/*
Generate an RSA keypair
*/
int rsa_gen_key(rsa_context *ctx, int nbits, int exponent)
{
mpi P1, Q1, H, G;
int ret;
if (ctx->f_rng == NULL || nbits < 128 || exponent < 3) {
return EST_ERR_RSA_BAD_INPUT_DATA;
}
mpi_init(&P1, &Q1, &H, &G, NULL);
/*
find primes P and Q with Q < P so that: GCD( E, (P-1)*(Q-1) ) == 1
*/
MPI_CHK(mpi_lset(&ctx->E, exponent));
do {
MPI_CHK(mpi_gen_prime(&ctx->P, (nbits + 1) >> 1, 0, ctx->f_rng, ctx->p_rng));
MPI_CHK(mpi_gen_prime(&ctx->Q, (nbits + 1) >> 1, 0, ctx->f_rng, ctx->p_rng));
if (mpi_cmp_mpi(&ctx->P, &ctx->Q) < 0) {
mpi_swap(&ctx->P, &ctx->Q);
}
if (mpi_cmp_mpi(&ctx->P, &ctx->Q) == 0) {
continue;
}
MPI_CHK(mpi_mul_mpi(&ctx->N, &ctx->P, &ctx->Q));
if (mpi_msb(&ctx->N) != nbits) {
continue;
}
MPI_CHK(mpi_sub_int(&P1, &ctx->P, 1));
MPI_CHK(mpi_sub_int(&Q1, &ctx->Q, 1));
MPI_CHK(mpi_mul_mpi(&H, &P1, &Q1));
MPI_CHK(mpi_gcd(&G, &ctx->E, &H));
} while (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
*/
MPI_CHK(mpi_inv_mod(&ctx->D, &ctx->E, &H));
MPI_CHK(mpi_mod_mpi(&ctx->DP, &ctx->D, &P1));
MPI_CHK(mpi_mod_mpi(&ctx->DQ, &ctx->D, &Q1));
MPI_CHK(mpi_inv_mod(&ctx->QP, &ctx->Q, &ctx->P));
ctx->len = (mpi_msb(&ctx->N) + 7) >> 3;
cleanup:
mpi_free(&G, &H, &Q1, &P1, NULL);
if (ret != 0) {
rsa_free(ctx);
return EST_ERR_RSA_KEY_GEN_FAILED | ret;
}
return 0;
}
/*
Check a public RSA key
*/
int rsa_check_pubkey(rsa_context *ctx)
{
if ((ctx->N.p[0] & 1) == 0 || (ctx->E.p[0] & 1) == 0) {
return EST_ERR_RSA_KEY_CHECK_FAILED;
}
if (mpi_msb(&ctx->N) < 128 || mpi_msb(&ctx->N) > 4096) {
return EST_ERR_RSA_KEY_CHECK_FAILED;
}
if (mpi_msb(&ctx->E) < 2 || mpi_msb(&ctx->E) > 64) {
return EST_ERR_RSA_KEY_CHECK_FAILED;
}
return 0;
}
void
check_key_length (ssl_context *ssl)
{
uint32_t key_bits;
const x509_cert *certificate;
const rsa_context *public_key;
char buf[1024];
certificate = ssl_get_peer_cert (ssl);
if (NULL == certificate)
{
die ("Getting certificate failed");
}
x509parse_dn_gets(buf, 1024, &certificate->subject);
verb_debug ("V: Certificate for subject '%s'", buf);
public_key = &certificate->rsa;
if (NULL == public_key)
{
die ("public key extraction failure");
} else {
verb_debug ("V: public key is ready for inspection");
}
key_bits = mpi_msb (&public_key->N);
if (MIN_PUB_KEY_LEN >= key_bits)
{
die ("Unsafe public key size: %d bits", key_bits);
} else {
verb_debug ("V: key length appears safe");
}
}
/*
* Check a public RSA key
*/
int rsa_check_pubkey( rsa_context *ctx )
{
if( ( ctx->N.p[0] & 1 ) == 0 ||
( ctx->E.p[0] & 1 ) == 0 )
return( XYSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->N ) < 128 ||
mpi_msb( &ctx->N ) > 4096 )
return( XYSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->E ) < 2 ||
mpi_msb( &ctx->E ) > 64 )
return( XYSSL_ERR_RSA_KEY_CHECK_FAILED );
return( 0 );
}
/*
* Check a public RSA key
*/
int rsa_check_pubkey( const rsa_context *ctx )
{
if( !ctx->N.p || !ctx->E.p )
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( ( ctx->N.p[0] & 1 ) == 0 ||
( ctx->E.p[0] & 1 ) == 0 )
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->N ) < 128 ||
mpi_msb( &ctx->N ) > POLARSSL_MPI_MAX_BITS )
