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authorMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
committerMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
commit674a60748884dc55ee7091b7c23a41240e75f73c (patch)
tree3b5a173c356f867b94df3873b57ff36d33129ea7 /signkey.c
Makefile.in contains updated files required
--HG-- extra : convert_revision : cc8a8c49dc70e632c352853a39801089b08149be
Diffstat (limited to 'signkey.c')
-rw-r--r--signkey.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/signkey.c b/signkey.c
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+++ b/signkey.c
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+/*
+ * Dropbear - a SSH2 server
+ *
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "dbutil.h"
+#include "signkey.h"
+#include "buffer.h"
+#include "ssh.h"
+
+/* malloc a new sign_key and set the dss and rsa keys to NULL */
+sign_key * new_sign_key() {
+
+ sign_key * ret;
+
+ ret = (sign_key*)m_malloc(sizeof(sign_key));
+#ifdef DROPBEAR_DSS
+ ret->dsskey = NULL;
+#endif
+#ifdef DROPBEAR_RSA
+ ret->rsakey = NULL;
+#endif
+ return ret;
+
+}
+
+/* returns DROPBEAR_SUCCESS on success, DROPBEAR_FAILURE on fail.
+ * type is set to hold the type returned */
+int buf_get_pub_key(buffer *buf, sign_key *key, int *type) {
+
+ unsigned char* ident;
+ unsigned int len;
+
+ ident = buf_getstring(buf, &len);
+
+#ifdef DROPBEAR_DSS
+ if (memcmp(ident, SSH_SIGNKEY_DSS, len) == 0
+ && (*type == DROPBEAR_SIGNKEY_ANY
+ || *type == DROPBEAR_SIGNKEY_DSS)) {
+ m_free(ident);
+ buf_setpos(buf, buf->pos - len - 4);
+ dss_key_free(key->dsskey);
+ key->dsskey = (dss_key*)m_malloc(sizeof(dss_key));
+ *type = DROPBEAR_SIGNKEY_DSS;
+ return buf_get_dss_pub_key(buf, key->dsskey);
+ }
+#endif
+#ifdef DROPBEAR_RSA
+ if (memcmp(ident, SSH_SIGNKEY_RSA, len) == 0
+ && (*type == DROPBEAR_SIGNKEY_ANY
+ || *type == DROPBEAR_SIGNKEY_RSA)) {
+ m_free(ident);
+ buf_setpos(buf, buf->pos - len - 4);
+ rsa_key_free(key->rsakey);
+ key->rsakey = (rsa_key*)m_malloc(sizeof(rsa_key));
+ *type = DROPBEAR_SIGNKEY_RSA;
+ return buf_get_rsa_pub_key(buf, key->rsakey);
+ }
+#endif
+
+ m_free(ident);
+
+ return DROPBEAR_FAILURE;
+
+}
+
+/* returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+/* type is set to hold the type returned */
+int buf_get_priv_key(buffer *buf, sign_key *key, int *type) {
+
+ unsigned char* ident;
+ unsigned int len;
+ int ret;
+
+ TRACE(("enter buf_get_priv_key"));
+ ident = buf_getstring(buf, &len);
+
+#ifdef DROPBEAR_DSS
+ if (memcmp(ident, SSH_SIGNKEY_DSS, len) == 0
+ && (*type == DROPBEAR_SIGNKEY_ANY
+ || *type == DROPBEAR_SIGNKEY_DSS)) {
+ m_free(ident);
+ buf_setpos(buf, buf->pos - len - 4);
