const bool FrostIdentity::FromPublicKey(const std::string &publickey)
{
std::vector<std::string> keyparts;
std::vector<unsigned char> edata;
std::vector<unsigned char> ndata;
mbedtls_rsa_free(&m_rsa);
mbedtls_rsa_init(&m_rsa,MBEDTLS_RSA_PKCS_V21,MBEDTLS_MD_SHA1);
StringFunctions::Split(publickey,":",keyparts);
if(keyparts.size()==2)
{
Base64::Decode(keyparts[0],edata);
Base64::Decode(keyparts[1],ndata);
mbedtls_mpi_init(&m_rsa.N);
mbedtls_mpi_init(&m_rsa.E);
mbedtls_mpi_read_binary(&m_rsa.N,&ndata[0],ndata.size());
mbedtls_mpi_read_binary(&m_rsa.E,&edata[0],edata.size());
m_publickey=publickey;
return true;
}
else
{
return false;
}
}
/*
* Parse a PKCS#1 encoded private RSA key
*/
static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
const unsigned char *key,
size_t keylen )
{
int ret;
size_t len;
unsigned char *p, *end;
p = (unsigned char *) key;
end = p + keylen;
/*
* This function parses the RSAPrivateKey (PKCS#1)
*
* RSAPrivateKey ::= SEQUENCE {
* version Version,
* modulus INTEGER, -- n
* publicExponent INTEGER, -- e
* privateExponent INTEGER, -- d
* prime1 INTEGER, -- p
* prime2 INTEGER, -- q
* exponent1 INTEGER, -- d mod (p-1)
* exponent2 INTEGER, -- d mod (q-1)
* coefficient INTEGER, -- (inverse of q) mod p
* otherPrimeInfos OtherPrimeInfos OPTIONAL
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = mbedtls_asn1_get_int( &p, end, &rsa->ver ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
if( rsa->ver != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
}
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->N ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->E ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->D ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->P ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->Q ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DP ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DQ ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->QP ) ) != 0 )
{
mbedtls_rsa_free( rsa );
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
rsa->len = mbedtls_mpi_size( &rsa->N );
if( p != end )
{
mbedtls_rsa_free( rsa );
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
if( ( ret = mbedtls_rsa_check_privkey( rsa ) ) != 0 )
{
mbedtls_rsa_free( rsa );
return( ret );
}
return( 0 );
}
int main( void )
{
FILE *f;
int ret;
size_t n, buflen;
mbedtls_net_context server_fd;
unsigned char *p, *end;
unsigned char buf[2048];
unsigned char hash[32];
const char *pers = "dh_client";
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
mbedtls_rsa_context rsa;
mbedtls_dhm_context dhm;
mbedtls_aes_context aes;
mbedtls_net_init( &server_fd );
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, MBEDTLS_MD_SHA256 );
mbedtls_dhm_init( &dhm );
mbedtls_aes_init( &aes );
mbedtls_ctr_drbg_init( &ctr_drbg );
/*
* 1. Setup the RNG
*/
mbedtls_printf( "\n . Seeding the random number generator" );
fflush( stdout );
mbedtls_entropy_init( &entropy );
if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
goto exit;
}
/*
* 2. Read the server's public RSA key
*/
mbedtls_printf( "\n . Reading public key from rsa_pub.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
{
ret = 1;