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->E ) < 2 ||
mpi_msb( &ctx->E ) > 64 )
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
return( 0 );
}
static int Btohex(lua_State *L)
{
mpi *a=Bget(L,1);
int n = mpi_msb(a);
size_t numChars = 3 + n/4;
char *s = (char *) malloc(numChars); /*for radix 16, we are safe with one char for every 4 bits with one extra for the terminating 0*/
mpi_write_string(a, 16, s, &numChars);
lua_pushstring(L,s);
free(s);
return 1;
}
int chiffrer_rsa(char* data, char* sortie, int taille_data )
{
FILE *f;
int ret;
size_t i;
rsa_context rsa;
entropy_context entropy;
ctr_drbg_context ctr_drbg;
char *pers = "rsa_encrypt";
printf( "[i] Seeding the random number generator\n" );
entropy_init( &entropy );
if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
(unsigned char *) pers, strlen( pers ) ) ) != 0 )
{
printf( "[-] ctr_drbg_init returned %d\n", ret );
goto exit;
}
printf( "[i] Reading private key\n" );
rsa_init( &rsa, RSA_PKCS_V15, 0 );
if( ( ret = mpi_read_string( &rsa.N, RSA_N_BASE, RSA_N ) ) != 0 ||
( ret = mpi_read_string( &rsa.D, RSA_D_BASE, RSA_D ) ) != 0 )
{
printf( "[-] mpi_read_file returned %d\n", ret );
goto exit;
}
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
/*
* Calculate the RSA encryption of the hash.
*/
printf( "[i] Generating the RSA encrypted value (%d/%d)\n", rsa.len, taille_data );
fflush( stdout );
if( ( ret = rsa_pkcs1_encrypt( &rsa, ctr_drbg_random, &ctr_drbg,
RSA_PRIVATE, taille_data,
data, sortie ) ) != 0 )
{
printf( "[-] rsa_pkcs1_encrypt returned %d\n\n", ret );
goto exit;
}
printf( "[i] Cryptogramme copie\n");
exit:
return( ret );
}
/*
* Generate an RSA keypair
*/
int rsa_gen_key( rsa_context *ctx,
int (*f_rng)(void *),
void *p_rng,
int nbits, int exponent )
{
int ret;
mpi P1, Q1, H, G;
if( f_rng == NULL || nbits < 128 || exponent < 3 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
mpi_init( &P1, &Q1, &H, &G, NULL );
/*
* find primes P and Q with Q < P so that:
* GCD( E, (P-1)*(Q-1) ) == 1
*/
MPI_CHK( mpi_lset( &ctx->E, exponent ) );
do
{
MPI_CHK( mpi_gen_prime( &ctx->P, ( nbits + 1 ) >> 1, 0,
f_rng, p_rng ) );
MPI_CHK( mpi_gen_prime( &ctx->Q, ( nbits + 1 ) >> 1, 0,
f_rng, p_rng ) );
if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
mpi_swap( &ctx->P, &ctx->Q );
if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
continue;
MPI_CHK( mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
if( mpi_msb( &ctx->N ) != nbits )
continue;
MPI_CHK( mpi_sub_int( &P1, &ctx->P, 1 ) );
MPI_CHK( mpi_sub_int( &Q1, &ctx->Q, 1 ) );
MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) );
MPI_CHK( mpi_gcd( &G, &ctx->E, &H ) );
}
while( 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
*/
MPI_CHK( mpi_inv_mod( &ctx->D , &ctx->E, &H ) );
MPI_CHK( mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) );
MPI_CHK( mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) );
MPI_CHK( mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) );
ctx->len = ( mpi_msb( &ctx->N ) + 7 ) >> 3;
cleanup:
mpi_free( &G, &H, &Q1, &P1, NULL );
