upstream: remove single-letter flags for moduli options

Move all moduli generation options to live under the -O flag.

Frees up seven single-letter flags.

NB. this change break existing ssh-keygen commandline syntax for moduli-
related operations. Very few people use these fortunately.

feedback and ok markus@

OpenBSD-Commit-ID: d498f3eaf28128484826a4fcb343612764927935

1 files changed, 150 insertions, 99 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 43f2e1e82..447810fb1 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.375 2019/12/30 03:28:41 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.376 2019/12/30 03:30:09 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -162,10 +162,7 @@ static int private_key_format = SSHKEY_PRIVATE_OPENSSH;
 /* Cipher for new-format private keys */
 static char *openssh_format_cipher = NULL;
 
-/*
- * Number of KDF rounds to derive new format keys /
- * number of primality trials when screening moduli.
- */
+/* Number of KDF rounds to derive new format keys. */
 static int rounds = 0;
 
 /* argv0 */
@@ -2759,6 +2756,122 @@ done:
 }
 
 static void
+do_moduli_gen(const char *out_file, char **opts, size_t nopts)
+{
+#ifdef WITH_OPENSSL
+        /* Moduli generation/screening */
+        u_int32_t memory = 0;
+        BIGNUM *start = NULL;
+        int moduli_bits = 0;
+        FILE *out;
+        size_t i;
+        const char *errstr;
+
+        /* Parse options */
+        for (i = 0; i < nopts; i++) {
+                if (strncmp(opts[i], "memory=", 7) == 0) {
+                        memory = (u_int32_t)strtonum(opts[i]+7, 1,
+                            UINT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Memory limit is %s: %s",
+                                    errstr, opts[i]+7);
+                        }
+                } else if (strncmp(opts[i], "start=", 6) == 0) {
+                        /* XXX - also compare length against bits */
+                        if (BN_hex2bn(&start, opts[i]+6) == 0)
+                                fatal("Invalid start point.");
+                } else if (strncmp(opts[i], "bits=", 5) == 0) {
+                        moduli_bits = (int)strtonum(opts[i]+5, 1,
+                            INT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Invalid number: %s (%s)",
+                                        opts[i]+12, errstr);
+                        }
+                } else {
+                        fatal("Option \"%s\" is unsupported for moduli "
+                            "generation", opts[i]);
+                }
+        }
+
+        if ((out = fopen(out_file, "w")) == NULL) {
+                fatal("Couldn't open modulus candidate file \"%s\": %s",
+                    out_file, strerror(errno));
+        }
+        setvbuf(out, NULL, _IOLBF, 0);
+
+        if (moduli_bits == 0)
+                moduli_bits = DEFAULT_BITS;
+        if (gen_candidates(out, memory, moduli_bits, start) != 0)
+                fatal("modulus candidate generation failed");
+#else /* WITH_OPENSSL */
+        fatal("Moduli generation is not supported");
+#endif /* WITH_OPENSSL */
+}
+
+static void
+do_moduli_screen(const char *out_file, char **opts, size_t nopts)
+{
+#ifdef WITH_OPENSSL
+        /* Moduli generation/screening */
+        char *checkpoint = NULL;
+        u_int32_t generator_wanted = 0;
+        unsigned long start_lineno = 0, lines_to_process = 0;
+        int prime_tests = 0;
+        FILE *out, *in = stdin;
+        size_t i;
+        const char *errstr;
+
+        /* Parse options */
+        for (i = 0; i < nopts; i++) {
+                if (strncmp(opts[i], "lines=", 6) == 0) {
+                        lines_to_process = strtoul(opts[i]+6, NULL, 10);
+                } else if (strncmp(opts[i], "start-line=", 11) == 0) {