+ dss_key_free(key->dsskey);
+ key->dsskey = (dss_key*)m_malloc(sizeof(dss_key));
+ ret = buf_get_dss_priv_key(buf, key->dsskey);
+ *type = DROPBEAR_SIGNKEY_DSS;
+ if (ret == DROPBEAR_FAILURE) {
+ m_free(key->dsskey);
+ }
+ TRACE(("leave buf_get_priv_key: done get dss"));
+ return ret;
+ }
+#endif
+#ifdef DROPBEAR_RSA
+ if (memcmp(ident, SSH_SIGNKEY_RSA, len) == 0
+ && (*type == DROPBEAR_SIGNKEY_ANY
+ || *type == DROPBEAR_SIGNKEY_RSA)) {
+ m_free(ident);
+ buf_setpos(buf, buf->pos - len - 4);
+ rsa_key_free(key->rsakey);
+ key->rsakey = (rsa_key*)m_malloc(sizeof(rsa_key));
+ ret = buf_get_rsa_priv_key(buf, key->rsakey);
+ *type = DROPBEAR_SIGNKEY_RSA;
+ if (ret == DROPBEAR_FAILURE) {
+ m_free(key->rsakey);
+ }
+ TRACE(("leave buf_get_priv_key: done get rsa"));
+ return ret;
+ }
+#endif
+
+ m_free(ident);
+
+ TRACE(("leave buf_get_priv_key"));
+ return DROPBEAR_FAILURE;
+
+}
+
+/* type is either DROPBEAR_SIGNKEY_DSS or DROPBEAR_SIGNKEY_RSA */
+void buf_put_pub_key(buffer* buf, sign_key *key, int type) {
+
+ buffer *pubkeys;
+
+ TRACE(("enter buf_put_pub_key"));
+ pubkeys = buf_new(1000);
+
+#ifdef DROPBEAR_DSS
+ if (type == DROPBEAR_SIGNKEY_DSS) {
+ buf_put_dss_pub_key(pubkeys, key->dsskey);
+ }
+#endif
+#ifdef DROPBEAR_RSA
+ if (type == DROPBEAR_SIGNKEY_RSA) {
+ buf_put_rsa_pub_key(pubkeys, key->rsakey);
+ }
+#endif
+ if (pubkeys->len == 0) {
+ dropbear_exit("bad key types in buf_put_pub_key");
+ }
+
+ buf_setpos(pubkeys, 0);
+ buf_putstring(buf, buf_getptr(pubkeys, pubkeys->len),
+ pubkeys->len);
+
+ buf_free(pubkeys);
+ TRACE(("leave buf_put_pub_key"));
+}
+
+/* type is either DROPBEAR_SIGNKEY_DSS or DROPBEAR_SIGNKEY_RSA */
+void buf_put_priv_key(buffer* buf, sign_key *key, int type) {
+
+ TRACE(("enter buf_put_priv_key"));
+ TRACE(("type is %d", type));
+
+#ifdef DROPBEAR_DSS
+ if (type == DROPBEAR_SIGNKEY_DSS) {
+ buf_put_dss_priv_key(buf, key->dsskey);
+ TRACE(("leave buf_put_priv_key: dss done"));
+ return;
+ }
+#endif
+#ifdef DROPBEAR_RSA
+ if (type == DROPBEAR_SIGNKEY_RSA) {
+ buf_put_rsa_priv_key(buf, key->rsakey);
+ TRACE(("leave buf_put_priv_key: rsa done"));
+ return;
+ }
+#endif
+ dropbear_exit("bad key types in put pub key");
+}
+
+void sign_key_free(sign_key *key) {
+
+ TRACE(("enter sign_key_free"));
+
+#ifdef DROPBEAR_DSS
+ dss_key_free(key->dsskey);
+ key->dsskey = NULL;
+#endif
+#ifdef DROPBEAR_RSA
+ rsa_key_free(key->rsakey);
+ key->rsakey = NULL;
+#endif
+
+ m_free(key);
+ TRACE(("leave sign_key_free"));
+}
+
+static char hexdig(unsigned char x) {
+
+ if (x > 0xf)
+ return 'X';
+
+ if (x < 10)
+ return '0' + x;
+ else
+ return 'a' + x - 10;
+}
+
+/* Since we're not sure if we'll have md5 or sha1, we present both.
