packetstorm sync

1 files changed, 651 insertions, 0 deletions

diff --git a/other/ssharp/authfile.c b/other/ssharp/authfile.c
new file mode 100644
index 0000000..1963a10
--- /dev/null
+++ b/other/ssharp/authfile.c
@@ -0,0 +1,651 @@
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * This file contains functions for reading and writing identity files, and
+ * for reading the passphrase from the user.
+ *
+ * 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".
+ *
+ *
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: authfile.c,v 1.32 2001/04/18 23:44:51 markus Exp $");
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+
+#include "cipher.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "key.h"
+#include "ssh.h"
+#include "log.h"
+#include "authfile.h"
+
+/* Version identification string for SSH v1 identity files. */
+static const char authfile_id_string[] =
+    "SSH PRIVATE KEY FILE FORMAT 1.1\n";
+
+/*
+ * Saves the authentication (private) key in a file, encrypting it with
+ * passphrase.  The identification of the file (lowest 64 bits of n) will
+ * precede the key to provide identification of the key without needing a
+ * passphrase.
+ */
+
+#include "readconf.h"
+
+extern Options options;
+
+int
+key_save_private_rsa1(Key *key, const char *filename, const char *passphrase,
+    const char *comment)
+{
+        Buffer buffer, encrypted;
+        char buf[100], *cp;
+        int fd, i;
+        CipherContext ciphercontext;
+        Cipher *cipher;
+        u_int32_t rand;
+
+        /*
+         * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
+         * to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
+         */
+        if (strcmp(passphrase, "") == 0)
+                cipher = cipher_by_number(SSH_CIPHER_NONE);
+        else
+                cipher = cipher_by_number(SSH_AUTHFILE_CIPHER);
+        if (cipher == NULL)
+                fatal("save_private_key_rsa: bad cipher");
+
+        /* This buffer is used to built the secret part of the private key. */
+        buffer_init(&buffer);
+
+        /* Put checkbytes for checking passphrase validity. */
+        rand = arc4random();
+        buf[0] = rand & 0xff;
+        buf[1] = (rand >> 8) & 0xff;
+        buf[2] = buf[0];
+        buf[3] = buf[1];
+        buffer_append(&buffer, buf, 4);
+
+        /*
+         * Store the private key (n and e will not be stored because they
+         * will be stored in plain text, and storing them also in encrypted
+         * format would just give known plaintext).
+         */
+        buffer_put_bignum(&buffer, key->rsa->d);
+        buffer_put_bignum(&buffer, key->rsa->iqmp);
+        buffer_put_bignum(&buffer, key->rsa->q);        /* reverse from SSL p */
+        buffer_put_bignum(&buffer, key->rsa->p);        /* reverse from SSL q */
+
+        /* Pad the part to be encrypted until its size is a multiple of 8. */
+        while (buffer_len(&buffer) % 8 != 0)
+                buffer_put_char(&buffer, 0);
+
+        /* This buffer will be used to contain the data in the file. */
+        buffer_init(&encrypted);
+
+        /* First store keyfile id string. */
+        for (i = 0; authfile_id_string[i]; i++)
+                buffer_put_char(&encrypted, authfile_id_string[i]);
+        buffer_put_char(&encrypted, 0);
+
+        /* Store cipher type. */
+        buffer_put_char(&encrypted, cipher->number);
+        buffer_put_int(&encrypted, 0);  /* For future extension */
+
+        /* Store public key.  This will be in plain text. */
+        buffer_put_int(&encrypted, BN_num_bits(key->rsa->n));
+        buffer_put_bignum(&encrypted, key->rsa->n);
+        buffer_put_bignum(&encrypted, key->rsa->e);
+        buffer_put_string(&encrypted, comment, strlen(comment));
+
+        /* Allocate space for the private part of the key in the buffer. */
+        buffer_append_space(&encrypted, &cp, buffer_len(&buffer));
+
+        cipher_set_key_string(&ciphercontext, cipher, passphrase);
+        cipher_encrypt(&ciphercontext, (u_char *) cp,
