| /* $OpenBSD: sshbuf-getput-basic.c,v 1.10 2019/12/13 19:09:37 djm Exp $ */ |
| /* |
| * Copyright (c) 2011 Damien Miller |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| */ |
| |
| #define SSHBUF_INTERNAL |
| #include "includes.h" |
| |
| #include <sys/types.h> |
| |
| #include <stdarg.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #ifdef HAVE_STDINT_H |
| # include <stdint.h> |
| #endif |
| |
| #include "ssherr.h" |
| #include "sshbuf.h" |
| |
| int |
| sshbuf_get(struct sshbuf *buf, void *v, size_t len) |
| { |
| const u_char *p = sshbuf_ptr(buf); |
| int r; |
| |
| if ((r = sshbuf_consume(buf, len)) < 0) |
| return r; |
| if (v != NULL && len != 0) |
| memcpy(v, p, len); |
| return 0; |
| } |
| |
| int |
| sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp) |
| { |
| const u_char *p = sshbuf_ptr(buf); |
| int r; |
| |
| if ((r = sshbuf_consume(buf, 8)) < 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U64(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp) |
| { |
| const u_char *p = sshbuf_ptr(buf); |
| int r; |
| |
| if ((r = sshbuf_consume(buf, 4)) < 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U32(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp) |
| { |
| const u_char *p = sshbuf_ptr(buf); |
| int r; |
| |
| if ((r = sshbuf_consume(buf, 2)) < 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U16(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_get_u8(struct sshbuf *buf, u_char *valp) |
| { |
| const u_char *p = sshbuf_ptr(buf); |
| int r; |
| |
| if ((r = sshbuf_consume(buf, 1)) < 0) |
| return r; |
| if (valp != NULL) |
| *valp = (u_int8_t)*p; |
| return 0; |
| } |
| |
| static int |
| check_offset(const struct sshbuf *buf, int wr, size_t offset, size_t len) |
| { |
| if (sshbuf_ptr(buf) == NULL) /* calls sshbuf_check_sanity() */ |
| return SSH_ERR_INTERNAL_ERROR; |
| if (offset >= SIZE_MAX - len) |
| return SSH_ERR_INVALID_ARGUMENT; |
| if (offset + len > sshbuf_len(buf)) { |
| return wr ? |
| SSH_ERR_NO_BUFFER_SPACE : SSH_ERR_MESSAGE_INCOMPLETE; |
| } |
| return 0; |
| } |
| |
| static int |
| check_roffset(const struct sshbuf *buf, size_t offset, size_t len, |
| const u_char **p) |
| { |
| int r; |
| |
| *p = NULL; |
| if ((r = check_offset(buf, 0, offset, len)) != 0) |
| return r; |
| *p = sshbuf_ptr(buf) + offset; |
| return 0; |
| } |
| |
| int |
| sshbuf_peek_u64(const struct sshbuf *buf, size_t offset, u_int64_t *valp) |
| { |
| const u_char *p = NULL; |
| int r; |
| |
| if (valp != NULL) |
| *valp = 0; |
| if ((r = check_roffset(buf, offset, 8, &p)) != 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U64(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_peek_u32(const struct sshbuf *buf, size_t offset, u_int32_t *valp) |
| { |
| const u_char *p = NULL; |
| int r; |
| |
| if (valp != NULL) |
| *valp = 0; |
| if ((r = check_roffset(buf, offset, 4, &p)) != 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U32(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_peek_u16(const struct sshbuf *buf, size_t offset, u_int16_t *valp) |
| { |
| const u_char *p = NULL; |
| int r; |
| |
| if (valp != NULL) |
| *valp = 0; |
| if ((r = check_roffset(buf, offset, 2, &p)) != 0) |
| return r; |
| if (valp != NULL) |
| *valp = PEEK_U16(p); |
| return 0; |
| } |
| |
| int |
| sshbuf_peek_u8(const struct sshbuf *buf, size_t offset, u_char *valp) |
| { |
| const u_char *p = NULL; |
| int r; |
| |
