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encrypted dms

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Signed-off-by: William Casarin <jb55@jb55.com>
This commit is contained in:
William Casarin 2022-04-14 12:35:26 -07:00
parent 435380f327
commit 6719988d8d
8 changed files with 1333 additions and 24 deletions
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4
Makefile
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@ -1,6 +1,6 @@
CFLAGS = -Wall -O2
OBJS = sha256.o nostril.o
CFLAGS = -Wall -Og
OBJS = sha256.o nostril.o aes.o base64.o
HEADERS = hex.h random.h config.h sha256.h
all: nostril

572
aes.c Normal file
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/*
This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode.
Block size can be chosen in aes.h - available choices are AES128, AES192, AES256.
The implementation is verified against the test vectors in:
National Institute of Standards and Technology Special Publication 800-38A 2001 ED
ECB-AES128
----------
plain-text:
6bc1bee22e409f96e93d7e117393172a
ae2d8a571e03ac9c9eb76fac45af8e51
30c81c46a35ce411e5fbc1191a0a52ef
f69f2445df4f9b17ad2b417be66c3710
key:
2b7e151628aed2a6abf7158809cf4f3c
resulting cipher
3ad77bb40d7a3660a89ecaf32466ef97
f5d3d58503b9699de785895a96fdbaaf
43b1cd7f598ece23881b00e3ed030688
7b0c785e27e8ad3f8223207104725dd4
NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
You should pad the end of the string with zeros if this is not the case.
For AES192/256 the key size is proportionally larger.
*/
/*****************************************************************************/
/* Includes: */
/*****************************************************************************/
#include <string.h> // CBC mode, for memset
#include "aes.h"
/*****************************************************************************/
/* Defines: */
/*****************************************************************************/
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
#if defined(AES256) && (AES256 == 1)
#define Nk 8
#define Nr 14
#elif defined(AES192) && (AES192 == 1)
#define Nk 6
#define Nr 12
#else
#define Nk 4 // The number of 32 bit words in a key.
#define Nr 10 // The number of rounds in AES Cipher.
#endif
// jcallan@github points out that declaring Multiply as a function
// reduces code size considerably with the Keil ARM compiler.
// See this link for more information: https://github.com/kokke/tiny-AES-C/pull/3
#ifndef MULTIPLY_AS_A_FUNCTION
#define MULTIPLY_AS_A_FUNCTION 0
#endif
/*****************************************************************************/
/* Private variables: */
/*****************************************************************************/
// state - array holding the intermediate results during decryption.
typedef uint8_t state_t[4][4];
// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM
// The numbers below can be computed dynamically trading ROM for RAM -
// This can be useful in (embedded) bootloader applications, where ROM is often limited.
static const uint8_t sbox[256] = {
//0 1 2 3 4 5 6 7 8 9 A B C D E F
0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
static const uint8_t rsbox[256] = {
0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
#endif
// The round constant word array, Rcon[i], contains the values given by
// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
static const uint8_t Rcon[11] = {
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
/*
* Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12),
* that you can remove most of the elements in the Rcon array, because they are unused.
*
* From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon
*
* "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed),
* up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm."
*/
/*****************************************************************************/
/* Private functions: */
/*****************************************************************************/
/*
static uint8_t getSBoxValue(uint8_t num)
{
return sbox[num];
}
*/
#define getSBoxValue(num) (sbox[(num)])
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key)
{
unsigned i, j, k;
uint8_t tempa[4]; // Used for the column/row operations
// The first round key is the key itself.
for (i = 0; i < Nk; ++i)
{
RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
}
// All other round keys are found from the previous round keys.
for (i = Nk; i < Nb * (Nr + 1); ++i)
{
{
k = (i - 1) * 4;
tempa[0]=RoundKey[k + 0];
tempa[1]=RoundKey[k + 1];
tempa[2]=RoundKey[k + 2];
tempa[3]=RoundKey[k + 3];
}
if (i % Nk == 0)
{
// This function shifts the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// Function RotWord()
{
const uint8_t u8tmp = tempa[0];
tempa[0] = tempa[1];
tempa[1] = tempa[2];
tempa[2] = tempa[3];
tempa[3] = u8tmp;
}
// SubWord() is a function that takes a four-byte input word and
// applies the S-box to each of the four bytes to produce an output word.
// Function Subword()
{
tempa[0] = getSBoxValue(tempa[0]);
tempa[1] = getSBoxValue(tempa[1]);
tempa[2] = getSBoxValue(tempa[2]);
tempa[3] = getSBoxValue(tempa[3]);
}
tempa[0] = tempa[0] ^ Rcon[i/Nk];
}
#if defined(AES256) && (AES256 == 1)
if (i % Nk == 4)
{
// Function Subword()
{
tempa[0] = getSBoxValue(tempa[0]);
tempa[1] = getSBoxValue(tempa[1]);
tempa[2] = getSBoxValue(tempa[2]);
tempa[3] = getSBoxValue(tempa[3]);
}
}
#endif
j = i * 4; k=(i - Nk) * 4;
RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];
RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];
RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];
RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];
}
}
void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key)
{
KeyExpansion(ctx->RoundKey, key);
}
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv)
{
KeyExpansion(ctx->RoundKey, key);
memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv)
{
memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
#endif
// This function adds the round key to state.
