--- /dev/null
+/**
+ * @file encryption_payload.c
+ *
+ * @brief Implementation of encryption_payload_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+/* offsetof macro */
+#include <stddef.h>
+
+#include "encryption_payload.h"
+
+#include <encoding/payloads/encodings.h>
+#include <utils/allocator.h>
+#include <utils/linked_list.h>
+#include <encoding/generator.h>
+#include <encoding/parser.h>
+#include <utils/iterator.h>
+#include <utils/randomizer.h>
+#include <transforms/signers/signer.h>
+
+
+
+
+typedef struct private_encryption_payload_t private_encryption_payload_t;
+
+/**
+ * Private data of an encryption_payload_t' Object
+ *
+ */
+struct private_encryption_payload_t {
+ /**
+ * public encryption_payload_t interface
+ */
+ encryption_payload_t public;
+
+ /**
+ * There is no next payload for an encryption payload,
+ * since encryption payload MUST be the last one.
+ * next_payload means here the first payload of the
+ * contained, encrypted payload.
+ */
+ u_int8_t next_payload;
+
+ /**
+ * Critical flag
+ */
+ bool critical;
+
+ /**
+ * Length of this payload
+ */
+ u_int16_t payload_length;
+
+ /**
+ * initialization vector
+ */
+ chunk_t iv;
+
+ /**
+ * integrity checksum
+ */
+ chunk_t checksum;
+
+ /**
+ * chunk containing the iv, data, padding,
+ * and (an eventually not calculated) signature
+ */
+ chunk_t encrypted;
+
+ /**
+ * chunk containing the data in decrypted (unpadded) form
+ */
+ chunk_t decrypted;
+
+ /**
+ * signer set by set_signer
+ */
+ signer_t *signer;
+
+ /**
+ * Contained payloads of this encrpytion_payload
+ */
+ linked_list_t *payloads;
+
+ /**
+ * @brief Computes the length of this payload.
+ *
+ * @param this calling private_encryption_payload_t object
+ * @return
+ * SUCCESS in any case
+ */
+ status_t (*compute_length) (private_encryption_payload_t *this);
+
+ /**
+ * @brief Generate payloads (unencrypted) in chunk decrypted.
+ *
+ * @param this calling private_encryption_payload_t object
+ * @return
+ * SUCCESS in any case
+ */
+ status_t (*generate) (private_encryption_payload_t *this);
+ status_t (*parse) (private_encryption_payload_t *this);
+};
+
+/**
+ * Encoding rules to parse or generate a IKEv2-Encryption Payload
+ *
+ * The defined offsets are the positions in a object of type
+ * private_encryption_payload_t.
+ *
+ */
+encoding_rule_t encryption_payload_encodings[] = {
+ /* 1 Byte next payload type, stored in the field next_payload */
+ { U_INT_8, offsetof(private_encryption_payload_t, next_payload) },
+ /* the critical bit */
+ { FLAG, offsetof(private_encryption_payload_t, critical) },
+ /* 7 Bit reserved bits, nowhere stored */
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ { RESERVED_BIT, 0 },
+ /* Length of the whole encryption payload*/
+ { PAYLOAD_LENGTH, offsetof(private_encryption_payload_t, payload_length) },
+ /* encrypted data, stored in a chunk. contains iv, data, padding */
+ { ENCRYPTED_DATA, offsetof(private_encryption_payload_t, encrypted) },
+};
+
+/*
+ 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ ! Next Payload !C! RESERVED ! Payload Length !
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ ! Initialization Vector !
+ ! (length is block size for encryption algorithm) !
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ ! Encrypted IKE Payloads !
+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ ! ! Padding (0-255 octets) !
+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
+ ! ! Pad Length !
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ ~ Integrity Checksum Data ~
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+/**
+ * Implements payload_t's verify function.
+ * See #payload_s.verify for description.