| if (valp != NULL) |
| *valp = 0; |
| if ((r = check_roffset(buf, offset, 1, &p)) != 0) |
| return r; |
| if (valp != NULL) |
| *valp = *p; |
| return 0; |
| } |
| |
| int |
| sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp) |
| { |
| const u_char *val; |
| size_t len; |
| int r; |
| |
| if (valp != NULL) |
| *valp = NULL; |
| if (lenp != NULL) |
| *lenp = 0; |
| if ((r = sshbuf_get_string_direct(buf, &val, &len)) < 0) |
| return r; |
| if (valp != NULL) { |
| if ((*valp = malloc(len + 1)) == NULL) { |
| SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL")); |
| return SSH_ERR_ALLOC_FAIL; |
| } |
| if (len != 0) |
| memcpy(*valp, val, len); |
| (*valp)[len] = '\0'; |
| } |
| if (lenp != NULL) |
| *lenp = len; |
| return 0; |
| } |
| |
| int |
| sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, size_t *lenp) |
| { |
| size_t len; |
| const u_char *p; |
| int r; |
| |
| if (valp != NULL) |
| *valp = NULL; |
| if (lenp != NULL) |
| *lenp = 0; |
| if ((r = sshbuf_peek_string_direct(buf, &p, &len)) < 0) |
| return r; |
| if (valp != NULL) |
| *valp = p; |
| if (lenp != NULL) |
| *lenp = len; |
| if (sshbuf_consume(buf, len + 4) != 0) { |
| /* Shouldn't happen */ |
| SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); |
| SSHBUF_ABORT(); |
| return SSH_ERR_INTERNAL_ERROR; |
| } |
| return 0; |
| } |
| |
| int |
| sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, |
| size_t *lenp) |
| { |
| u_int32_t len; |
| const u_char *p = sshbuf_ptr(buf); |
| |
| if (valp != NULL) |
| *valp = NULL; |
| if (lenp != NULL) |
| *lenp = 0; |
| if (sshbuf_len(buf) < 4) { |
| SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE")); |
| return SSH_ERR_MESSAGE_INCOMPLETE; |
| } |
| len = PEEK_U32(p); |
| if (len > SSHBUF_SIZE_MAX - 4) { |
| SSHBUF_DBG(("SSH_ERR_STRING_TOO_LARGE")); |
| return SSH_ERR_STRING_TOO_LARGE; |
| } |
| if (sshbuf_len(buf) - 4 < len) { |
| SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE")); |
| return SSH_ERR_MESSAGE_INCOMPLETE; |
| } |
| if (valp != NULL) |
| *valp = p + 4; |
| if (lenp != NULL) |
| *lenp = len; |
| return 0; |
| } |
| |
| int |
| sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp) |
| { |
| size_t len; |
| const u_char *p, *z; |
| int r; |
| |
| if (valp != NULL) |
| *valp = NULL; |
| if (lenp != NULL) |
| *lenp = 0; |
| if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0) |
| return r; |
| /* Allow a \0 only at the end of the string */ |
| if (len > 0 && |
| (z = memchr(p , '\0', len)) != NULL && z < p + len - 1) { |
| SSHBUF_DBG(("SSH_ERR_INVALID_FORMAT")); |
| return SSH_ERR_INVALID_FORMAT; |
| } |
| if ((r = sshbuf_skip_string(buf)) != 0) |
| return -1; |
| if (valp != NULL) { |
| if ((*valp = malloc(len + 1)) == NULL) { |
| SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL")); |
| return SSH_ERR_ALLOC_FAIL; |
| } |
| if (len != 0) |
| memcpy(*valp, p, len); |
| (*valp)[len] = '\0'; |
| } |
| if (lenp != NULL) |
| *lenp = (size_t)len; |
| return 0; |
| } |
| |
| int |
| sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v) |
| { |
| u_int32_t len; |
| u_char *p; |
| int r; |
| |
| /* |
| * Use sshbuf_peek_string_direct() to figure out if there is |
| * a complete string in 'buf' and copy the string directly |
| * into 'v'. |
| */ |
| if ((r = sshbuf_peek_string_direct(buf, NULL, NULL)) != 0 || |
| (r = sshbuf_get_u32(buf, &len)) != 0 || |
| (r = sshbuf_reserve(v, len, &p)) != 0 || |