// The round key is added to the state by an XOR function.
static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey)
{
uint8_t i,j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
}
}
}
// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void SubBytes(state_t* state)
{
uint8_t i, j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[j][i] = getSBoxValue((*state)[j][i]);
}
}
}
// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
static void ShiftRows(state_t* state)
{
uint8_t temp;
// Rotate first row 1 columns to left
temp = (*state)[0][1];
(*state)[0][1] = (*state)[1][1];
(*state)[1][1] = (*state)[2][1];
(*state)[2][1] = (*state)[3][1];
(*state)[3][1] = temp;
// Rotate second row 2 columns to left
temp = (*state)[0][2];
(*state)[0][2] = (*state)[2][2];
(*state)[2][2] = temp;
temp = (*state)[1][2];
(*state)[1][2] = (*state)[3][2];
(*state)[3][2] = temp;
// Rotate third row 3 columns to left
temp = (*state)[0][3];
(*state)[0][3] = (*state)[3][3];
(*state)[3][3] = (*state)[2][3];
(*state)[2][3] = (*state)[1][3];
(*state)[1][3] = temp;
}
static uint8_t xtime(uint8_t x)
{
return ((x<<1) ^ (((x>>7) & 1) * 0x1b));
}
// MixColumns function mixes the columns of the state matrix
static void MixColumns(state_t* state)
{
uint8_t i;
uint8_t Tmp, Tm, t;
for (i = 0; i < 4; ++i)
{
t = (*state)[i][0];
Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ;
Tm = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm); (*state)[i][0] ^= Tm ^ Tmp ;
Tm = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm); (*state)[i][1] ^= Tm ^ Tmp ;
Tm = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm); (*state)[i][2] ^= Tm ^ Tmp ;
Tm = (*state)[i][3] ^ t ; Tm = xtime(Tm); (*state)[i][3] ^= Tm ^ Tmp ;
}
}
// Multiply is used to multiply numbers in the field GF(2^8)
// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
// The compiler seems to be able to vectorize the operation better this way.
// See https://github.com/kokke/tiny-AES-c/pull/34
#if MULTIPLY_AS_A_FUNCTION
static uint8_t Multiply(uint8_t x, uint8_t y)
{
return (((y & 1) * x) ^
((y>>1 & 1) * xtime(x)) ^
((y>>2 & 1) * xtime(xtime(x))) ^
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
}
#else
#define Multiply(x, y) \
( ((y & 1) * x) ^ \
((y>>1 & 1) * xtime(x)) ^ \
((y>>2 & 1) * xtime(xtime(x))) ^ \
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ \
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))) \
#endif
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
/*
static uint8_t getSBoxInvert(uint8_t num)
{
return rsbox[num];
}
*/
#define getSBoxInvert(num) (rsbox[(num)])
// MixColumns function mixes the columns of the state matrix.
// The method used to multiply may be difficult to understand for the inexperienced.
// Please use the references to gain more information.
static void InvMixColumns(state_t* state)
{
int i;
uint8_t a, b, c, d;
for (i = 0; i < 4; ++i)
{
a = (*state)[i][0];
b = (*state)[i][1];
c = (*state)[i][2];
d = (*state)[i][3];
(*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
(*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
(*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
(*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
}
}
// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void InvSubBytes(state_t* state)
{
uint8_t i, j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[j][i] = getSBoxInvert((*state)[j][i]);
}
}
}
static void InvShiftRows(state_t* state)
{
uint8_t temp;
// Rotate first row 1 columns to right
temp = (*state)[3][1];
(*state)[3][1] = (*state)[2][1];
(*state)[2][1] = (*state)[1][1];
(*state)[1][1] = (*state)[0][1];
(*state)[0][1] = temp;
// Rotate second row 2 columns to right
temp = (*state)[0][2];
(*state)[0][2] = (*state)[2][2];
(*state)[2][2] = temp;
temp = (*state)[1][2];
(*state)[1][2] = (*state)[3][2];
(*state)[3][2] = temp;
// Rotate third row 3 columns to right
temp = (*state)[0][3];
(*state)[0][3] = (*state)[1][3];
(*state)[1][3] = (*state)[2][3];
(*state)[2][3] = (*state)[3][3];
(*state)[3][3] = temp;
}
#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
// Cipher is the main function that encrypts the PlainText.
static void Cipher(state_t* state, const uint8_t* RoundKey)
{
uint8_t round = 0;
// Add the First round key to the state before starting the rounds.
AddRoundKey(0, state, RoundKey);
// There will be Nr rounds.
// The first Nr-1 rounds are identical.
// These Nr rounds are executed in the loop below.
// Last one without MixColumns()
for (round = 1; ; ++round)
{
SubBytes(state);
ShiftRows(state);
if (round == Nr) {
break;
}
MixColumns(state);
AddRoundKey(round, state, RoundKey);
}
// Add round key to last round
AddRoundKey(Nr, state, RoundKey);
}
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
static void InvCipher(state_t* state, const uint8_t* RoundKey)
{
uint8_t round = 0;
// Add the First round key to the state before starting the rounds.