+                        start_lineno = strtoul(opts[i]+11, NULL, 10);
+                } else if (strncmp(opts[i], "checkpoint=", 11) == 0) {
+                        checkpoint = xstrdup(opts[i]+11);
+                } else if (strncmp(opts[i], "generator=", 10) == 0) {
+                        generator_wanted = (u_int32_t)strtonum(
+                            opts[i]+10, 1, UINT_MAX, &errstr);
+                        if (errstr != NULL) {
+                                fatal("Generator invalid: %s (%s)",
+                                    opts[i]+10, errstr);
+                        }
+                } else if (strncmp(opts[i], "prime-tests=", 12) == 0) {
+                        prime_tests = (int)strtonum(opts[i]+12, 1,
+                            INT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Invalid number: %s (%s)",
+                                        opts[i]+12, errstr);
+                        }
+                } else {
+                        fatal("Option \"%s\" is unsupported for moduli "
+                            "screening", opts[i]);
+                }
+        }
+
+        if (have_identity && strcmp(identity_file, "-") != 0) {
+                if ((in = fopen(identity_file, "r")) == NULL) {
+                        fatal("Couldn't open modulus candidate "
+                            "file \"%s\": %s", identity_file,
+                            strerror(errno));
+                }
+        }
+
+        if ((out = fopen(out_file, "a")) == NULL) {
+                fatal("Couldn't open moduli file \"%s\": %s",
+                    out_file, strerror(errno));
+        }
+        setvbuf(out, NULL, _IOLBF, 0);
+        if (prime_test(in, out, prime_tests == 0 ? 100 : prime_tests,
+            generator_wanted, checkpoint,
+            start_lineno, lines_to_process) != 0)
+                fatal("modulus screening failed");
+#else /* WITH_OPENSSL */
+        fatal("Moduli screening is not supported");
+#endif /* WITH_OPENSSL */
+}
+
+static void
 usage(void)
 {
         fprintf(stderr,
@@ -2783,9 +2896,8 @@ usage(void)
             "       ssh-keygen -R hostname [-f known_hosts_file]\n"
             "       ssh-keygen -r hostname [-g] [-f input_keyfile]\n"
 #ifdef WITH_OPENSSL
-            "       ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]\n"
-            "       ssh-keygen -f input_file -T output_file [-v] [-a rounds] [-J num_lines]\n"
-            "                  [-j start_line] [-K checkpt] [-W generator]\n"
+            "       ssh-keygen -M generate [-O option] output\n"
+            "       ssh-keygen -M screen [-f input_file] [-O option] [-a rounds] output_file\n"
 #endif
             "       ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]\n"
             "                  [-n principals] [-O option] [-V validity_interval]\n"
@@ -2819,6 +2931,7 @@ main(int argc, char **argv)
         int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
         int prefer_agent = 0, convert_to = 0, convert_from = 0;
         int print_public = 0, print_generic = 0, cert_serial_autoinc = 0;
+        int do_gen_candidates = 0, do_screen_candidates = 0;
         unsigned long long ull, cert_serial = 0;
         char *identity_comment = NULL, *ca_key_path = NULL, **opts = NULL;
         size_t i, nopts = 0;
@@ -2828,14 +2941,6 @@ main(int argc, char **argv)
         const char *errstr;
         int log_level = SYSLOG_LEVEL_INFO;
         char *sign_op = NULL;
-#ifdef WITH_OPENSSL
-        /* Moduli generation/screening */
-        char out_file[PATH_MAX], *checkpoint = NULL;
-        u_int32_t memory = 0, generator_wanted = 0;
-        int do_gen_candidates = 0, do_screen_candidates = 0;
-        unsigned long start_lineno = 0, lines_to_process = 0;
-        BIGNUM *start = NULL;
-#endif
 
