diff options
Diffstat (limited to 'sshbuf-getput-basic.c')
| -rw-r--r-- | sshbuf-getput-basic.c | 633 |
1 files changed, 633 insertions, 0 deletions
diff --git a/sshbuf-getput-basic.c b/sshbuf-getput-basic.c new file mode 100644 index 0000000..5c71b0e --- /dev/null +++ b/sshbuf-getput-basic.c @@ -0,0 +1,633 @@ +/* $OpenBSD: sshbuf-getput-basic.c,v 1.13 2022/05/25 06:03:44 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) +{ + if (v == NULL) + return 0; + 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; +} |