X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/1e3b8b0749ec6793df5d8a9aca41ad4cae79bd4a..6367063f5f9df10d9c7d11977daf6694cad956e7:/ssh-dss.c

diff --git a/ssh-dss.c b/ssh-dss.c
index 96b1565d..bd709a22 100644
--- a/ssh-dss.c
+++ b/ssh-dss.c
@@ -23,20 +23,18 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-dss.c,v 1.2 2000/12/19 23:17:58 markus Exp $");
+RCSID("$OpenBSD: ssh-dss.c,v 1.11 2001/12/27 18:22:16 markus Exp $");
+
+#include <openssl/bn.h>
+#include <openssl/evp.h>
 
-#include "ssh.h"
 #include "xmalloc.h"
 #include "buffer.h"
 #include "bufaux.h"
 #include "compat.h"
-
-#include <openssl/bn.h>
-#include <openssl/rsa.h>
-#include <openssl/dsa.h>
-#include <openssl/evp.h>
-
+#include "log.h"
 #include "key.h"
+#include "ssh-dss.h"
 
 #define INTBLOB_LEN	20
 #define SIGBLOB_LEN	(2*INTBLOB_LEN)
@@ -47,29 +45,30 @@ ssh_dss_sign(
     u_char **sigp, int *lenp,
     u_char *data, int datalen)
 {
-	u_char *digest;
-	u_char *ret;
 	DSA_SIG *sig;
 	EVP_MD *evp_md = EVP_sha1();
 	EVP_MD_CTX md;
-	u_int rlen;
-	u_int slen;
-	u_int len;
-	u_char sigblob[SIGBLOB_LEN];
+	u_char *digest, *ret, sigblob[SIGBLOB_LEN];
+	u_int rlen, slen, len, dlen;
 	Buffer b;
 
 	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
 		error("ssh_dss_sign: no DSA key");
 		return -1;
 	}
-	digest = xmalloc(evp_md->md_size);
+	dlen = evp_md->md_size;
+	digest = xmalloc(dlen);
 	EVP_DigestInit(&md, evp_md);
 	EVP_DigestUpdate(&md, data, datalen);
 	EVP_DigestFinal(&md, digest, NULL);
 
-	sig = DSA_do_sign(digest, evp_md->md_size, key->dsa);
+	sig = DSA_do_sign(digest, dlen, key->dsa);
+
+	memset(digest, 0, dlen);
+	xfree(digest);
 	if (sig == NULL) {
-		fatal("ssh_dss_sign: cannot sign");
+		error("ssh_dss_sign: sign failed");
+		return -1;
 	}
 
 	rlen = BN_num_bytes(sig->r);
@@ -79,15 +78,12 @@ ssh_dss_sign(
 		DSA_SIG_free(sig);
 		return -1;
 	}
-	debug("sig size %d %d", rlen, slen);
-
 	memset(sigblob, 0, SIGBLOB_LEN);
 	BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
 	BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
 	DSA_SIG_free(sig);
 
 	if (datafellows & SSH_BUG_SIGBLOB) {
-		debug("datafellows");
 		ret = xmalloc(SIGBLOB_LEN);
 		memcpy(ret, sigblob, SIGBLOB_LEN);
 		if (lenp != NULL)
@@ -116,34 +112,19 @@ ssh_dss_verify(
     u_char *signature, int signaturelen,
     u_char *data, int datalen)
 {
-	Buffer b;
-	u_char *digest;
 	DSA_SIG *sig;
 	EVP_MD *evp_md = EVP_sha1();
 	EVP_MD_CTX md;
-	u_char *sigblob;
-	char *txt;
+	u_char *digest, *sigblob;
 	u_int len, dlen;
-	int rlen;
-	int ret;
+	int rlen, ret;
+	Buffer b;
 
 	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
 		error("ssh_dss_verify: no DSA key");
 		return -1;
 	}
 
-	if (!(datafellows & SSH_BUG_SIGBLOB) &&
-	    signaturelen == SIGBLOB_LEN) {
-		datafellows |= ~SSH_BUG_SIGBLOB;
-		log("autodetect SSH_BUG_SIGBLOB");
-	} else if ((datafellows & SSH_BUG_SIGBLOB) &&
-	    signaturelen != SIGBLOB_LEN) {
-		log("autoremove SSH_BUG_SIGBLOB");
-		datafellows &= ~SSH_BUG_SIGBLOB;
-	}
-
-	debug("len %d datafellows %d", signaturelen, datafellows);
-
 	/* fetch signature */
 	if (datafellows & SSH_BUG_SIGBLOB) {
 		sigblob = signature;
@@ -152,22 +133,24 @@ ssh_dss_verify(
 		/* ietf-drafts */
 		char *ktype;
 		buffer_init(&b);
-		buffer_append(&b, (char *) signature, signaturelen);
+		buffer_append(&b, signature, signaturelen);
 		ktype = buffer_get_string(&b, NULL);
 		if (strcmp("ssh-dss", ktype) != 0) {
 			error("ssh_dss_verify: cannot handle type %s", ktype);
 			buffer_free(&b);
+			xfree(ktype);
 			return -1;
 		}
-		sigblob = (u_char *)buffer_get_string(&b, &len);
+		xfree(ktype);
+		sigblob = buffer_get_string(&b, &len);
 		rlen = buffer_len(&b);
-		if(rlen != 0) {
-			error("remaining bytes in signature %d", rlen);
-			buffer_free(&b);
+		buffer_free(&b);
+		if (rlen != 0) {
+			error("ssh_dss_verify: "
+			    "remaining bytes in signature %d", rlen);
+			xfree(sigblob);
 			return -1;
 		}
-		buffer_free(&b);
-		xfree(ktype);
 	}
 
 	if (len != SIGBLOB_LEN) {
@@ -175,9 +158,12 @@ ssh_dss_verify(
 	}
 
 	/* parse signature */
-	sig = DSA_SIG_new();
-	sig->r = BN_new();
-	sig->s = BN_new();
+	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");
 	BN_bin2bn(sigblob, INTBLOB_LEN, sig->r);
 	BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s);
 
@@ -185,7 +171,7 @@ ssh_dss_verify(
 		memset(sigblob, 0, len);
 		xfree(sigblob);
 	}
-	
+
 	/* sha1 the data */
 	dlen = evp_md->md_size;
 	digest = xmalloc(dlen);
@@ -199,18 +185,7 @@ ssh_dss_verify(
 	xfree(digest);
 	DSA_SIG_free(sig);
 
-	switch (ret) {
-	case 1:
-		txt = "correct";
-		break;
-	case 0:
-		txt = "incorrect";
-		break;
-	case -1:
-	default:
-		txt = "error";
-		break;
-	}
-	debug("ssh_dss_verify: signature %s", txt);
+	debug("ssh_dss_verify: signature %s",
+	    ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
 	return ret;
 }