Mirror/Momentum-Firmware
1
0
Fork 0
mirror of https://github.com/Next-Flip/Momentum-Firmware.git synced 2026-05-14 22:28:36 -07:00
Code Issues Packages Projects Releases Wiki Activity

Add e-subghz chat app (by @twisted-pear)

Browse Source
This commit is contained in:
Willy-JL
2023-08-11 22:48:35 +02:00
parent a30ced8f17
commit 29c3031942
24 changed files with 4298 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

483
applications/external/esubghz_chat/crypto/aes.c vendored Normal file
View File

@@ -0,0 +1,483 @@
/******************************************************************************
*
* THIS SOURCE CODE IS HEREBY PLACED INTO THE PUBLIC DOMAIN FOR THE GOOD OF ALL
*
* This is a simple and straightforward implementation of the AES Rijndael
* 128-bit block cipher designed by Vincent Rijmen and Joan Daemen. The focus
* of this work was correctness & accuracy. It is written in 'C' without any
* particular focus upon optimization or speed. It should be endian (memory
* byte order) neutral since the few places that care are handled explicitly.
*
* This implementation of Rijndael was created by Steven M. Gibson of GRC.com.
*
* It is intended for general purpose use, but was written in support of GRC's
* reference implementation of the SQRL (Secure Quick Reliable Login) client.
*
* See: http://csrc.nist.gov/archive/aes/rijndael/wsdindex.html
*
* NO COPYRIGHT IS CLAIMED IN THIS WORK, HOWEVER, NEITHER IS ANY WARRANTY MADE
* REGARDING ITS FITNESS FOR ANY PARTICULAR PURPOSE. USE IT AT YOUR OWN RISK.
*
*******************************************************************************/
#include "aes.h"
static int aes_tables_inited = 0; // run-once flag for performing key
// expasion table generation (see below)
/*
* The following static local tables must be filled-in before the first use of
* the GCM or AES ciphers. They are used for the AES key expansion/scheduling
* and once built are read-only and thread safe. The "gcm_initialize" function
* must be called once during system initialization to populate these arrays
* for subsequent use by the AES key scheduler. If they have not been built
* before attempted use, an error will be returned to the caller.
*
* NOTE: GCM Encryption/Decryption does NOT REQUIRE AES decryption. Since
* GCM uses AES in counter-mode, where the AES cipher output is XORed with
* the GCM input, we ONLY NEED AES encryption. Thus, to save space AES
* decryption is typically disabled by setting AES_DECRYPTION to 0 in aes.h.
*/
// We always need our forward tables
static uchar FSb[256]; // Forward substitution box (FSb)
static uint32_t FT0[256]; // Forward key schedule assembly tables
static uint32_t FT1[256];
static uint32_t FT2[256];
static uint32_t FT3[256];
#if AES_DECRYPTION // We ONLY need reverse for decryption
static uchar RSb[256]; // Reverse substitution box (RSb)
static uint32_t RT0[256]; // Reverse key schedule assembly tables
static uint32_t RT1[256];
static uint32_t RT2[256];
static uint32_t RT3[256];
#endif /* AES_DECRYPTION */
static uint32_t RCON[10]; // AES round constants
/*
* Platform Endianness Neutralizing Load and Store Macro definitions
* AES wants platform-neutral Little Endian (LE) byte ordering
*/
#define GET_UINT32_LE(n,b,i) { \
(n) = ( (uint32_t) (b)[(i) ] ) \
| ( (uint32_t) (b)[(i) + 1] << 8 ) \
| ( (uint32_t) (b)[(i) + 2] << 16 ) \
| ( (uint32_t) (b)[(i) + 3] << 24 ); }
#define PUT_UINT32_LE(n,b,i) { \
(b)[(i) ] = (uchar) ( (n) ); \
(b)[(i) + 1] = (uchar) ( (n) >> 8 ); \
(b)[(i) + 2] = (uchar) ( (n) >> 16 ); \
(b)[(i) + 3] = (uchar) ( (n) >> 24 ); }
/*
* AES forward and reverse encryption round processing macros
*/
#define AES_FROUND(X0,X1,X2,X3,Y0,Y1,Y2,Y3) \
{ \
X0 = *RK++ ^ FT0[ ( Y0 ) & 0xFF ] ^ \
FT1[ ( Y1 >> 8 ) & 0xFF ] ^ \
FT2[ ( Y2 >> 16 ) & 0xFF ] ^ \
FT3[ ( Y3 >> 24 ) & 0xFF ]; \
\
X1 = *RK++ ^ FT0[ ( Y1 ) & 0xFF ] ^ \
FT1[ ( Y2 >> 8 ) & 0xFF ] ^ \
FT2[ ( Y3 >> 16 ) & 0xFF ] ^ \
FT3[ ( Y0 >> 24 ) & 0xFF ]; \
\
X2 = *RK++ ^ FT0[ ( Y2 ) & 0xFF ] ^ \
FT1[ ( Y3 >> 8 ) & 0xFF ] ^ \
FT2[ ( Y0 >> 16 ) & 0xFF ] ^ \
FT3[ ( Y1 >> 24 ) & 0xFF ]; \
\
X3 = *RK++ ^ FT0[ ( Y3 ) & 0xFF ] ^ \
FT1[ ( Y0 >> 8 ) & 0xFF ] ^ \
FT2[ ( Y1 >> 16 ) & 0xFF ] ^ \
FT3[ ( Y2 >> 24 ) & 0xFF ]; \
}
#define AES_RROUND(X0,X1,X2,X3,Y0,Y1,Y2,Y3) \
{ \
X0 = *RK++ ^ RT0[ ( Y0 ) & 0xFF ] ^ \
RT1[ ( Y3 >> 8 ) & 0xFF ] ^ \
RT2[ ( Y2 >> 16 ) & 0xFF ] ^ \
RT3[ ( Y1 >> 24 ) & 0xFF ]; \
\
X1 = *RK++ ^ RT0[ ( Y1 ) & 0xFF ] ^ \
RT1[ ( Y0 >> 8 ) & 0xFF ] ^ \
RT2[ ( Y3 >> 16 ) & 0xFF ] ^ \
RT3[ ( Y2 >> 24 ) & 0xFF ]; \
\
X2 = *RK++ ^ RT0[ ( Y2 ) & 0xFF ] ^ \
RT1[ ( Y1 >> 8 ) & 0xFF ] ^ \
RT2[ ( Y0 >> 16 ) & 0xFF ] ^ \
RT3[ ( Y3 >> 24 ) & 0xFF ]; \
\
X3 = *RK++ ^ RT0[ ( Y3 ) & 0xFF ] ^ \
RT1[ ( Y2 >> 8 ) & 0xFF ] ^ \
RT2[ ( Y1 >> 16 ) & 0xFF ] ^ \
RT3[ ( Y0 >> 24 ) & 0xFF ]; \
}
/*
* These macros improve the readability of the key
* generation initialization code by collapsing
* repetitive common operations into logical pieces.
