diff options
Diffstat (limited to 'sshbuf-getput-basic.c')
| -rw-r--r-- | sshbuf-getput-basic.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/sshbuf-getput-basic.c b/sshbuf-getput-basic.c index 06d6cc49..8ff8a0a2 100644 --- a/sshbuf-getput-basic.c +++ b/sshbuf-getput-basic.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshbuf-getput-basic.c,v 1.3 2015/01/12 15:18:07 djm Exp $ */ +/* $OpenBSD: sshbuf-getput-basic.c,v 1.4 2015/01/14 15:02:39 djm Exp $ */ /* * Copyright (c) 2011 Damien Miller * @@ -424,3 +424,39 @@ sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len) 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 != 0) + *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; +} |