+ */
+static status_t verify(private_encryption_payload_t *this)
+{
+// int proposal_number = 1;
+ status_t status;
+// iterator_t *iterator;
+// bool first = TRUE;
+//
+// if (this->critical)
+// {
+// /* critical bit set! */
+// return FAILED;
+// }
+//
+// /* check proposal numbering */
+// status = this->proposals->create_iterator(this->proposals,&iterator,TRUE);
+// if (status != SUCCESS)
+// {
+// return status;
+// }
+//
+// while(iterator->has_next(iterator))
+// {
+// proposal_substructure_t *current_proposal;
+// status = iterator->current(iterator,(void **)¤t_proposal);
+// {
+// break;
+// }
+// if (current_proposal->get_proposal_number(current_proposal) > proposal_number)
+// {
+// if (first)
+// {
+// /* first number must be 1 */
+// status = FAILED;
+// break;
+// }
+//
+// if (current_proposal->get_proposal_number(current_proposal) != (proposal_number + 1))
+// {
+// /* must be only one more then previous proposal */
+// status = FAILED;
+// break;
+// }
+// }
+// else if (current_proposal->get_proposal_number(current_proposal) < proposal_number)
+// {
+// iterator->destroy(iterator);
+// /* must not be smaller then proceeding one */
+// status = FAILED;
+// break;
+// }
+// first = FALSE;
+// }
+//
+// iterator->destroy(iterator);
+ return status;
+}
+
+/**
+ * implements payload_t.destroy
+ */
+static status_t destroy(private_encryption_payload_t *this)
+{
+ /* all proposals are getting destroyed */
+ while (this->payloads->get_count(this->payloads) > 0)
+ {
+ payload_t *current_payload;
+ if (this->payloads->remove_last(this->payloads,(void **)¤t_payload) != SUCCESS)
+ {
+ break;
+ }
+ current_payload->destroy(current_payload);
+ }
+ this->payloads->destroy(this->payloads);
+
+ allocator_free(this->iv.ptr);
+ allocator_free(this->encrypted.ptr);
+ allocator_free(this->decrypted.ptr);
+ allocator_free(this->checksum.ptr);
+ allocator_free(this);
+
+ return SUCCESS;
+}
+
+/**
+ * implements payload_t.get_encoding_rules
+ */
+static status_t get_encoding_rules(private_encryption_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
+{
+ *rules = encryption_payload_encodings;
+ *rule_count = sizeof(encryption_payload_encodings) / sizeof(encoding_rule_t);
+
+ return SUCCESS;
+}
+
+/**
+ * implements payload_t.get_type
+ */
+static payload_type_t get_type(private_encryption_payload_t *this)
+{
+ return ENCRYPTED;
+}
+
+/**
+ * implements payload_t.get_next_type
+ */
+static payload_type_t get_next_type(private_encryption_payload_t *this)
+{
+ /* returns first contained payload here */
+ return (this->next_payload);
+}
+
+/**
+ * implements payload_t.set_next_type
+ */
+static status_t set_next_type(private_encryption_payload_t *this, payload_type_t type)
+{
+ /* set next type is not allowed, since this payload MUST be the last one */
+ return FAILED;
+}
+
+/**
+ * implements payload_t.get_length
+ */
+static size_t get_length(private_encryption_payload_t *this)
+{
+ this->compute_length(this);
+ return this->payload_length;
+}
+
+/**
+ * implements encryption_payload_t.create_payload_iterator
+ */
+static status_t create_payload_iterator (private_encryption_payload_t *this, iterator_t **iterator, bool forward)
+{
+ return (this->payloads->create_iterator(this->payloads, iterator, forward));
+}
+
+/**
+ * implements encryption_payload_t.add_payload
+ */
+static status_t add_payload(private_encryption_payload_t *this, payload_t *payload)
+{
+ payload_t *last_payload;
+ if ((this->payloads->get_count(this->payloads) > 0) &&
+ (this->payloads->get_last(this->payloads,(void **) &last_payload) != SUCCESS))
+ {
+ return OUT_OF_RES;
+ }
+
+ if (this->payloads->insert_last(this->payloads, payload) != SUCCESS)