*/
#define ROTL8(x) ( ( x << 8 ) & 0xFFFFFFFF ) | ( x >> 24 )
#define XTIME(x) ( ( x << 1 ) ^ ( ( x & 0x80 ) ? 0x1B : 0x00 ) )
#define MUL(x,y) ( ( x && y ) ? pow[(log[x]+log[y]) % 255] : 0 )
#define MIX(x,y) { y = ( (y << 1) | (y >> 7) ) & 0xFF; x ^= y; }
#define CPY128 { *RK++ = *SK++; *RK++ = *SK++; \
*RK++ = *SK++; *RK++ = *SK++; }
/******************************************************************************
*
* AES_INIT_KEYGEN_TABLES
*
* Fills the AES key expansion tables allocated above with their static
* data. This is not "per key" data, but static system-wide read-only
* table data. THIS FUNCTION IS NOT THREAD SAFE. It must be called once
* at system initialization to setup the tables for all subsequent use.
*
******************************************************************************/
void aes_init_keygen_tables( void )
{
int i, x, y, z; // general purpose iteration and computation locals
int pow[256];
int log[256];
if (aes_tables_inited) return;
// fill the 'pow' and 'log' tables over GF(2^8)
for( i = 0, x = 1; i < 256; i++ ) {
pow[i] = x;
log[x] = i;
x = ( x ^ XTIME( x ) ) & 0xFF;
}
// compute the round constants
for( i = 0, x = 1; i < 10; i++ ) {
RCON[i] = (uint32_t) x;
x = XTIME( x ) & 0xFF;
}
// fill the forward and reverse substitution boxes
FSb[0x00] = 0x63;
#if AES_DECRYPTION // whether AES decryption is supported
RSb[0x63] = 0x00;
#endif /* AES_DECRYPTION */
for( i = 1; i < 256; i++ ) {
x = y = pow[255 - log[i]];
MIX(x,y);
MIX(x,y);
MIX(x,y);
MIX(x,y);
FSb[i] = (uchar) ( x ^= 0x63 );
#if AES_DECRYPTION // whether AES decryption is supported
RSb[x] = (uchar) i;
#endif /* AES_DECRYPTION */
}
// generate the forward and reverse key expansion tables
for( i = 0; i < 256; i++ ) {
x = FSb[i];
y = XTIME( x ) & 0xFF;
z = ( y ^ x ) & 0xFF;
FT0[i] = ( (uint32_t) y ) ^ ( (uint32_t) x << 8 ) ^
( (uint32_t) x << 16 ) ^ ( (uint32_t) z << 24 );
FT1[i] = ROTL8( FT0[i] );
FT2[i] = ROTL8( FT1[i] );
FT3[i] = ROTL8( FT2[i] );
#if AES_DECRYPTION // whether AES decryption is supported
x = RSb[i];
RT0[i] = ( (uint32_t) MUL( 0x0E, x ) ) ^
( (uint32_t) MUL( 0x09, x ) << 8 ) ^
( (uint32_t) MUL( 0x0D, x ) << 16 ) ^
( (uint32_t) MUL( 0x0B, x ) << 24 );
RT1[i] = ROTL8( RT0[i] );
RT2[i] = ROTL8( RT1[i] );
RT3[i] = ROTL8( RT2[i] );
#endif /* AES_DECRYPTION */
}
aes_tables_inited = 1; // flag that the tables have been generated
} // to permit subsequent use of the AES cipher
/******************************************************************************
*
* AES_SET_ENCRYPTION_KEY
*
* This is called by 'aes_setkey' when we're establishing a key for
* subsequent encryption. We give it a pointer to the encryption
* context, a pointer to the key, and the key's length in bytes.
* Valid lengths are: 16, 24 or 32 bytes (128, 192, 256 bits).
*
******************************************************************************/
int aes_set_encryption_key( aes_context *ctx,
const uchar *key,
uint keysize )
{
uint i; // general purpose iteration local
uint32_t *RK = ctx->rk; // initialize our RoundKey buffer pointer
for( i = 0; i < (keysize >> 2); i++ ) {
GET_UINT32_LE( RK[i], key, i << 2 );
}
switch( ctx->rounds )
{
case 10:
for( i = 0; i < 10; i++, RK += 4 ) {
RK[4] = RK[0] ^ RCON[i] ^
( (uint32_t) FSb[ ( RK[3] >> 8 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( RK[3] >> 16 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( RK[3] >> 24 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( RK[3] ) & 0xFF ] << 24 );
RK[5] = RK[1] ^ RK[4];
RK[6] = RK[2] ^ RK[5];
RK[7] = RK[3] ^ RK[6];
}
break;
case 12:
for( i = 0; i < 8; i++, RK += 6 ) {
RK[6] = RK[0] ^ RCON[i] ^
( (uint32_t) FSb[ ( RK[5] >> 8 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( RK[5] >> 16 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( RK[5] >> 24 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( RK[5] ) & 0xFF ] << 24 );
RK[7] = RK[1] ^ RK[6];
RK[8] = RK[2] ^ RK[7];
RK[9] = RK[3] ^ RK[8];
RK[10] = RK[4] ^ RK[9];
RK[11] = RK[5] ^ RK[10];
}
break;
case 14:
for( i = 0; i < 7; i++, RK += 8 ) {
RK[8] = RK[0] ^ RCON[i] ^
( (uint32_t) FSb[ ( RK[7] >> 8 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( RK[7] >> 16 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( RK[7] >> 24 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( RK[7] ) & 0xFF ] << 24 );
RK[9] = RK[1] ^ RK[8];
RK[10] = RK[2] ^ RK[9];
RK[11] = RK[3] ^ RK[10];
RK[12] = RK[4] ^
( (uint32_t) FSb[ ( RK[11] ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( RK[11] >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( RK[11] >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( RK[11] >> 24 ) & 0xFF ] << 24 );
RK[13] = RK[5] ^ RK[12];
RK[14] = RK[6] ^ RK[13];
RK[15] = RK[7] ^ RK[14];
}
break;
default:
return -1;
}
return( 0 );
}
#if AES_DECRYPTION // whether AES decryption is supported
/******************************************************************************
*
* AES_SET_DECRYPTION_KEY
*
* This is called by 'aes_setkey' when we're establishing a
* key for subsequent decryption. We give it a pointer to
* the encryption context, a pointer to the key, and the key's
* length in bits. Valid lengths are: 128, 192, or 256 bits.