AddRoundKey(Nr, state, RoundKey);
// There will be Nr rounds.
// The first Nr-1 rounds are identical.
// These Nr rounds are executed in the loop below.
// Last one without InvMixColumn()
for (round = (Nr - 1); ; --round)
{
InvShiftRows(state);
InvSubBytes(state);
AddRoundKey(round, state, RoundKey);
if (round == 0) {
break;
}
InvMixColumns(state);
}
}
#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
/*****************************************************************************/
/* Public functions: */
/*****************************************************************************/
#if defined(ECB) && (ECB == 1)
void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf)
{
// The next function call encrypts the PlainText with the Key using AES algorithm.
Cipher((state_t*)buf, ctx->RoundKey);
}
void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf)
{
// The next function call decrypts the PlainText with the Key using AES algorithm.
InvCipher((state_t*)buf, ctx->RoundKey);
}
#endif // #if defined(ECB) && (ECB == 1)
#if defined(CBC) && (CBC == 1)
static void XorWithIv(uint8_t* buf, const uint8_t* Iv)
{
uint8_t i;
for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size
{
buf[i] ^= Iv[i];
}
}
void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, size_t length)
{
size_t i;
uint8_t *Iv = ctx->Iv;
for (i = 0; i < length; i += AES_BLOCKLEN)
{
XorWithIv(buf, Iv);
Cipher((state_t*)buf, ctx->RoundKey);
Iv = buf;
buf += AES_BLOCKLEN;
}
/* store Iv in ctx for next call */
memcpy(ctx->Iv, Iv, AES_BLOCKLEN);
}
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
{
size_t i;
uint8_t storeNextIv[AES_BLOCKLEN];
for (i = 0; i < length; i += AES_BLOCKLEN)
{
memcpy(storeNextIv, buf, AES_BLOCKLEN);
InvCipher((state_t*)buf, ctx->RoundKey);
XorWithIv(buf, ctx->Iv);
memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);
buf += AES_BLOCKLEN;
}
}
#endif // #if defined(CBC) && (CBC == 1)
#if defined(CTR) && (CTR == 1)
/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
{
uint8_t buffer[AES_BLOCKLEN];
size_t i;
int bi;
for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi)
{
if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */
{
memcpy(buffer, ctx->Iv, AES_BLOCKLEN);
Cipher((state_t*)buffer,ctx->RoundKey);
/* Increment Iv and handle overflow */
for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
{
/* inc will overflow */
if (ctx->Iv[bi] == 255)
{
ctx->Iv[bi] = 0;
continue;
}
ctx->Iv[bi] += 1;
break;
}
bi = 0;
}
buf[i] = (buf[i] ^ buffer[bi]);
}
}
#endif // #if defined(CTR) && (CTR == 1)

91
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#ifndef _AES_H_
#define _AES_H_
#include <stdint.h>
#include <stddef.h>
// #define the macros below to 1/0 to enable/disable the mode of operation.
//
// CBC enables AES encryption in CBC-mode of operation.
// CTR enables encryption in counter-mode.
// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously.
// The #ifndef-guard allows it to be configured before #include'ing or at compile time.
#ifndef CBC
#define CBC 1
#endif
#ifndef ECB
#define ECB 0
#endif
#ifndef CTR
#define CTR 0
#endif
//#define AES128 1
//#define AES192 1
#define AES256 1
#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
#if defined(AES256) && (AES256 == 1)
#define AES_KEYLEN 32
#define AES_keyExpSize 240
#elif defined(AES192) && (AES192 == 1)
#define AES_KEYLEN 24
#define AES_keyExpSize 208
#else
#define AES_KEYLEN 16 // Key length in bytes
#define AES_keyExpSize 176
#endif
struct AES_ctx
{
uint8_t RoundKey[AES_keyExpSize];
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
uint8_t Iv[AES_BLOCKLEN];
#endif
};
void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
#endif
#if defined(ECB) && (ECB == 1)
// buffer size is exactly AES_BLOCKLEN bytes;
// you need only AES_init_ctx as IV is not used in ECB
// NB: ECB is considered insecure for most uses
void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);
#endif // #if defined(ECB) && (ECB == !)
#if defined(CBC) && (CBC == 1)
// buffer size MUST be mutile of AES_BLOCKLEN;
// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
// no IV should ever be reused with the same key
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
#endif // #if defined(CBC) && (CBC == 1)
#if defined(CTR) && (CTR == 1)
// Same function for encrypting as for decrypting.
