- djm@cvs.openbsd.org 2010/01/30 02:54:53

[openssh.git] / ssh-dss.c

diff --git a/ssh-dss.c b/ssh-dss.c
index 9f3a28706dde1b23ec7263218d150992474e3fe0..51a06e98fe270a3e0faf5957a82657a761c879a5 100644 (file)
--- a/ssh-dss.c
+++ b/ssh-dss.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: ssh-dss.c,v 1.24 2006/11/06 21:25:28 markus Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -23,32 +24,32 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-dss.c,v 1.9 2001/11/07 22:10:28 markus Exp $");
+
+#include <sys/types.h>
 
 #include <openssl/bn.h>
 #include <openssl/evp.h>
 
+#include <stdarg.h>
+#include <string.h>
+
 #include "xmalloc.h"
 #include "buffer.h"
-#include "bufaux.h"
 #include "compat.h"
 #include "log.h"
 #include "key.h"
-#include "ssh-dss.h"
 
 #define INTBLOB_LEN    20
 #define SIGBLOB_LEN    (2*INTBLOB_LEN)
 
 int
-ssh_dss_sign(
-    Key *key,
-    u_char **sigp, int *lenp,
-    u_char *data, int datalen)
+ssh_dss_sign(const Key *key, u_char **sigp, u_int *lenp,
+    const u_char *data, u_int datalen)
 {
        DSA_SIG *sig;
-       EVP_MD *evp_md = EVP_sha1();
+       const EVP_MD *evp_md = EVP_sha1();
        EVP_MD_CTX md;
-       u_char *digest, *ret, sigblob[SIGBLOB_LEN];
+       u_char digest[EVP_MAX_MD_SIZE], sigblob[SIGBLOB_LEN];
        u_int rlen, slen, len, dlen;
        Buffer b;
 
@@ -56,16 +57,13 @@ ssh_dss_sign(
                error("ssh_dss_sign: no DSA key");
                return -1;
        }
-       dlen = evp_md->md_size;
-       digest = xmalloc(dlen);
        EVP_DigestInit(&md, evp_md);
        EVP_DigestUpdate(&md, data, datalen);
-       EVP_DigestFinal(&md, digest, NULL);
+       EVP_DigestFinal(&md, digest, &dlen);
 
        sig = DSA_do_sign(digest, dlen, key->dsa);
+       memset(digest, 'd', sizeof(digest));
 
-       memset(digest, 0, dlen);
-       xfree(digest);
        if (sig == NULL) {
                error("ssh_dss_sign: sign failed");
                return -1;
@@ -74,7 +72,7 @@ ssh_dss_sign(
        rlen = BN_num_bytes(sig->r);
        slen = BN_num_bytes(sig->s);
        if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
-               error("bad sig size %d %d", rlen, slen);
+               error("bad sig size %u %u", rlen, slen);
                DSA_SIG_free(sig);
                return -1;
        }
@@ -84,38 +82,36 @@ ssh_dss_sign(
        DSA_SIG_free(sig);
 
        if (datafellows & SSH_BUG_SIGBLOB) {
-               ret = xmalloc(SIGBLOB_LEN);
-               memcpy(ret, sigblob, SIGBLOB_LEN);
                if (lenp != NULL)
                        *lenp = SIGBLOB_LEN;
-               if (sigp != NULL)
-                       *sigp = ret;
+               if (sigp != NULL) {
+                       *sigp = xmalloc(SIGBLOB_LEN);
+                       memcpy(*sigp, sigblob, SIGBLOB_LEN);
+               }
        } else {
                /* ietf-drafts */
                buffer_init(&b);
                buffer_put_cstring(&b, "ssh-dss");
                buffer_put_string(&b, sigblob, SIGBLOB_LEN);
                len = buffer_len(&b);
-               ret = xmalloc(len);
-               memcpy(ret, buffer_ptr(&b), len);
-               buffer_free(&b);
                if (lenp != NULL)
                        *lenp = len;
-               if (sigp != NULL)
-                       *sigp = ret;
+               if (sigp != NULL) {
+                       *sigp = xmalloc(len);
+                       memcpy(*sigp, buffer_ptr(&b), len);
+               }
+               buffer_free(&b);
        }
        return 0;
 }
 int
-ssh_dss_verify(
-    Key *key,
-    u_char *signature, int signaturelen,
-    u_char *data, int datalen)
+ssh_dss_verify(const Key *key, const u_char *signature, u_int signaturelen,
+    const u_char *data, u_int datalen)
 {
        DSA_SIG *sig;
-       EVP_MD *evp_md = EVP_sha1();
+       const EVP_MD *evp_md = EVP_sha1();
        EVP_MD_CTX md;
-       u_char *digest, *sigblob;
+       u_char digest[EVP_MAX_MD_SIZE], *sigblob;
        u_int len, dlen;
        int rlen, ret;
        Buffer b;
@@ -127,7 +123,8 @@ ssh_dss_verify(
 
        /* fetch signature */
        if (datafellows & SSH_BUG_SIGBLOB) {
-               sigblob = signature;
+               sigblob = xmalloc(signaturelen);
+               memcpy(sigblob, signature, signaturelen);
                len = signaturelen;
        } else {
                /* ietf-drafts */
@@ -145,7 +142,7 @@ ssh_dss_verify(
                sigblob = buffer_get_string(&b, &len);
                rlen = buffer_len(&b);
                buffer_free(&b);
-               if(rlen != 0) {
+               if (rlen != 0) {
                        error("ssh_dss_verify: "
                            "remaining bytes in signature %d", rlen);
                        xfree(sigblob);
@@ -154,32 +151,32 @@ ssh_dss_verify(
        }
 
        if (len != SIGBLOB_LEN) {
-               fatal("bad sigbloblen %d != SIGBLOB_LEN", len);
+               fatal("bad sigbloblen %u != SIGBLOB_LEN", len);
        }
 
        /* parse signature */
-       sig = DSA_SIG_new();
-       sig->r = BN_new();
-       sig->s = BN_new();
-       BN_bin2bn(sigblob, INTBLOB_LEN, sig->r);
-       BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s);
-
-       if (!(datafellows & SSH_BUG_SIGBLOB)) {
-               memset(sigblob, 0, len);
-               xfree(sigblob);
-       }
+       if ((sig = DSA_SIG_new()) == NULL)
+               fatal("ssh_dss_verify: DSA_SIG_new failed");
+       if ((sig->r = BN_new()) == NULL)
+               fatal("ssh_dss_verify: BN_new failed");
+       if ((sig->s = BN_new()) == NULL)
+               fatal("ssh_dss_verify: BN_new failed");
+       if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) ||
+           (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL))
+               fatal("ssh_dss_verify: BN_bin2bn failed");
+
+       /* clean up */
+       memset(sigblob, 0, len);
+       xfree(sigblob);
 
        /* sha1 the data */
-       dlen = evp_md->md_size;
-       digest = xmalloc(dlen);
        EVP_DigestInit(&md, evp_md);
        EVP_DigestUpdate(&md, data, datalen);
-       EVP_DigestFinal(&md, digest, NULL);
+       EVP_DigestFinal(&md, digest, &dlen);
 
        ret = DSA_do_verify(digest, dlen, sig, key->dsa);
+       memset(digest, 'd', sizeof(digest));
 
-       memset(digest, 0, dlen);
-       xfree(digest);
        DSA_SIG_free(sig);
 
        debug("ssh_dss_verify: signature %s",