*
******************************************************************************/
int aes_set_decryption_key( aes_context *ctx,
const uchar *key,
uint keysize )
{
int i, j;
aes_context cty; // a calling aes context for set_encryption_key
uint32_t *RK = ctx->rk; // initialize our RoundKey buffer pointer
uint32_t *SK;
int ret;
cty.rounds = ctx->rounds; // initialize our local aes context
cty.rk = cty.buf; // round count and key buf pointer
if (( ret = aes_set_encryption_key( &cty, key, keysize )) != 0 )
return( ret );
SK = cty.rk + cty.rounds * 4;
CPY128 // copy a 128-bit block from *SK to *RK
for( i = ctx->rounds - 1, SK -= 8; i > 0; i--, SK -= 8 ) {
for( j = 0; j < 4; j++, SK++ ) {
*RK++ = RT0[ FSb[ ( *SK ) & 0xFF ] ] ^
RT1[ FSb[ ( *SK >> 8 ) & 0xFF ] ] ^
RT2[ FSb[ ( *SK >> 16 ) & 0xFF ] ] ^
RT3[ FSb[ ( *SK >> 24 ) & 0xFF ] ];
}
}
CPY128 // copy a 128-bit block from *SK to *RK
memset( &cty, 0, sizeof( aes_context ) ); // clear local aes context
return( 0 );
}
#endif /* AES_DECRYPTION */
/******************************************************************************
*
* AES_SETKEY
*
* Invoked to establish the key schedule for subsequent encryption/decryption
*
******************************************************************************/
int aes_setkey( aes_context *ctx, // AES context provided by our caller
int mode, // ENCRYPT or DECRYPT flag
const uchar *key, // pointer to the key
uint keysize ) // key length in bytes
{
// since table initialization is not thread safe, we could either add
// system-specific mutexes and init the AES key generation tables on
// demand, or ask the developer to simply call "gcm_initialize" once during
// application startup before threading begins. That's what we choose.
if( !aes_tables_inited ) return ( -1 ); // fail the call when not inited.
ctx->mode = mode; // capture the key type we're creating
ctx->rk = ctx->buf; // initialize our round key pointer
switch( keysize ) // set the rounds count based upon the keysize
{
case 16: ctx->rounds = 10; break; // 16-byte, 128-bit key
case 24: ctx->rounds = 12; break; // 24-byte, 192-bit key
case 32: ctx->rounds = 14; break; // 32-byte, 256-bit key
default: return(-1);
}
#if AES_DECRYPTION
if( mode == DECRYPT ) // expand our key for encryption or decryption
return( aes_set_decryption_key( ctx, key, keysize ) );
else /* ENCRYPT */
#endif /* AES_DECRYPTION */
return( aes_set_encryption_key( ctx, key, keysize ) );
}
/******************************************************************************
*
* AES_CIPHER
*
* Perform AES encryption and decryption.
* The AES context will have been setup with the encryption mode
* and all keying information appropriate for the task.
*
******************************************************************************/
int aes_cipher( aes_context *ctx,
const uchar input[16],
uchar output[16] )
{
int i;
uint32_t *RK, X0, X1, X2, X3, Y0, Y1, Y2, Y3; // general purpose locals
RK = ctx->rk;
GET_UINT32_LE( X0, input, 0 ); X0 ^= *RK++; // load our 128-bit
GET_UINT32_LE( X1, input, 4 ); X1 ^= *RK++; // input buffer in a storage
GET_UINT32_LE( X2, input, 8 ); X2 ^= *RK++; // memory endian-neutral way
GET_UINT32_LE( X3, input, 12 ); X3 ^= *RK++;
#if AES_DECRYPTION // whether AES decryption is supported
if( ctx->mode == DECRYPT )
{
for( i = (ctx->rounds >> 1) - 1; i > 0; i-- )
{
AES_RROUND( Y0, Y1, Y2, Y3, X0, X1, X2, X3 );
AES_RROUND( X0, X1, X2, X3, Y0, Y1, Y2, Y3 );
}
AES_RROUND( Y0, Y1, Y2, Y3, X0, X1, X2, X3 );
X0 = *RK++ ^ \
( (uint32_t) RSb[ ( Y0 ) & 0xFF ] ) ^
( (uint32_t) RSb[ ( Y3 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) RSb[ ( Y2 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) RSb[ ( Y1 >> 24 ) & 0xFF ] << 24 );
X1 = *RK++ ^ \
( (uint32_t) RSb[ ( Y1 ) & 0xFF ] ) ^
( (uint32_t) RSb[ ( Y0 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) RSb[ ( Y3 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) RSb[ ( Y2 >> 24 ) & 0xFF ] << 24 );
X2 = *RK++ ^ \
( (uint32_t) RSb[ ( Y2 ) & 0xFF ] ) ^
( (uint32_t) RSb[ ( Y1 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) RSb[ ( Y0 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) RSb[ ( Y3 >> 24 ) & 0xFF ] << 24 );
X3 = *RK++ ^ \
( (uint32_t) RSb[ ( Y3 ) & 0xFF ] ) ^
( (uint32_t) RSb[ ( Y2 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) RSb[ ( Y1 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) RSb[ ( Y0 >> 24 ) & 0xFF ] << 24 );
}
else /* ENCRYPT */
{
#endif /* AES_DECRYPTION */
for( i = (ctx->rounds >> 1) - 1; i > 0; i-- )
{
AES_FROUND( Y0, Y1, Y2, Y3, X0, X1, X2, X3 );
AES_FROUND( X0, X1, X2, X3, Y0, Y1, Y2, Y3 );
}
AES_FROUND( Y0, Y1, Y2, Y3, X0, X1, X2, X3 );
X0 = *RK++ ^ \
( (uint32_t) FSb[ ( Y0 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( Y1 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( Y2 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( Y3 >> 24 ) & 0xFF ] << 24 );
X1 = *RK++ ^ \
( (uint32_t) FSb[ ( Y1 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( Y2 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( Y3 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( Y0 >> 24 ) & 0xFF ] << 24 );
X2 = *RK++ ^ \
( (uint32_t) FSb[ ( Y2 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( Y3 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( Y0 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( Y1 >> 24 ) & 0xFF ] << 24 );
X3 = *RK++ ^ \
( (uint32_t) FSb[ ( Y3 ) & 0xFF ] ) ^
( (uint32_t) FSb[ ( Y0 >> 8 ) & 0xFF ] << 8 ) ^
( (uint32_t) FSb[ ( Y1 >> 16 ) & 0xFF ] << 16 ) ^