// IV is incremented for every block, and used after encryption as XOR-compliment for output
// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv()
// no IV should ever be reused with the same key
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
#endif // #if defined(CTR) && (CTR == 1)
#endif // _AES_H_

254
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@ -0,0 +1,254 @@
/* Licensed under BSD-MIT - see LICENSE file for details */
#include "base64.h"
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <stdint.h>
/**
* sixbit_to_b64 - maps a 6-bit value to the base64 alphabet
* @param map A base 64 map (see base64_init_map)
* @param sixbit Six-bit value to map
* @return a base 64 character
*/
static char sixbit_to_b64(const base64_maps_t *maps, const uint8_t sixbit)
{
assert(sixbit <= 63);
return maps->encode_map[(unsigned char)sixbit];
}
/**
* sixbit_from_b64 - maps a base64-alphabet character to its 6-bit value
* @param maps A base 64 maps structure (see base64_init_maps)
* @param sixbit Six-bit value to map
* @return a six-bit value
*/
static int8_t sixbit_from_b64(const base64_maps_t *maps,
const unsigned char b64letter)
{
int8_t ret;
ret = maps->decode_map[(unsigned char)b64letter];
if (ret == (char)0xff) {
errno = EDOM;
return -1;
}
return ret;
}
bool base64_char_in_alphabet(const base64_maps_t *maps, const char b64char)
{
return (maps->decode_map[(const unsigned char)b64char] != (char)0xff);
}
void base64_init_maps(base64_maps_t *dest, const char src[64])
{
unsigned char i;
memcpy(dest->encode_map,src,64);
memset(dest->decode_map,0xff,256);
for (i=0; i<64; i++) {
dest->decode_map[(unsigned char)src[i]] = i;
}
}
size_t base64_encoded_length(size_t srclen)
{
return ((srclen + 2) / 3) * 4;
}
void base64_encode_triplet_using_maps(const base64_maps_t *maps,
char dest[4], const char src[3])
{
char a = src[0];
char b = src[1];
char c = src[2];
dest[0] = sixbit_to_b64(maps, (a & 0xfc) >> 2);
dest[1] = sixbit_to_b64(maps, ((a & 0x3) << 4) | ((b & 0xf0) >> 4));
dest[2] = sixbit_to_b64(maps, ((c & 0xc0) >> 6) | ((b & 0xf) << 2));
dest[3] = sixbit_to_b64(maps, c & 0x3f);
}
void base64_encode_tail_using_maps(const base64_maps_t *maps, char dest[4],
const char *src, const size_t srclen)
{
char longsrc[3] = { 0 };
assert(srclen <= 3);
memcpy(longsrc, src, srclen);
base64_encode_triplet_using_maps(maps, dest, longsrc);
memset(dest+1+srclen, '=', 3-srclen);
}
ssize_t base64_encode_using_maps(const base64_maps_t *maps,
char *dest, const size_t destlen,
const char *src, const size_t srclen)
{
size_t src_offset = 0;
size_t dest_offset = 0;
if (destlen < base64_encoded_length(srclen)) {
errno = EOVERFLOW;
return -1;
}
while (srclen - src_offset >= 3) {
base64_encode_triplet_using_maps(maps, &dest[dest_offset], &src[src_offset]);
src_offset += 3;
dest_offset += 4;
}
if (src_offset < srclen) {
base64_encode_tail_using_maps(maps, &dest[dest_offset], &src[src_offset], srclen-src_offset);
dest_offset += 4;
}
memset(&dest[dest_offset], '\0', destlen-dest_offset);
return dest_offset;
}
size_t base64_decoded_length(size_t srclen)
{
return ((srclen+3)/4*3);
}
ssize_t base64_decode_quartet_using_maps(const base64_maps_t *maps, char dest[3],
const char src[4])
{
signed char a;
signed char b;
signed char c;
signed char d;
a = sixbit_from_b64(maps, src[0]);
b = sixbit_from_b64(maps, src[1]);
c = sixbit_from_b64(maps, src[2]);
d = sixbit_from_b64(maps, src[3]);
if ((a == -1) || (b == -1) || (c == -1) || (d == -1)) {
return -1;
}
dest[0] = (a << 2) | (b >> 4);
dest[1] = ((b & 0xf) << 4) | (c >> 2);
dest[2] = ((c & 0x3) << 6) | d;
return 0;
}
ssize_t base64_decode_tail_using_maps(const base64_maps_t *maps, char dest[3],
const char * src, const size_t srclen)
{
char longsrc[4];
int quartet_result;
size_t insize = srclen;
while (insize != 0 &&
src[insize-1] == '=') { /* throw away padding symbols */
insize--;
}
if (insize == 0) {
return 0;
}
if (insize == 1) {
/* the input is malformed.... */
errno = EINVAL;
return -1;
}
memcpy(longsrc, src, insize);
memset(longsrc+insize, 'A', 4-insize);
quartet_result = base64_decode_quartet_using_maps(maps, dest, longsrc);
if (quartet_result == -1) {
return -1;
}
return insize - 1;
}
ssize_t base64_decode_using_maps(const base64_maps_t *maps,
char *dest, const size_t destlen,
const char *src, const size_t srclen)
{
ssize_t dest_offset = 0;
ssize_t i;
ssize_t more;
if (destlen < base64_decoded_length(srclen)) {
errno = EOVERFLOW;
return -1;
}
for(i=0; srclen - i > 4; i+=4) {
