/* * Author: Tatu Ylonen * Copyright (c) 1994 Tatu Ylonen , Espoo, Finland * All rights reserved * Identity and host key generation and maintenance. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ #include "includes.h" RCSID("$OpenBSD: ssh-keygen.c,v 1.48 2001/03/11 16:39:03 deraadt Exp $"); #include #include #include "xmalloc.h" #include "key.h" #include "authfile.h" #include "uuencode.h" #include "buffer.h" #include "bufaux.h" #include "pathnames.h" #include "log.h" #include "readpass.h" /* Number of bits in the RSA/DSA key. This value can be changed on the command line. */ int bits = 1024; /* * Flag indicating that we just want to change the passphrase. This can be * set on the command line. */ int change_passphrase = 0; /* * Flag indicating that we just want to change the comment. This can be set * on the command line. */ int change_comment = 0; int quiet = 0; /* Flag indicating that we just want to see the key fingerprint */ int print_fingerprint = 0; /* The identity file name, given on the command line or entered by the user. */ char identity_file[1024]; int have_identity = 0; /* This is set to the passphrase if given on the command line. */ char *identity_passphrase = NULL; /* This is set to the new passphrase if given on the command line. */ char *identity_new_passphrase = NULL; /* This is set to the new comment if given on the command line. */ char *identity_comment = NULL; /* Dump public key file in format used by real and the original SSH 2 */ int convert_to_ssh2 = 0; int convert_from_ssh2 = 0; int print_public = 0; int print_verbose = 0; /* default to RSA for SSH-1 */ char *key_type_name = "rsa1"; /* argv0 */ extern char *__progname; char hostname[MAXHOSTNAMELEN]; void ask_filename(struct passwd *pw, const char *prompt) { char buf[1024]; char *name = NULL; switch (key_type_from_name(key_type_name)) { case KEY_RSA1: name = _PATH_SSH_CLIENT_IDENTITY; break; case KEY_DSA: name = _PATH_SSH_CLIENT_ID_DSA; break; case KEY_RSA: name = _PATH_SSH_CLIENT_ID_RSA; break; default: fprintf(stderr, "bad key type"); exit(1); break; } snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name); fprintf(stderr, "%s (%s): ", prompt, identity_file); fflush(stderr); if (fgets(buf, sizeof(buf), stdin) == NULL) exit(1); if (strchr(buf, '\n')) *strchr(buf, '\n') = 0; if (strcmp(buf, "") != 0) strlcpy(identity_file, buf, sizeof(identity_file)); have_identity = 1; } int try_load_key(char *filename, Key *k) { int success = 1; if (!load_private_key(filename, "", k, NULL)) { char *pass = read_passphrase("Enter passphrase: ", 1); if (!load_private_key(filename, pass, k, NULL)) { success = 0; } memset(pass, 0, strlen(pass)); xfree(pass); } return success; } #define SSH_COM_PUBLIC_BEGIN "---- BEGIN SSH2 PUBLIC KEY ----" #define SSH_COM_PUBLIC_END "---- END SSH2 PUBLIC KEY ----" #define SSH_COM_PRIVATE_BEGIN "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----" #define SSH_COM_PRIVATE_KEY_MAGIC 0x3f6ff9eb void do_convert_to_ssh2(struct passwd *pw) { Key *k; int len; u_char *blob; struct stat st; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } k = key_new(KEY_UNSPEC); if (!try_load_key(identity_file, k)) { fprintf(stderr, "load failed\n"); exit(1); } key_to_blob(k, &blob, &len); fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN); fprintf(stdout, "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n", key_size(k), key_type(k), pw->pw_name, hostname); dump_base64(stdout, blob, len); fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END); key_free(k); xfree(blob); exit(0); } void buffer_get_bignum_bits(Buffer *b, BIGNUM *value) { int bits = buffer_get_int(b); int bytes = (bits + 7) / 8; if (buffer_len(b) < bytes) fatal("buffer_get_bignum_bits: input buffer too small"); BN_bin2bn((u_char *)buffer_ptr(b), bytes, value); buffer_consume(b, bytes); } Key * do_convert_private_ssh2_from_blob(char *blob, int blen) { Buffer b; DSA *dsa; Key *key = NULL; int ignore, magic, rlen; char *type, *cipher; buffer_init(&b); buffer_append(&b, blob, blen); magic = buffer_get_int(&b); if (magic != SSH_COM_PRIVATE_KEY_MAGIC) { error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC); buffer_free(&b); return NULL; } ignore = buffer_get_int(&b); type = buffer_get_string(&b, NULL); cipher = buffer_get_string(&b, NULL); ignore = buffer_get_int(&b); ignore = buffer_get_int(&b); ignore = buffer_get_int(&b); xfree(type); if (strcmp(cipher, "none") != 0) { error("unsupported cipher %s", cipher); xfree(cipher); buffer_free(&b); return NULL; } xfree(cipher); key = key_new(KEY_DSA); dsa = key->dsa; dsa->priv_key = BN_new(); if (dsa->priv_key == NULL) { error("alloc priv_key failed"); key_free(key); return NULL; } buffer_get_bignum_bits(&b, dsa->p); buffer_get_bignum_bits(&b, dsa->g); buffer_get_bignum_bits(&b, dsa->q); buffer_get_bignum_bits(&b, dsa->pub_key); buffer_get_bignum_bits(&b, dsa->priv_key); rlen = buffer_len(&b); if(rlen != 0) error("do_convert_private_ssh2_from_blob: remaining bytes in key blob %d", rlen); buffer_free(&b); return key; } void do_convert_from_ssh2(struct passwd *pw) { Key *k; int blen; char line[1024], *p; char blob[8096]; char encoded[8096]; struct stat st; int escaped = 0, private = 0, ok; FILE *fp; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } fp = fopen(identity_file, "r"); if (fp == NULL) { perror(identity_file); exit(1); } encoded[0] = '\0'; while (fgets(line, sizeof(line), fp)) { if (!(p = strchr(line, '\n'))) { fprintf(stderr, "input line too long.\n"); exit(1); } if (p > line && p[-1] == '\\') escaped++; if (strncmp(line, "----", 4) == 0 || strstr(line, ": ") != NULL) { if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL) private = 1; fprintf(stderr, "ignore: %s", line); continue; } if (escaped) { escaped--; fprintf(stderr, "escaped: %s", line); continue; } *p = '\0'; strlcat(encoded, line, sizeof(encoded)); } blen = uudecode(encoded, (u_char *)blob, sizeof(blob)); if (blen < 0) { fprintf(stderr, "uudecode failed.\n"); exit(1); } k = private ? do_convert_private_ssh2_from_blob(blob, blen) : key_from_blob(blob, blen); if (k == NULL) { fprintf(stderr, "decode blob failed.\n"); exit(1); } ok = private ? PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) : key_write(k, stdout); if (!ok) { fprintf(stderr, "key write failed"); exit(1); } key_free(k); fprintf(stdout, "\n"); fclose(fp); exit(0); } void do_print_public(struct passwd *pw) { Key *k; struct stat st; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } k = key_new(KEY_UNSPEC); if (!try_load_key(identity_file, k)) { fprintf(stderr, "load failed\n"); exit(1); } if (!key_write(k, stdout)) fprintf(stderr, "key_write failed"); key_free(k); fprintf(stdout, "\n"); exit(0); } void do_fingerprint(struct passwd *pw) { FILE *f; Key *public; char *comment = NULL, *cp, *ep, line[16*1024]; int i, skip = 0, num = 1, invalid = 1, success = 0; struct stat st; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } public = key_new(KEY_RSA1); if (load_public_key(identity_file, public, &comment)) { success = 1; } else { key_free(public); public = key_new(KEY_UNSPEC); if (try_load_public_key(identity_file, public, &comment)) success = 1; else debug("try_load_public_key KEY_UNSPEC failed"); } if (success) { char *digest_md5, *digest_bubblebabble; digest_md5 = key_fingerprint_ex(public, SSH_FP_MD5, SSH_FP_HEX); digest_bubblebabble = key_fingerprint_ex(public, SSH_FP_SHA1, SSH_FP_BUBBLEBABBLE); if (print_verbose) { printf("comment: %s\n", comment); printf("size: %d\n", key_size(public)); printf("md5: %s\n", digest_md5); printf("bubblebabble: %s\n", digest_bubblebabble); } else { printf("%d %s %s\n", key_size(public), digest_md5, comment); } key_free(public); xfree(comment); xfree(digest_md5); xfree(digest_bubblebabble); exit(0); } f = fopen(identity_file, "r"); if (f != NULL) { while (fgets(line, sizeof(line), f)) { i = strlen(line) - 1; if (line[i] != '\n') { error("line %d too long: %.40s...", num, line); skip = 1; continue; } num++; if (skip) { skip = 0; continue; } line[i] = '\0'; /* Skip leading whitespace, empty and comment lines. */ for (cp = line; *cp == ' ' || *cp == '\t'; cp++) ; if (!