Merge branch 'pkcs12-no-pw'

This adds support for password-less PKCS#12 containers and PKCS#8 files.

A new option for charon-cmd also allows loading private keys of any
type (previously only RSA keys were supported).

References strongswan/strongswan#1955

src/charon-cmd/charon-cmd.8.in

@@ -95,6 +95,10 @@ options can be used.
 .TP
 .BI "\-\-rsa " path
 RSA private key to use for authentication (if a password is required, it will
+be requested on demand). For other key types use \fI\-\-priv\fR.
+.TP
+.BI "\-\-priv " path
+Pivate key to use for authentication (if a password is required, it will
 be requested on demand).
 .TP
 .BI "\-\-p12 " path

src/charon-cmd/cmd/cmd_connection.c

@@ -499,6 +499,7 @@ METHOD(cmd_connection_t, handle, bool,
 			this->xautheap = arg;
 			break;
 		case CMD_OPT_RSA:
+		case CMD_OPT_PRIV:
 		case CMD_OPT_AGENT:
 		case CMD_OPT_PKCS12:
 			this->key_seen = TRUE;

src/charon-cmd/cmd/cmd_creds.c

@@ -237,6 +237,9 @@ METHOD(cmd_creds_t, handle, bool,
 		case CMD_OPT_RSA:
 			load_key(this, KEY_RSA, arg);
 			break;
+		case CMD_OPT_PRIV:
+			load_key(this, KEY_ANY, arg);
+			break;
 		case CMD_OPT_PKCS12:
 			load_pkcs12(this, arg);
 			break;

src/charon-cmd/cmd/cmd_options.c

@@ -43,6 +43,8 @@ cmd_option_t cmd_options[CMD_OPT_COUNT] = {
 	  "certificate for authentication or trust chain validation", {}},
 	{ CMD_OPT_RSA, "rsa", required_argument, "path",
 	  "RSA private key to use for authentication", {}},
+	{ CMD_OPT_PRIV, "priv", required_argument, "path",
+	  "Private key to use for authentication", {}},
 	{ CMD_OPT_PKCS12, "p12", required_argument, "path",
 	  "PKCS#12 file with private key and certificates to use for ", {
 		"authentication and trust chain validation"

src/charon-cmd/cmd/cmd_options.h

@@ -40,6 +40,7 @@ enum cmd_option_type_t {
 	CMD_OPT_REMOTE_IDENTITY,
 	CMD_OPT_CERT,
 	CMD_OPT_RSA,
+	CMD_OPT_PRIV,
 	CMD_OPT_PKCS12,
 	CMD_OPT_AGENT,
 	CMD_OPT_LOCAL_TS,

src/libstrongswan/credentials/containers/pkcs12.c

@@ -157,7 +157,7 @@ bool pkcs12_derive_key(hash_algorithm_t hash, chunk_t password, chunk_t salt,
 	bool success;
 	int i;
 
-	if (password.len)
+	if (password.ptr)
 	{	/* convert the password to UTF-16BE (without BOM) with 0 terminator */
 		unicode = chunk_alloca(password.len * 2 + 2);
 		for (i = 0; i < password.len; i++)

src/libstrongswan/plugins/openssl/openssl_pkcs12.c

@@ -139,6 +139,29 @@ static bool add_key(private_pkcs12_t *this, EVP_PKEY *private)
 	return key != NULL;
 }
 
+/**
+ * Decrypt PKCS#12 file using the given password and unpack credentials
+ */
+static status_t decrypt_and_unpack_pw(private_pkcs12_t *this, char *password)
+{
+	STACK_OF(X509) *cas = NULL;
+	EVP_PKEY *private;
+	X509 *cert;
+
+	if (PKCS12_parse(this->p12, password, &private, &cert, &cas))
+	{
+		/* if at least one is successful, we accept it */
+		if ((int)add_key(this, private) |
+			(int)add_cert(this, cert) |
+			(int)add_cas(this, cas))
+		{
+			return SUCCESS;
+		}
+		return FAILED;
+	}
+	return PARSE_ERROR;
+}
+
 /**
  * Decrypt PKCS#12 file and unpack credentials
  */
@@ -146,13 +169,21 @@ static bool decrypt_and_unpack(private_pkcs12_t *this)
 {
 	enumerator_t *enumerator;
 	shared_key_t *shared;
-	STACK_OF(X509) *cas = NULL;
-	EVP_PKEY *private;
-	X509 *cert;
 	chunk_t key;
 	char *password;
 	bool success = FALSE;
 