if( ret != 0 )
{
rsa_free( ctx );
return( POLARSSL_ERR_RSA_KEY_GEN_FAILED | ret );
}
return( 0 );
}
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
*/
int rsa_rsassa_pss_sign( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
size_t olen;
unsigned char *p = sig;
unsigned char salt[POLARSSL_MD_MAX_SIZE];
unsigned int slen, hlen, offset = 0;
int ret;
size_t msb;
const md_info_t *md_info;
md_context_t md_ctx;
if( ctx->padding != RSA_PKCS_V21 || f_rng == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
olen = ctx->len;
switch( hash_id )
{
case SIG_RSA_MD2:
case SIG_RSA_MD4:
case SIG_RSA_MD5:
hashlen = 16;
break;
case SIG_RSA_SHA1:
hashlen = 20;
break;
case SIG_RSA_SHA224:
hashlen = 28;
break;
case SIG_RSA_SHA256:
hashlen = 32;
break;
case SIG_RSA_SHA384:
hashlen = 48;
break;
case SIG_RSA_SHA512:
hashlen = 64;
break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
md_info = md_info_from_type( ctx->hash_id );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
slen = hlen;
if( olen < hlen + slen + 2 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
memset( sig, 0, olen );
msb = mpi_msb( &ctx->N ) - 1;
// Generate salt of length slen
//
if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
return( POLARSSL_ERR_RSA_RNG_FAILED + ret );
// Note: EMSA-PSS encoding is over the length of N - 1 bits
//
msb = mpi_msb( &ctx->N ) - 1;
p += olen - hlen * 2 - 2;
*p++ = 0x01;
memcpy( p, salt, slen );
p += slen;
md_init_ctx( &md_ctx, md_info );
// Generate H = Hash( M' )
//
md_starts( &md_ctx );
md_update( &md_ctx, p, 8 );
md_update( &md_ctx, hash, hashlen );
md_update( &md_ctx, salt, slen );
md_finish( &md_ctx, p );
// Compensate for boundary condition when applying mask
//
if( msb % 8 == 0 )
offset = 1;
// maskedDB: Apply dbMask to DB
//
mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx );
md_free_ctx( &md_ctx );
msb = mpi_msb( &ctx->N ) - 1;
sig[0] &= 0xFF >> ( olen * 8 - msb );
p += hlen;
*p++ = 0xBC;
return( ( mode == RSA_PUBLIC )
? rsa_public( ctx, sig, sig )
: rsa_private( ctx, sig, sig ) );
}
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
*/
int rsa_rsassa_pss_verify( rsa_context *ctx,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
int ret;
size_t siglen;
unsigned char *p;
unsigned char buf[POLARSSL_MPI_MAX_SIZE];
unsigned char result[POLARSSL_MD_MAX_SIZE];
unsigned char zeros[8];
unsigned int hlen;
size_t slen, msb;
const md_info_t *md_info;
md_context_t md_ctx;
if( ctx->padding != RSA_PKCS_V21 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
siglen = ctx->len;
if( siglen < 16 || siglen > sizeof( buf ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
ret = ( mode == RSA_PUBLIC )
? rsa_public( ctx, sig, buf )
: rsa_private( ctx, sig, buf );
if( ret != 0 )
return( ret );
p = buf;
if( buf[siglen - 1] != 0xBC )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
switch( hash_id )
{
case SIG_RSA_MD2:
case SIG_RSA_MD4:
case SIG_RSA_MD5:
hashlen = 16;
break;
case SIG_RSA_SHA1:
hashlen = 20;
break;
case SIG_RSA_SHA224:
hashlen = 28;
break;
case SIG_RSA_SHA256:
hashlen = 32;
break;
case SIG_RSA_SHA384:
hashlen = 48;
break;
case SIG_RSA_SHA512:
hashlen = 64;
break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
md_info = md_info_from_type( ctx->hash_id );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
slen = siglen - hlen - 1;
memset( zeros, 0, 8 );
// Note: EMSA-PSS verification is over the length of N - 1 bits
//
msb = mpi_msb( &ctx->N ) - 1;
// Compensate for boundary condition when applying mask
//
if( msb % 8 == 0 )
{
p++;
siglen -= 1;
}
if( buf[0] >> ( 8 - siglen * 8 + msb ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
md_init_ctx( &md_ctx, md_info );
mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx );
buf[0] &= 0xFF >> ( siglen * 8 - msb );
while( *p == 0 && p < buf + siglen )
p++;
if( p == buf + siglen ||
*p++ != 0x01 )
{
md_free_ctx( &md_ctx );
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
slen -= p - buf;
// Generate H = Hash( M' )
//
md_starts( &md_ctx );
md_update( &md_ctx, zeros, 8 );
md_update( &md_ctx, hash, hashlen );
md_update( &md_ctx, p, slen );
md_finish( &md_ctx, result );
md_free_ctx( &md_ctx );
if( memcmp( p + slen, result, hlen ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
/*
* Do an RSA operation and check the message digest
*/
int rsa_pkcs1_verify( rsa_context *ctx,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
int ret;
size_t len, siglen;
unsigned char *p, c;
unsigned char buf[1024];
#if defined(POLARSSL_PKCS1_V21)
unsigned char zeros[8];
unsigned int hlen;
size_t slen, msb;
const md_info_t *md_info;
md_context_t md_ctx;
#endif
siglen = ctx->len;
if( siglen < 16 || siglen > (int) sizeof( buf ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
ret = ( mode == RSA_PUBLIC )
? rsa_public( ctx, sig, buf )
: rsa_private( ctx, sig, buf );
if( ret != 0 )
return( ret );
p = buf;
switch( ctx->padding )
{
case RSA_PKCS_V15:
if( *p++ != 0 || *p++ != RSA_SIGN )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
while( *p != 0 )
{
if( p >= buf + siglen - 1 || *p != 0xFF )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
p++;
}
p++;
len = siglen - (int)( p - buf );
if( len == 34 )
{
c = p[13];
p[13] = 0;
if( memcmp( p, ASN1_HASH_MDX, 18 ) != 0 )
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
if( ( c == 2 && hash_id == SIG_RSA_MD2 ) ||
( c == 4 && hash_id == SIG_RSA_MD4 ) ||
( c == 5 && hash_id == SIG_RSA_MD5 ) )
{
if( memcmp( p + 18, hash, 16 ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
}
if( len == 35 && hash_id == SIG_RSA_SHA1 )
{
if( memcmp( p, ASN1_HASH_SHA1, 15 ) == 0 &&
memcmp( p + 15, hash, 20 ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
if( ( len == 19 + 28 && p[14] == 4 && hash_id == SIG_RSA_SHA224 ) ||
( len == 19 + 32 && p[14] == 1 && hash_id == SIG_RSA_SHA256 ) ||
( len == 19 + 48 && p[14] == 2 && hash_id == SIG_RSA_SHA384 ) ||
( len == 19 + 64 && p[14] == 3 && hash_id == SIG_RSA_SHA512 ) )
{
c = p[1] - 17;
p[1] = 17;
p[14] = 0;
if( p[18] == c &&
memcmp( p, ASN1_HASH_SHA2X, 18 ) == 0 &&
memcmp( p + 19, hash, c ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
if( len == hashlen && hash_id == SIG_RSA_RAW )