*cp || *cp == '\n' || *cp == '#') continue ; i = strtol(cp, &ep, 10); if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) { int quoted = 0; comment = cp; for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { if (*cp == '\\' && cp[1] == '"') cp++; /* Skip both */ else if (*cp == '"') quoted = !quoted; } if (!*cp) continue; *cp++ = '\0'; } ep = cp; public = key_new(KEY_RSA1); if (key_read(public, &cp) != 1) { cp = ep; key_free(public); public = key_new(KEY_UNSPEC); if (key_read(public, &cp) != 1) { key_free(public); continue; } } comment = *cp ? cp : comment; printf("%d %s %s\n", key_size(public), key_fingerprint(public), comment ? comment : "no comment"); invalid = 0; } fclose(f); } key_free(public); if (invalid) { printf("%s is not a valid key file.\n", identity_file); exit(1); } exit(0); } /* * Perform changing a passphrase. The argument is the passwd structure * for the current user. */ void do_change_passphrase(struct passwd *pw) { char *comment; char *old_passphrase, *passphrase1, *passphrase2; struct stat st; Key *private; Key *public; int type = KEY_RSA1; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } public = key_new(type); if (!load_public_key(identity_file, public, NULL)) { type = KEY_UNSPEC; } else { /* Clear the public key since we are just about to load the whole file. */ key_free(public); } /* Try to load the file with empty passphrase. */ private = key_new(type); if (!load_private_key(identity_file, "", private, &comment)) { if (identity_passphrase) old_passphrase = xstrdup(identity_passphrase); else old_passphrase = read_passphrase("Enter old passphrase: ", 1); if (!load_private_key(identity_file, old_passphrase, private, &comment)) { memset(old_passphrase, 0, strlen(old_passphrase)); xfree(old_passphrase); printf("Bad passphrase.\n"); exit(1); } memset(old_passphrase, 0, strlen(old_passphrase)); xfree(old_passphrase); } printf("Key has comment '%s'\n", comment); /* Ask the new passphrase (twice). */ if (identity_new_passphrase) { passphrase1 = xstrdup(identity_new_passphrase); passphrase2 = NULL; } else { passphrase1 = read_passphrase("Enter new passphrase (empty for no passphrase): ", 1); passphrase2 = read_passphrase("Enter same passphrase again: ", 1); /* Verify that they are the same. */ if (strcmp(passphrase1, passphrase2) != 0) { memset(passphrase1, 0, strlen(passphrase1)); memset(passphrase2, 0, strlen(passphrase2)); xfree(passphrase1); xfree(passphrase2); printf("Pass phrases do not match. Try again.\n"); exit(1); } /* Destroy the other copy. */ memset(passphrase2, 0, strlen(passphrase2)); xfree(passphrase2); } /* Save the file using the new passphrase. */ if (!save_private_key(identity_file, passphrase1, private, comment)) { printf("Saving the key failed: %s: %s.\n", identity_file, strerror(errno)); memset(passphrase1, 0, strlen(passphrase1)); xfree(passphrase1); key_free(private); xfree(comment); exit(1); } /* Destroy the passphrase and the copy of the key in memory. */ memset(passphrase1, 0, strlen(passphrase1)); xfree(passphrase1); key_free(private); /* Destroys contents */ xfree(comment); printf("Your identification has been saved with the new passphrase.