+	/* try without password first */
+	switch (decrypt_and_unpack_pw(this, NULL))
+	{
+		case PARSE_ERROR:
+			break;
+		case SUCCESS:
+			return TRUE;
+		default:
+			return FALSE;
+	}
+
 	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 										SHARED_PRIVATE_KEY_PASS, NULL, NULL);
 	while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
@@ -160,17 +191,25 @@ static bool decrypt_and_unpack(private_pkcs12_t *this)
 		key = shared->get_key(shared);
 		if (!key.ptr || asprintf(&password, "%.*s", (int)key.len, key.ptr) < 0)
 		{
-			password = NULL;
+			password = strdup("");
 		}
-		if (PKCS12_parse(this->p12, password, &private, &cert, &cas))
+		switch (decrypt_and_unpack_pw(this, password))
 		{
-			success = add_key(this, private);
-			success &= add_cert(this, cert);
-			success &= add_cas(this, cas);
-			free(password);
-			break;
+			case PARSE_ERROR:
+				/* password was incorrect, try another */
+				memwipe(password, strlen(password));
+				free(password);
+				continue;
+			case SUCCESS:
+				success = TRUE;
+				break;
+			default:
+				/* password was correct but we were unable to unpack anything */
+				break;
 		}
+		memwipe(password, strlen(password));
 		free(password);
+		break;
 	}
 	enumerator->destroy(enumerator);
 	return success;

src/libstrongswan/plugins/pkcs12/pkcs12_decode.c

@@ -321,43 +321,62 @@ end:
 	return success;
 }
 
+/**
+ * Verify the given MAC using the given password.
+ */
+static bool verify_mac_pw(signer_t *signer, hash_algorithm_t hash, chunk_t salt,
+						  uint64_t iterations, chunk_t data, chunk_t mac,
+						  chunk_t pw)
+{
+	chunk_t key, calculated;
+	bool success = FALSE;
+
+	key = chunk_alloca(signer->get_key_size(signer));
+	calculated = chunk_alloca(signer->get_block_size(signer));
+
+	if (pkcs12_derive_key(hash, pw, salt, iterations, PKCS12_KEY_MAC, key) &&
+		signer->set_key(signer, key) &&
+		signer->get_signature(signer, data, calculated.ptr) &&
+		chunk_equals_const(mac, calculated))
+	{
+		success = TRUE;
+	}
+	memwipe(key.ptr, key.len);
+	return success;
+}
+
 /**
  * Verify the given MAC with available passwords.
  */
 static bool verify_mac(hash_algorithm_t hash, chunk_t salt,
 					   uint64_t iterations, chunk_t data, chunk_t mac)
 {
-	integrity_algorithm_t integ;
 	enumerator_t *enumerator;
 	shared_key_t *shared;
 	signer_t *signer;
-	chunk_t key, calculated;
 	bool success = FALSE;
 
-	integ = hasher_algorithm_to_integrity(hash, mac.len);
-	signer = lib->crypto->create_signer(lib->crypto, integ);
+	signer = lib->crypto->create_signer(lib->crypto,
+								hasher_algorithm_to_integrity(hash, mac.len));
 	if (!signer)
 	{
 		return FALSE;
 	}
-	key = chunk_alloca(signer->get_key_size(signer));
-	calculated = chunk_alloca(signer->get_block_size(signer));
+
+	/* try without and with an empty password, which is not the same thing */
+	if (verify_mac_pw(signer, hash, salt, iterations, data, mac, chunk_empty) ||
+		verify_mac_pw(signer, hash, salt, iterations, data, mac, chunk_from_str("")))
+	{
+		signer->destroy(signer);
+		return TRUE;
+	}
 
