Make PKCS#12 code handle missing passwords.

Add a couple of FAQs.

CHANGES

@@ -4,6 +4,19 @@
 
  Changes between 0.9.5a and 0.9.6  [xx XXX 2000]
 
+  *) Make PKCS#12 code work with no password. The PKCS#12 spec
+     is a little unclear about how a blank password is handled.
+     Since the password in encoded as a BMPString with terminating
+     double NULL a zero length password would end up as just the
+     double NULL. However no password at all is different and is
+     handled differently in the PKCS#12 key generation code. NS
+     treats a blank password as zero length. MSIE treats it as no
+     password on export: but it will try both on import. We now do
+     the same: PKCS12_parse() tries zero length and no password if
+     the password is set to "" or NULL (NULL is now a valid password:
+     it wasn't before) as does the pkcs12 application.
+     [Steve Henson]
+
   *) Bugfixes in apps/x509.c: Avoid a memory leak; and don't use
      perror when PEM_read_bio_X509_REQ fails, the error message must
      be obtained from the error queue.

FAQ

@@ -16,8 +16,10 @@ OpenSSL  -  Frequently Asked Questions
 * How do I create certificates or certificate requests?
 * Why can't I create certificate requests?
 * Why does <SSL program> fail with a certificate verify error?
+* Why can I only use weak ciphers when I connect to a server using OpenSSL?
 * How can I create DSA certificates?
 * Why can't I make an SSL connection using a DSA certificate?
+* How can I remove the passphrase on a private key?
 * Why can't the OpenSSH configure script detect OpenSSL?
 
 
@@ -232,6 +234,13 @@ or file and the relevant program configured to read it. The OpenSSL program
 the verify(1) program manual page for more information.
 
 
+* Why can I only use weak ciphers when I connect to a server using OpenSSL?
+
+This is almost certainly because you are using an old "export grade" browser
+which only supports weak encryption. Upgrade your browser to support 128 bit
+ciphers.
+
+
 * How can I create DSA certificates?
 
 Check the CA.pl(1) manual page for a DSA certificate example.
@@ -242,11 +251,19 @@ Check the CA.pl(1) manual page for a DSA certificate example.
 Typically you'll see a message saying there are no shared ciphers when
 the same setup works fine with an RSA certificate. There are two possible
 causes. The client may not support connections to DSA servers most web
-browsers only support connections to servers supporting RSA cipher suites.
-The other cause is that a set of DH parameters has not been supplied to
-the server. DH parameters can be created with the dhparam(1) command and
-loaded using the SSL_CTX_set_tmp_dh() for example: check the source to
-s_server in apps/s_server.c for an example.
+browsers (including Netscape and MSIE) only support connections to servers
+supporting RSA cipher suites. The other cause is that a set of DH parameters
+has not been supplied to the server. DH parameters can be created with the
+dhparam(1) command and loaded using the SSL_CTX_set_tmp_dh() for example:
+check the source to s_server in apps/s_server.c for an example.
+
+
+* How can I remove the passphrase on a private key?
+
+Firstly you should be really *really* sure you want to do this. Leaving
+a private key unencrypted is a major security risk. If you decide that
+you do have to do this check the EXAMPLES sections of the rsa(1) and
+dsa(1) manual pages.
 
 
 * Why can't the OpenSSH configure script detect OpenSSL?

apps/pkcs12.c

@@ -528,11 +528,16 @@ int MAIN(int argc, char **argv)
 #ifdef CRYPTO_MDEBUG
     CRYPTO_push_info("verify MAC");
 #endif
-	if (!PKCS12_verify_mac (p12, mpass, -1)) {
+	/* If we enter empty password try no password first */
+	if(!macpass[0] && PKCS12_verify_mac(p12, NULL, 0)) {
+		/* If mac and crypto pass the same set it to NULL too */
+		if(!twopass) cpass = NULL;
+	} else if (!PKCS12_verify_mac(p12, mpass, -1)) {
 	    BIO_printf (bio_err, "Mac verify error: invalid password?\n");
 	    ERR_print_errors (bio_err);
 	    goto end;
-	} else BIO_printf (bio_err, "MAC verified OK\n");
+	}
+	BIO_printf (bio_err, "MAC verified OK\n");
 #ifdef CRYPTO_MDEBUG
     CRYPTO_pop_info();
 #endif
@@ -549,9 +554,9 @@ int MAIN(int argc, char **argv)
 #ifdef CRYPTO_MDEBUG
     CRYPTO_pop_info();
 #endif
-    PKCS12_free(p12);
     ret = 0;
     end:
+    PKCS12_free(p12);
     if(export_cert || inrand) app_RAND_write_file(NULL, bio_err);
 #ifdef CRYPTO_MDEBUG
     CRYPTO_remove_all_info();

crypto/evp/evp_pbe.c

@@ -92,7 +92,8 @@ int EVP_PBE_CipherInit (ASN1_OBJECT *pbe_obj, const char *pass, int passlen,
 		ERR_add_error_data(2, "TYPE=", obj_tmp);
 		return 0;
 	}
-	if (passlen == -1) passlen = strlen(pass);
+	if(!pass) passlen = 0;
+	else if (passlen == -1) passlen = strlen(pass);
 	pbetmp = (EVP_PBE_CTL *)sk_value (pbe_algs, i);
 	i = (*pbetmp->keygen)(ctx, pass, passlen, param, pbetmp->cipher,
 						 pbetmp->md, en_de);

crypto/evp/p5_crpt.c

@@ -125,6 +125,9 @@ int PKCS5_PBE_keyivgen(EVP_CIPHER_CTX *cctx, const char *pass, int passlen,
 	salt = pbe->salt->data;
 	saltlen = pbe->salt->length;
 