         extern int optind;
         extern char *optarg;
@@ -2860,10 +2965,10 @@ main(int argc, char **argv)
 
         sk_provider = getenv("SSH_SK_PROVIDER");
 
-        /* Remaining character: d */
+        /* Remaining characters: dGjJKSTW */
         while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvy"
-            "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Y:Z:"
-            "a:b:f:g:j:m:n:r:s:t:w:x:z:")) != -1) {
+            "C:D:E:F:I:M:N:O:P:R:V:Y:Z:"
+            "a:b:f:g:m:n:r:s:t:w:x:z:")) != -1) {
                 switch (opt) {
                 case 'A':
                         gen_all_hostkeys = 1;
@@ -3053,50 +3158,14 @@ main(int argc, char **argv)
                             (errno == ERANGE && cert_serial == ULLONG_MAX))
                                 fatal("Invalid serial number \"%s\"", optarg);
                         break;
-#ifdef WITH_OPENSSL
-                /* Moduli generation/screening */
-                case 'G':
-                        do_gen_candidates = 1;
-                        if (strlcpy(out_file, optarg, sizeof(out_file)) >=
-                            sizeof(out_file))
-                                fatal("Output filename too long");
-                        break;
-                case 'J':
-                        lines_to_process = strtoul(optarg, NULL, 10);
-                        break;
-                case 'j':
-                        start_lineno = strtoul(optarg, NULL, 10);
-                        break;
-                case 'K':
-                        if (strlen(optarg) >= PATH_MAX)
-                                fatal("Checkpoint filename too long");
-                        checkpoint = xstrdup(optarg);
-                        break;
                 case 'M':
-                        memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX,
-                            &errstr);
-                        if (errstr)
-                                fatal("Memory limit is %s: %s", errstr, optarg);
-                        break;
-                case 'S':
-                        /* XXX - also compare length against bits */
-                        if (BN_hex2bn(&start, optarg) == 0)
-                                fatal("Invalid start point.");
-                        break;
-                case 'T':
-                        do_screen_candidates = 1;
-                        if (strlcpy(out_file, optarg, sizeof(out_file)) >=
-                            sizeof(out_file))
-                                fatal("Output filename too long");
-                        break;
-                case 'W':
-                        generator_wanted = (u_int32_t)strtonum(optarg, 1,
-                            UINT_MAX, &errstr);
-                        if (errstr != NULL)
-                                fatal("Desired generator invalid: %s (%s)",
-                                    optarg, errstr);
+                        if (strcmp(optarg, "generate") == 0)
+                                do_gen_candidates = 1;
+                        else if (strcmp(optarg, "screen") == 0)
+                                do_screen_candidates = 1;
+                        else
+                                fatal("Unsupported moduli option %s", optarg);
                         break;
-#endif /* WITH_OPENSSL */
                 case '?':
                 default:
                         usage();
@@ -3163,7 +3232,8 @@ main(int argc, char **argv)
                         error("Too few arguments.");
                         usage();
                 }
-        } else if (argc > 0 && !gen_krl && !check_krl) {
+        } else if (argc > 0 && !gen_krl && !check_krl &&
+            !do_gen_candidates && !do_screen_candidates) {
                 error("Too many arguments.");
                 usage();
         }
@@ -3176,13 +3246,21 @@ main(int argc, char **argv)
                 usage();
         }
         if (gen_krl) {
+#ifdef WITH_OPENSSL
                 do_gen_krl(pw, update_krl, ca_key_path,
                     cert_serial, identity_comment, argc, argv);
                 return (0);
+#else
+                fatal("KRL generation not supported");
+#endif
         }
         if (check_krl) {
+#ifdef WITH_OPENSSL
                 do_check_krl(pw, argc, argv);
                 return (0);
+#else
+                fatal("KRL checking not supported");
+#endif
         }
         if (ca_key_path != NULL) {
                 if (cert_key_id == NULL)
@@ -3249,47 +3327,20 @@ main(int argc, char **argv)
                 }
         }
 
-#ifdef WITH_OPENSSL
+        if (do_gen_candidates || do_screen_candidates) {
+                if (argc <= 0)
+                        fatal("No output file specified");
+                else if (argc > 1)
+                        fatal("Too many output files specified");
+        }
         if (do_gen_candidates) {
-                FILE *out = fopen(out_file, "w");
-
-                if (out == NULL) {
-                        error("Couldn't open modulus candidate file \"%s\": %s",
-                            out_file, strerror(errno));
-                        return (1);
-                }
-                if (bits == 0)
-                        bits = DEFAULT_BITS;
-                if (gen_candidates(out, memory, bits, start) != 0)
-                        fatal("modulus candidate generation failed");
-
-                return (0);
+                do_moduli_gen(argv[0], opts, nopts);
+                return 0;
         }
-
         if (do_screen_candidates) {
-                FILE *in;
-                FILE *out = fopen(out_file, "a");
-
-                if (have_identity && strcmp(identity_file, "-") != 0) {
-                        if ((in = fopen(identity_file, "r")) == NULL) {
-                                fatal("Couldn't open modulus candidate "
-                                    "file \"%s\": %s", identity_file,
-                                    strerror(errno));
-                        }
-                } else
-                        in = stdin;
-
-                if (out == NULL) {
-                        fatal("Couldn't open moduli file \"%s\": %s",
-                            out_file, strerror(errno));
-                }
-                if (prime_test(in, out, rounds == 0 ? 100 : rounds,
-                    generator_wanted, checkpoint,
-                    start_lineno, lines_to_process) != 0)
-                        fatal("modulus screening failed");
-                return (0);
+                do_moduli_screen(argv[0], opts, nopts);
+                return 0;
         }
-#endif
 
         if (gen_all_hostkeys) {
                 do_gen_all_hostkeys(pw);