( (uint32_t) FSb[ ( Y2 >> 24 ) & 0xFF ] << 24 );
#if AES_DECRYPTION // whether AES decryption is supported
}
#endif /* AES_DECRYPTION */
PUT_UINT32_LE( X0, output, 0 );
PUT_UINT32_LE( X1, output, 4 );
PUT_UINT32_LE( X2, output, 8 );
PUT_UINT32_LE( X3, output, 12 );
return( 0 );
}
/* end of aes.c */

81
applications/external/esubghz_chat/crypto/aes.h vendored Normal file
View File

@@ -0,0 +1,81 @@
/******************************************************************************
*
* THIS SOURCE CODE IS HEREBY PLACED INTO THE PUBLIC DOMAIN FOR THE GOOD OF ALL
*
* This is a simple and straightforward implementation of the AES Rijndael
* 128-bit block cipher designed by Vincent Rijmen and Joan Daemen. The focus
* of this work was correctness & accuracy. It is written in 'C' without any
* particular focus upon optimization or speed. It should be endian (memory
* byte order) neutral since the few places that care are handled explicitly.
*
* This implementation of Rijndael was created by Steven M. Gibson of GRC.com.
*
* It is intended for general purpose use, but was written in support of GRC's
* reference implementation of the SQRL (Secure Quick Reliable Login) client.
*
* See: http://csrc.nist.gov/archive/aes/rijndael/wsdindex.html
*
* NO COPYRIGHT IS CLAIMED IN THIS WORK, HOWEVER, NEITHER IS ANY WARRANTY MADE
* REGARDING ITS FITNESS FOR ANY PARTICULAR PURPOSE. USE IT AT YOUR OWN RISK.
*
*******************************************************************************/
#ifndef AES_HEADER
#define AES_HEADER
/******************************************************************************/
#define AES_DECRYPTION 0 // whether AES decryption is supported
/******************************************************************************/
#include <string.h>
#define ENCRYPT 1 // specify whether we're encrypting
#define DECRYPT 0 // or decrypting
#if defined(_MSC_VER)
#include <basetsd.h>
typedef UINT32 uint32_t;
#else
#include <inttypes.h>
#endif
typedef unsigned char uchar; // add some convienent shorter types
typedef unsigned int uint;
/******************************************************************************
* AES_INIT_KEYGEN_TABLES : MUST be called once before any AES use
******************************************************************************/
void aes_init_keygen_tables( void );
/******************************************************************************
* AES_CONTEXT : cipher context / holds inter-call data
******************************************************************************/
typedef struct {
int mode; // 1 for Encryption, 0 for Decryption
int rounds; // keysize-based rounds count
uint32_t *rk; // pointer to current round key
uint32_t buf[68]; // key expansion buffer
} aes_context;
/******************************************************************************
* AES_SETKEY : called to expand the key for encryption or decryption
******************************************************************************/
int aes_setkey( aes_context *ctx, // pointer to context
int mode, // 1 or 0 for Encrypt/Decrypt
const uchar *key, // AES input key
uint keysize ); // size in bytes (must be 16, 24, 32 for
// 128, 192 or 256-bit keys respectively)
// returns 0 for success
/******************************************************************************
* AES_CIPHER : called to encrypt or decrypt ONE 128-bit block of data
******************************************************************************/
int aes_cipher( aes_context *ctx, // pointer to context
const uchar input[16], // 128-bit block to en/decipher
uchar output[16] ); // 128-bit output result block
// returns 0 for success
#endif /* AES_HEADER */

511
applications/external/esubghz_chat/crypto/gcm.c vendored Normal file
View File

@@ -0,0 +1,511 @@
/******************************************************************************
*
* THIS SOURCE CODE IS HEREBY PLACED INTO THE PUBLIC DOMAIN FOR THE GOOD OF ALL
*
* This is a simple and straightforward implementation of AES-GCM authenticated
* encryption. The focus of this work was correctness & accuracy. It is written
* in straight 'C' without any particular focus upon optimization or speed. It
* should be endian (memory byte order) neutral since the few places that care
* are handled explicitly.
*
* This implementation of AES-GCM was created by Steven M. Gibson of GRC.com.
*
* It is intended for general purpose use, but was written in support of GRC's
* reference implementation of the SQRL (Secure Quick Reliable Login) client.
*
* See: http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf
* http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/
* gcm/gcm-revised-spec.pdf
*
* NO COPYRIGHT IS CLAIMED IN THIS WORK, HOWEVER, NEITHER IS ANY WARRANTY MADE
* REGARDING ITS FITNESS FOR ANY PARTICULAR PURPOSE. USE IT AT YOUR OWN RISK.
*
*******************************************************************************/
#include "gcm.h"
#include "aes.h"
/******************************************************************************
* ==== IMPLEMENTATION WARNING ====
*
* This code was developed for use within SQRL's fixed environmnent. Thus, it
* is somewhat less "general purpose" than it would be if it were designed as
* a general purpose AES-GCM library. Specifically, it bothers with almost NO
* error checking on parameter limits, buffer bounds, etc. It assumes that it
* is being invoked by its author or by someone who understands the values it
* expects to receive. Its behavior will be undefined otherwise.