if (base64_decode_quartet_using_maps(maps, &dest[dest_offset], &src[i]) == -1) {
return -1;
}
dest_offset += 3;
}
more = base64_decode_tail_using_maps(maps, &dest[dest_offset], &src[i], srclen - i);
if (more == -1) {
return -1;
}
dest_offset += more;
memset(&dest[dest_offset], '\0', destlen-dest_offset);
return dest_offset;
}
/**
* base64_maps_rfc4648 - pregenerated maps struct for rfc4648
*/
const base64_maps_t base64_maps_rfc4648 = {
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
"\xff\xff\xff\xff\xff" /* 0 */ \
"\xff\xff\xff\xff\xff" /* 5 */ \
"\xff\xff\xff\xff\xff" /* 10 */ \
"\xff\xff\xff\xff\xff" /* 15 */ \
"\xff\xff\xff\xff\xff" /* 20 */ \
"\xff\xff\xff\xff\xff" /* 25 */ \
"\xff\xff\xff\xff\xff" /* 30 */ \
"\xff\xff\xff\xff\xff" /* 35 */ \
"\xff\xff\xff\x3e\xff" /* 40 */ \
"\xff\xff\x3f\x34\x35" /* 45 */ \
"\x36\x37\x38\x39\x3a" /* 50 */ \
"\x3b\x3c\x3d\xff\xff" /* 55 */ \
"\xff\xff\xff\xff\xff" /* 60 */ \
"\x00\x01\x02\x03\x04" /* 65 A */ \
"\x05\x06\x07\x08\x09" /* 70 */ \
"\x0a\x0b\x0c\x0d\x0e" /* 75 */ \
"\x0f\x10\x11\x12\x13" /* 80 */ \
"\x14\x15\x16\x17\x18" /* 85 */ \
"\x19\xff\xff\xff\xff" /* 90 */ \
"\xff\xff\x1a\x1b\x1c" /* 95 */ \
"\x1d\x1e\x1f\x20\x21" /* 100 */ \
"\x22\x23\x24\x25\x26" /* 105 */ \
"\x27\x28\x29\x2a\x2b" /* 110 */ \
"\x2c\x2d\x2e\x2f\x30" /* 115 */ \
"\x31\x32\x33\xff\xff" /* 120 */ \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 125 */ \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 155 */ \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 185 */ \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 215 */ \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 245 */
};

241
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@ -0,0 +1,241 @@
/* Licensed under BSD-MIT - see LICENSE file for details */
#ifndef CCAN_BASE64_H
#define CCAN_BASE64_H
#include <stddef.h>
#include <stdbool.h>
#include <sys/types.h>
/**
* base64_maps_t - structure to hold maps for encode/decode
*/
typedef struct {
char encode_map[64];
signed char decode_map[256];
} base64_maps_t;
/**
* base64_encoded_length - Calculate encode buffer length
* @param srclen the size of the data to be encoded
* @note add 1 to this to get null-termination
* @return Buffer length required for encode
*/
size_t base64_encoded_length(size_t srclen);
/**
* base64_decoded_length - Calculate decode buffer length
* @param srclen Length of the data to be decoded
* @note This does not return the size of the decoded data! see base64_decode
* @return Minimum buffer length for safe decode
*/
size_t base64_decoded_length(size_t srclen);
/**
* base64_init_maps - populate a base64_maps_t based on a supplied alphabet
* @param dest A base64 maps object
* @param src Alphabet to populate the maps from (e.g. base64_alphabet_rfc4648)
*/
void base64_init_maps(base64_maps_t *dest, const char src[64]);
/**
* base64_encode_triplet_using_maps - encode 3 bytes into base64 using a specific alphabet
* @param maps Maps to use for encoding (see base64_init_maps)
* @param dest Buffer containing 3 bytes
* @param src Buffer containing 4 characters
*/
void base64_encode_triplet_using_maps(const base64_maps_t *maps,
char dest[4], const char src[3]);
/**
* base64_encode_tail_using_maps - encode the final bytes of a source using a specific alphabet
* @param maps Maps to use for encoding (see base64_init_maps)
* @param dest Buffer containing 4 bytes
* @param src Buffer containing srclen bytes
* @param srclen Number of bytes (<= 3) to encode in src
*/
void base64_encode_tail_using_maps(const base64_maps_t *maps, char dest[4],
const char *src, size_t srclen);
/**
* base64_encode_using_maps - encode a buffer into base64 using a specific alphabet
* @param maps Maps to use for encoding (see base64_init_maps)
* @param dest Buffer to encode into
* @param destlen Length of dest
* @param src Buffer to encode
* @param srclen Length of the data to encode
* @return Number of encoded bytes set in dest. -1 on error (and errno set)
* @note dest will be nul-padded to destlen (past any required padding)
* @note sets errno = EOVERFLOW if destlen is too small
*/
ssize_t base64_encode_using_maps(const base64_maps_t *maps,
char *dest, size_t destlen,
const char *src, size_t srclen);
/*
* base64_char_in_alphabet - returns true if character can be part of an encoded string
* @param maps A base64 maps object (see base64_init_maps)
* @param b64char Character to check
*/
bool base64_char_in_alphabet(const base64_maps_t *maps, char b64char);
/**