| (r = sshbuf_get(buf, p, len)) != 0) |
| return r; |
| return 0; |
| } |
| |
| int |
| sshbuf_put(struct sshbuf *buf, const void *v, size_t len) |
| { |
| u_char *p; |
| int r; |
| |
| if ((r = sshbuf_reserve(buf, len, &p)) < 0) |
| return r; |
| if (len != 0) |
| memcpy(p, v, len); |
| return 0; |
| } |
| |
| int |
| sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v) |
| { |
| return sshbuf_put(buf, sshbuf_ptr(v), sshbuf_len(v)); |
| } |
| |
| int |
| sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) |
| { |
| va_list ap; |
| int r; |
| |
| va_start(ap, fmt); |
| r = sshbuf_putfv(buf, fmt, ap); |
| va_end(ap); |
| return r; |
| } |
| |
| int |
| sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap) |
| { |
| va_list ap2; |
| int r, len; |
| u_char *p; |
| |
| VA_COPY(ap2, ap); |
| if ((len = vsnprintf(NULL, 0, fmt, ap2)) < 0) { |
| r = SSH_ERR_INVALID_ARGUMENT; |
| goto out; |
| } |
| if (len == 0) { |
| r = 0; |
| goto out; /* Nothing to do */ |
| } |
| va_end(ap2); |
| VA_COPY(ap2, ap); |
| if ((r = sshbuf_reserve(buf, (size_t)len + 1, &p)) < 0) |
| goto out; |
| if ((r = vsnprintf((char *)p, len + 1, fmt, ap2)) != len) { |
| r = SSH_ERR_INTERNAL_ERROR; |
| goto out; /* Shouldn't happen */ |
| } |
| /* Consume terminating \0 */ |
| if ((r = sshbuf_consume_end(buf, 1)) != 0) |
| goto out; |
| r = 0; |
| out: |
| va_end(ap2); |
| return r; |
| } |
| |
| int |
| sshbuf_put_u64(struct sshbuf *buf, u_int64_t val) |
| { |
| u_char *p; |
| int r; |
| |
| if ((r = sshbuf_reserve(buf, 8, &p)) < 0) |
| return r; |
| POKE_U64(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_put_u32(struct sshbuf *buf, u_int32_t val) |
| { |
| u_char *p; |
| int r; |
| |
| if ((r = sshbuf_reserve(buf, 4, &p)) < 0) |
| return r; |
| POKE_U32(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_put_u16(struct sshbuf *buf, u_int16_t val) |
| { |
| u_char *p; |
| int r; |
| |
| if ((r = sshbuf_reserve(buf, 2, &p)) < 0) |
| return r; |
| POKE_U16(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_put_u8(struct sshbuf *buf, u_char val) |
| { |
| u_char *p; |
| int r; |
| |
| if ((r = sshbuf_reserve(buf, 1, &p)) < 0) |
| return r; |
| p[0] = val; |
| return 0; |
| } |
| |
| static int |
| check_woffset(struct sshbuf *buf, size_t offset, size_t len, u_char **p) |
| { |
| int r; |
| |
| *p = NULL; |
| if ((r = check_offset(buf, 1, offset, len)) != 0) |
| return r; |
| if (sshbuf_mutable_ptr(buf) == NULL) |
| return SSH_ERR_BUFFER_READ_ONLY; |
| *p = sshbuf_mutable_ptr(buf) + offset; |
| return 0; |
| } |
| |
| int |
| sshbuf_poke_u64(struct sshbuf *buf, size_t offset, u_int64_t val) |
| { |
| u_char *p = NULL; |
| int r; |
| |
| if ((r = check_woffset(buf, offset, 8, &p)) != 0) |
| return r; |
| POKE_U64(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_poke_u32(struct sshbuf *buf, size_t offset, u_int32_t val) |
| { |
| u_char *p = NULL; |
| int r; |
| |
| if ((r = check_woffset(buf, offset, 4, &p)) != 0) |
| return r; |
| POKE_U32(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_poke_u16(struct sshbuf *buf, size_t offset, u_int16_t val) |
| { |
| u_char *p = NULL; |
| int r; |
| |
| if ((r = check_woffset(buf, offset, 2, &p)) != 0) |
| return r; |
| POKE_U16(p, val); |
| return 0; |
| } |
| |
| int |
| sshbuf_poke_u8(struct sshbuf *buf, size_t offset, u_char val) |
| { |
| u_char *p = NULL; |
| int r; |
| |
| if ((r = check_woffset(buf, offset, 1, &p)) != 0) |