\n"); exit(0); } /* * Change the comment of a private key file. */ void do_change_comment(struct passwd *pw) { char new_comment[1024], *comment, *passphrase; Key *private, *public; struct stat st; FILE *f; int fd; if (!have_identity) ask_filename(pw, "Enter file in which the key is"); if (stat(identity_file, &st) < 0) { perror(identity_file); exit(1); } /* * Try to load the public key from the file the verify that it is * readable and of the proper format. */ public = key_new(KEY_RSA1); if (!load_public_key(identity_file, public, NULL)) { printf("%s is not a valid key file.\n", identity_file); printf("Comments are only supported in RSA1 keys\n"); exit(1); } private = key_new(KEY_RSA1); if (load_private_key(identity_file, "", private, &comment)) passphrase = xstrdup(""); else { if (identity_passphrase) passphrase = xstrdup(identity_passphrase); else if (identity_new_passphrase) passphrase = xstrdup(identity_new_passphrase); else passphrase = read_passphrase("Enter passphrase: ", 1); /* Try to load using the passphrase. */ if (!load_private_key(identity_file, passphrase, private, &comment)) { memset(passphrase, 0, strlen(passphrase)); xfree(passphrase); printf("Bad passphrase.\n"); exit(1); } } printf("Key now has comment '%s'\n", comment); if (identity_comment) { strlcpy(new_comment, identity_comment, sizeof(new_comment)); } else { printf("Enter new comment: "); fflush(stdout); if (!fgets(new_comment, sizeof(new_comment), stdin)) { memset(passphrase, 0, strlen(passphrase)); key_free(private); exit(1); } if (strchr(new_comment, '\n')) *strchr(new_comment, '\n') = 0; } /* Save the file using the new passphrase. */ if (!save_private_key(identity_file, passphrase, private, new_comment)) { printf("Saving the key failed: %s: %s.\n", identity_file, strerror(errno)); memset(passphrase, 0, strlen(passphrase)); xfree(passphrase); key_free(private); xfree(comment); exit(1); } memset(passphrase, 0, strlen(passphrase)); xfree(passphrase); key_free(private); strlcat(identity_file, ".pub", sizeof(identity_file)); fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644); if (fd == -1) { printf("Could not save your public key in %s\n", identity_file); exit(1); } f = fdopen(fd, "w"); if (f == NULL) { printf("fdopen %s failed", identity_file); exit(1); } if (!key_write(public, f)) fprintf(stderr, "write key failed"); key_free(public); fprintf(f, " %s\n", new_comment); fclose(f); xfree(comment); printf("The comment in your key file has been changed.\n"); exit(0); } void usage(void) { printf("Usage: %s [-lpqxXyc] [-t type] [-b bits] [-f file] [-C comment] " "[-N new-pass] [-P pass]\n", __progname); exit(1); } /* * Main program for key management. */ int main(int ac, char **av) { char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2; Key *private, *public; struct passwd *pw; int opt, type, fd; struct stat st; FILE *f; extern int optind; extern char *optarg; SSLeay_add_all_algorithms(); /* we need this for the home * directory. */ pw = getpwuid(getuid()); if (!pw) { printf("You don't exist, go away!\n"); exit(1); } if (gethostname(hostname, sizeof(hostname)) < 0) { perror("gethostname"); exit(1); } while ((opt = getopt(ac, av, "dqpclRxXyvb:f:t:P:N:C:")) != -1) { switch (opt) { case 'b': bits = atoi(optarg); if (bits < 512 || bits > 32768) { printf("Bits has bad value.\n"); exit(1); } break; case 'l': print_fingerprint = 1; break; case 'p': change_passphrase = 1; break; case 'c': change_comment = 1; break; case 'f': strlcpy(identity_file, optarg, sizeof(identity_file)); have_identity = 1; break; case 'P': identity_passphrase = optarg; break; case 'N': identity_new_passphrase = optarg; break; case 'C': identity_comment = optarg; break; case 'q': quiet = 1; break; case 'R': /* unused */ exit(0); break; case 'x': convert_to_ssh2 = 1; break; case 'X': convert_from_ssh2 = 1; break; case 'y': print_public = 1; break; case 'v': print_verbose = 1; break; case 'd': key_type_name = "dsa"; break; case 't': key_type_name = optarg; break; case '?': default: usage(); } } if (optind < ac) { printf("Too many arguments.