{
if( memcmp( p, hash, hashlen ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
break;
#if defined(POLARSSL_PKCS1_V21)
case RSA_PKCS_V21:
if( buf[siglen - 1] != 0xBC )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
switch( hash_id )
{
case SIG_RSA_MD2:
case SIG_RSA_MD4:
case SIG_RSA_MD5:
hashlen = 16;
break;
case SIG_RSA_SHA1:
hashlen = 20;
break;
case SIG_RSA_SHA224:
hashlen = 28;
break;
case SIG_RSA_SHA256:
hashlen = 32;
break;
case SIG_RSA_SHA384:
hashlen = 48;
break;
case SIG_RSA_SHA512:
hashlen = 64;
break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
md_info = md_info_from_type( ctx->hash_id );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
slen = siglen - hlen - 1;
memset( &md_ctx, 0, sizeof( md_context_t ) );
memset( zeros, 0, 8 );
md_init_ctx( &md_ctx, md_info );
// Note: EMSA-PSS verification is over the length of N - 1 bits
//
msb = mpi_msb( &ctx->N ) - 1;
// Compensate for boundary condition when applying mask
//
if( msb % 8 == 0 )
{
p++;
siglen -= 1;
}
if( buf[0] >> ( 8 - siglen * 8 + msb ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx );
buf[0] &= 0xFF >> ( siglen * 8 - msb );
while( *p == 0 && p < buf + siglen )
p++;
if( p == buf + siglen )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
if( *p++ != 0x01 )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
slen -= p - buf;
// Generate H = Hash( M' )
//
md_starts( &md_ctx );
md_update( &md_ctx, zeros, 8 );
md_update( &md_ctx, hash, hashlen );
md_update( &md_ctx, p, slen );
md_finish( &md_ctx, p );
if( memcmp( p, p + slen, hlen ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
break;
#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
int sign(unsigned char *output,unsigned char *input, int input_len, char *pri_key_file)
{
unsigned char * cipher = NULL;
unsigned char * k_c = NULL;
unsigned char sign[128];
int ret;
FILE *fkey;
rsa_context rsa_ctx;
havege_state prng_ctx;
cipher = (unsigned char *)malloc((32)*sizeof(char));
/* ********************** HASH controle integrite *********************** */
k_c = (unsigned char *)malloc(2*KEY_LENGTH*sizeof(unsigned char));
memset(k_c, 0, 2*KEY_LENGTH);
//generation de la clef symetrique de KEY_LENGTH bits
gen_key(k_c, KEY_LENGTH);
sha2_hmac(k_c, KEY_LENGTH, input, input_len, cipher, 0);
print_hex(k_c, KEY_LENGTH, "cle secrete utilisée pour le hash : ");
/* *** Read the private asymetric key in the file*** */
if( ( fkey = fopen( pri_key_file, "rb" ) ) == NULL ) {
ret = 1;
printf( " failed\n ! Could not open %s\n" \
" ! Please run rsa_genkey first\n\n",pri_key_file );
goto cleanup;
}
rsa_init( &rsa_ctx, RSA_PKCS_V15, 0 );
if( ( ret = mpi_read_file( &rsa_ctx.N , 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.E , 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.D , 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.P , 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.Q , 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.DP, 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.DQ, 16, fkey ) ) != 0 ||
( ret = mpi_read_file( &rsa_ctx.QP, 16, fkey ) ) != 0 )
