/**
* \ingroup Core_WritePackets
* \brief Writes a User Id packet
* \param id
* \param output
* \return 1 if OK, otherwise 0
*/
unsigned
pgp_write_struct_userid(pgp_output_t *output, const uint8_t *id)
{
return pgp_write_ptag(output, PGP_PTAG_CT_USER_ID) &&
pgp_write_length(output, (unsigned)strlen((const char *) id)) &&
pgp_write(output, id, (unsigned)strlen((const char *) id));
}
/**
* \ingroup Core_WritePackets
* \brief Writes a Public Key packet
* \param key
* \param output
* \return 1 if OK, otherwise 0
*/
static unsigned
write_struct_pubkey(pgp_output_t *output, const pgp_pubkey_t *key)
{
return pgp_write_ptag(output, PGP_PTAG_CT_PUBLIC_KEY) &&
pgp_write_length(output, 1 + 4 + 1 + pubkey_length(key)) &&
write_pubkey_body(key, output);
}
/**
\ingroup Core_WritePackets
\brief Write Symmetrically Encrypted packet
\param data Data to encrypt
\param len Length of data
\param output Write settings
\return 1 if OK; else 0
\note Hard-coded to use AES256
*/
unsigned
pgp_write_symm_enc_data(const uint8_t *data,
const int len,
pgp_output_t * output)
{
pgp_crypt_t crypt_info;
uint8_t *encrypted = (uint8_t *) NULL;
size_t encrypted_sz;
int done = 0;
/* \todo assume AES256 for now */
pgp_crypt_any(&crypt_info, PGP_SA_AES_256);
pgp_encrypt_init(&crypt_info);
encrypted_sz = (size_t)(len + crypt_info.blocksize + 2);
if ((encrypted = calloc(1, encrypted_sz)) == NULL) {
(void) fprintf(stderr, "can't allocate %" PRIsize "d\n",
encrypted_sz);
return 0;
}
done = (int)pgp_encrypt_se(&crypt_info, encrypted, data, (unsigned)len);
if (done != len) {
(void) fprintf(stderr,
"pgp_write_symm_enc_data: done != len\n");
return 0;
}
return pgp_write_ptag(output, PGP_PTAG_CT_SE_DATA) &&
pgp_write_length(output, (unsigned)(1 + encrypted_sz)) &&
pgp_write(output, data, (unsigned)len);
}
unsigned
pgp_write_mdc(pgp_output_t *output, const uint8_t *hashed)
{
/* write it out */
return pgp_write_ptag(output, PGP_PTAG_CT_MDC) &&
pgp_write_length(output, PGP_SHA1_HASH_SIZE) &&
pgp_write(output, hashed, PGP_SHA1_HASH_SIZE);
}
unsigned
pgp_write_ss_header(pgp_output_t *output,
unsigned length,
pgp_content_enum type)
{
return pgp_write_length(output, length) &&
pgp_write_scalar(output, (unsigned)(type -
(unsigned)PGP_PTAG_SIG_SUBPKT_BASE), 1);
}
/**
\ingroup Core_WritePackets
\brief Writes Public Key Session Key packet
\param info Write settings
\param pksk Public Key Session Key to write out
\return 1 if OK; else 0
*/
unsigned
pgp_write_pk_sesskey(pgp_output_t *output, pgp_pk_sesskey_t *pksk)
{
/* XXX - Flexelint - Pointer parameter 'pksk' (line 1076) could be declared as pointing to const */
if (pksk == NULL) {
(void) fprintf(stderr,
"pgp_write_pk_sesskey: NULL pksk\n");
return 0;
}
switch (pksk->alg) {
case PGP_PKA_RSA:
return pgp_write_ptag(output, PGP_PTAG_CT_PK_SESSION_KEY) &&
pgp_write_length(output, (unsigned)(1 + 8 + 1 +
BN_num_bytes(pksk->params.rsa.encrypted_m) + 2)) &&
pgp_write_scalar(output, (unsigned)pksk->version, 1) &&
pgp_write(output, pksk->key_id, 8) &&
pgp_write_scalar(output, (unsigned)pksk->alg, 1) &&
pgp_write_mpi(output, pksk->params.rsa.encrypted_m)
/* ?? && pgp_write_scalar(output, 0, 2); */
;
case PGP_PKA_DSA:
case PGP_PKA_ELGAMAL:
return pgp_write_ptag(output, PGP_PTAG_CT_PK_SESSION_KEY) &&
pgp_write_length(output, (unsigned)(1 + 8 + 1 +
BN_num_bytes(pksk->params.elgamal.g_to_k) + 2 +
BN_num_bytes(pksk->params.elgamal.encrypted_m) + 2)) &&
pgp_write_scalar(output, (unsigned)pksk->version, 1) &&
pgp_write(output, pksk->key_id, 8) &&
pgp_write_scalar(output, (unsigned)pksk->alg, 1) &&
pgp_write_mpi(output, pksk->params.elgamal.g_to_k) &&
pgp_write_mpi(output, pksk->params.elgamal.encrypted_m)
/* ?? && pgp_write_scalar(output, 0, 2); */
;
default:
(void) fprintf(stderr,
"pgp_write_pk_sesskey: bad algorithm\n");
return 0;
}
}
/**
\ingroup Core_WritePackets
\brief Write a One Pass Signature packet
\param seckey Secret Key to use
\param hash_alg Hash Algorithm to use
\param sig_type Signature type
\param output Write settings
\return 1 if OK; else 0
*/
unsigned
pgp_write_one_pass_sig(pgp_output_t *output,
const pgp_seckey_t *seckey,
const pgp_hash_alg_t hash_alg,
const pgp_sig_type_t sig_type)
{
uint8_t keyid[PGP_KEY_ID_SIZE];
pgp_keyid(keyid, PGP_KEY_ID_SIZE, &seckey->pubkey, PGP_HASH_SHA1); /* XXX - hardcoded */
return pgp_write_ptag(output, PGP_PTAG_CT_1_PASS_SIG) &&
pgp_write_length(output, 1 + 1 + 1 + 1 + 8 + 1) &&
pgp_write_scalar(output, 3, 1) /* version */ &&
pgp_write_scalar(output, (unsigned)sig_type, 1) &&
pgp_write_scalar(output, (unsigned)hash_alg, 1) &&
pgp_write_scalar(output, (unsigned)seckey->pubkey.alg, 1) &&
pgp_write(output, keyid, 8) &&
pgp_write_scalar(output, 1, 1);
}
/**
\ingroup Core_WritePackets
\brief Writes Literal Data packet from buffer
\param data Buffer to write out
\param maxlen Max length of buffer
\param type Literal Data Type
\param output Write settings
\return 1 if OK; else 0
*/
unsigned
pgp_write_litdata(pgp_output_t *output,
const uint8_t *data,
const int maxlen,
const pgp_litdata_enum type)
{
/*
* RFC4880 does not specify a meaning for filename or date.
* It is implementation-dependent.
* We will not implement them.
*/
/* \todo do we need to check text data for <cr><lf> line endings ? */
return pgp_write_ptag(output, PGP_PTAG_CT_LITDATA) &&
pgp_write_length(output, (unsigned)(1 + 1 + 4 + maxlen)) &&
pgp_write_scalar(output, (unsigned)type, 1) &&
pgp_write_scalar(output, 0, 1) &&
pgp_write_scalar(output, 0, 4) &&
pgp_write(output, data, (unsigned)maxlen);
}
unsigned
pgp_write_sig(pgp_output_t *output,
pgp_create_sig_t *sig,
const pgp_pubkey_t *key,
const pgp_seckey_t *seckey)
{
unsigned ret = 0;
size_t len = pgp_mem_len(sig->mem);
/* check key not decrypted */
switch (seckey->pubkey.alg) {
case PGP_PKA_RSA:
case PGP_PKA_RSA_ENCRYPT_ONLY:
case PGP_PKA_RSA_SIGN_ONLY:
if (seckey->key.rsa.d == NULL) {
(void) fprintf(stderr, "pgp_write_sig: null rsa.d\n");
return 0;
}
break;
case PGP_PKA_DSA:
if (seckey->key.dsa.x == NULL) {
(void) fprintf(stderr, "pgp_write_sig: null dsa.x\n");
return 0;
}
break;
default:
(void) fprintf(stderr, "Unsupported algorithm %d\n",
seckey->pubkey.alg);
return 0;
}
if (sig->hashlen == (unsigned) -1) {
(void) fprintf(stderr,
"ops_write_sig: bad hashed data len\n");
return 0;
}
pgp_memory_place_int(sig->mem, sig->unhashoff,