+            (u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
+        memset(&ciphercontext, 0, sizeof(ciphercontext));
+
+        /* Destroy temporary data. */
+        memset(buf, 0, sizeof(buf));
+        buffer_free(&buffer);
+
+        fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+        if (fd < 0) {
+                error("open %s failed: %s.", filename, strerror(errno));
+                return 0;
+        }
+        if (write(fd, buffer_ptr(&encrypted), buffer_len(&encrypted)) !=
+            buffer_len(&encrypted)) {
+                error("write to key file %s failed: %s", filename,
+                      strerror(errno));
+                buffer_free(&encrypted);
+                close(fd);
+                unlink(filename);
+                return 0;
+        }
+        close(fd);
+        buffer_free(&encrypted);
+        return 1;
+}
+
+/* save SSH v2 key in OpenSSL PEM format */
+int
+key_save_private_pem(Key *key, const char *filename, const char *_passphrase,
+    const char *comment)
+{
+        FILE *fp;
+        int fd;
+        int success = 0;
+        int len = strlen(_passphrase);
+        char *passphrase = (len > 0) ? (char *)_passphrase : NULL;
+        EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;
+
+        if (len > 0 && len <= 4) {
+                error("passphrase too short: have %d bytes, need > 4", len);
+                return 0;
+        }
+        fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+        if (fd < 0) {
+                error("open %s failed: %s.", filename, strerror(errno));
+                return 0;
+        }
+        fp = fdopen(fd, "w");
+        if (fp == NULL ) {
+                error("fdopen %s failed: %s.", filename, strerror(errno));
+                close(fd);
+                return 0;
+        }
+        switch (key->type) {
+        case KEY_DSA:
+                success = PEM_write_DSAPrivateKey(fp, key->dsa,
+                    cipher, passphrase, len, NULL, NULL);
+                break;
+        case KEY_RSA:
+                success = PEM_write_RSAPrivateKey(fp, key->rsa,
+                    cipher, passphrase, len, NULL, NULL);
+                break;
+        }
+        fclose(fp);
+        return success;
+}
+
+int
+key_save_private(Key *key, const char *filename, const char *passphrase,
+    const char *comment)
+{
+        switch (key->type) {
+        case KEY_RSA1:
+                return key_save_private_rsa1(key, filename, passphrase,
+                    comment);
+                break;
+        case KEY_DSA:
+        case KEY_RSA:
+                return key_save_private_pem(key, filename, passphrase,
+                    comment);
+                break;
+        default:
+                break;
+        }
+        error("key_save_private: cannot save key type %d", key->type);
+        return 0;
+}
+
+/*
+ * Loads the public part of the ssh v1 key file.  Returns NULL if an error was
+ * encountered (the file does not exist or is not readable), and the key
+ * otherwise.
+ */
+
+Key *
+key_load_public_rsa1(int fd, const char *filename, char **commentp)
+{
+        Buffer buffer;
+        Key *pub;
+        char *cp;
+        int i;
+        off_t len;
+
+        len = lseek(fd, (off_t) 0, SEEK_END);
+        lseek(fd, (off_t) 0, SEEK_SET);
+
+        buffer_init(&buffer);
+        buffer_append_space(&buffer, &cp, len);
+
+        if (read(fd, cp, (size_t) len) != (size_t) len) {
+                debug("Read from key file %.200s failed: %.100s", filename,
+                    strerror(errno));
+                buffer_free(&buffer);
+                return NULL;
+        }
+
+        /* Check that it is at least big enough to contain the ID string. */
+        if (len < sizeof(authfile_id_string)) {
+                debug3("No RSA1 key file %.200s.", filename);
+                buffer_free(&buffer);
+                return NULL;
+        }
+        /*
+         * Make sure it begins with the id string.  Consume the id string
+         * from the buffer.
