denozord/strongswan-ext
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

libipsec: Wrap traditional algorithms in AEAD wrapper

Browse Source
This commit is contained in:
Tobias Brunner
2013-05-03 15:13:57 +02:00
parent 61fb3267b2
commit 24a8d1253f
3 changed files with 105 additions and 124 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libipsec/esp_packet.c
+27 -40
View File
@@ -1,5 +1,5 @@
/*
* Copyright (C) 2012 Tobias Brunner
* Copyright (C) 2012-2013 Tobias Brunner
* Copyright (C) 2012 Giuliano Grassi
* Copyright (C) 2012 Ralf Sager
* Hochschule fuer Technik Rapperswil
@@ -212,28 +212,27 @@ METHOD(esp_packet_t, decrypt, status_t,
{
bio_reader_t *reader;
u_int32_t spi, seq;
chunk_t data, iv, icv, ciphertext, plaintext;
crypter_t *crypter;
signer_t *signer;
chunk_t data, iv, icv, aad, ciphertext, plaintext;
aead_t *aead;
DESTROY_IF(this->payload);
this->payload = NULL;
data = this->packet->get_data(this->packet);
crypter = esp_context->get_crypter(esp_context);
signer = esp_context->get_signer(esp_context);
aead = esp_context->get_aead(esp_context);
reader = bio_reader_create(data);
if (!reader->read_uint32(reader, &spi) ||
!reader->read_uint32(reader, &seq) ||
!reader->read_data(reader, crypter->get_iv_size(crypter), &iv) ||
!reader->read_data_end(reader, signer->get_block_size(signer), &icv) ||
reader->remaining(reader) % crypter->get_block_size(crypter))
!reader->read_data(reader, aead->get_iv_size(aead), &iv) ||
!reader->read_data_end(reader, aead->get_icv_size(aead), &icv) ||
reader->remaining(reader) % aead->get_block_size(aead))
{
DBG1(DBG_ESP, "ESP decryption failed: invalid length");
return PARSE_ERROR;
}
ciphertext = reader->peek(reader);
ciphertext.len += icv.len;
reader->destroy(reader);
if (!esp_context->verify_seqno(esp_context, seq))
@@ -246,21 +245,16 @@ METHOD(esp_packet_t, decrypt, status_t,
DBG3(DBG_ESP, "ESP decryption:\n SPI %.8x [seq %u]\n IV %B\n "
"encrypted %B\n ICV %B", spi, seq, &iv, &ciphertext, &icv);
if (!signer->get_signature(signer, chunk_create(data.ptr, 8), NULL) ||
!signer->get_signature(signer, iv, NULL) ||
!signer->verify_signature(signer, ciphertext, icv))
/* aad = spi + seq */
aad = chunk_create(data.ptr, 8);
if (!aead->decrypt(aead, ciphertext, aad, iv, &plaintext))
{
DBG1(DBG_ESP, "ICV verification failed!");
DBG1(DBG_ESP, "ESP decryption or ICV verification failed");
return FAILED;
}
esp_context->set_authenticated_seqno(esp_context, seq);
if (!crypter->decrypt(crypter, ciphertext, iv, &plaintext))
{
DBG1(DBG_ESP, "ESP decryption failed");
return FAILED;
}
if (!remove_padding(this, plaintext))
{
return PARSE_ERROR;
@@ -284,12 +278,11 @@ static void generate_padding(chunk_t padding)
METHOD(esp_packet_t, encrypt, status_t,
private_esp_packet_t *this, esp_context_t *esp_context, u_int32_t spi)
{
chunk_t iv, icv, padding, payload, ciphertext, auth_data;
chunk_t iv, icv, aad, padding, payload, ciphertext;
bio_writer_t *writer;
u_int32_t next_seqno;
size_t blocksize, plainlen;
crypter_t *crypter;
signer_t *signer;
aead_t *aead;
rng_t *rng;
this->packet->set_data(this->packet, chunk_empty);
@@ -306,12 +299,11 @@ METHOD(esp_packet_t, encrypt, status_t,
DBG1(DBG_ESP, "ESP encryption failed: could not find RNG");
return NOT_FOUND;
}
crypter = esp_context->get_crypter(esp_context);
signer = esp_context->get_signer(esp_context);
aead = esp_context->get_aead(esp_context);
blocksize = crypter->get_block_size(crypter);
iv.len = crypter->get_iv_size(crypter);
icv.len = signer->get_block_size(signer);
blocksize = aead->get_block_size(aead);
iv.len = aead->get_iv_size(aead);
icv.len = aead->get_icv_size(aead);
/* plaintext = payload, padding, pad_length, next_header */
payload = this->payload ? this->payload->get_encoding(this->payload)
@@ -349,24 +341,19 @@ METHOD(esp_packet_t, encrypt, status_t,
writer->write_uint8(writer, padding.len);
writer->write_uint8(writer, this->next_header);
/* aad = spi + seq */
aad = writer->get_buf(writer);
aad.len = 8;
icv = writer->skip(writer, icv.len);
DBG3(DBG_ESP, "ESP before encryption:\n payload = %B\n padding = %B\n "
"padding length = %hhu, next header = %hhu", &payload, &padding,
(u_int8_t)padding.len, this->next_header);
/* encrypt the content inline */
if (!crypter->encrypt(crypter, ciphertext, iv, NULL))
/* encrypt/authenticate the content inline */
if (!aead->encrypt(aead, ciphertext, aad, iv, NULL))
{
DBG1(DBG_ESP, "ESP encryption failed");
writer->destroy(writer);
return FAILED;
}
/* calculate signature */
auth_data = writer->get_buf(writer);
icv = writer->skip(writer, icv.len);
if (!signer->get_signature(signer, auth_data, icv.ptr))
{
DBG1(DBG_ESP, "ESP encryption failed: signature generation failed");
DBG1(DBG_ESP, "ESP encryption or ICV generation failed");
writer->destroy(writer);
return FAILED;
}