(unsigned)(len - sig->unhashoff - 2), 2);
/* add the packet from version number to end of hashed subpackets */
if (pgp_get_debug_level(__FILE__)) {
(void) fprintf(stderr, "ops_write_sig: hashed packet info\n");
}
sig->hash.add(&sig->hash, pgp_mem_data(sig->mem), sig->unhashoff);
/* add final trailer */
pgp_hash_add_int(&sig->hash, (unsigned)sig->sig.info.version, 1);
pgp_hash_add_int(&sig->hash, 0xff, 1);
/* +6 for version, type, pk alg, hash alg, hashed subpacket length */
pgp_hash_add_int(&sig->hash, sig->hashlen + 6, 4);
if (pgp_get_debug_level(__FILE__)) {
(void) fprintf(stderr, "ops_write_sig: done writing hashed\n");
}
/* XXX: technically, we could figure out how big the signature is */
/* and write it directly to the output instead of via memory. */
switch (seckey->pubkey.alg) {
case PGP_PKA_RSA:
case PGP_PKA_RSA_ENCRYPT_ONLY:
case PGP_PKA_RSA_SIGN_ONLY:
if (!rsa_sign(&sig->hash, &key->key.rsa, &seckey->key.rsa,
sig->output)) {
(void) fprintf(stderr,
"pgp_write_sig: rsa_sign failure\n");
return 0;
}
break;
case PGP_PKA_DSA:
if (!dsa_sign(&sig->hash, &key->key.dsa, &seckey->key.dsa,
sig->output)) {
(void) fprintf(stderr,
"pgp_write_sig: dsa_sign failure\n");
return 0;
}
break;
default:
(void) fprintf(stderr, "Unsupported algorithm %d\n",
seckey->pubkey.alg);
return 0;
}
ret = pgp_write_ptag(output, PGP_PTAG_CT_SIGNATURE);
if (ret) {
len = pgp_mem_len(sig->mem);
ret = pgp_write_length(output, (unsigned)len) &&
pgp_write(output, pgp_mem_data(sig->mem), (unsigned)len);
}
pgp_memory_free(sig->mem);
if (ret == 0) {
PGP_ERROR_1(&output->errors, PGP_E_W, "%s",
"Cannot write signature");
}
return ret;
}
/**
* \ingroup Core_WritePackets
* \brief Writes a Secret Key packet.
* \param key The secret key
* \param passphrase The passphrase
* \param pplen Length of passphrase
* \param output
* \return 1 if OK; else 0
*/
unsigned
pgp_write_struct_seckey(const pgp_seckey_t *key,
const uint8_t *passphrase,
const size_t pplen,
pgp_output_t *output)
{
int length = 0;
if (key->pubkey.version != 4) {
(void) fprintf(stderr,
"pgp_write_struct_seckey: public key version\n");
return 0;
}
/* Ref: RFC4880 Section 5.5.3 */
/* pubkey, excluding MPIs */
length += 1 + 4 + 1 + 1;
/* s2k usage */
length += 1;
switch (key->s2k_usage) {
case PGP_S2KU_NONE:
/* nothing to add */
break;
case PGP_S2KU_ENCRYPTED_AND_HASHED: /* 254 */
case PGP_S2KU_ENCRYPTED: /* 255 */
/* Ref: RFC4880 Section 3.7 */
length += 1; /* s2k_specifier */
switch (key->s2k_specifier) {
case PGP_S2KS_SIMPLE:
length += 1; /* hash algorithm */
break;
case PGP_S2KS_SALTED:
length += 1 + 8; /* hash algorithm + salt */
break;
case PGP_S2KS_ITERATED_AND_SALTED:
length += 1 + 8 + 1; /* hash algorithm, salt +
* count */
break;
default:
(void) fprintf(stderr,
"pgp_write_struct_seckey: s2k spec\n");
return 0;
}
break;
default:
(void) fprintf(stderr,
"pgp_write_struct_seckey: s2k usage\n");
return 0;
}
/* IV */
if (key->s2k_usage) {
length += pgp_block_size(key->alg);
}
/* checksum or hash */
switch (key->s2k_usage) {
case PGP_S2KU_NONE:
case PGP_S2KU_ENCRYPTED:
length += 2;
break;
case PGP_S2KU_ENCRYPTED_AND_HASHED:
length += PGP_CHECKHASH_SIZE;
break;
default:
(void) fprintf(stderr,
