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-rw-r--r--src/libcharon/encoding/payloads/encryption_payload.c619
1 files changed, 619 insertions, 0 deletions
diff --git a/src/libcharon/encoding/payloads/encryption_payload.c b/src/libcharon/encoding/payloads/encryption_payload.c
new file mode 100644
index 000000000..2adbb88b9
--- /dev/null
+++ b/src/libcharon/encoding/payloads/encryption_payload.c
@@ -0,0 +1,619 @@
+/*
+ * Copyright (C) 2005-2006 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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.
+ */
+
+#include <stddef.h>
+#include <string.h>
+
+#include "encryption_payload.h"
+
+#include <daemon.h>
+#include <encoding/payloads/encodings.h>
+#include <utils/linked_list.h>
+#include <encoding/generator.h>
+#include <encoding/parser.h>
+#include <utils/iterator.h>
+#include <crypto/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;
+
+ /**
+ * 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;
+
+ /**
+ * Crypter, supplied by encrypt/decrypt
+ */
+ crypter_t *crypter;
+
+ /**
+ * Contained payloads of this encrpytion_payload.
+ */
+ linked_list_t *payloads;
+};
+
+/**
+ * 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 ~
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+/**
+ * Implementation of payload_t.verify.
+ */
+static status_t verify(private_encryption_payload_t *this)
+{
+ return SUCCESS;
+}
+
+/**
+ * Implementation of payload_t.get_encoding_rules.
+ */
+static void 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);
+}
+
+/**
+ * Implementation of payload_t.get_type.
+ */
+static payload_type_t get_type(private_encryption_payload_t *this)
+{
+ return ENCRYPTED;
+}
+
+/**
+ * Implementation of 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);
+}
+
+/**
+ * Implementation of payload_t.set_next_type.
+ */
+static void 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
+ * and so nothing is done in here*/
+}
+
+/**
+ * (re-)compute the lenght of the whole payload
+ */
+static void compute_length(private_encryption_payload_t *this)
+{
+ iterator_t *iterator;
+ payload_t *current_payload;
+ size_t block_size, length = 0;
+ iterator = this->payloads->create_iterator(this->payloads, TRUE);
+
+ /* count payload length */
+ while (iterator->iterate(iterator, (void **) &current_payload))
+ {
+ length += current_payload->get_length(current_payload);
+ }
+ iterator->destroy(iterator);
+
+ if (this->crypter && this->signer)
+ {
+ /* append one byte for padding length */
+ length++;
+ /* append padding */
+ block_size = this->crypter->get_block_size(this->crypter);
+ length += block_size - length % block_size;
+ /* add iv */
+ length += block_size;
+ /* add signature */
+ length += this->signer->get_block_size(this->signer);
+ }
+ length += ENCRYPTION_PAYLOAD_HEADER_LENGTH;
+ this->payload_length = length;
+}
+
+/**
+ * Implementation of payload_t.get_length.
+ */
+static size_t get_length(private_encryption_payload_t *this)
+{
+ compute_length(this);
+ return this->payload_length;
+}
+
+/**
+ * Implementation of payload_t.create_payload_iterator.
+ */
+static iterator_t *create_payload_iterator (private_encryption_payload_t *this, bool forward)
+{
+ return (this->payloads->create_iterator(this->payloads, forward));
+}
+
+/**
+ * Implementation of payload_t.add_payload.
+ */
+static void 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);
+ last_payload->set_next_type(last_payload, payload->get_type(payload));
+ }
+ else
+ {
+ this->next_payload = payload->get_type(payload);
+ }
+ payload->set_next_type(payload, NO_PAYLOAD);
+ this->payloads->insert_last(this->payloads, (void*)payload);
+ compute_length(this);
+}
+
+/**
+ * Implementation of encryption_payload_t.remove_first_payload.
+ */
+static status_t remove_first_payload(private_encryption_payload_t *this, payload_t **payload)
+{
+ return this->payloads->remove_first(this->payloads, (void**)payload);
+}
+
+/**
+ * Implementation of encryption_payload_t.get_payload_count.
+ */
+static size_t get_payload_count(private_encryption_payload_t *this)
+{
+ return this->payloads->get_count(this->payloads);
+}
+
+/**
+ * Generate payload before encryption.
+ */
+static void generate(private_encryption_payload_t *this)
+{
+ payload_t *current_payload, *next_payload;
+ generator_t *generator;
+ iterator_t *iterator;
+
+ /* recalculate length before generating */
+ compute_length(this);
+
+ /* create iterator */
+ iterator = this->payloads->create_iterator(this->payloads, TRUE);
+
+ /* get first payload */
+ if (iterator->iterate(iterator, (void**)&current_payload))
+ {
+ this->next_payload = current_payload->get_type(current_payload);
+ }
+ else
+ {
+ /* no paylads? */
+ DBG2(DBG_ENC, "generating contained payloads, but none available");
+ free(this->decrypted.ptr);
+ this->decrypted = chunk_empty;
+ iterator->destroy(iterator);
+ return;
+ }
+
+ generator = generator_create();
+
+ /* build all payload, except last */
+ while(iterator->iterate(iterator, (void**)&next_payload))
+ {
+ current_payload->set_next_type(current_payload, next_payload->get_type(next_payload));
+ generator->generate_payload(generator, current_payload);
+ current_payload = next_payload;
+ }
+ iterator->destroy(iterator);
+
+ /* build last payload */
+ current_payload->set_next_type(current_payload, NO_PAYLOAD);
+ generator->generate_payload(generator, current_payload);
+
+ /* free already generated data */
+ free(this->decrypted.ptr);
+
+ generator->write_to_chunk(generator, &(this->decrypted));
+ generator->destroy(generator);
+ DBG2(DBG_ENC, "successfully generated content in encryption payload");
+}
+
+/**
+ * Implementation of encryption_payload_t.encrypt.