* base64_decode_using_maps - decode a base64-encoded string using a specific alphabet
* @param maps A base64 maps object (see base64_init_maps)
* @param dest Buffer to decode into
* @param destlen length of dest
* @param src the buffer to decode
* @param srclen the length of the data to decode
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note dest will be nul-padded to destlen
* @note sets errno = EOVERFLOW if destlen is too small
* @note sets errno = EDOM if src contains invalid characters
*/
ssize_t base64_decode_using_maps(const base64_maps_t *maps,
char *dest, size_t destlen,
const char *src, size_t srclen);
/**
* base64_decode_quartet_using_maps - decode 4 bytes from base64 using a specific alphabet
* @param maps A base64 maps object (see base64_init_maps)
* @param dest Buffer containing 3 bytes
* @param src Buffer containing 4 bytes
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note sets errno = EDOM if src contains invalid characters
*/
ssize_t base64_decode_quartet_using_maps(const base64_maps_t *maps,
char dest[3], const char src[4]);
/**
* base64_decode_tail_using_maps - decode the final bytes of a base64 string using a specific alphabet
* @param maps A base64 maps object (see base64_init_maps)
* @param dest Buffer containing 3 bytes
* @param src Buffer containing 4 bytes - padded with '=' as required
* @param srclen Number of bytes to decode in src
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note sets errno = EDOM if src contains invalid characters
* @note sets errno = EINVAL if src is an invalid base64 tail
*/
ssize_t base64_decode_tail_using_maps(const base64_maps_t *maps, char *dest,
const char *src, size_t srclen);
/* the rfc4648 functions: */
extern const base64_maps_t base64_maps_rfc4648;
/**
* base64_encode - Encode a buffer into base64 according to rfc4648
* @param dest Buffer to encode into
* @param destlen Length of the destination buffer
* @param src Buffer to encode
* @param srclen Length of the data to encode
* @return Number of encoded bytes set in dest. -1 on error (and errno set)
* @note dest will be nul-padded to destlen (past any required padding)
* @note sets errno = EOVERFLOW if destlen is too small
*
* This function encodes src according to http://tools.ietf.org/html/rfc4648
*
* Example:
* size_t encoded_length;
* char dest[100];
* const char *src = "This string gets encoded";
* encoded_length = base64_encode(dest, sizeof(dest), src, strlen(src));
* printf("Returned data of length %zd @%p\n", encoded_length, &dest);
*/
static inline
ssize_t base64_encode(char *dest, size_t destlen,
const char *src, size_t srclen)
{
return base64_encode_using_maps(&base64_maps_rfc4648,
dest, destlen, src, srclen);
}
/**
* base64_encode_triplet - encode 3 bytes into base64 according to rfc4648
* @param dest Buffer containing 4 bytes
* @param src Buffer containing 3 bytes
*/
static inline
void base64_encode_triplet(char dest[4], const char src[3])
{
base64_encode_triplet_using_maps(&base64_maps_rfc4648, dest, src);
}
/**
* base64_encode_tail - encode the final bytes of a source according to rfc4648
* @param dest Buffer containing 4 bytes
* @param src Buffer containing srclen bytes
* @param srclen Number of bytes (<= 3) to encode in src
*/
static inline
void base64_encode_tail(char dest[4], const char *src, size_t srclen)
{
base64_encode_tail_using_maps(&base64_maps_rfc4648, dest, src, srclen);
}
/**
* base64_decode - decode An rfc4648 base64-encoded string
* @param dest Buffer to decode into
* @param destlen Length of the destination buffer
* @param src Buffer to decode
* @param srclen Length of the data to decode
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note dest will be nul-padded to destlen
* @note sets errno = EOVERFLOW if destlen is too small
* @note sets errno = EDOM if src contains invalid characters
*
* This function decodes the buffer according to
* http://tools.ietf.org/html/rfc4648
*
* Example:
* size_t decoded_length;
* char ret[100];
* const char *src = "Zm9vYmFyYmF6";
* decoded_length = base64_decode(ret, sizeof(ret), src, strlen(src));
* printf("Returned data of length %zd @%p\n", decoded_length, &ret);
*/
static inline
ssize_t base64_decode(char *dest, size_t destlen,
const char *src, size_t srclen)
{
return base64_decode_using_maps(&base64_maps_rfc4648,
dest, destlen, src, srclen);
}
/**
* base64_decode_quartet - decode the first 4 characters in src into dest
* @param dest Buffer containing 3 bytes
* @param src Buffer containing 4 characters