"pgp_write_struct_seckey: s2k cksum usage\n");
return 0;
}
/* secret key and public key MPIs */
length += (unsigned)seckey_length(key);
return pgp_write_ptag(output, PGP_PTAG_CT_SECRET_KEY) &&
/* pgp_write_length(output,1+4+1+1+seckey_length(key)+2) && */
pgp_write_length(output, (unsigned)length) &&
write_seckey_body(key, passphrase, pplen, output);
}
int dc_pgp_symm_encrypt(dc_context_t* context,
const char* passphrase,
const void* plain, size_t plain_bytes,
char** ret_ctext_armored)
{
int success = 0;
uint8_t salt[PGP_SALT_SIZE];
pgp_crypt_t crypt_info;
uint8_t* key = NULL;
pgp_output_t* payload_output = NULL;
pgp_memory_t* payload_mem = NULL;
pgp_output_t* encr_output = NULL;
pgp_memory_t* encr_mem = NULL;
if (context==NULL || passphrase==NULL || plain==NULL || plain_bytes==0
|| ret_ctext_armored==NULL ) {
goto cleanup;
}
//printf("\n~~~~~~~~~~~~~~~~~~~~SETUP-PAYLOAD~~~~~~~~~~~~~~~~~~~~\n%s~~~~~~~~~~~~~~~~~~~~/SETUP-PAYLOAD~~~~~~~~~~~~~~~~~~~~\n",key_asc); // DEBUG OUTPUT
/* put the payload into a literal data packet which will be encrypted then, see RFC 4880, 5.7 :
"When it has been decrypted, it contains other packets (usually a literal data packet or compressed data
packet, but in theory other Symmetrically Encrypted Data packets or sequences of packets that form whole OpenPGP messages)" */
pgp_setup_memory_write(&payload_output, &payload_mem, 128);
pgp_write_litdata(payload_output, (const uint8_t*)plain, plain_bytes, PGP_LDT_BINARY);
/* create salt for the key */
pgp_random(salt, PGP_SALT_SIZE);
/* S2K */
#define SYMM_ALGO PGP_SA_AES_128
if (!pgp_crypt_any(&crypt_info, SYMM_ALGO)) {
goto cleanup;
}
int s2k_spec = PGP_S2KS_ITERATED_AND_SALTED; // 0=simple, 1=salted, 3=salted+iterated
int s2k_iter_id = 96; // 0=1024 iterations, 96=65536 iterations
#define HASH_ALG PGP_HASH_SHA256
if ((key = pgp_s2k_do(passphrase, crypt_info.keysize, s2k_spec, HASH_ALG, salt, s2k_iter_id))==NULL) {
goto cleanup;
}
/* encrypt the payload using the key using AES-128 and put it into
OpenPGP's "Symmetric-Key Encrypted Session Key" (Tag 3, https://tools.ietf.org/html/rfc4880#section-5.3) followed by
OpenPGP's "Symmetrically Encrypted Data Packet" (Tag 18, https://tools.ietf.org/html/rfc4880#section-5.13 , better than Tag 9) */
pgp_setup_memory_write(&encr_output, &encr_mem, 128);
pgp_writer_push_armor_msg(encr_output);
/* Tag 3 - PGP_PTAG_CT_SK_SESSION_KEY */
pgp_write_ptag (encr_output, PGP_PTAG_CT_SK_SESSION_KEY);
pgp_write_length (encr_output, 1/*version*/
+ 1/*symm. algo*/
+ 1/*s2k_spec*/
+ 1/*S2 hash algo*/
+ ((s2k_spec==PGP_S2KS_SALTED || s2k_spec==PGP_S2KS_ITERATED_AND_SALTED)? PGP_SALT_SIZE : 0)/*the salt*/
+ ((s2k_spec==PGP_S2KS_ITERATED_AND_SALTED)? 1 : 0)/*number of iterations*/);
pgp_write_scalar (encr_output, 4, 1); // 1 octet: version
pgp_write_scalar (encr_output, SYMM_ALGO, 1); // 1 octet: symm. algo
pgp_write_scalar (encr_output, s2k_spec, 1); // 1 octet: s2k_spec
pgp_write_scalar (encr_output, HASH_ALG, 1); // 1 octet: S2 hash algo
if (s2k_spec==PGP_S2KS_SALTED || s2k_spec==PGP_S2KS_ITERATED_AND_SALTED) {
pgp_write (encr_output, salt, PGP_SALT_SIZE); // 8 octets: the salt
}