+ */
+static status_t encrypt(private_encryption_payload_t *this)
+{
+ chunk_t iv, padding, to_crypt, result;
+ rng_t *rng;
+ size_t block_size;
+
+ if (this->signer == NULL || this->crypter == NULL)
+ {
+ DBG1(DBG_ENC, "could not encrypt, signer/crypter not set");
+ return INVALID_STATE;
+ }
+
+ /* for random data in iv and padding */
+ rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
+ if (!rng)
+ {
+ DBG1(DBG_ENC, "could not encrypt, no RNG found");
+ return FAILED;
+ }
+ /* build payload chunk */
+ generate(this);
+
+ DBG2(DBG_ENC, "encrypting payloads");
+ DBG3(DBG_ENC, "data to encrypt %B", &this->decrypted);
+
+ /* build padding */
+ block_size = this->crypter->get_block_size(this->crypter);
+ padding.len = block_size - ((this->decrypted.len + 1) % block_size);
+ rng->allocate_bytes(rng, padding.len, &padding);
+
+ /* concatenate payload data, padding, padding len */
+ to_crypt.len = this->decrypted.len + padding.len + 1;
+ to_crypt.ptr = malloc(to_crypt.len);
+
+ memcpy(to_crypt.ptr, this->decrypted.ptr, this->decrypted.len);
+ memcpy(to_crypt.ptr + this->decrypted.len, padding.ptr, padding.len);
+ *(to_crypt.ptr + to_crypt.len - 1) = padding.len;
+
+ /* build iv */
+ iv.len = block_size;
+ rng->allocate_bytes(rng, iv.len, &iv);
+ rng->destroy(rng);
+
+ DBG3(DBG_ENC, "data before encryption with padding %B", &to_crypt);
+
+ /* encrypt to_crypt chunk */
+ free(this->encrypted.ptr);
+ this->crypter->encrypt(this->crypter, to_crypt, iv, &result);
+ free(padding.ptr);
+ free(to_crypt.ptr);
+
+ DBG3(DBG_ENC, "data after encryption %B", &result);
+
+ /* build encrypted result with iv and signature */
+ this->encrypted.len = iv.len + result.len + this->signer->get_block_size(this->signer);
+ free(this->encrypted.ptr);
+ this->encrypted.ptr = malloc(this->encrypted.len);
+
+ /* fill in result, signature is left out */
+ memcpy(this->encrypted.ptr, iv.ptr, iv.len);
+ memcpy(this->encrypted.ptr + iv.len, result.ptr, result.len);
+
+ free(result.ptr);
+ free(iv.ptr);
+ DBG3(DBG_ENC, "data after encryption with IV and (invalid) signature %B",
+ &this->encrypted);
+
+ return SUCCESS;
+}
+
+/**
+ * Parse the payloads after decryption.
+ */
+static status_t parse(private_encryption_payload_t *this)
+{
+ parser_t *parser;
+ status_t status;
+ payload_type_t current_payload_type;
+
+ /* build a parser on the decrypted data */
+ parser = parser_create(this->decrypted);
+
+ 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**)&current_payload);
+ if (status != SUCCESS)
+ {
+ parser->destroy(parser);
+ return PARSE_ERROR;
+ }
+
+ status = current_payload->verify(current_payload);
+ if (status != SUCCESS)
+ {
+ DBG1(DBG_ENC, "%N verification failed",
+ payload_type_names, current_payload->get_type(current_payload));
+ current_payload->destroy(current_payload);
+ parser->destroy(parser);
+ return VERIFY_ERROR;
+ }
+
+ /* get next payload type */
+ current_payload_type = current_payload->get_next_type(current_payload);
+
+ this->payloads->insert_last(this->payloads,current_payload);
+ }
+ parser->destroy(parser);
+ DBG2(DBG_ENC, "succesfully parsed content of encryption payload");
+ return SUCCESS;
+}
+
+/**
+ * Implementation of encryption_payload_t.encrypt.