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note sets errno = EDOM if src contains invalid characters
*/
static inline
ssize_t base64_decode_quartet(char dest[3], const char src[4])
{
return base64_decode_quartet_using_maps(&base64_maps_rfc4648,
dest, src);
}
/**
* @brief decode the final bytes of a base64 string from src into dest
* @param dest Buffer containing 3 bytes
* @param src Buffer containing 4 bytes - padded with '=' as required
* @param srclen Number of bytes to decode in src
* @return Number of decoded bytes set in dest. -1 on error (and errno set)
* @note sets errno = EDOM if src contains invalid characters
* @note sets errno = EINVAL if src is an invalid base64 tail
*/
static inline
ssize_t base64_decode_tail(char dest[3], const char *src, size_t srclen)
{
return base64_decode_tail_using_maps(&base64_maps_rfc4648,
dest, src, srclen);
}
/* end rfc4648 functions */
#endif /* CCAN_BASE64_H */

188
nostril.c
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@ -7,10 +7,13 @@
#include <inttypes.h>
#include <secp256k1.h>
#include <secp256k1_ecdh.h>
#include <secp256k1_schnorrsig.h>
#include "cursor.h"
#include "hex.h"
#include "base64.h"
#include "aes.h"
#include "sha256.h"
#include "random.h"
@ -20,9 +23,11 @@
#define HAS_CREATED_AT (1<<1)
#define HAS_KIND (1<<2)
#define HAS_ENVELOPE (1<<3)
#define HAS_ENCRYPT (1<<4)
struct key {
secp256k1_keypair pair;
unsigned char secret[32];
unsigned char pubkey[32];
};
@ -30,9 +35,10 @@ struct args {
unsigned int flags;
int kind;
unsigned char encrypt_to[32];
const char *sec;
const char *content;
uint64_t created_at;
};
@ -184,13 +190,13 @@ static int make_sig(secp256k1_context *ctx, struct key *key,
return secp256k1_schnorrsig_sign(ctx, sig, id, &key->pair, aux);
}
static int create_key(secp256k1_context *ctx, struct key *key, unsigned char seckey[32])
static int create_key(secp256k1_context *ctx, struct key *key)
{
secp256k1_xonly_pubkey pubkey;
/* Try to create a keypair with a valid context, it should only
* fail if the secret key is zero or out of range. */
if (!secp256k1_keypair_create(ctx, &key->pair, seckey))
if (!secp256k1_keypair_create(ctx, &key->pair, key->secret))
return 0;
if (!secp256k1_keypair_xonly_pub(ctx, &pubkey, NULL, &key->pair))
@ -202,28 +208,24 @@ static int create_key(secp256k1_context *ctx, struct key *key, unsigned char sec
static int decode_key(secp256k1_context *ctx, const char *secstr, struct key *key)
{
unsigned char seckey[32];
if (!hex_decode(secstr, strlen(secstr), seckey, 32)) {
if (!hex_decode(secstr, strlen(secstr), key->secret, 32)) {
fprintf(stderr, "could not hex decode secret key\n");
return 0;
}
return create_key(ctx, key, seckey);
return create_key(ctx, key);
}
static int generate_key(secp256k1_context *ctx, struct key *key)
{
unsigned char seckey[32];
/* If the secret key is zero or out of range (bigger than secp256k1's
* order), we try to sample a new key. Note that the probability of this
* happening is negligible. */
if (!fill_random(seckey, sizeof(seckey))) {
if (!fill_random(key->secret, sizeof(key->secret))) {
return 0;
}
return create_key(ctx, key, seckey);
return create_key(ctx, key);
}
@ -254,7 +256,7 @@ static int generate_event_id(struct nostr_event *ev)
}
//fprintf(stderr, "commitment: '%.*s'\n", len, buf);
sha256((struct sha256*)ev->id, buf, len);
return 1;
@ -262,10 +264,8 @@ static int generate_event_id(struct nostr_event *ev)
static int sign_event(secp256k1_context *ctx, struct key *key, struct nostr_event *ev)
{
if (!make_sig(ctx, key, ev->id, ev->sig)) {
fprintf(stderr, "Signature generation failed\n");
if (!make_sig(ctx, key, ev->id, ev->sig))
return 0;
}
return 1;
}
@ -309,7 +309,7 @@ static int print_event(struct nostr_event *ev, int envelope)
printf("]");
printf("\n");
return 1;
}
@ -327,7 +327,7 @@ static void make_event_from_args(struct nostr_event *ev, struct args *args)
static int parse_num(const char *arg, uint64_t *t)
{
*t = strtol(arg, NULL, 10);
*t = strtol(arg, NULL, 10);
return errno != EINVAL;
}
@ -363,6 +363,13 @@ static int parse_args(int argc, const char *argv[], struct args *args)
args->flags |= HAS_KIND;
} else if (!strcmp(arg, "--envelope")) {
args->flags |= HAS_ENVELOPE;
} else if (!strcmp(arg, "--dm")) {
arg = *argv++; argc--;
if (!hex_decode(arg, strlen(arg), args->encrypt_to, 32)) {
fprintf(stderr, "could not decode encrypt-to pubkey");
return 0;
}
args->flags |= HAS_ENCRYPT;
} else if (!strncmp(arg, "--", 2)) {
fprintf(stderr, "unknown argument: %s\n", arg);
return 0;
