upstream: 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

OpenBSD-Commit-ID: 1b536404b9da74a84b3a1c8d0b05fd564cdc96cd

diff --git a/ssh-keygen.1 b/ssh-keygen.1
index 58b1f6820ebd49e8285c190d53aead02d8d18c17..212e3525a2563716121d236db79bc445a5ad8426 100644 (file)
--- a/ssh-keygen.1
+++ b/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 <ylo@cs.hut.fi>
 .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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/ssh-keygen.c b/ssh-keygen.c
index f8a9f59ba88d7b75846e970746b6da559ba05cdc..a8a21ee2709398687eb04e0f2dd686da2f470ba0 100644 (file)
--- a/ssh-keygen.c
+++ b/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 <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2512,7 +2512,8 @@ 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;
@@ -2542,7 +2543,7 @@ 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;
@@ -2603,8 +2604,8 @@ 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;
@@ -2613,8 +2614,13 @@ 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) {
@@ -2641,12 +2647,14 @@ 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++) {
@@ -2656,6 +2664,9 @@ 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;
@@ -2682,7 +2693,7 @@ 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++) {
@@ -2694,7 +2705,7 @@ 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);
@@ -2708,6 +2719,7 @@ done:
                close(fd);
        sshkey_free(pubkey);
        sshkey_free(privkey);
+       free(hashalg);
        return ret;
 }
 
@@ -2724,7 +2736,8 @@ 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));
@@ -2812,7 +2825,7 @@ 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) {
@@ -2858,7 +2871,7 @@ 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,
@@ -3216,9 +3229,9 @@ 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);
 }
 
@@ -3522,7 +3535,7 @@ 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: "