+ */
+static status_t decrypt(private_encryption_payload_t *this)
+{
+ chunk_t iv, concatenated;
+ u_int8_t padding_length;
+
+ DBG2(DBG_ENC, "decrypting encryption payload");
+ DBG3(DBG_ENC, "data before decryption with IV and (invalid) signature %B",
+ &this->encrypted);
+
+ if (this->signer == NULL || this->crypter == NULL)
+ {
+ DBG1(DBG_ENC, "could not decrypt, no crypter/signer set");
+ return INVALID_STATE;
+ }
+
+ /* get IV */
+ iv.len = this->crypter->get_block_size(this->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);
+
+ /* concatenated must be a multiple of block_size of crypter */
+ if (concatenated.len < iv.len || concatenated.len % iv.len)
+ {
+ DBG1(DBG_ENC, "could not decrypt, invalid input");
+ return FAILED;
+ }
+
+ /* free previus data, if any */
+ free(this->decrypted.ptr);
+
+ DBG3(DBG_ENC, "data before decryption %B", &concatenated);
+
+ this->crypter->decrypt(this->crypter, concatenated, iv, &this->decrypted);
+
+ DBG3(DBG_ENC, "data after decryption with padding %B", &this->decrypted);
+
+ /* get padding length, sits just bevore signature */
+ padding_length = *(this->decrypted.ptr + this->decrypted.len - 1);
+ /* add one byte to the padding length, since the padding_length field is
+ * not included */
+ padding_length++;
+
+ /* check size again */
+ if (padding_length > concatenated.len || padding_length > this->decrypted.len)
+ {
+ DBG1(DBG_ENC, "decryption failed, invalid padding length found. Invalid key?");
+ /* decryption failed :-/ */
+ return FAILED;
+ }
+ this->decrypted.len -= padding_length;
+
+ /* free padding */
+ this->decrypted.ptr = realloc(this->decrypted.ptr, this->decrypted.len);
+ DBG3(DBG_ENC, "data after decryption without padding %B", &this->decrypted);
+ DBG2(DBG_ENC, "decryption successful, trying to parse content");
+ return parse(this);
+}
+
+/**
+ * Implementation of encryption_payload_t.set_transforms.
+ */
+static void set_transforms(private_encryption_payload_t *this, crypter_t* crypter, signer_t* signer)
+{
+ this->signer = signer;
+ this->crypter = crypter;
+}
+
+/**
+ * Implementation of 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)
+ {
+ DBG1(DBG_ENC, "unable to build signature, no signer set");
+ 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;
+ DBG2(DBG_ENC, "building signature");
+ this->signer->get_signature(this->signer, data_without_sig, sig.ptr);
+ return SUCCESS;
+}
+
+/**
+ * Implementation of 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)
+ {
+ DBG1(DBG_ENC, "unable to verify signature, no signer set");
+ return INVALID_STATE;
+ }
+ /* find signature in data chunk */
+ sig.len = this->signer->get_block_size(this->signer);
+ if (data.len <= sig.len)
+ {
+ DBG1(DBG_ENC, "unable to verify signature, invalid input");
+ 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;
+ valid = this->signer->verify_signature(this->signer, data_without_sig, sig);
+
+ if (!valid)
+ {
+ DBG1(DBG_ENC, "signature verification failed");
+ return FAILED;
+ }
+
+ DBG2(DBG_ENC, "signature verification successful");
+ return SUCCESS;
+}
+
+/**
+ * Implementation of payload_t.destroy.
+ */
+static void destroy(private_encryption_payload_t *this)
+{
+ this->payloads->destroy_offset(this->payloads, offsetof(payload_t, destroy));
+ free(this->encrypted.ptr);
+ free(this->decrypted.ptr);
+ free(this);
+}
+
+/*
+ * Described in header
+ */
+encryption_payload_t *encryption_payload_create()
+{
+ private_encryption_payload_t *this = malloc_thing(private_encryption_payload_t);
+
+ /* payload_t interface functions */
+ this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
+ this->public.payload_interface.get_encoding_rules = (void (*) (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 = (void (*) (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 = (void (*) (payload_t *))destroy;
+
+ /* public functions */
+ this->public.create_payload_iterator = (iterator_t * (*) (encryption_payload_t *,bool)) create_payload_iterator;
+ this->public.add_payload = (void (*) (encryption_payload_t *,payload_t *)) add_payload;
+ this->public.remove_first_payload = (status_t (*)(encryption_payload_t*, payload_t **)) remove_first_payload;
+ this->public.get_payload_count = (size_t (*)(encryption_payload_t*)) get_payload_count;
+
+ this->public.encrypt = (status_t (*) (encryption_payload_t *)) encrypt;
+ this->public.decrypt = (status_t (*) (encryption_payload_t *)) decrypt;
+ this->public.set_transforms = (void (*) (encryption_payload_t*,crypter_t*,signer_t*)) set_transforms;
+ 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 = (void (*) (encryption_payload_t *)) destroy;
+
+ /* set default values of the fields */
+ this->critical = FALSE;
+ this->next_payload = NO_PAYLOAD;
+ this->payload_length = ENCRYPTION_PAYLOAD_HEADER_LENGTH;
+ this->encrypted = chunk_empty;
+ this->decrypted = chunk_empty;
+ this->signer = NULL;
+ this->crypter = NULL;
+ this->payloads = linked_list_create();
+
+ return (&(this->public));
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 14:55:25 +0000