 	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 										SHARED_PRIVATE_KEY_PASS, NULL, NULL);
 	while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
 	{
-		if (!pkcs12_derive_key(hash, shared->get_key(shared), salt, iterations,
-							   PKCS12_KEY_MAC, key))
-		{
-			break;
-		}
-		if (!signer->set_key(signer, key) ||
-			!signer->get_signature(signer, data, calculated.ptr))
-		{
-			break;
-		}
-		if (chunk_equals_const(mac, calculated))
+		if (verify_mac_pw(signer, hash, salt, iterations, data, mac,
+						  shared->get_key(shared)))
 		{
 			success = TRUE;
 			break;

src/libstrongswan/plugins/pkcs7/pkcs7_encrypted_data.c

@@ -54,6 +54,11 @@ static bool decrypt(pkcs5_t *pkcs5, chunk_t data, chunk_t *decrypted)
 	shared_key_t *shared;
 	bool success = FALSE;
 
+	if (pkcs5->decrypt(pkcs5, chunk_empty, data, decrypted))
+	{
+		return TRUE;
+	}
+
 	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 										SHARED_PRIVATE_KEY_PASS, NULL, NULL);
 	while (enumerator->enumerate(enumerator, &shared, NULL, NULL))

src/libstrongswan/plugins/pkcs8/pkcs8_builder.c

@@ -121,6 +121,32 @@ end:
 	return key;
 }
 
+/**
+ * Try to decrypt the given blob using the given password and pkcs5 object.
+ */
+static private_key_t *decrypt_private_key_pw(key_type_t type, pkcs5_t *pkcs5,
+											 chunk_t blob, chunk_t password)
+{
+	private_key_t *private_key;
+	chunk_t decrypted;
+
+	if (!pkcs5->decrypt(pkcs5, password, blob, &decrypted))
+	{
+		return NULL;
+	}
+	/* do a quick check to validate whether the password was correct */
+	if (!is_asn1(decrypted))
+	{
+		chunk_clear(&decrypted);
+		return NULL;
+	}
+	private_key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
+									 type, BUILD_BLOB_ASN1_DER,
+									 decrypted, BUILD_END);
+	chunk_clear(&decrypted);
+	return private_key;
+}
+
 /**
  * Try to decrypt the given blob with multiple passwords using the given
  * pkcs5 object.
@@ -130,36 +156,26 @@ static private_key_t *decrypt_private_key(key_type_t type, pkcs5_t *pkcs5,
 {
 	enumerator_t *enumerator;
 	shared_key_t *shared;
-	private_key_t *private_key = NULL;
+	private_key_t *private_key;
+
+	private_key = decrypt_private_key_pw(type, pkcs5, blob, chunk_empty);
+	if (private_key)
+	{
+		return private_key;
+	}
 
 	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 										SHARED_PRIVATE_KEY_PASS, NULL, NULL);
 	while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
 	{
-		chunk_t decrypted;
-
-		if (!pkcs5->decrypt(pkcs5, shared->get_key(shared), blob, &decrypted))
-		{
-			continue;
-		}
-		/* do a quick check to validate whether the password was correct */
-		if (!is_asn1(decrypted))
-		{
-			chunk_clear(&decrypted);
-			continue;
-		}
-		private_key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
-										 type, BUILD_BLOB_ASN1_DER,
-										 decrypted, BUILD_END);
+		private_key = decrypt_private_key_pw(type, pkcs5, blob,
+											 shared->get_key(shared));
 		if (private_key)
 		{
-			chunk_clear(&decrypted);
 			break;
 		}
-		chunk_free(&decrypted);
 	}
 	enumerator->destroy(enumerator);
-
 	return private_key;
 }