diff options
author | djm@openbsd.org <djm@openbsd.org> | 2017-07-07 03:53:12 +0000 |
---|---|---|
committer | Damien Miller <djm@mindrot.org> | 2017-07-21 14:17:32 +1000 |
commit | 853edbe057a84ebd0024c8003e4da21bf2b469f7 (patch) | |
tree | 2f7010fb3e1a780ba438b06753c1be99fab3abe9 /ssh-keygen.c | |
parent | 43616876ba68a2ffaece6a6c792def4b039f2d6e (diff) |
upstream commit
When generating all hostkeys (ssh-keygen -A), clobber
existing keys if they exist but are zero length. zero-length keys could
previously be made if ssh-keygen failed part way through generating them, so
avoid that case too. bz#2561 reported by Krzysztof Cieplucha; ok dtucker@
Upstream-ID: f662201c28ab8e1f086b5d43c59cddab5ade4044
Diffstat (limited to 'ssh-keygen.c')
-rw-r--r-- | ssh-keygen.c | 106 |
1 files changed, 72 insertions, 34 deletions
diff --git a/ssh-keygen.c b/ssh-keygen.c index d8f942f5..835f7d01 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keygen.c,v 1.306 2017/07/01 13:50:45 djm Exp $ */ +/* $OpenBSD: ssh-keygen.c,v 1.307 2017/07/07 03:53:12 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -997,20 +997,38 @@ do_gen_all_hostkeys(struct passwd *pw) int first = 0; struct stat st; struct sshkey *private, *public; - char comment[1024]; + char comment[1024], *prv_tmp, *pub_tmp, *prv_file, *pub_file; int i, type, fd, r; FILE *f; for (i = 0; key_types[i].key_type; i++) { - if (stat(key_types[i].path, &st) == 0) - continue; - if (errno != ENOENT) { + public = private = NULL; + prv_tmp = pub_tmp = prv_file = pub_file = NULL; + + xasprintf(&prv_file, "%s%s", + identity_file, key_types[i].path); + + /* Check whether private key exists and is not zero-length */ + if (stat(prv_file, &st) == 0) { + if (st.st_size != 0) + goto next; + } else if (errno != ENOENT) { error("Could not stat %s: %s", key_types[i].path, strerror(errno)); - first = 0; - continue; + goto failnext; } + /* + * Private key doesn't exist or is invalid; proceed with + * key generation. + */ + xasprintf(&prv_tmp, "%s%s.XXXXXXXXXX", + identity_file, key_types[i].path); + xasprintf(&pub_tmp, "%s%s.pub.XXXXXXXXXX", + identity_file, key_types[i].path); + xasprintf(&pub_file, "%s%s.pub", + identity_file, key_types[i].path); + if (first == 0) { first = 1; printf("%s: generating new host keys: ", __progname); @@ -1018,56 +1036,76 @@ do_gen_all_hostkeys(struct passwd *pw) printf("%s ", key_types[i].key_type_display); fflush(stdout); type = sshkey_type_from_name(key_types[i].key_type); - strlcpy(identity_file, key_types[i].path, sizeof(identity_file)); + if ((fd = mkstemp(prv_tmp)) == -1) { + error("Could not save your public key in %s: %s", + prv_tmp, strerror(errno)); + goto failnext; + } + close(fd); /* just using mkstemp() to generate/reserve a name */ bits = 0; type_bits_valid(type, NULL, &bits); if ((r = sshkey_generate(type, bits, &private)) != 0) { error("sshkey_generate failed: %s", ssh_err(r)); - first = 0; - continue; + goto failnext; } if ((r = sshkey_from_private(private, &public)) != 0) fatal("sshkey_from_private failed: %s", ssh_err(r)); snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname); - if ((r = sshkey_save_private(private, identity_file, "", + if ((r = sshkey_save_private(private, prv_tmp, "", comment, use_new_format, new_format_cipher, rounds)) != 0) { error("Saving key \"%s\" failed: %s", - identity_file, ssh_err(r)); - sshkey_free(private); - sshkey_free(public); - first = 0; - continue; + prv_tmp, ssh_err(r)); + goto failnext; } - sshkey_free(private); - strlcat(identity_file, ".pub", sizeof(identity_file)); - fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644); - if (fd == -1) { - error("Could not save your public key in %s", - identity_file); - sshkey_free(public); - first = 0; - continue; + if ((fd = mkstemp(pub_tmp)) == -1) { + error("Could not save your public key in %s: %s", + pub_tmp, strerror(errno)); + goto failnext; } + (void)fchmod(fd, 0644); f = fdopen(fd, "w"); if (f == NULL) { - error("fdopen %s failed", identity_file); + error("fdopen %s failed: %s", pub_tmp, strerror(errno)); close(fd); - sshkey_free(public); - first = 0; - continue; + goto failnext; } if ((r = sshkey_write(public, f)) != 0) { error("write key failed: %s", ssh_err(r)); fclose(f); - sshkey_free(public); - first = 0; - continue; + goto failnext; } fprintf(f, " %s\n", comment); - fclose(f); - sshkey_free(public); + if (ferror(f) != 0) { + error("write key failed: %s", strerror(errno)); + fclose(f); + goto failnext; + } + if (fclose(f) != 0) { + error("key close failed: %s", strerror(errno)); + goto failnext; + } + /* Rename temporary files to their permanent locations. */ + if (rename(pub_tmp, pub_file) != 0) { + error("Unable to move %s into position: %s", + pub_file, strerror(errno)); + goto failnext; + } + if (rename(prv_tmp, prv_file) != 0) { + error("Unable to move %s into position: %s", + key_types[i].path, strerror(errno)); + failnext: + first = 0; + goto next; + } + next: + sshkey_free(private); + sshkey_free(public); + free(prv_tmp); + free(pub_tmp); + free(prv_file); + free(pub_file); } if (first != 0) printf("\n"); |