{
printf( " failed\n ! mpi_read_file returned %d\n\n", ret );
goto cleanup;
}
rsa_ctx.len = ( mpi_msb( &rsa_ctx.N ) + 7 ) >> 3;
fclose( fkey );
/* *** SYM_K(key) : chiffrement RSA de la clé de chiffrement key (16) => rsa-1024 bits = 128 octets en sortie *** */
/* *** cipher = ASYM_Kpriv (Hash) *** */
havege_init(&prng_ctx);
memset(sign, 0, 128);
if( ( ret = rsa_pkcs1_encrypt( &rsa_ctx, havege_random, &prng_ctx, RSA_PRIVATE, KEY_LENGTH, cipher, sign ) ) != 0 ) {
printf( " failed\n ! rsa_pkcs1_encrypt returned %d\n\n", ret );
goto cleanup;
}
print_hex(sign, sizeof(sign), "Hash chiffrée avec RSA : ");
/* *** ASYM_Kpub (K) *** */
output = (unsigned char *) malloc( 128 * sizeof(unsigned char));
memcpy(output, sign, 128);
cleanup:
if(cipher != NULL) {
memset(cipher, 0, 32);
free(cipher);
}
if(k_c != NULL) {
memset(k_c, 0, 2*KEY_LENGTH);
free(k_c);
}
memset(&prng_ctx,0x00, sizeof(havege_state));
memset(&rsa_ctx, 0x00, sizeof(rsa_ctx));
memset(sign, 0, 128);
return ret;
}
int decipher_buffer(unsigned char **output, int *output_len,
unsigned char *input, int input_len,
char *priv_key_file)
{
int offset, ret;
size_t key_len;
unsigned char s_key[32] = {0};
aes_context aes_ctx;
rsa_context rsa_ctx;
FILE *f;
unsigned char iv[16] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
/* *** Init *** */
ret = 1;
offset = 0;
key_len = 0;
f = NULL;
/* *** Get private key *** */
f = fopen(priv_key_file, "rb");
if (f == NULL) {
fprintf(stderr, "error : unable to open %s\n", priv_key_file);
ret = 1;
goto cleanup;
}
rsa_init(&rsa_ctx, RSA_PKCS_V15, 0 );
if (mpi_read_file(&rsa_ctx.N, 16, f) != 0
|| mpi_read_file(&rsa_ctx.E, 16, f) != 0
|| mpi_read_file(&rsa_ctx.D, 16, f) != 0
|| mpi_read_file(&rsa_ctx.P, 16, f) != 0
|| mpi_read_file(&rsa_ctx.Q, 16, f) != 0
|| mpi_read_file(&rsa_ctx.DP, 16, f) != 0
|| mpi_read_file(&rsa_ctx.DQ, 16, f) != 0
|| mpi_read_file(&rsa_ctx.QP, 16, f) != 0) {
fprintf(stderr, "error : unable to read private key\n");
ret = 1;
goto cleanup;
}
rsa_ctx.len = (mpi_msb(&rsa_ctx.N ) + 7 ) >> 3;
/* *** Decipher *** */
ret = rsa_pkcs1_decrypt(&rsa_ctx, RSA_PRIVATE, &key_len,
input, s_key, 16);
if (ret != 0) {
fprintf(stderr, "error : rsa_pkcs1_decrypt failed\n");
ret = 1;
goto cleanup;
}
ret = aes_setkey_dec(&aes_ctx, s_key, 256);
if (ret != 0) {
fprintf(stderr, "error : aes_setkey_dec failed\n");
ret = 1;
goto cleanup;
}
/* *** Plain text *** */
*output = (unsigned char *) malloc((input_len - 128) *
sizeof(unsigned char));
memset(*output, 0, input_len - 128);
ret = aes_crypt_cbc(&aes_ctx, AES_DECRYPT, input_len - 128 , iv,
input + 128, *output);
if (ret != 0) {
fprintf(stderr, "error : aes_crypt_cbc failed\n");
ret = 1;
goto cleanup;
}
/* *** Padding *** */
for (offset = input_len - 128 - 1; offset >= 0; offset--) {
if((*output)[offset] == 0x80) {
*output_len = offset;
(*output)[offset] = 0x00;
break;
}
}
cleanup:
if(f != NULL)
fclose(f);
rsa_free(&rsa_ctx);
return ret;
}
/**
* Adds padding and encrypts a string using either private or public key.
* (depending on mode).
* @param message: arbitrary binary string to be encrypted.