if (s2k_spec==PGP_S2KS_ITERATED_AND_SALTED) {
pgp_write_scalar (encr_output, s2k_iter_id, 1); // 1 octet: number of iterations
}
// for(int j=0; j<AES_KEY_LENGTH; j++) { printf("%02x", key[j]); } printf("\n----------------\n");
/* Tag 18 - PGP_PTAG_CT_SE_IP_DATA */
//pgp_write_symm_enc_data((const uint8_t*)payload_mem->buf, payload_mem->length, PGP_SA_AES_128, key, encr_output); //-- would generate Tag 9
{
uint8_t* iv = calloc(1, crypt_info.blocksize); if (iv==NULL) { goto cleanup; }
crypt_info.set_iv(&crypt_info, iv);
free(iv);
crypt_info.set_crypt_key(&crypt_info, &key[0]);
pgp_encrypt_init(&crypt_info);
pgp_write_se_ip_pktset(encr_output, payload_mem->buf, payload_mem->length, &crypt_info);
crypt_info.decrypt_finish(&crypt_info);
}
/* done with symmetric key block */
pgp_writer_close(encr_output);
*ret_ctext_armored = dc_null_terminate((const char*)encr_mem->buf, encr_mem->length);
//printf("\n~~~~~~~~~~~~~~~~~~~~SYMMETRICALLY ENCRYPTED~~~~~~~~~~~~~~~~~~~~\n%s~~~~~~~~~~~~~~~~~~~~/SYMMETRICALLY ENCRYPTED~~~~~~~~~~~~~~~~~~~~\n",encr_string); // DEBUG OUTPUT
success = 1;
cleanup:
if (payload_output) { pgp_output_delete(payload_output); }
if (payload_mem) { pgp_memory_free(payload_mem); }
if (encr_output) { pgp_output_delete(encr_output); }
if (encr_mem) { pgp_memory_free(encr_mem); }
free(key);
return success;
}
unsigned
pgp_writez(pgp_output_t *out, const uint8_t *data, const unsigned len)
{
compress_t *zip;
size_t sz_in;
size_t sz_out;
int ret;
int r = 0;
/* compress the data */
const int level = Z_DEFAULT_COMPRESSION; /* \todo allow varying
* levels */
if ((zip = calloc(1, sizeof(*zip))) == NULL) {
(void) fprintf(stderr, "pgp_writez: bad alloc\n");
return 0;
}
zip->stream.zalloc = Z_NULL;
zip->stream.zfree = Z_NULL;
zip->stream.opaque = NULL;
/* all other fields set to zero by use of calloc */
/* LINTED */ /* this is a lint problem in zlib.h header */
if ((int)deflateInit(&zip->stream, level) != Z_OK) {
(void) fprintf(stderr, "pgp_writez: can't initialise\n");
return 0;
}
/* do necessary transformation */
/* copy input to maintain const'ness of src */
if (zip->src != NULL || zip->dst != NULL) {
(void) fprintf(stderr, "pgp_writez: non-null streams\n");
return 0;
}
sz_in = len * sizeof(uint8_t);
sz_out = ((101 * sz_in) / 100) + 12; /* from zlib webpage */
if ((zip->src = calloc(1, sz_in)) == NULL) {
free(zip);
(void) fprintf(stderr, "pgp_writez: bad alloc2\n");
return 0;
}
if ((zip->dst = calloc(1, sz_out)) == NULL) {
free(zip->src);
free(zip);
(void) fprintf(stderr, "pgp_writez: bad alloc3\n");
return 0;
}
(void) memcpy(zip->src, data, len);
/* setup stream */
zip->stream.next_in = zip->src;
zip->stream.avail_in = (unsigned)sz_in;
zip->stream.total_in = 0;
zip->stream.next_out = zip->dst;
zip->stream.avail_out = (unsigned)sz_out;
zip->stream.total_out = 0;
do {
r = deflate(&zip->stream, Z_FINISH);
} while (r != Z_STREAM_END);
/* write it out */
ret = pgp_write_ptag(out, PGP_PTAG_CT_COMPRESSED) &&
pgp_write_length(out, (unsigned)(zip->stream.total_out + 1))&&
pgp_write_scalar(out, PGP_C_ZLIB, 1) &&
pgp_write(out, zip->dst, (unsigned)zip->stream.total_out);
free(zip->src);
free(zip->dst);
free(zip);
return ret;
}