@ -372,6 +379,144 @@ static int parse_args(int argc, const char *argv[], struct args *args)
return 1;
}
static int nostr_add_tag(struct nostr_event *ev, const char *t1, const char *t2)
{
struct nostr_tag *tag;
if (ev->num_tags + 1 > MAX_TAGS)
return 0;
tag = &ev->tags[ev->num_tags++];
tag->strs[0] = t1;
tag->strs[1] = t2;
tag->num_elems = 2;
return 1;
}
static int aes_encrypt(unsigned char *key, unsigned char *iv,
unsigned char *buf, size_t buflen)
{
struct AES_ctx ctx;
unsigned char padding;
int i;
struct cursor cur;
padding = 16 - (buflen % 16);
make_cursor(buf, buf + buflen + padding, &cur);
cur.p += buflen;
//fprintf(stderr, "aes_encrypt: len %ld, padding %d\n", buflen, padding);
for (i = 0; i < padding; i++) {
if (!cursor_push_byte(&cur, padding)) {
return 0;
}
}
assert(cur.p == cur.end);
assert((cur.p - cur.start) % 16 == 0);
AES_init_ctx_iv(&ctx, key, iv);
//fprintf(stderr, "encrypting %ld bytes: ", cur.p - cur.start);
//print_hex(cur.start, cur.p - cur.start);
AES_CBC_encrypt_buffer(&ctx, cur.start, cur.p - cur.start);
return cur.p - cur.start;
}
static int copyx(unsigned char *output, const unsigned char *x32, const unsigned char *y32, void *data) {
memcpy(output, x32, 32);
return 1;
}
static int make_encrypted_dm(secp256k1_context *ctx, struct key *key,
struct nostr_event *ev, unsigned char nostr_pubkey[32])
{
size_t inl = strlen(ev->content);
int enclen = inl + 16;
size_t buflen = enclen * 3 + 65 * 10;
unsigned char *buf = malloc(buflen);
unsigned char shared_secret[32];
unsigned char iv[16];
unsigned char compressed_pubkey[33];
int content_len = strlen(ev->content);
unsigned char encbuf[content_len + (content_len % 16) + 1];
struct cursor cur;
secp256k1_pubkey pubkey;
compressed_pubkey[0] = 2;
memcpy(&compressed_pubkey[1], nostr_pubkey, 32);
make_cursor(buf, buf + buflen, &cur);
if (!secp256k1_ec_seckey_verify(ctx, key->secret)) {
fprintf(stderr, "make_encrypted_dm: ec_seckey_verify failed\n");
return 0;
}
if (!secp256k1_ec_pubkey_parse(ctx, &pubkey, compressed_pubkey, sizeof(compressed_pubkey))) {
fprintf(stderr, "make_encrypted_dm: ec_pubkey_parse failed\n");
return 0;
}
if (!secp256k1_ecdh(ctx, shared_secret, &pubkey, key->secret, copyx, NULL)) {
fprintf(stderr, "make_encrypted_dm: secp256k1_ecdh failed\n");
return 0;
}
if (!fill_random(iv, sizeof(iv))) {
fprintf(stderr, "make_encrypted_dm: fill_random failed\n");
return 0;
}
fprintf(stderr, "shared secret: ");
print_hex(shared_secret, 32);
memcpy(encbuf, ev->content, strlen(ev->content));
enclen = aes_encrypt(shared_secret, iv, encbuf, strlen(ev->content));
if (enclen == 0) {
fprintf(stderr, "make_encrypted_dm: aes_encrypt failed\n");
free(buf);
free(encbuf);
return 0;
}
if ((enclen = base64_encode((char *)buf, buflen, (const char*)encbuf, enclen)) == -1) {
fprintf(stderr, "make_encrypted_dm: base64 encode of encrypted fata failed\n");
return 0;
}
cur.p += enclen;
if (!cursor_push_str(&cur, "?iv=")) {
fprintf(stderr, "make_encrypted_dm: buffer too small\n");
return 0;
}
if ((enclen = base64_encode((char *)cur.p, cur.end - cur.p, (const char*)iv, 16)) == -1) {
fprintf(stderr, "make_encrypted_dm: base64 encode of iv failed\n");
return 0;
}
cur.p += enclen;
if (!cursor_push_byte(&cur, 0)) {
fprintf(stderr, "make_encrypted_dm: out of memory by 1 byte!\n");
return 0;
}
ev->content = (const char*)cur.start;
ev->kind = 4;
if (!hex_encode(nostr_pubkey, 32, (char*)cur.p, cur.end - cur.p))
return 0;
if (!nostr_add_tag(ev, "p", (const char*)cur.p)) {
fprintf(stderr, "too many tags\n");
return 0;
}
cur.p += 65;
return 1;
}
int main(int argc, const char *argv[])
{
struct args args = {0};
@ -396,11 +541,18 @@ int main(int argc, const char *argv[])
}
} else {
if (!generate_key(ctx, &key)) {
fprintf(stderr, "could not generate key");
fprintf(stderr, "could not generate key\n");
return 4;
}
}
if (args.flags & HAS_ENCRYPT) {
if (!make_encrypted_dm(ctx, &key, &ev, args.encrypt_to)) {
fprintf(stderr, "error making encrypted dm\n");
return 0;
}
}
// set the event's pubkey
memcpy(ev.pubkey, key.pubkey, 32);

5
random.h
View File

@ -65,9 +65,8 @@ static int fill_random(unsigned char* data, size_t size) {
static void print_hex(unsigned char* data, size_t size) {
size_t i;
printf("0x");
for (i = 0; i < size; i++) {
printf("%02x", data[i]);
fprintf(stderr, "%02x", data[i]);
}
printf("\n");
fprintf(stderr, "\n");
}

2
shell.nix
View File

@ -1,5 +1,5 @@
{ pkgs ? import <nixpkgs> {} }:
with pkgs;
mkShell {
buildInputs = [ secp256k1 ];
buildInputs = [ secp256k1 openssl gdb ];
}