*
* All functions that might fail are defined to return 'ints' to indicate a
* problem. Most do not do so now. But this allows for error propagation out
* of internal functions if robust error checking should ever be desired.
*
******************************************************************************/
/* Calculating the "GHASH"
*
* There are many ways of calculating the so-called GHASH in software, each with
* a traditional size vs performance tradeoff. The GHASH (Galois field hash) is
* an intriguing construction which takes two 128-bit strings (also the cipher's
* block size and the fundamental operation size for the system) and hashes them
* into a third 128-bit result.
*
* Many implementation solutions have been worked out that use large precomputed
* table lookups in place of more time consuming bit fiddling, and this approach
* can be scaled easily upward or downward as needed to change the time/space
* tradeoff. It's been studied extensively and there's a solid body of theory and
* practice. For example, without using any lookup tables an implementation
* might obtain 119 cycles per byte throughput, whereas using a simple, though
* large, key-specific 64 kbyte 8-bit lookup table the performance jumps to 13
* cycles per byte.
*
* And Intel's processors have, since 2010, included an instruction which does
* the entire 128x128->128 bit job in just several 64x64->128 bit pieces.
*
* Since SQRL is interactive, and only processing a few 128-bit blocks, I've
* settled upon a relatively slower but appealing small-table compromise which
* folds a bunch of not only time consuming but also bit twiddling into a simple
* 16-entry table which is attributed to Victor Shoup's 1996 work while at
* Bellcore: "On Fast and Provably Secure MessageAuthentication Based on
* Universal Hashing." See: http://www.shoup.net/papers/macs.pdf
* See, also section 4.1 of the "gcm-revised-spec" cited above.
*/
/*
* This 16-entry table of pre-computed constants is used by the
* GHASH multiplier to improve over a strictly table-free but
* significantly slower 128x128 bit multiple within GF(2^128).
*/
static const uint64_t last4[16] = {
0x0000, 0x1c20, 0x3840, 0x2460, 0x7080, 0x6ca0, 0x48c0, 0x54e0,
0xe100, 0xfd20, 0xd940, 0xc560, 0x9180, 0x8da0, 0xa9c0, 0xb5e0 };
/*
* Platform Endianness Neutralizing Load and Store Macro definitions
* GCM wants platform-neutral Big Endian (BE) byte ordering
*/
#define GET_UINT32_BE(n,b,i) { \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); }
#define PUT_UINT32_BE(n,b,i) { \
(b)[(i) ] = (uchar) ( (n) >> 24 ); \
(b)[(i) + 1] = (uchar) ( (n) >> 16 ); \
(b)[(i) + 2] = (uchar) ( (n) >> 8 ); \
(b)[(i) + 3] = (uchar) ( (n) ); }
/******************************************************************************
*
* GCM_INITIALIZE
*
* Must be called once to initialize the GCM library.
*
* At present, this only calls the AES keygen table generator, which expands
* the AES keying tables for use. This is NOT A THREAD-SAFE function, so it
* MUST be called during system initialization before a multi-threading
* environment is running.
*
******************************************************************************/
int gcm_initialize( void )
{
aes_init_keygen_tables();
return( 0 );
}
/******************************************************************************
*
* GCM_MULT
*
* Performs a GHASH operation on the 128-bit input vector 'x', setting
* the 128-bit output vector to 'x' times H using our precomputed tables.
* 'x' and 'output' are seen as elements of GCM's GF(2^128) Galois field.
*
******************************************************************************/
static void gcm_mult( gcm_context *ctx, // pointer to established context
const uchar x[16], // pointer to 128-bit input vector
uchar output[16] ) // pointer to 128-bit output vector
{
int i;
uchar lo, hi, rem;
uint64_t zh, zl;
lo = (uchar)( x[15] & 0x0f );
hi = (uchar)( x[15] >> 4 );
zh = ctx->HH[lo];
zl = ctx->HL[lo];
for( i = 15; i >= 0; i-- ) {
lo = (uchar) ( x[i] & 0x0f );
hi = (uchar) ( x[i] >> 4 );
if( i != 15 ) {
rem = (uchar) ( zl & 0x0f );
zl = ( zh << 60 ) | ( zl >> 4 );
zh = ( zh >> 4 );
zh ^= (uint64_t) last4[rem] << 48;
zh ^= ctx->HH[lo];
zl ^= ctx->HL[lo];
}
rem = (uchar) ( zl & 0x0f );
zl = ( zh << 60 ) | ( zl >> 4 );
zh = ( zh >> 4 );
zh ^= (uint64_t) last4[rem] << 48;
zh ^= ctx->HH[hi];
zl ^= ctx->HL[hi];
}
PUT_UINT32_BE( zh >> 32, output, 0 );
PUT_UINT32_BE( zh, output, 4 );
PUT_UINT32_BE( zl >> 32, output, 8 );
PUT_UINT32_BE( zl, output, 12 );
}
/******************************************************************************
*
* GCM_SETKEY
*
* This is called to set the AES-GCM key. It initializes the AES key
* and populates the gcm context's pre-calculated HTables.
*
******************************************************************************/
int gcm_setkey( gcm_context *ctx, // pointer to caller-provided gcm context
const uchar *key, // pointer to the AES encryption key
const uint keysize) // size in bytes (must be 16, 24, 32 for
// 128, 192 or 256-bit keys respectively)
{
int ret, i, j;
uint64_t hi, lo;
uint64_t vl, vh;
unsigned char h[16];
memset( ctx, 0, sizeof(gcm_context) ); // zero caller-provided GCM context
memset( h, 0, 16 ); // initialize the block to encrypt
// encrypt the null 128-bit block to generate a key-based value
// which is then used to initialize our GHASH lookup tables
if(( ret = aes_setkey( &ctx->aes_ctx, ENCRYPT, key, keysize )) != 0 )
return( ret );
if(( ret = aes_cipher( &ctx->aes_ctx, h, h )) != 0 )
return( ret );
GET_UINT32_BE( hi, h, 0 ); // pack h as two 64-bit ints, big-endian
GET_UINT32_BE( lo, h, 4 );
vh = (uint64_t) hi << 32 | lo;
GET_UINT32_BE( hi, h, 8 );
GET_UINT32_BE( lo, h, 12 );
vl = (uint64_t) hi << 32 | lo;
ctx->HL[8] = vl; // 8 = 1000 corresponds to 1 in GF(2^128)
ctx->HH[8] = vh;
ctx->HH[0] = 0; // 0 corresponds to 0 in GF(2^128)
ctx->HL[0] = 0;
for( i = 4; i > 0; i >>= 1 ) {
uint32_t T = (uint32_t) ( vl & 1 ) * 0xe1000000U;
vl = ( vh << 63 ) | ( vl >> 1 );
vh = ( vh >> 1 ) ^ ( (uint64_t) T << 32);
ctx->HL[i] = vl;
ctx->HH[i] = vh;
}
for (i = 2; i < 16; i <<= 1 ) {
uint64_t *HiL = ctx->HL + i, *HiH = ctx->HH + i;
vh = *HiH;
vl = *HiL;
for( j = 1; j < i; j++ ) {
HiH[j] = vh ^ ctx->HH[j];
HiL[j] = vl ^ ctx->HL[j];
}
}
return( 0 );
}
/******************************************************************************
*
* GCM processing occurs four phases: SETKEY, START, UPDATE and FINISH.