+ {
+ return OUT_OF_RES;
+ }
+ if (this->payloads->get_count(this->payloads) == 1)
+ {
+ this->next_payload = payload->get_type(payload);
+ }
+ else
+ {
+ last_payload->set_next_type(last_payload, payload->get_type(payload));
+ }
+ payload->set_next_type(payload, NO_PAYLOAD);
+ this->compute_length(this);
+ return SUCCESS;
+}
+
+/**
+ * implements encryption_payload_t.encrypt
+ */
+static status_t encrypt(private_encryption_payload_t *this, crypter_t *crypter)
+{
+ chunk_t iv, padding, concatenated;
+ randomizer_t *randomizer;
+ status_t status;
+
+ if (this->signer == NULL)
+ {
+ return INVALID_STATE;
+ }
+
+ /* for random data in iv and padding */
+ randomizer = randomizer_create();
+ if (randomizer == NULL)
+ {
+ return OUT_OF_RES;
+ }
+
+ /* build payload chunk */
+ status = this->generate(this);
+ if (status != SUCCESS)
+ {
+ randomizer->destroy(randomizer);
+ return status;
+ }
+
+ /* build padding */
+ padding.len = (this->decrypted.len + 1) % crypter->get_block_size(crypter);
+ status = randomizer->allocate_pseudo_random_bytes(randomizer, padding.len, &padding);
+ if (status != SUCCESS)
+ {
+ randomizer->destroy(randomizer);
+ return status;
+ }
+
+ /* concatenate payload data, padding, padding len */
+ concatenated.len = this->decrypted.len + padding.len + 1;
+ concatenated.ptr = allocator_alloc(concatenated.len);
+ if (concatenated.ptr == NULL)
+ {
+ randomizer->destroy(randomizer);
+ allocator_free(padding.ptr);
+ return OUT_OF_RES;
+ }
+ memcpy(concatenated.ptr, this->decrypted.ptr, this->decrypted.len);
+ memcpy(concatenated.ptr + this->decrypted.len, padding.ptr, padding.len);
+ *(concatenated.ptr + concatenated.len - 1) = padding.len;
+
+
+ /* build iv */
+ iv.len = crypter->get_block_size(crypter);
+ status = randomizer->allocate_pseudo_random_bytes(randomizer, iv.len, &iv);
+ randomizer->destroy(randomizer);
+ if (status != SUCCESS)
+ {
+ allocator_free(padding.ptr);
+ allocator_free(concatenated.ptr);
+ return status;
+ }
+
+
+ /* encrypt concatenated chunk */
+ allocator_free(this->encrypted.ptr);
+ status = crypter->encrypt(crypter, iv, concatenated, &(this->encrypted));
+ allocator_free(padding.ptr);
+ allocator_free(concatenated.ptr);
+ allocator_free(iv.ptr);
+ if (status != SUCCESS)
+ {
+ return status;
+ }
+
+ /* append an empty signature */
+ this->encrypted.len += this->signer->get_block_size(this->signer);
+ allocator_realloc(this->encrypted.ptr, this->encrypted.len);
+ if (this->encrypted.ptr == NULL)
+ {
+ return OUT_OF_RES;
+ }
+
+ return SUCCESS;
+}
+
+/**
+ * implements encryption_payload_t.decrypt
+ */
+static status_t decrypt(private_encryption_payload_t *this, crypter_t *crypter)
+{
+ chunk_t iv, concatenated;
+ u_int8_t padding_length;
+ status_t status;
+
+ if (this->signer == NULL)
+ {
+ return INVALID_STATE;
+ }
+
+ /* get IV */
+ iv.len = crypter->get_block_size(crypter);
+ iv.ptr = this->encrypted.ptr;
+
+ /* point concatenated to data + padding + padding_length*/
+ concatenated.ptr = this->encrypted.ptr + iv.len;
+ concatenated.len = this->encrypted.len - iv.len - this->signer->get_block_size(this->signer);
+
+ /* check the size of input:
+ * concatenated must be at least on block_size of crypter
+ */
+ if (concatenated.len < iv.len)
+ {
+ return FAILED;
+ }
+
+ /* free previus data, if any */
+ allocator_free(this->decrypted.ptr);
+
+ status = crypter->decrypt(crypter, iv, concatenated, &(this->decrypted));
+ if (status != SUCCESS)
+ {
+ return FAILED;
+ }
+
+ /* get padding length, sits just bevore signature */
+ padding_length = *(this->decrypted.ptr + this->decrypted.len - 1);
+ this->decrypted.len -= padding_length;
+
+ /* check size again */