+	if(!pass) passlen = 0;
+	else if(passlen == -1) passlen = strlen(pass);
+
 	EVP_DigestInit (&ctx, md);
 	EVP_DigestUpdate (&ctx, pass, passlen);
 	EVP_DigestUpdate (&ctx, salt, saltlen);

crypto/evp/p5_crpt2.c

@@ -86,7 +86,8 @@ int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,
 	HMAC_CTX hctx;
 	p = out;
 	tkeylen = keylen;
-	if(passlen == -1) passlen = strlen(pass);
+	if(!pass) passlen = 0;
+	else if(passlen == -1) passlen = strlen(pass);
 	while(tkeylen) {
 		if(tkeylen > SHA_DIGEST_LENGTH) cplen = SHA_DIGEST_LENGTH;
 		else cplen = tkeylen;

crypto/pkcs12/p12_key.c

@@ -74,25 +74,30 @@ void h__dump (unsigned char *p, int len);
 #define min(a,b) ((a) < (b) ? (a) : (b))
 #endif
 
-int PKCS12_key_gen_asc (const char *pass, int passlen, unsigned char *salt,
+int PKCS12_key_gen_asc(const char *pass, int passlen, unsigned char *salt,
 	     int saltlen, int id, int iter, int n, unsigned char *out,
 	     const EVP_MD *md_type)
 {
 	int ret;
 	unsigned char *unipass;
 	int uniplen;
-	if (!asc2uni (pass, &unipass, &uniplen)) {
+	if(!pass) {
+		unipass = NULL;
+		uniplen = 0;
+	} else if (!asc2uni(pass, &unipass, &uniplen)) {
 		PKCS12err(PKCS12_F_PKCS12_KEY_GEN_ASC,ERR_R_MALLOC_FAILURE);
 		return 0;
 	}
-	ret = PKCS12_key_gen_uni (unipass, uniplen, salt, saltlen,
+	ret = PKCS12_key_gen_uni(unipass, uniplen, salt, saltlen,
 						 id, iter, n, out, md_type);
-	memset(unipass, 0, uniplen);	/* Clear password from memory */
-	Free(unipass);
+	if(unipass) {
+		memset(unipass, 0, uniplen);	/* Clear password from memory */
+		Free(unipass);
+	}
 	return ret;
 }
 
-int PKCS12_key_gen_uni (unsigned char *pass, int passlen, unsigned char *salt,
+int PKCS12_key_gen_uni(unsigned char *pass, int passlen, unsigned char *salt,
 	     int saltlen, int id, int iter, int n, unsigned char *out,
 	     const EVP_MD *md_type)
 {
@@ -106,10 +111,12 @@ int PKCS12_key_gen_uni (unsigned char *pass, int passlen, unsigned char *salt,
 	int tmpn = n;
 #endif
 
+#if 0
 	if (!pass) {
 		PKCS12err(PKCS12_F_PKCS12_KEY_GEN_UNI,ERR_R_PASSED_NULL_PARAMETER);
 		return 0;
 	}
+#endif
 
 #ifdef  DEBUG_KEYGEN
 	fprintf(stderr, "KEYGEN DEBUG\n");
@@ -125,7 +132,8 @@ int PKCS12_key_gen_uni (unsigned char *pass, int passlen, unsigned char *salt,
 	Ai = Malloc (u);
 	B = Malloc (v + 1);
 	Slen = v * ((saltlen+v-1)/v);
-	Plen = v * ((passlen+v-1)/v);
+	if(passlen) Plen = v * ((passlen+v-1)/v);
+	else Plen = 0;
 	Ilen = Slen + Plen;
 	I = Malloc (Ilen);
 	Ij = BN_new();

crypto/pkcs12/p12_kiss.c

@@ -106,11 +106,23 @@ int PKCS12_parse (PKCS12 *p12, const char *pass, EVP_PKEY **pkey, X509 **cert,
 
 	/* Check the mac */
 
-	if (!PKCS12_verify_mac (p12, pass, -1))
-		{
+	/* If password is zero length or NULL then try verifying both cases
+	 * to determine which password is correct. The reason for this is that
+	 * under PKCS#12 password based encryption no password and a zero length
+	 * password are two different things...
+	 */
+
+	if(!pass || !*pass) {
+		if(PKCS12_verify_mac(p12, NULL, 0)) pass = NULL;
+		else if(PKCS12_verify_mac(p12, "", 0)) pass = "";
+		else {
+			PKCS12err(PKCS12_F_PKCS12_PARSE,PKCS12_R_MAC_VERIFY_FAILURE);
+			goto err;
+		}
+	} else if (!PKCS12_verify_mac(p12, pass, -1)) {
 		PKCS12err(PKCS12_F_PKCS12_PARSE,PKCS12_R_MAC_VERIFY_FAILURE);
 		goto err;
-		}
+	}
 
 	if (!parse_pk12 (p12, pass, -1, pkey, cert, ca))
 		{

crypto/pkcs12/p12_mutl.c

@@ -106,10 +106,7 @@ int PKCS12_verify_mac (PKCS12 *p12, const char *pass, int passlen)
 		return 0;
 	}
 	if ((maclen != (unsigned int)p12->mac->dinfo->digest->length)
-	|| memcmp (mac, p12->mac->dinfo->digest->data, maclen)) {
-		PKCS12err(PKCS12_F_VERIFY_MAC,PKCS12_R_MAC_VERIFY_ERROR);
-		return 0;
-	}
+	|| memcmp (mac, p12->mac->dinfo->digest->data, maclen)) return 0;
 	return 1;
 }