* @param keytable: table containing either the public or the private key, as generated by gen_key.
* @return The cyphertext (as a binary string).
* @see rsa_genkey
*/
static int luarsa_pkcs1_encrypt (lua_State *L) {
int res = 0;
int mode;
size_t lmsg, lresult;
rsa_context rsa;
char *message = (char*)luaL_checklstring(L, 1, &lmsg); /* message */
char result[KEY_SIZE];
char alt_result[KEY_SIZE];
char* strMode=NULL;
if(lua_type(L, 3)==LUA_TSTRING) {
printf("Got parameter\n");
strMode = (char*)lua_tostring(L, 3);
printf("[%s]\n", strMode);
mode = strncmp(strMode, "private", 7) ? RSA_PUBLIC : RSA_PRIVATE;
}
rsa_init( &rsa, RSA_PKCS_V15, 0, NULL, NULL );
processKey(L, 2, &rsa); /* keytable */
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
memset(result, 0, KEY_SIZE);
// <test> by Jason
printf("\nMode==%s\n", mode==RSA_PUBLIC ? "RSA_PUBLIC" : "RSA_PRIVATE" );
printf("Size==%d\n", lmsg );
printf("Crypt.Size==%d\n", rsa.len );
printf("ver: %d\n", rsa.ver);
printf("len: %d\n", rsa.len);
printf("padding: %d\n", rsa.padding);
printf("hash_id: %d\n", rsa.hash_id);
mpi_print("N:%s\n", &rsa.N);
mpi_print("E:%s\n", &rsa.E);
if(mode!=RSA_PUBLIC) {
//mpi_print("D:%s\n", &rsa.D);
//mpi_print("P:%s\n", &rsa.P);
//mpi_print("Q:%s\n", &rsa.Q);
//mpi_print("DP:%s\n", &rsa.DP);
//mpi_print("DQ:%s\n", &rsa.DQ);
//mpi_print("QP:%s\n", &rsa.QP);
//mpi_print("RN:%s\n", &rsa.RN);
//mpi_print("RP:%s\n", &rsa.RP);
//mpi_print("RQ:%s\n", &rsa.RQ);
}
// </test> by Jason
// pass rsa context and message to encryption engine
res = rsa_pkcs1_encrypt(&rsa, RSA_PUBLIC, lmsg, message, result);
if(res)
luaL_error(L, "Error during cipher (%d)", res);
/*
lmsg = 128;
res = rsa_pkcs1_decrypt(&rsa, mode, &lmsg, result, alt_result);
if(res)
luaL_error(L, "Error during decipher (%d)", res);
printf("(%d)", lmsg);
*/
push_private_key(L, &rsa);
// push encrypted result buffer
lua_pushlstring(L, result, rsa.len); /* ciphertext */
rsa_free( &rsa );
return 1;
}
static int Bbits(lua_State *L)
{
mpi *a=Bget(L,1);
lua_pushinteger(L, mpi_msb(a));
return 1;
}
/*
* Parse a SpecifiedECDomain (SEC 1 C.2) and (mostly) fill the group with it.
* WARNING: the resulting group should only be used with
* pk_group_id_from_specified(), since its base point may not be set correctly
* if it was encoded compressed.
*
* SpecifiedECDomain ::= SEQUENCE {
* version SpecifiedECDomainVersion(ecdpVer1 | ecdpVer2 | ecdpVer3, ...),
* fieldID FieldID {{FieldTypes}},
* curve Curve,
* base ECPoint,
* order INTEGER,
* cofactor INTEGER OPTIONAL,
* hash HashAlgorithm OPTIONAL,
* ...
* }
*
* We only support prime-field as field type, and ignore hash and cofactor.
