/* $OpenBSD: sshbuf-getput-crypto.c,v 1.10 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. */ #include "includes.h" __RCSID("$NetBSD: sshbuf-getput-crypto.c,v 1.9.2.1 2023/12/25 12:31:09 martin Exp $"); #include #include #include #include #include #include #include "ssherr.h" #define SSHBUF_INTERNAL #include "sshbuf.h" int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM **valp) { BIGNUM *v; const u_char *d; size_t len; int r; if (valp != NULL) *valp = NULL; if ((r = sshbuf_get_bignum2_bytes_direct(buf, &d, &len)) != 0) return r; if (valp != NULL) { if ((v = BN_new()) == NULL || BN_bin2bn(d, len, v) == NULL) { BN_clear_free(v); return SSH_ERR_ALLOC_FAIL; } *valp = v; } return 0; } static int get_ec(const u_char *d, size_t len, EC_POINT *v, const EC_GROUP *g) { /* Refuse overlong bignums */ if (len == 0 || len > SSHBUF_MAX_ECPOINT) return SSH_ERR_ECPOINT_TOO_LARGE; /* Only handle uncompressed points */ if (*d != POINT_CONVERSION_UNCOMPRESSED) return SSH_ERR_INVALID_FORMAT; if (v != NULL && EC_POINT_oct2point(g, v, d, len, NULL) != 1) return SSH_ERR_INVALID_FORMAT; /* XXX assumption */ return 0; } int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g) { const u_char *d; size_t len; int r; if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) return r; if ((r = get_ec(d, len, v, g)) != 0) return r; /* Skip string */ if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) { /* Shouldn't happen */ SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); SSHBUF_ABORT(); return SSH_ERR_INTERNAL_ERROR; } return 0; } int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v) { EC_POINT *pt = EC_POINT_new(EC_KEY_get0_group(v)); int r; const u_char *d; size_t len; if (pt == NULL) { SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL")); return SSH_ERR_ALLOC_FAIL; } if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) { EC_POINT_free(pt); return r; } if ((r = get_ec(d, len, pt, EC_KEY_get0_group(v))) != 0) { EC_POINT_free(pt); return r; } if (EC_KEY_set_public_key(v, pt) != 1) { EC_POINT_free(pt); return SSH_ERR_ALLOC_FAIL; /* XXX assumption */ } EC_POINT_free(pt); /* Skip string */ if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) { /* Shouldn't happen */ SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); SSHBUF_ABORT(); return SSH_ERR_INTERNAL_ERROR; } return 0; } int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v) { u_char d[SSHBUF_MAX_BIGNUM + 1]; int len = BN_num_bytes(v), prepend = 0, r; if (len < 0 || len > SSHBUF_MAX_BIGNUM) return SSH_ERR_INVALID_ARGUMENT; *d = '\0'; if (BN_bn2bin(v, d + 1) != len) return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */ /* If MSB is set, prepend a \0 */ if (len > 0 && (d[1] & 0x80) != 0) prepend = 1; if ((r = sshbuf_put_string(buf, d + 1 - prepend, len + prepend)) < 0) { explicit_bzero(d, sizeof(d)); return r; } explicit_bzero(d, sizeof(d)); return 0; } int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g) { u_char d[SSHBUF_MAX_ECPOINT]; size_t len; int ret; if ((len = EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED, NULL, 0, NULL)) > SSHBUF_MAX_ECPOINT) { return SSH_ERR_INVALID_ARGUMENT; } if (EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED, d, len, NULL) != len) { return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */ } ret = sshbuf_put_string(buf, d, len); explicit_bzero(d, len); return ret; } int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v) { return sshbuf_put_ec(buf, EC_KEY_get0_public_key(v), EC_KEY_get0_group(v)); }