+ if (padding_length > concatenated.len || this->decrypted.len < 0)
+ {
+ /* decryption failed :-/ */
+ return FAILED;
+ }
+
+ /* free padding */
+ this->decrypted.ptr = allocator_realloc(this->decrypted.ptr, this->decrypted.len);
+ if (this->decrypted.ptr == NULL)
+ {
+ return OUT_OF_RES;
+ }
+
+ return SUCCESS;
+}
+
+/**
+ * implements encryption_payload_t.set_signer
+ */
+static status_t set_signer(private_encryption_payload_t *this, signer_t* signer)
+{
+ this->signer = signer;
+ return SUCCESS;
+}
+
+/**
+ * implements encryption_payload_t.build_signature
+ */
+static status_t build_signature(private_encryption_payload_t *this, chunk_t data)
+{
+ chunk_t data_without_sig = data;
+ chunk_t sig;
+
+ if (this->signer == NULL)
+ {
+ return INVALID_STATE;
+ }
+
+ sig.len = this->signer->get_block_size(this->signer);
+ data_without_sig.len -= sig.len;
+ sig.ptr = data.ptr + data_without_sig.len;
+ this->signer->get_signature(this->signer, data_without_sig, sig.ptr);
+ return SUCCESS;
+}
+
+/**
+ * implements encryption_payload_t.verify_signature
+ */
+static status_t verify_signature(private_encryption_payload_t *this, chunk_t data)
+{
+ chunk_t sig, data_without_sig;
+ bool valid;
+
+ if (this->signer == NULL)
+ {
+ return INVALID_STATE;
+ }
+ /* find signature in data chunk */
+ sig.len = this->signer->get_block_size(this->signer);
+ if (data.len <= sig.len)
+ {
+ return FAILED;
+ }
+ sig.ptr = data.ptr + data.len - sig.len;
+
+ /* verify it */
+ data_without_sig.len = data.len - sig.len;
+ data_without_sig.ptr = data.ptr;
+ this->signer->verify_signature(this->signer, data_without_sig, sig, &valid);
+
+ if (!valid)
+ {
+ return FAILED;
+ }
+
+ return SUCCESS;
+}
+
+/**
+ * implements private_encryption_payload_t.generate
+ */
+static status_t generate(private_encryption_payload_t *this)
+{
+ status_t status;
+ payload_t *current_payload, *next_payload;
+ generator_t *generator;
+ iterator_t *iterator;
+
+ /* create iterator */
+ status = this->payloads->create_iterator(this->payloads, &iterator, TRUE);
+ if (status != SUCCESS)
+ {
+ return status;
+ }
+
+ /* get first payload */
+ if (iterator->has_next(iterator))
+ {
+ iterator->current(iterator, (void**)¤t_payload);
+ this->next_payload = current_payload->get_type(current_payload);
+ }
+ else
+ {
+ /* no paylads? */
+ allocator_free(this->decrypted.ptr);
+ this->decrypted = CHUNK_INITIALIZER;
+ iterator->destroy(iterator);
+ return SUCCESS;
+ }
+
+ generator = generator_create();
+ if (generator == NULL)
+ {
+ iterator->destroy(iterator);
+ return OUT_OF_RES;
+ }
+
+ /* build all payload, except last */
+ while(iterator->has_next(iterator))
+ {
+ iterator->current(iterator, (void**)&next_payload);
+ current_payload->set_next_type(current_payload, next_payload->get_type(next_payload));
+
+ status = generator->generate_payload(generator, current_payload);
+ if (status != SUCCESS)
+ {
+ generator->destroy(generator);
+ iterator->destroy(iterator);
+ return status;
+ }
+ current_payload = next_payload;
+ }
+ iterator->destroy(iterator);
+
+ /* build last payload */
+ current_payload->set_next_type(current_payload, NO_PAYLOAD);
+ status = generator->generate_payload(generator, current_payload);
+ if (status != SUCCESS)
+ {
+ generator->destroy(generator);
+ return status;
+ }
+
+ /* free already generated data */
+ allocator_free(this->decrypted.ptr);
+
+ status = generator->write_to_chunk(generator, &(this->decrypted));
+ generator->destroy(generator);
+ return status;
+}
+
+static status_t parse(private_encryption_payload_t *this)
+{
+ parser_t *parser;
+ status_t status;
+ payload_type_t current_payload_type;
+
+ /* check if there is decrypted data */
+ if (this->decrypted.ptr == NULL)