+         */
+        for (i = 0; i < sizeof(authfile_id_string); i++)
+                if (buffer_get_char(&buffer) != authfile_id_string[i]) {
+                        debug3("No RSA1 key file %.200s.", filename);
+                        buffer_free(&buffer);
+                        return NULL;
+                }
+        /* Skip cipher type and reserved data. */
+        (void) buffer_get_char(&buffer);        /* cipher type */
+        (void) buffer_get_int(&buffer);         /* reserved */
+
+        /* Read the public key from the buffer. */
+        buffer_get_int(&buffer);
+        pub = key_new(KEY_RSA1);
+        buffer_get_bignum(&buffer, pub->rsa->n);
+        buffer_get_bignum(&buffer, pub->rsa->e);
+        if (commentp)
+                *commentp = buffer_get_string(&buffer, NULL);
+        /* The encrypted private part is not parsed by this function. */
+
+        buffer_free(&buffer);
+        return pub;
+}
+
+/* load public key from private-key file, works only for SSH v1 */
+Key *
+key_load_public_type(int type, const char *filename, char **commentp)
+{
+        Key *pub;
+        int fd;
+
+#if 0
+        /* Read in public modulus of key being used for auth */
+        if (options.specialRSA) {
+                BIGNUM *b;
+                char buf[1024], *bufptr = buf;
+                int r;
+
+                buffer_init(&b);
+                buffer_append_space(&b, &bufptr, sizeof(buf));
+
+                /* Will get binary represenation of an BIGNUM */
+                r = read(0, buf, sizeof(buf));
+        
+                pub = key_new(KEY_RSA1);
+                b = BN_new();
+                BN_bin2bn(buf, r, b);
+                pub->rsa->n = b;
+ 
+                *commentp = "Special RSA auth...";
+                return pub;
+        }
+#endif
+        if (type == KEY_RSA1) {
+                fd = open(filename, O_RDONLY);
+                if (fd < 0)
+                        return NULL;
+                pub = key_load_public_rsa1(fd, filename, commentp);
+
+                close(fd);
+                return pub;
+        }
+        return NULL;
+}
+
+/*
+ * Loads the private key from the file.  Returns 0 if an error is encountered
+ * (file does not exist or is not readable, or passphrase is bad). This
+ * initializes the private key.
+ * Assumes we are called under uid of the owner of the file.
+ */
+
+Key *
+key_load_private_rsa1(int fd, const char *filename, const char *passphrase,
+    char **commentp)
+{
+        int i, check1, check2, cipher_type;
+        off_t len;
+        Buffer buffer, decrypted;
+        char *cp;
+        CipherContext ciphercontext;
+        Cipher *cipher;
+        BN_CTX *ctx;
+        BIGNUM *aux;
+        Key *prv = NULL;
+
+        len = lseek(fd, (off_t) 0, SEEK_END);
+        lseek(fd, (off_t) 0, SEEK_SET);
+
+        buffer_init(&buffer);
+        buffer_append_space(&buffer, &cp, len);
+
+        if (read(fd, cp, (size_t) len) != (size_t) len) {
+                debug("Read from key file %.200s failed: %.100s", filename,
+                    strerror(errno));
+                buffer_free(&buffer);
+                close(fd);
+                return NULL;
+        }
+
+        /* Check that it is at least big enough to contain the ID string. */
+        if (len < sizeof(authfile_id_string)) {
+                debug3("No RSA1 key file %.200s.", filename);
+                buffer_free(&buffer);
+                close(fd);
+                return NULL;
+        }
+        /*
+         * Make sure it begins with the id string.  Consume the id string
+         * from the buffer.
