From 784f5587478845d3bae11a98e490826b2c69f500 Mon Sep 17 00:00:00 2001 From: djm Date: Wed, 5 Jan 2022 04:50:11 +0000 Subject: [PATCH] allow selection of hash at sshsig signing time; code already supported either sha512 (default) or sha256, but plumbing wasn't there mostly by Linus Nordberg --- usr.bin/ssh/ssh-keygen.1 | 13 ++++++++++-- usr.bin/ssh/ssh-keygen.c | 43 ++++++++++++++++++++++++++-------------- 2 files changed, 39 insertions(+), 17 deletions(-) diff --git a/usr.bin/ssh/ssh-keygen.1 b/usr.bin/ssh/ssh-keygen.1 index 58b1f6820eb..212e3525a25 100644 --- a/usr.bin/ssh/ssh-keygen.1 +++ b/usr.bin/ssh/ssh-keygen.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: ssh-keygen.1,v 1.218 2021/11/28 07:15:10 djm Exp $ +.\" $OpenBSD: ssh-keygen.1,v 1.219 2022/01/05 04:50:11 djm Exp $ .\" .\" Author: Tatu Ylonen .\" Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -35,7 +35,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.Dd $Mdocdate: November 28 2021 $ +.Dd $Mdocdate: January 5 2022 $ .Dt SSH-KEYGEN 1 .Os .Sh NAME @@ -161,6 +161,7 @@ .Fl s Ar signature_file .Nm ssh-keygen .Fl Y Cm sign +.Op Fl O Ar option .Fl f Ar key_file .Fl n Ar namespace .Ar @@ -541,6 +542,14 @@ When performing signature-related options using the .Fl Y flag, the following options are accepted: .Bl -tag -width Ds +.It Cm hashalg Ns = Ns Ar algorithm +Selects the hash algorithm to use for hashing the message to be signed. +Valid algorithms are +.Dq sha256 +and +.Dq sha512. +The default is +.Dq sha512. .It Cm print-pubkey Print the full public key to standard output after signature verification. .It Cm verify-time Ns = Ns Ar timestamp diff --git a/usr.bin/ssh/ssh-keygen.c b/usr.bin/ssh/ssh-keygen.c index 5c1e108bdf3..c7ef19742a7 100644 --- a/usr.bin/ssh/ssh-keygen.c +++ b/usr.bin/ssh/ssh-keygen.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keygen.c,v 1.444 2022/01/05 04:27:54 djm Exp $ */ +/* $OpenBSD: ssh-keygen.c,v 1.445 2022/01/05 04:50:11 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1994 Tatu Ylonen , Espoo, Finland @@ -2489,7 +2489,8 @@ load_sign_key(const char *keypath, const struct sshkey *pubkey) static int sign_one(struct sshkey *signkey, const char *filename, int fd, - const char *sig_namespace, sshsig_signer *signer, void *signer_ctx) + const char *sig_namespace, const char *hashalg, sshsig_signer *signer, + void *signer_ctx) { struct sshbuf *sigbuf = NULL, *abuf = NULL; int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno; @@ -2519,7 +2520,7 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, free(fp); } } - if ((r = sshsig_sign_fd(signkey, NULL, sk_provider, pin, + if ((r = sshsig_sign_fd(signkey, hashalg, sk_provider, pin, fd, sig_namespace, &sigbuf, signer, signer_ctx)) != 0) { error_r(r, "Signing %s failed", filename); goto out; @@ -2580,8 +2581,8 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, } static int -sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, - int *print_pubkey) +sig_process_opts(char * const *opts, size_t nopts, char **hashalgp, + uint64_t *verify_timep, int *print_pubkey) { size_t i; time_t now; @@ -2590,8 +2591,13 @@ sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, *verify_timep = 0; if (print_pubkey != NULL) *print_pubkey = 0; + if (hashalgp != NULL) + *hashalgp = NULL; for (i = 0; i < nopts; i++) { - if (verify_timep && + if (hashalgp != NULL && + strncasecmp(opts[i], "hashalg=", 8) == 0) { + *hashalgp = xstrdup(opts[i] + 8); + } else if (verify_timep && strncasecmp(opts[i], "verify-time=", 12) == 0) { if (parse_absolute_time(opts[i] + 