*
* SETKEY:
*
* START: Sets the Encryption/Decryption mode.
* Accepts the initialization vector and additional data.
*
* UPDATE: Encrypts or decrypts the plaintext or ciphertext.
*
* FINISH: Performs a final GHASH to generate the authentication tag.
*
******************************************************************************
*
* GCM_START
*
* Given a user-provided GCM context, this initializes it, sets the encryption
* mode, and preprocesses the initialization vector and additional AEAD data.
*
******************************************************************************/
int gcm_start( gcm_context *ctx, // pointer to user-provided GCM context
int mode, // GCM_ENCRYPT or GCM_DECRYPT
const uchar *iv, // pointer to initialization vector
size_t iv_len, // IV length in bytes (should == 12)
const uchar *add, // ptr to additional AEAD data (NULL if none)
size_t add_len ) // length of additional AEAD data (bytes)
{
int ret; // our error return if the AES encrypt fails
uchar work_buf[16]; // XOR source built from provided IV if len != 16
const uchar *p; // general purpose array pointer
size_t use_len; // byte count to process, up to 16 bytes
size_t i; // local loop iterator
// since the context might be reused under the same key
// we zero the working buffers for this next new process
memset( ctx->y, 0x00, sizeof(ctx->y ) );
memset( ctx->buf, 0x00, sizeof(ctx->buf) );
ctx->len = 0;
ctx->add_len = 0;
ctx->mode = mode; // set the GCM encryption/decryption mode
ctx->aes_ctx.mode = ENCRYPT; // GCM *always* runs AES in ENCRYPTION mode
if( iv_len == 12 ) { // GCM natively uses a 12-byte, 96-bit IV
memcpy( ctx->y, iv, iv_len ); // copy the IV to the top of the 'y' buff
ctx->y[15] = 1; // start "counting" from 1 (not 0)
}
else // if we don't have a 12-byte IV, we GHASH whatever we've been given
{
memset( work_buf, 0x00, 16 ); // clear the working buffer
PUT_UINT32_BE( iv_len * 8, work_buf, 12 ); // place the IV into buffer
p = iv;
while( iv_len > 0 ) {
use_len = ( iv_len < 16 ) ? iv_len : 16;
for( i = 0; i < use_len; i++ ) ctx->y[i] ^= p[i];
gcm_mult( ctx, ctx->y, ctx->y );
iv_len -= use_len;
p += use_len;
}
for( i = 0; i < 16; i++ ) ctx->y[i] ^= work_buf[i];
gcm_mult( ctx, ctx->y, ctx->y );
}
if( ( ret = aes_cipher( &ctx->aes_ctx, ctx->y, ctx->base_ectr ) ) != 0 )
return( ret );
ctx->add_len = add_len;
p = add;
while( add_len > 0 ) {
use_len = ( add_len < 16 ) ? add_len : 16;
for( i = 0; i < use_len; i++ ) ctx->buf[i] ^= p[i];
gcm_mult( ctx, ctx->buf, ctx->buf );
add_len -= use_len;
p += use_len;
}
return( 0 );
}
/******************************************************************************
*
* GCM_UPDATE
*
* This is called once or more to process bulk plaintext or ciphertext data.
* We give this some number of bytes of input and it returns the same number
* of output bytes. If called multiple times (which is fine) all but the final
* invocation MUST be called with length mod 16 == 0. (Only the final call can
* have a partial block length of < 128 bits.)
*
******************************************************************************/
int gcm_update( gcm_context *ctx, // pointer to user-provided GCM context
size_t length, // length, in bytes, of data to process
const uchar *input, // pointer to source data
uchar *output ) // pointer to destination data
{
int ret; // our error return if the AES encrypt fails
uchar ectr[16]; // counter-mode cipher output for XORing
size_t use_len; // byte count to process, up to 16 bytes
size_t i; // local loop iterator
ctx->len += length; // bump the GCM context's running length count
while( length > 0 ) {
// clamp the length to process at 16 bytes
use_len = ( length < 16 ) ? length : 16;
// increment the context's 128-bit IV||Counter 'y' vector
for( i = 16; i > 12; i-- ) if( ++ctx->y[i - 1] != 0 ) break;
// encrypt the context's 'y' vector under the established key
if( ( ret = aes_cipher( &ctx->aes_ctx, ctx->y, ectr ) ) != 0 )
return( ret );
// encrypt or decrypt the input to the output
if( ctx->mode == ENCRYPT )
{
for( i = 0; i < use_len; i++ ) {
// XOR the cipher's ouptut vector (ectr) with our input
output[i] = (uchar) ( ectr[i] ^ input[i] );
// now we mix in our data into the authentication hash.