+ {
+ return INVALID_STATE;
+ }
+
+ /* build a parser on the decrypted data */
+ parser = parser_create(this->decrypted);
+ if (parser == NULL)
+ {
+ return OUT_OF_RES;
+ }
+
+
+ current_payload_type = this->next_payload;
+ /* parse all payloads */
+ while (current_payload_type != NO_PAYLOAD)
+ {
+ payload_t *current_payload;
+
+ status = parser->parse_payload(parser, current_payload_type, (payload_t**)¤t_payload);
+ if (status != SUCCESS)
+ {
+ return PARSE_ERROR;
+ }
+
+ status = current_payload->verify(current_payload);
+ if (status != SUCCESS)
+ {
+ return VERIFY_ERROR;
+ }
+
+ /* get next payload type */
+ current_payload_type = current_payload->get_next_type(current_payload);
+
+ status = this->payloads->insert_last(this->payloads,current_payload);
+ if (status != SUCCESS)
+ {
+ return OUT_OF_RES;
+ }
+ }
+ return SUCCESS;
+}
+
+/**
+ * implements private_encryption_payload_t.compute_length
+ */
+static status_t compute_length(private_encryption_payload_t *this)
+{
+ iterator_t *iterator;
+ status_t status;
+ size_t length = ENCRYPTION_PAYLOAD_HEADER_LENGTH;
+ status = this->payloads->create_iterator(this->payloads, &iterator, TRUE);
+ if (status != SUCCESS)
+ {
+ return status;
+ }
+ while (iterator->has_next(iterator))
+ {
+ payload_t *current_payload;
+ iterator->current(iterator, (void **) ¤t_payload);
+ length += current_payload->get_length(current_payload);
+ }
+ iterator->destroy(iterator);
+
+ this->payload_length = length;
+
+ return SUCCESS;
+}
+
+/*
+ * Described in header
+ */
+encryption_payload_t *encryption_payload_create()
+{
+ private_encryption_payload_t *this = allocator_alloc_thing(private_encryption_payload_t);
+ if (this == NULL)
+ {
+ return NULL;
+ }
+
+ /* payload_t interface functions */
+ this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
+ this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
+ this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
+ this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
+ this->public.payload_interface.set_next_type = (status_t (*) (payload_t *,payload_type_t)) set_next_type;
+ this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
+ this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
+
+ /* public functions */
+ this->public.create_payload_iterator = (status_t (*) (encryption_payload_t *,iterator_t **,bool)) create_payload_iterator;
+ this->public.add_payload = (status_t (*) (encryption_payload_t *,payload_t *)) add_payload;
+ this->public.encrypt = (status_t (*) (encryption_payload_t *, crypter_t*)) encrypt;
+ this->public.decrypt = (status_t (*) (encryption_payload_t *, crypter_t*)) decrypt;
+ this->public.set_signer = (status_t (*) (encryption_payload_t *,signer_t*)) set_signer;
+ this->public.build_signature = (status_t (*) (encryption_payload_t*, chunk_t)) build_signature;
+ this->public.verify_signature = (status_t (*) (encryption_payload_t*, chunk_t)) verify_signature;
+ this->public.destroy = (status_t (*) (encryption_payload_t *)) destroy;
+
+ /* private functions */
+ this->compute_length = compute_length;
+ this->generate = generate;
+ this->parse = parse;
+
+ /* set default values of the fields */
+ this->critical = TRUE;
+ this->next_payload = NO_PAYLOAD;
+ this->payload_length = ENCRYPTION_PAYLOAD_HEADER_LENGTH;
+ this->iv = CHUNK_INITIALIZER;
+ this->encrypted = CHUNK_INITIALIZER;
+ this->decrypted = CHUNK_INITIALIZER;
+ this->checksum = CHUNK_INITIALIZER;
+ this->signer = NULL;
+
+ this->payloads = linked_list_create();
+
+ if (this->payloads == NULL)
+ {
+ allocator_free(this);
+ return NULL;
+ }
+ return (&(this->public));
+}
+
+
projects / people / ms / strongswan.git / commitdiff