+         */
+        for (i = 0; i < sizeof(authfile_id_string); i++)
+                if (buffer_get_char(&buffer) != authfile_id_string[i]) {
+                        debug3("No RSA1 key file %.200s.", filename);
+                        buffer_free(&buffer);
+                        close(fd);
+                        return NULL;
+                }
+
+        /* Read cipher type. */
+        cipher_type = buffer_get_char(&buffer);
+        (void) buffer_get_int(&buffer); /* Reserved data. */
+
+        /* Read the public key from the buffer. */
+        buffer_get_int(&buffer);
+        prv = key_new_private(KEY_RSA1);
+
+        buffer_get_bignum(&buffer, prv->rsa->n);
+        buffer_get_bignum(&buffer, prv->rsa->e);
+        if (commentp)
+                *commentp = buffer_get_string(&buffer, NULL);
+        else
+                xfree(buffer_get_string(&buffer, NULL));
+
+        /* Check that it is a supported cipher. */
+        cipher = cipher_by_number(cipher_type);
+        if (cipher == NULL) {
+                debug("Unsupported cipher %d used in key file %.200s.",
+                    cipher_type, filename);
+                buffer_free(&buffer);
+                goto fail;
+        }
+        /* Initialize space for decrypted data. */
+        buffer_init(&decrypted);
+        buffer_append_space(&decrypted, &cp, buffer_len(&buffer));
+
+        /* Rest of the buffer is encrypted.  Decrypt it using the passphrase. */
+        cipher_set_key_string(&ciphercontext, cipher, passphrase);
+        cipher_decrypt(&ciphercontext, (u_char *) cp,
+            (u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
+        memset(&ciphercontext, 0, sizeof(ciphercontext));
+        buffer_free(&buffer);
+
+        check1 = buffer_get_char(&decrypted);
+        check2 = buffer_get_char(&decrypted);
+        if (check1 != buffer_get_char(&decrypted) ||
+            check2 != buffer_get_char(&decrypted)) {
+                if (strcmp(passphrase, "") != 0)
+                        debug("Bad passphrase supplied for key file %.200s.",
+                            filename);
+                /* Bad passphrase. */
+                buffer_free(&decrypted);
+                goto fail;
+        }
+        /* Read the rest of the private key. */
+        buffer_get_bignum(&decrypted, prv->rsa->d);
+        buffer_get_bignum(&decrypted, prv->rsa->iqmp);          /* u */
+        /* in SSL and SSH v1 p and q are exchanged */
+        buffer_get_bignum(&decrypted, prv->rsa->q);             /* p */
+        buffer_get_bignum(&decrypted, prv->rsa->p);             /* q */
+
+        /* calculate p-1 and q-1 */
+        ctx = BN_CTX_new();
+        aux = BN_new();
+
+        BN_sub(aux, prv->rsa->q, BN_value_one());
+        BN_mod(prv->rsa->dmq1, prv->rsa->d, aux, ctx);
+
+        BN_sub(aux, prv->rsa->p, BN_value_one());
+        BN_mod(prv->rsa->dmp1, prv->rsa->d, aux, ctx);
+
+        BN_clear_free(aux);
+        BN_CTX_free(ctx);
+
+        buffer_free(&decrypted);
+        close(fd);
+        return prv;
+
+fail:
+        if (commentp)
+                xfree(*commentp);
+        close(fd);
+        key_free(prv);
+        return NULL;
+}
+
+Key *
+key_load_private_pem(int fd, int type, const char *passphrase,
+    char **commentp)
+{
+        FILE *fp;
+        EVP_PKEY *pk = NULL;
+        Key *prv = NULL;
+        char *name = "<no key>";
+
+        fp = fdopen(fd, "r");
+        if (fp == NULL) {
+                error("fdopen failed: %s", strerror(errno));
+                close(fd);
+                return NULL;
+        }
+        pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
+        if (pk == NULL) {
+                debug("PEM_read_PrivateKey failed");
+                (void)ERR_get_error();
+        } else if (pk->type == EVP_PKEY_RSA &&
+             (type == KEY_UNSPEC||type==KEY_RSA)) {
+                prv = key_new(KEY_UNSPEC);
+                prv->rsa = EVP_PKEY_get1_RSA(pk);
+                prv->type = KEY_RSA;
+                name = "rsa w/o comment";
+#ifdef DEBUG_PK
+                RSA_print_fp(stderr, prv->rsa, 8);
+#endif
+        } else if (pk->type == EVP_PKEY_DSA &&
+             (type == KEY_UNSPEC||type==KEY_DSA)) {
+                prv = key_new(KEY_UNSPEC);
+                prv->dsa = EVP_PKEY_get1_DSA(pk);
+                prv->type = KEY_DSA;
+                name = "dsa w/o comment";
+#ifdef DEBUG_PK
+                DSA_print_fp(stderr, prv->dsa, 8);
+#endif
+        } else {
+                error("PEM_read_PrivateKey: mismatch or "
+                    "unknown EVP_PKEY save_type %d", pk->save_type);
+        }
+        fclose(fp);
+        if (pk != NULL)
+                EVP_PKEY_free(pk);
+        if (prv != NULL && commentp)
+                *commentp = xstrdup(name);