// if we're ENcrypting we XOR in the post-XOR (output)
// results, but if we're DEcrypting we XOR in the input
// data
ctx->buf[i] ^= output[i];
}
}
else
{
for( i = 0; i < use_len; i++ ) {
// but if we're DEcrypting we XOR in the input data first,
// i.e. before saving to ouput data, otherwise if the input
// and output buffer are the same (inplace decryption) we
// would not get the correct auth tag
ctx->buf[i] ^= input[i];
// XOR the cipher's ouptut vector (ectr) with our input
output[i] = (uchar) ( ectr[i] ^ input[i] );
}
}
gcm_mult( ctx, ctx->buf, ctx->buf ); // perform a GHASH operation
length -= use_len; // drop the remaining byte count to process
input += use_len; // bump our input pointer forward
output += use_len; // bump our output pointer forward
}
return( 0 );
}
/******************************************************************************
*
* GCM_FINISH
*
* This is called once after all calls to GCM_UPDATE to finalize the GCM.
* It performs the final GHASH to produce the resulting authentication TAG.
*
******************************************************************************/
int gcm_finish( gcm_context *ctx, // pointer to user-provided GCM context
uchar *tag, // pointer to buffer which receives the tag
size_t tag_len ) // length, in bytes, of the tag-receiving buf
{
uchar work_buf[16];
uint64_t orig_len = ctx->len * 8;
uint64_t orig_add_len = ctx->add_len * 8;
size_t i;
if( tag_len != 0 ) memcpy( tag, ctx->base_ectr, tag_len );
if( orig_len || orig_add_len ) {
memset( work_buf, 0x00, 16 );
PUT_UINT32_BE( ( orig_add_len >> 32 ), work_buf, 0 );
PUT_UINT32_BE( ( orig_add_len ), work_buf, 4 );
PUT_UINT32_BE( ( orig_len >> 32 ), work_buf, 8 );
PUT_UINT32_BE( ( orig_len ), work_buf, 12 );
for( i = 0; i < 16; i++ ) ctx->buf[i] ^= work_buf[i];
gcm_mult( ctx, ctx->buf, ctx->buf );
for( i = 0; i < tag_len; i++ ) tag[i] ^= ctx->buf[i];
}
return( 0 );
}
/******************************************************************************
*
* GCM_CRYPT_AND_TAG
*
* This either encrypts or decrypts the user-provided data and, either
* way, generates an authentication tag of the requested length. It must be
* called with a GCM context whose key has already been set with GCM_SETKEY.
*
* The user would typically call this explicitly to ENCRYPT a buffer of data
* and optional associated data, and produce its an authentication tag.
*
* To reverse the process the user would typically call the companion
* GCM_AUTH_DECRYPT function to decrypt data and verify a user-provided
* authentication tag. The GCM_AUTH_DECRYPT function calls this function
* to perform its decryption and tag generation, which it then compares.
*
******************************************************************************/
int gcm_crypt_and_tag(
gcm_context *ctx, // gcm context with key already setup
int mode, // cipher direction: GCM_ENCRYPT or GCM_DECRYPT
const uchar *iv, // pointer to the 12-byte initialization vector
size_t iv_len, // byte length if the IV. should always be 12
const uchar *add, // pointer to the non-ciphered additional data
size_t add_len, // byte length of the additional AEAD data
const uchar *input, // pointer to the cipher data source
uchar *output, // pointer to the cipher data destination
size_t length, // byte length of the cipher data
uchar *tag, // pointer to the tag to be generated
size_t tag_len ) // byte length of the tag to be generated
{ /*
assuming that the caller has already invoked gcm_setkey to
prepare the gcm context with the keying material, we simply
invoke each of the three GCM sub-functions in turn...
*/
gcm_start ( ctx, mode, iv, iv_len, add, add_len );
gcm_update ( ctx, length, input, output );
gcm_finish ( ctx, tag, tag_len );
return( 0 );
}
/******************************************************************************
*
* GCM_AUTH_DECRYPT
*
* This DECRYPTS a user-provided data buffer with optional associated data.
* It then verifies a user-supplied authentication tag against the tag just
* re-created during decryption to verify that the data has not been altered.
*
* This function calls GCM_CRYPT_AND_TAG (above) to perform the decryption
* and authentication tag generation.
*
******************************************************************************/
int gcm_auth_decrypt(
gcm_context *ctx, // gcm context with key already setup
const uchar *iv, // pointer to the 12-byte initialization vector
size_t iv_len, // byte length if the IV. should always be 12
const uchar *add, // pointer to the non-ciphered additional data
size_t add_len, // byte length of the additional AEAD data
const uchar *input, // pointer to the cipher data source
uchar *output, // pointer to the cipher data destination
size_t length, // byte length of the cipher data
const uchar *tag, // pointer to the tag to be authenticated
size_t tag_len ) // byte length of the tag <= 16
{
uchar check_tag[16]; // the tag generated and returned by decryption
int diff; // an ORed flag to detect authentication errors
size_t i; // our local iterator
/*
we use GCM_DECRYPT_AND_TAG (above) to perform our decryption
(which is an identical XORing to reverse the previous one)
and also to re-generate the matching authentication tag
*/
gcm_crypt_and_tag( ctx, DECRYPT, iv, iv_len, add, add_len,
input, output, length, check_tag, tag_len );
// now we verify the authentication tag in 'constant time'
for( diff = 0, i = 0; i < tag_len; i++ )
diff |= tag[i] ^ check_tag[i];
if( diff != 0 ) { // see whether any bits differed?
memset( output, 0, length ); // if so... wipe the output data
return( GCM_AUTH_FAILURE ); // return GCM_AUTH_FAILURE
}
return( 0 );
}
/******************************************************************************
*
* GCM_ZERO_CTX
*
* The GCM context contains both the GCM context and the AES context.
* This includes keying and key-related material which is security-
* sensitive, so it MUST be zeroed after use. This function does that.
*
******************************************************************************/
void gcm_zero_ctx( gcm_context *ctx )
{
// zero the context originally provided to us
memset( ctx, 0, sizeof( gcm_context ) );
}

187
applications/external/esubghz_chat/crypto/gcm.h vendored Normal file
View File

@@ -0,0 +1,187 @@
/******************************************************************************
*
* THIS SOURCE CODE IS HEREBY PLACED INTO THE PUBLIC DOMAIN FOR THE GOOD OF ALL
*
* This is a simple and straightforward implementation of AES-GCM authenticated
* encryption. The focus of this work was correctness & accuracy. It is written
* in straight 'C' without any particular focus upon optimization or speed. It
* should be endian (memory byte order) neutral since the few places that care
* are handled explicitly.
*
* This implementation of AES-GCM was created by Steven M. Gibson of GRC.com.