| return r; |
| *p = val; |
| return 0; |
| } |
| |
| int |
| sshbuf_poke(struct sshbuf *buf, size_t offset, void *v, size_t len) |
| { |
| u_char *p = NULL; |
| int r; |
| |
| if ((r = check_woffset(buf, offset, len, &p)) != 0) |
| return r; |
| memcpy(p, v, len); |
| return 0; |
| } |
| |
| int |
| sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len) |
| { |
| u_char *d; |
| int r; |
| |
| if (len > SSHBUF_SIZE_MAX - 4) { |
| SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE")); |
| return SSH_ERR_NO_BUFFER_SPACE; |
| } |
| if ((r = sshbuf_reserve(buf, len + 4, &d)) < 0) |
| return r; |
| POKE_U32(d, len); |
| if (len != 0) |
| memcpy(d + 4, v, len); |
| return 0; |
| } |
| |
| int |
| sshbuf_put_cstring(struct sshbuf *buf, const char *v) |
| { |
| return sshbuf_put_string(buf, v, v == NULL ? 0 : strlen(v)); |
| } |
| |
| int |
| sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v) |
| { |
| if (v == NULL) |
| return sshbuf_put_string(buf, NULL, 0); |
| |
| return sshbuf_put_string(buf, sshbuf_ptr(v), sshbuf_len(v)); |
| } |
| |
| int |
| sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp) |
| { |
| const u_char *p; |
| size_t len; |
| struct sshbuf *ret; |
| int r; |
| |
| if (buf == NULL || bufp == NULL) |
| return SSH_ERR_INVALID_ARGUMENT; |
| *bufp = NULL; |
| if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0) |
| return r; |
| if ((ret = sshbuf_from(p, len)) == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| if ((r = sshbuf_consume(buf, len + 4)) != 0 || /* Shouldn't happen */ |
| (r = sshbuf_set_parent(ret, buf)) != 0) { |
| sshbuf_free(ret); |
| return r; |
| } |
| *bufp = ret; |
| return 0; |
| } |
| |
| int |
| sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len) |
| { |
| u_char *d; |
| const u_char *s = (const u_char *)v; |
| int r, prepend; |
| |
| if (len > SSHBUF_SIZE_MAX - 5) { |
| SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE")); |
| return SSH_ERR_NO_BUFFER_SPACE; |
| } |
| /* Skip leading zero bytes */ |
| for (; len > 0 && *s == 0; len--, s++) |
| ; |
| /* |
| * If most significant bit is set then prepend a zero byte to |
| * avoid interpretation as a negative number. |
| */ |
| prepend = len > 0 && (s[0] & 0x80) != 0; |
| if ((r = sshbuf_reserve(buf, len + 4 + prepend, &d)) < 0) |
| return r; |
| POKE_U32(d, len + prepend); |
| if (prepend) |
| d[4] = 0; |
| if (len != 0) |
| memcpy(d + 4 + prepend, s, len); |
| return 0; |
| } |
| |
| int |
| sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, |
| const u_char **valp, size_t *lenp) |
| { |
| const u_char *d; |
| size_t len, olen; |
| int r; |
| |
| if ((r = sshbuf_peek_string_direct(buf, &d, &olen)) < 0) |
| return r; |
| len = olen; |
| /* Refuse negative (MSB set) bignums */ |
| if ((len != 0 && (*d & 0x80) != 0)) |
| return SSH_ERR_BIGNUM_IS_NEGATIVE; |
| /* Refuse overlong bignums, allow prepended \0 to avoid MSB set */ |
| if (len > SSHBUF_MAX_BIGNUM + 1 || |
| (len == SSHBUF_MAX_BIGNUM + 1 && *d != 0)) |
| return SSH_ERR_BIGNUM_TOO_LARGE; |
| /* Trim leading zeros */ |
| while (len > 0 && *d == 0x00) { |
| d++; |
| len--; |
| } |
| if (valp != NULL) |
| *valp = d; |
| if (lenp != NULL) |
| *lenp = len; |
| if (sshbuf_consume(buf, olen + 4) != 0) { |
| /* Shouldn't happen */ |
| SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); |
| SSHBUF_ABORT(); |
| return SSH_ERR_INTERNAL_ERROR; |
| } |
| return 0; |
| } |