Mercurial > dropbear
diff svr-authpubkey.c @ 476:df7f7da7f6e4 pubkey-options
- Rework pubkey options to be more careful about buffer lengths. Needs review.
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Fri, 12 Sep 2008 17:23:56 +0000 |
parents | 52a644e7b8e1 |
children | a98a2138364a |
line wrap: on
line diff
--- a/svr-authpubkey.c Mon Sep 08 15:14:02 2008 +0000 +++ b/svr-authpubkey.c Fri Sep 12 17:23:56 2008 +0000 @@ -189,8 +189,9 @@ char * filename = NULL; int ret = DROPBEAR_FAILURE; buffer * line = NULL; - unsigned int len, pos, quoted; - const char *options = NULL; + unsigned int len, pos; + buffer * options_buf = NULL; + int line_num; TRACE(("enter checkpubkey")) @@ -225,17 +226,22 @@ TRACE(("checkpubkey: opened authorized_keys OK")) line = buf_new(MAX_AUTHKEYS_LINE); + line_num = 0; /* iterate through the lines */ do { /* new line : potentially new options */ - options = NULL; + if (options_buf) { + buf_free(options_buf); + options_buf = NULL; + } if (buf_getline(line, authfile) == DROPBEAR_FAILURE) { /* EOF reached */ TRACE(("checkpubkey: authorized_keys EOF reached")) break; } + line_num++; if (line->len < MIN_AUTHKEYS_LINE) { TRACE(("checkpubkey: line too short")) @@ -243,38 +249,59 @@ } /* check the key type - will fail if there are options */ + TRACE(("a line!")) + if (strncmp(buf_getptr(line, algolen), algo, algolen) != 0) { - /* there may be options or a commented line */ - if ('#' == line->data[line->pos]) continue; - /* no comment, skip to next space character */ - len = 0; - pos = line->pos; - options = buf_getptr(line, 1); + int is_comment = 0; + char *options_start = NULL; + int options_len = 0; + int escape, quoted; + + /* skip over any comments or leading whitespace */ + while (line->pos < line->len) { + const char c = buf_getbyte(line); + if (c == ' ' || c == '\t') { + continue; + } else if (c == '#') { + is_comment = 1; + break; + } + buf_incrpos(line, -1); + break; + } + if (is_comment) { + /* next line */ + continue; + } + + /* remember start of options */ + options_start = buf_getptr(line, 1); quoted = 0; - while (line->data[pos] - && (quoted || (line->data[pos] != ' ' - && line->data[pos] != '\t' - && line->data[pos] != '\n' - && line->data[pos] != '\r'))) { - pos++; - if (line->data[pos] == '\\' - && line->data[pos+1] == '"') { - pos++; /* skip both */ - } else if (line->data[pos] == '"') - quoted = !quoted; - } /* line->data[pos] == ['\0'|' '|'\t'] */ + escape = 0; + options_len = 0; + + /* figure out where the options are */ + while (line->pos < line->len) { + const char c = buf_getbyte(line); + if (!quoted && (c == ' ' || c == '\t')) { + break; + } + escape = (!escape && c == '\\'); + if (!escape && c == '"') { + quoted = !quoted; + } + options_len++; + } + options_buf = buf_new(options_len); + buf_putbytes(options_buf, options_start, options_len); - /* skip line if there is nothing left */ - if (pos >= line->len) continue; - /* skip line if it begins with a space or tab character */ - if (pos == line->pos) continue; - /* set the position of the line after what we have read */ - buf_setpos(line, pos+1); - /* give a second chance to the algo */ - if (line->pos + algolen > line->len) continue; + /* compare the algorithm */ + if (line->pos + algolen > line->len) { + continue; + } if (strncmp(buf_getptr(line, algolen), algo, algolen) != 0) { continue; - } + } } buf_incrpos(line, algolen); @@ -296,8 +323,8 @@ ret = cmp_base64_key(keyblob, keybloblen, algo, algolen, line, NULL); - if (ret == DROPBEAR_SUCCESS) { - ret = svr_add_pubkey_options(options); + if (ret == DROPBEAR_SUCCESS && options_buf) { + ret = svr_add_pubkey_options(options_buf, line_num, filename); } if (ret == DROPBEAR_SUCCESS) { @@ -316,6 +343,9 @@ buf_free(line); } m_free(filename); + if (options_buf) { + buf_free(options_buf); + } TRACE(("leave checkpubkey: ret=%d", ret)) return ret; }