12, verify_timep) != 0 || *verify_timep == 0) { @@ -2618,12 +2624,14 @@ sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, static int -sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) +sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv, + char * const *opts, size_t nopts) { int i, fd = -1, r, ret = -1; int agent_fd = -1; struct sshkey *pubkey = NULL, *privkey = NULL, *signkey = NULL; sshsig_signer *signer = NULL; + char *hashalg = NULL; /* Check file arguments. */ for (i = 0; i < argc; i++) { @@ -2633,6 +2641,9 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) fatal("Cannot sign mix of paths and standard input"); } + if (sig_process_opts(opts, nopts, &hashalg, NULL, NULL) != 0) + goto done; /* error already logged */ + if ((r = sshkey_load_public(keypath, &pubkey, NULL)) != 0) { error_r(r, "Couldn't load public key %s", keypath); goto done; @@ -2659,7 +2670,7 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) if (argc == 0) { if ((r = sign_one(signkey, "(stdin)", STDIN_FILENO, - sig_namespace, signer, &agent_fd)) != 0) + sig_namespace, hashalg, signer, &agent_fd)) != 0) goto done; } else { for (i = 0; i < argc; i++) { @@ -2671,7 +2682,7 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) goto done; } if ((r = sign_one(signkey, argv[i], fd, sig_namespace, - signer, &agent_fd)) != 0) + hashalg, signer, &agent_fd)) != 0) goto done; if (fd != STDIN_FILENO) close(fd); @@ -2685,6 +2696,7 @@ done: close(fd); sshkey_free(pubkey); sshkey_free(privkey); + free(hashalg); return ret; } @@ -2701,7 +2713,8 @@ sig_verify(const char *signature, const char *sig_namespace, struct sshkey_sig_details *sig_details = NULL; uint64_t verify_time = 0; - if (sig_process_opts(opts, nopts, &verify_time, &print_pubkey) != 0) + if (sig_process_opts(opts, nopts, NULL, &verify_time, + &print_pubkey) != 0) goto done; /* error already logged */ memset(&sig_details, 0, sizeof(sig_details)); @@ -2789,7 +2802,7 @@ sig_find_principals(const char *signature, const char *allowed_keys, char *principals = NULL, *cp, *tmp; uint64_t verify_time = 0; - if (sig_process_opts(opts, nopts, &verify_time, NULL) != 0) + if (sig_process_opts(opts, nopts, NULL, &verify_time, NULL) != 0) goto done; /* error already logged */ if ((r = sshbuf_load_file(signature, &abuf)) != 0) { @@ -2835,7 +2848,7 @@ sig_match_principals(const char *allowed_keys, char *principal, char **principals = NULL; size_t i, nprincipals = 0; - if ((r = sig_process_opts(opts, nopts, NULL, NULL)) != 0) + if ((r = sig_process_opts(opts, nopts, NULL, NULL, NULL)) != 0) return r; /* error already logged */ if ((r = sshsig_match_principals(allowed_keys, principal, @@ -3193,9 +3206,9 @@ usage(void) " ssh-keygen -Y find-principals -s signature_file -f allowed_signers_file\n" " ssh-keygen -Y match-principals -I signer_identity -f allowed_signers_file\n" " ssh-keygen -Y check-novalidate -n namespace -s signature_file\n" - " ssh-keygen -Y sign -f key_file -n namespace file ...\n" + " ssh-keygen -Y sign -f key_file -n namespace file [-O option] ...\n" " ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n" - " -n namespace -s signature_file [-r revocation_file] [-O option]\n"); + " -n namespace -s signature_file [-r krl_file] [-O option]\n"); exit(1); } @@ -3496,7 +3509,7 @@ main(int argc, char **argv) exit(1); } return sig_sign(identity_file, cert_principals, - argc, argv); + argc, argv, opts, nopts); } else if (strncmp(sign_op, "check-novalidate", 16) == 0) { if (ca_key_path == NULL) { error("Too few arguments for check-novalidate: " -- 2.20.1