+ * MD5 is used in preference, but sha1 could still be useful */
+#ifdef DROPBEAR_MD5_HMAC
+static char * sign_key_md5_fingerprint(sign_key *key, int type) {
+
+ char * ret;
+ hash_state hs;
+ buffer *pubkeys;
+ unsigned char hash[MD5_HASH_SIZE];
+ unsigned int h, i;
+ unsigned int buflen;
+
+ md5_init(&hs);
+
+ pubkeys = buf_new(1000);
+ buf_put_pub_key(pubkeys, key, type);
+ /* skip the size int of the string - this is a bit messy */
+ buf_setpos(pubkeys, 4);
+ md5_process(&hs, buf_getptr(pubkeys, pubkeys->len-pubkeys->pos),
+ pubkeys->len-pubkeys->pos);
+
+ buf_free(pubkeys);
+ md5_done(&hs, hash);
+
+ /* "md5 hexfingerprinthere\0", each hex digit is "AB:" etc */
+ buflen = 4 + 3*MD5_HASH_SIZE;
+ ret = (char*)m_malloc(buflen);
+
+ memset(ret, 'Z', buflen);
+ strcpy(ret, "md5 ");
+
+ for (i = 4, h = 0; i < buflen; i+=3, h++) {
+ ret[i] = hexdig(hash[h] >> 4);
+ ret[i+1] = hexdig(hash[h] & 0x0f);
+ ret[i+2] = ':';
+ }
+ ret[buflen-1] = 0x0;
+
+ return ret;
+}
+
+#else /* use SHA1 rather than MD5 for fingerprint */
+static char * sign_key_sha1_fingerprint(sign_key *key, int type) {
+
+ char * ret;
+ hash_state hs;
+ buffer *pubkeys;
+ unsigned char hash[SHA1_HASH_SIZE];
+ unsigned int h, i;
+ unsigned int buflen;
+
+ sha1_init(&hs);
+
+ pubkeys = buf_new(1000);
+ buf_put_pub_key(pubkeys, key, type);
+ buf_setpos(pubkeys, 4);
+ /* skip the size int of the string - this is a bit messy */
+ sha1_process(&hs, buf_getptr(pubkeys, pubkeys->len-pubkeys->pos),
+ pubkeys->len-pubkeys->pos);
+
+ buf_free(pubkeys);
+ sha1_done(&hs, hash);
+
+ /* "sha1 hexfingerprinthere\0", each hex digit is "AB:" etc */
+ buflen = 5 + 3*SHA1_HASH_SIZE;
+ ret = (char*)m_malloc(buflen);
+
+ strcpy(ret, "sha1 ");
+
+ for (i = 5, h = 0; i < buflen; i+=3, h++) {
+ ret[i] = hexdig(hash[h] >> 4);
+ ret[i+1] = hexdig(hash[h] & 0x0f);
+ ret[i+2] = ':';
+ }
+ ret[buflen-1] = 0x0;
+
+ return ret;
+}
+
+#endif /* MD5/SHA1 switch */
+
+/* This will return a freshly malloced string, containing a fingerprint
+ * in either sha1 or md5 */
+char * sign_key_fingerprint(sign_key *key, int type) {
+
+#ifdef DROPBEAR_MD5_HMAC
+ return sign_key_md5_fingerprint(key, type);
+#else
+ return sign_key_sha1_fingerprint(key, type);
+#endif
+}
+
+void buf_put_sign(buffer* buf, sign_key *key, int type,
+ const unsigned char *data, unsigned int len) {
+
+ buffer *sigblob;
+
+ sigblob = buf_new(1000);
+
+#ifdef DROPBEAR_DSS
+ if (type == DROPBEAR_SIGNKEY_DSS) {
+ buf_put_dss_sign(sigblob, key->dsskey, data, len);
+ }
+#endif
+#ifdef DROPBEAR_RSA
+ if (type == DROPBEAR_SIGNKEY_RSA) {
+ buf_put_rsa_sign(sigblob, key->rsakey, data, len);
+ }
+#endif
+ if (sigblob->len == 0) {
+ dropbear_exit("non-matching signing type");
+ }
+
+ buf_setpos(sigblob, 0);
+ buf_putstring(buf, buf_getptr(sigblob, sigblob->len),
+ sigblob->len);
+
+ buf_free(sigblob);
+
+}
+
+#ifdef DROPBEAR_SIGNKEY_VERIFY
+/* Return DROPBEAR_SUCCESS or DROPBEAR_FAILURE.
+ * If FAILURE is returned, the position of
+ * buf is undefined. If SUCCESS is returned, buf will be positioned after the
+ * signature blob */
+int buf_verify(buffer * buf, sign_key *key, const unsigned char *data,
+ unsigned int len) {
+
+ unsigned int bloblen;
+ unsigned char * ident = NULL;
+ unsigned int identlen = 0;
+
+ bloblen = buf_getint(buf);
+ ident = buf_getstring(buf, &identlen);
+
+#ifdef DROPBEAR_DSS
+ if (bloblen == DSS_SIGNATURE_SIZE &&
+ memcmp(ident, SSH_SIGNKEY_DSS, identlen) == 0) {
+ m_free(ident);
+ return buf_dss_verify(buf, key->dsskey, data, len);
+ }
+#endif
+
+#ifdef DROPBEAR_RSA
+ if (memcmp(ident, SSH_SIGNKEY_RSA, identlen) == 0) {
+ m_free(ident);
+ return buf_rsa_verify(buf, key->rsakey, data, len);
+ }
+#endif
+
+ m_free(ident);
+ dropbear_exit("non-matching signing type");
+ return DROPBEAR_FAILURE;
+}
+#endif /* DROPBEAR_SIGNKEY_VERIFY */