*
* It is intended for general purpose use, but was written in support of GRC's
* reference implementation of the SQRL (Secure Quick Reliable Login) client.
*
* See: http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf
* http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/ \
* gcm/gcm-revised-spec.pdf
*
* NO COPYRIGHT IS CLAIMED IN THIS WORK, HOWEVER, NEITHER IS ANY WARRANTY MADE
* REGARDING ITS FITNESS FOR ANY PARTICULAR PURPOSE. USE IT AT YOUR OWN RISK.
*
*******************************************************************************/
#ifndef GCM_HEADER
#define GCM_HEADER
#define GCM_AUTH_FAILURE 0x55555555 // authentication failure
#include "aes.h" // gcm_context includes aes_context
#if defined(_MSC_VER)
#include <basetsd.h>
typedef unsigned int size_t;// use the right type for length declarations
typedef UINT32 uint32_t;
typedef UINT64 uint64_t;
#else
#include <stdint.h>
#endif
/******************************************************************************
* GCM_CONTEXT : GCM context / holds keytables, instance data, and AES ctx
******************************************************************************/
typedef struct {
int mode; // cipher direction: encrypt/decrypt
uint64_t len; // cipher data length processed so far
uint64_t add_len; // total add data length
uint64_t HL[16]; // precalculated lo-half HTable
uint64_t HH[16]; // precalculated hi-half HTable
uchar base_ectr[16]; // first counter-mode cipher output for tag
uchar y[16]; // the current cipher-input IV|Counter value
uchar buf[16]; // buf working value
aes_context aes_ctx; // cipher context used
} gcm_context;
/******************************************************************************
* GCM_CONTEXT : MUST be called once before ANY use of this library
******************************************************************************/
int gcm_initialize( void );
/******************************************************************************
* GCM_SETKEY : sets the GCM (and AES) keying material for use
******************************************************************************/
int gcm_setkey( gcm_context *ctx, // caller-provided context ptr
const uchar *key, // pointer to cipher key
const uint keysize // size in bytes (must be 16, 24, 32 for
// 128, 192 or 256-bit keys respectively)
); // returns 0 for success
/******************************************************************************
*
* GCM_CRYPT_AND_TAG
*
* This either encrypts or decrypts the user-provided data and, either
* way, generates an authentication tag of the requested length. It must be
* called with a GCM context whose key has already been set with GCM_SETKEY.
*
* The user would typically call this explicitly to ENCRYPT a buffer of data
* and optional associated data, and produce its an authentication tag.
*
* To reverse the process the user would typically call the companion
* GCM_AUTH_DECRYPT function to decrypt data and verify a user-provided
* authentication tag. The GCM_AUTH_DECRYPT function calls this function
* to perform its decryption and tag generation, which it then compares.
*
******************************************************************************/
int gcm_crypt_and_tag(
gcm_context *ctx, // gcm context with key already setup
int mode, // cipher direction: ENCRYPT (1) or DECRYPT (0)
const uchar *iv, // pointer to the 12-byte initialization vector
size_t iv_len, // byte length if the IV. should always be 12
const uchar *add, // pointer to the non-ciphered additional data
size_t add_len, // byte length of the additional AEAD data
const uchar *input, // pointer to the cipher data source
uchar *output, // pointer to the cipher data destination
size_t length, // byte length of the cipher data
uchar *tag, // pointer to the tag to be generated
size_t tag_len ); // byte length of the tag to be generated
/******************************************************************************
*
* GCM_AUTH_DECRYPT
*
* This DECRYPTS a user-provided data buffer with optional associated data.
* It then verifies a user-supplied authentication tag against the tag just
* re-created during decryption to verify that the data has not been altered.
*
* This function calls GCM_CRYPT_AND_TAG (above) to perform the decryption
* and authentication tag generation.
*
******************************************************************************/
int gcm_auth_decrypt(
gcm_context *ctx, // gcm context with key already setup
const uchar *iv, // pointer to the 12-byte initialization vector
size_t iv_len, // byte length if the IV. should always be 12
const uchar *add, // pointer to the non-ciphered additional data
size_t add_len, // byte length of the additional AEAD data
const uchar *input, // pointer to the cipher data source
uchar *output, // pointer to the cipher data destination
size_t length, // byte length of the cipher data
const uchar *tag, // pointer to the tag to be authenticated
size_t tag_len ); // byte length of the tag <= 16
/******************************************************************************
*
* GCM_START
*
* Given a user-provided GCM context, this initializes it, sets the encryption
* mode, and preprocesses the initialization vector and additional AEAD data.
*
******************************************************************************/
int gcm_start( gcm_context *ctx, // pointer to user-provided GCM context
int mode, // ENCRYPT (1) or DECRYPT (0)
const uchar *iv, // pointer to initialization vector
size_t iv_len, // IV length in bytes (should == 12)
const uchar *add, // pointer to additional AEAD data (NULL if none)
size_t add_len ); // length of additional AEAD data (bytes)
/******************************************************************************
*
* GCM_UPDATE
*
* This is called once or more to process bulk plaintext or ciphertext data.
* We give this some number of bytes of input and it returns the same number
* of output bytes. If called multiple times (which is fine) all but the final
* invocation MUST be called with length mod 16 == 0. (Only the final call can
* have a partial block length of < 128 bits.)
*
******************************************************************************/
int gcm_update( gcm_context *ctx, // pointer to user-provided GCM context
size_t length, // length, in bytes, of data to process
const uchar *input, // pointer to source data
uchar *output ); // pointer to destination data
/******************************************************************************
*
* GCM_FINISH
*
* This is called once after all calls to GCM_UPDATE to finalize the GCM.
* It performs the final GHASH to produce the resulting authentication TAG.
*
******************************************************************************/
int gcm_finish( gcm_context *ctx, // pointer to user-provided GCM context
uchar *tag, // ptr to tag buffer - NULL if tag_len = 0
size_t tag_len ); // length, in bytes, of the tag-receiving buf
/******************************************************************************
*
* GCM_ZERO_CTX
*
* The GCM context contains both the GCM context and the AES context.
* This includes keying and key-related material which is security-
* sensitive, so it MUST be zeroed after use. This function does that.
*
******************************************************************************/
void gcm_zero_ctx( gcm_context *ctx );
#endif /* GCM_HEADER */