((u_char *)(p))[3] = __v & 0xff; \
1.1 djm 277: } while (0)
278: #define POKE_U16(p, v) \
279: do { \
1.5 djm 280: const u_int16_t __v = (v); \
281: ((u_char *)(p))[0] = (__v >> 8) & 0xff; \
282: ((u_char *)(p))[1] = __v & 0xff; \
1.1 djm 283: } while (0)
284:
285: /* Internal definitions follow. Exposed for regress tests */
286: #ifdef SSHBUF_INTERNAL
287:
288: /*
289: * Return the allocation size of buf
290: */
291: size_t sshbuf_alloc(const struct sshbuf *buf);
292:
293: /*
294: * Increment the reference count of buf.
295: */
296: int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent);
297:
298: /*
299: * Return the parent buffer of buf, or NULL if it has no parent.
300: */
301: const struct sshbuf *sshbuf_parent(const struct sshbuf *buf);
302:
303: /*
304: * Return the reference count of buf
305: */
306: u_int sshbuf_refcount(const struct sshbuf *buf);
307:
308: # define SSHBUF_SIZE_INIT 256 /* Initial allocation */
309: # define SSHBUF_SIZE_INC 256 /* Preferred increment length */
310: # define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */
311:
312: /* # define SSHBUF_ABORT abort */
313: /* # define SSHBUF_DEBUG */
314:
315: # ifndef SSHBUF_ABORT
316: # define SSHBUF_ABORT()
317: # endif
318:
319: # ifdef SSHBUF_DEBUG
320: # define SSHBUF_TELL(what) do { \
321: printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
322: __FILE__, __LINE__, __func__, what, \
323: buf->size, buf->alloc, buf->off, buf->max_size); \
324: fflush(stdout); \
325: } while (0)
326: # define SSHBUF_DBG(x) do { \
327: printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
328: printf x; \
329: printf("\n"); \
330: fflush(stdout); \
331: } while (0)
332: # else
333: # define SSHBUF_TELL(what)
334: # define SSHBUF_DBG(x)
335: # endif
336: #endif /* SSHBUF_INTERNAL */
337:
338: #endif /* _SSHBUF_H */