mbedtls_printf( " failed\n ! Could not open rsa_pub.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
if( ( ret = mbedtls_mpi_read_file( &rsa.N, 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &rsa.E, 16, f ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* 3. Initiate the connection
*/
mbedtls_printf( "\n . Connecting to tcp/%s/%s", SERVER_NAME,
SERVER_PORT );
fflush( stdout );
if( ( ret = mbedtls_net_connect( &server_fd, SERVER_NAME,
SERVER_PORT, MBEDTLS_NET_PROTO_TCP ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_net_connect returned %d\n\n", ret );
goto exit;
}
/*
* 4a. First get the buffer length
*/
mbedtls_printf( "\n . Receiving the server's DH parameters" );
fflush( stdout );
memset( buf, 0, sizeof( buf ) );
if( ( ret = mbedtls_net_recv( &server_fd, buf, 2 ) ) != 2 )
{
mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
goto exit;
}
n = buflen = ( buf[0] << 8 ) | buf[1];
if( buflen < 1 || buflen > sizeof( buf ) )
{
mbedtls_printf( " failed\n ! Got an invalid buffer length\n\n" );
goto exit;
}
/*
* 4b. Get the DHM parameters: P, G and Ys = G^Xs mod P
*/
memset( buf, 0, sizeof( buf ) );
if( ( ret = mbedtls_net_recv( &server_fd, buf, n ) ) != (int) n )
{
mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
goto exit;
}
p = buf, end = buf + buflen;
if( ( ret = mbedtls_dhm_read_params( &dhm, &p, end ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_dhm_read_params returned %d\n\n", ret );
goto exit;
}
if( dhm.len < 64 || dhm.len > 512 )
{
ret = 1;
mbedtls_printf( " failed\n ! Invalid DHM modulus size\n\n" );
goto exit;
}
/*
* 5. Check that the server's RSA signature matches
* the SHA-256 hash of (P,G,Ys)
*/
mbedtls_printf( "\n . Verifying the server's RSA signature" );
fflush( stdout );
p += 2;
if( ( n = (size_t) ( end - p ) ) != rsa.len )
{
ret = 1;
mbedtls_printf( " failed\n ! Invalid RSA signature size\n\n" );
goto exit;
}
mbedtls_sha1( buf, (int)( p - 2 - buf ), hash );
if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC,
MBEDTLS_MD_SHA256, 0, hash, p ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_verify returned %d\n\n", ret );
goto exit;
}
/*
* 6. Send our public value: Yc = G ^ Xc mod P
*/
mbedtls_printf( "\n . Sending own public value to server" );
fflush( stdout );
n = dhm.len;
if( ( ret = mbedtls_dhm_make_public( &dhm, (int) dhm.len, buf, n,
mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_dhm_make_public returned %d\n\n", ret );
goto exit;
}
if( ( ret = mbedtls_net_send( &server_fd, buf, n ) ) != (int) n )
{
mbedtls_printf( " failed\n ! mbedtls_net_send returned %d\n\n", ret );
goto exit;
}
/*
* 7. Derive the shared secret: K = Ys ^ Xc mod P
*/
mbedtls_printf( "\n . Shared secret: " );
fflush( stdout );
if( ( ret = mbedtls_dhm_calc_secret( &dhm, buf, sizeof( buf ), &n,
mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_dhm_calc_secret returned %d\n\n", ret );
goto exit;
}
for( n = 0; n < 16; n++ )
mbedtls_printf( "%02x", buf[n] );
/*
* 8. Setup the AES-256 decryption key
*
* This is an overly simplified example; best practice is
* to hash the shared secret with a random value to derive
* the keying material for the encryption/decryption keys,
* IVs and MACs.