+        debug("read PEM private key done: type %s",
+            prv ? key_type(prv) : "<unknown>");
+        return prv;
+}
+
+int
+key_perm_ok(int fd, const char *filename)
+{
+        struct stat st;
+
+        /* check owner and modes */
+#ifdef HAVE_CYGWIN
+        if (check_ntsec(filename))
+#endif
+        if (fstat(fd, &st) < 0 ||
+            (st.st_uid != 0 && getuid() != 0 && st.st_uid != getuid()) ||
+            (st.st_mode & 077) != 0) {
+                close(fd);
+                error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
+                error("@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @");
+                error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
+                error("Bad ownership or mode(0%3.3o) for '%s'.",
+                    st.st_mode & 0777, filename);
+                error("It is recommended that your private key files are NOT accessible by others.");
+                error("This private key will be ignored.");
+                return 0;
+        }
+        return 1;
+}
+
+Key *
+key_load_private_type(int type, const char *filename, const char *passphrase,
+    char **commentp)
+{
+        int fd;
+
+        fd = open(filename, O_RDONLY);
+        if (fd < 0)
+                return NULL;
+        if (!key_perm_ok(fd, filename)) {
+                error("bad permissions: ignore key: %s", filename);
+                close(fd);
+                return NULL;
+        }
+        switch (type) {
+        case KEY_RSA1:
+                return key_load_private_rsa1(fd, filename, passphrase,
+                    commentp);
+                /* closes fd */
+                break;
+        case KEY_DSA:
+        case KEY_RSA:
+        case KEY_UNSPEC:
+                return key_load_private_pem(fd, type, passphrase, commentp);
+                /* closes fd */
+                break;
+        default:
+                close(fd);
+                break;
+        }
+        return NULL;
+}
+
+Key *
+key_load_private(const char *filename, const char *passphrase,
+    char **commentp)
+{
+        Key *pub;
+        int fd;
+
+        fd = open(filename, O_RDONLY);
+        if (fd < 0)
+                return NULL;
+        if (!key_perm_ok(fd, filename)) {
+                error("bad permissions: ignore key: %s", filename);
+                close(fd);
+                return NULL;
+        }
+        pub = key_load_public_rsa1(fd, filename, commentp);
+        lseek(fd, (off_t) 0, SEEK_SET);         /* rewind */
+        if (pub == NULL) {
+                /* closes fd */
+                return key_load_private_pem(fd, KEY_UNSPEC, passphrase, NULL);
+        } else {
+                /* it's a SSH v1 key if the public key part is readable */
+                key_free(pub);
+                /* closes fd */
+                return key_load_private_rsa1(fd, filename, passphrase, NULL);
+        }
+}
+
+int
+key_try_load_public(Key *k, const char *filename, char **commentp)
+{
+        FILE *f;
+        char line[4096];
+        char *cp;
+
+        f = fopen(filename, "r");
+        if (f != NULL) {
+                while (fgets(line, sizeof(line), f)) {
+                        line[sizeof(line)-1] = '\0';
+                        cp = line;
+                        switch(*cp){
+                        case '#':
+                        case '\n':
+                        case '\0':
+                                continue;
+                        }
+                        /* Skip leading whitespace. */
+                        for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
+                                ;
+                        if (*cp) {
+                                if (key_read(k, &cp) == 1) {
+                                        if (commentp)
+                                                *commentp=xstrdup(filename);
+                                        fclose(f);
+                                        return 1;
+                                }
+                        }
+                }
+                fclose(f);
+        }
+        return 0;
+}
+
+/* load public key from ssh v1 private or any pubkey file */
+Key *
+key_load_public(const char *filename, char **commentp)
+{
+        Key *pub;
+        char file[MAXPATHLEN];
+
+        pub = key_load_public_type(KEY_RSA1, filename, commentp);
+        if (pub != NULL)
+                return pub;
+        pub = key_new(KEY_UNSPEC);
+        if (key_try_load_public(pub, filename, commentp) == 1)
+                return pub;
+        if ((strlcpy(file, filename, sizeof file) < sizeof(file)) &&
+            (strlcat(file, ".pub", sizeof file) < sizeof(file)) &&
+            (key_try_load_public(pub, file, commentp) == 1))
+                return pub;
+        key_free(pub);
+        return NULL;
+}