\n"); usage(); } if (change_passphrase && change_comment) { printf("Can only have one of -p and -c.\n"); usage(); } if (print_fingerprint) do_fingerprint(pw); if (change_passphrase) do_change_passphrase(pw); if (change_comment) do_change_comment(pw); if (convert_to_ssh2) do_convert_to_ssh2(pw); if (convert_from_ssh2) do_convert_from_ssh2(pw); if (print_public) do_print_public(pw); arc4random_stir(); type = key_type_from_name(key_type_name); if (type == KEY_UNSPEC) { fprintf(stderr, "unknown key type %s\n", key_type_name); exit(1); } if (!quiet) printf("Generating public/private %s key pair.\n", key_type_name); private = key_generate(type, bits); if (private == NULL) { fprintf(stderr, "key_generate failed"); exit(1); } public = key_from_private(private); if (!have_identity) ask_filename(pw, "Enter file in which to save the key"); /* Create ~/.ssh directory if it doesn\'t already exist. */ snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR); if (strstr(identity_file, dotsshdir) != NULL && stat(dotsshdir, &st) < 0) { if (mkdir(dotsshdir, 0700) < 0) error("Could not create directory '%s'.", dotsshdir); else if (!quiet) printf("Created directory '%s'.\n", dotsshdir); } /* If the file already exists, ask the user to confirm. */ if (stat(identity_file, &st) >= 0) { char yesno[3]; printf("%s already exists.\n", identity_file); printf("Overwrite (y/n)? "); fflush(stdout); if (fgets(yesno, sizeof(yesno), stdin) == NULL) exit(1); if (yesno[0] != 'y' && yesno[0] != 'Y') exit(1); } /* Ask for a passphrase (twice). */ if (identity_passphrase) passphrase1 = xstrdup(identity_passphrase); else if (identity_new_passphrase) passphrase1 = xstrdup(identity_new_passphrase); else { passphrase_again: passphrase1 = read_passphrase("Enter passphrase (empty for no passphrase): ", 1); passphrase2 = read_passphrase("Enter same passphrase again: ", 1); if (strcmp(passphrase1, passphrase2) != 0) { /* The passphrases do not match. Clear them and retry. */ memset(passphrase1, 0, strlen(passphrase1)); memset(passphrase2, 0, strlen(passphrase2)); xfree(passphrase1); xfree(passphrase2); printf("Passphrases do not match. Try again.\n"); goto passphrase_again; } /* Clear the other copy of the passphrase. */ memset(passphrase2, 0, strlen(passphrase2)); xfree(passphrase2); } if (identity_comment) { strlcpy(comment, identity_comment, sizeof(comment)); } else { /* Create default commend field for the passphrase. */ snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname); } /* Save the key with the given passphrase and comment. */ if (!save_private_key(identity_file, passphrase1, private, comment)) { printf("Saving the key failed: %s: %s.\n", identity_file, strerror(errno)); memset(passphrase1, 0, strlen(passphrase1)); xfree(passphrase1); exit(1); } /* Clear the passphrase. */ memset(passphrase1, 0, strlen(passphrase1)); xfree(passphrase1); /* Clear the private key and the random number generator. */ key_free(private); arc4random_stir(); if (!quiet) printf("Your identification has been saved in %s.\n", identity_file); strlcat(identity_file, ".pub", sizeof(identity_file)); fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644); if (fd == -1) { printf("Could not save your public key in %s\n", identity_file); exit(1); } f = fdopen(fd, "w"); if (f == NULL) { printf("fdopen %s failed", identity_file); exit(1); } if (!key_write(public, f)) fprintf(stderr, "write key failed"); fprintf(f, " %s\n", comment); fclose(f); if (!quiet) { printf("Your public key has been saved in %s.\n", identity_file); printf("The key fingerprint is:\n"); printf("%s %s\n", key_fingerprint(public), comment); } key_free(public); exit(0); }