*/
mbedtls_printf( "...\n . Receiving and decrypting the ciphertext" );
fflush( stdout );
mbedtls_aes_setkey_dec( &aes, buf, 256 );
memset( buf, 0, sizeof( buf ) );
if( ( ret = mbedtls_net_recv( &server_fd, buf, 16 ) ) != 16 )
{
mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
goto exit;
}
mbedtls_aes_crypt_ecb( &aes, MBEDTLS_AES_DECRYPT, buf, buf );
buf[16] = '\0';
mbedtls_printf( "\n . Plaintext is \"%s\"\n\n", (char *) buf );
exit:
mbedtls_net_free( &server_fd );
mbedtls_aes_free( &aes );
mbedtls_rsa_free( &rsa );
mbedtls_dhm_free( &dhm );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
static void rsa_free_wrap( void *ctx )
{
mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
mbedtls_free( ctx );
}
FrostIdentity::~FrostIdentity()
{
mbedtls_rsa_free(&m_rsa);
}
/*
* Generate an RSA keypair
*/
int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
unsigned int nbits, int exponent )
{
int ret;
mbedtls_mpi P1, Q1, H, G;
if( f_rng == NULL || nbits < 128 || exponent < 3 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 ); mbedtls_mpi_init( &H ); mbedtls_mpi_init( &G );
/*
* find primes P and Q with Q < P so that:
* GCD( E, (P-1)*(Q-1) ) == 1
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
do
{
MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, ( nbits + 1 ) >> 1, 0,
f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, ( nbits + 1 ) >> 1, 0,
f_rng, p_rng ) );
if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
mbedtls_mpi_swap( &ctx->P, &ctx->Q );
if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
continue;
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
if( mbedtls_mpi_bitlen( &ctx->N ) != nbits )
continue;
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P1, &Q1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
}
while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 );
/*
* D = E^-1 mod ((P-1)*(Q-1))
* DP = D mod (P - 1)
* DQ = D mod (Q - 1)
* QP = Q^-1 mod P
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D , &ctx->E, &H ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) );
ctx->len = ( mbedtls_mpi_bitlen( &ctx->N ) + 7 ) >> 3;
cleanup:
mbedtls_mpi_free( &P1 ); mbedtls_mpi_free( &Q1 ); mbedtls_mpi_free( &H ); mbedtls_mpi_free( &G );
if( ret != 0 )
{
mbedtls_rsa_free( ctx );
return( MBEDTLS_ERR_RSA_KEY_GEN_FAILED + ret );
}
return( 0 );
}
RSAKey::~RSAKey() {
mbedtls_rsa_free(&impl_->rsa_context);
}
int main( int argc, char *argv[] )
{
FILE *f;
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
size_t i;
mbedtls_rsa_context rsa;
unsigned char hash[32];
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
char filename[512];
mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP );
mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP );
if( argc != 2 )
{
mbedtls_printf( "usage: rsa_sign <filename>\n" );
#if defined(_WIN32)
mbedtls_printf( "\n" );
#endif
goto exit;
}
mbedtls_printf( "\n . Reading private key from rsa_priv.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_priv.txt", "rb" ) ) == NULL )
{
mbedtls_printf( " failed\n ! Could not open rsa_priv.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
if( ( ret = mbedtls_mpi_read_file( &N , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &E , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &D , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &P , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &Q , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &DP , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &DQ , 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &QP , 16, f ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
fclose( f );
goto exit;
}
fclose( f );
if( ( ret = mbedtls_rsa_import( &rsa, &N, &P, &Q, &D, &E ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_import returned %d\n\n",
ret );
goto exit;
}
if( ( ret = mbedtls_rsa_complete( &rsa ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_complete returned %d\n\n",
ret );
goto exit;
}
mbedtls_printf( "\n . Checking the private key" );
fflush( stdout );
if( ( ret = mbedtls_rsa_check_privkey( &rsa ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_check_privkey failed with -0x%0x\n", -ret );
goto exit;
}
/*
* Compute the SHA-256 hash of the input file,
* then calculate the RSA signature of the hash.
*/
mbedtls_printf( "\n . Generating the RSA/SHA-256 signature" );
fflush( stdout );
if( ( ret = mbedtls_md_file(
mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
argv[1], hash ) ) != 0 )
{
mbedtls_printf( " failed\n ! Could not open or read %s\n\n", argv[1] );
goto exit;
}
if( ( ret = mbedtls_rsa_pkcs1_sign( &rsa, NULL, NULL, MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA256,
20, hash, buf ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_sign returned -0x%0x\n\n", -ret );
goto exit;
}
/*
* Write the signature into <filename>.sig
*/
mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[1] );
if( ( f = fopen( filename, "wb+" ) ) == NULL )
{
mbedtls_printf( " failed\n ! Could not create %s\n\n", argv[1] );
goto exit;
}
for( i = 0; i < rsa.len; i++ )
mbedtls_fprintf( f, "%02X%s", buf[i],
( i + 1 ) % 16 == 0 ? "\r\n" : " " );
fclose( f );
mbedtls_printf( "\n . Done (created \"%s\")\n\n", filename );
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
mbedtls_rsa_free( &rsa );
mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP );
mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( exit_code );
}