*/
static int pk_group_from_specified( const asn1_buf *params, ecp_group *grp )
{
int ret;
unsigned char *p = params->p;
const unsigned char * const end = params->p + params->len;
const unsigned char *end_field, *end_curve;
size_t len;
int ver;
/* SpecifiedECDomainVersion ::= INTEGER { 1, 2, 3 } */
if( ( ret = asn1_get_int( &p, end, &ver ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ver < 1 || ver > 3 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
/*
* FieldID { FIELD-ID:IOSet } ::= SEQUENCE { -- Finite field
* fieldType FIELD-ID.&id({IOSet}),
* parameters FIELD-ID.&Type({IOSet}{@fieldType})
* }
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_field = p + len;
/*
* FIELD-ID ::= TYPE-IDENTIFIER
* FieldTypes FIELD-ID ::= {
* { Prime-p IDENTIFIED BY prime-field } |
* { Characteristic-two IDENTIFIED BY characteristic-two-field }
* }
* prime-field OBJECT IDENTIFIER ::= { id-fieldType 1 }
*/
if( ( ret = asn1_get_tag( &p, end_field, &len, ASN1_OID ) ) != 0 )
return( ret );
if( len != OID_SIZE( OID_ANSI_X9_62_PRIME_FIELD ) ||
memcmp( p, OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
{
return( POLARSSL_ERR_PK_FEATURE_UNAVAILABLE );
}
p += len;
/* Prime-p ::= INTEGER -- Field of size p. */
if( ( ret = asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->pbits = mpi_msb( &grp->P );
if( p != end_field )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
/*
* Curve ::= SEQUENCE {
* a FieldElement,
* b FieldElement,
* seed BIT STRING OPTIONAL
* -- Shall be present if used in SpecifiedECDomain
* -- with version equal to ecdpVer2 or ecdpVer3
* }
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_curve = p + len;
/*
* FieldElement ::= OCTET STRING
* containing an integer in the case of a prime field
*/
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_OCTET_STRING ) ) != 0 ||
( ret = mpi_read_binary( &grp->A, p, len ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_OCTET_STRING ) ) != 0 ||
( ret = mpi_read_binary( &grp->B, p, len ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
/* Ignore seed BIT STRING OPTIONAL */
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_BIT_STRING ) ) == 0 )
p += len;
if( p != end_curve )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
/*
* ECPoint ::= OCTET STRING
*/
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = ecp_point_read_binary( grp, &grp->G,
( const unsigned char *) p, len ) ) != 0 )
{
/*
* If we can't read the point because it's compressed, cheat by
* reading only the X coordinate and the parity bit of Y.
*/
if( ret != POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE ||
( p[0] != 0x02 && p[0] != 0x03 ) ||
len != mpi_size( &grp->P ) + 1 ||
mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
mpi_lset( &grp->G.Z, 1 ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
}
}
p += len;
/*
* order INTEGER
*/
if( ( ret = asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->nbits = mpi_msb( &grp->N );
/*
* Allow optional elements by purposefully not enforcing p == end here.
*/
return( 0 );
}
int main( int argc, char *argv[] )
{
FILE *f;
int ret, i;
rsa_context rsa;
unsigned char hash[20];
unsigned char buf[512];
ret = 1;
if( argc != 2 )
{
printf( "usage: rsa_sign <filename>\n" );
#ifdef WIN32
printf( "\n" );
#endif
goto exit;
}
printf( "\n . Reading private key from rsa_priv.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_priv.txt", "rb" ) ) == NULL )
{
ret = 1;
printf( " failed\n ! Could not open rsa_priv.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
rsa_init( &rsa, RSA_PKCS_V15, 0, NULL, NULL );
if( ( ret = mpi_read_file( &rsa.N , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.E , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.D , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.P , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.Q , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.DP, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.DQ, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.QP, 16, f ) ) != 0 )
{
printf( " failed\n ! mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* Compute the SHA-1 hash of the input file,
* then calculate the RSA signature of the hash.
*/
printf( "\n . Generating the RSA/SHA-1 signature" );
fflush( stdout );
if( ( ret = sha1_file( argv[1], hash ) ) != 0 )
{
printf( " failed\n ! Could not open or read %s\n\n", argv[1] );
goto exit;
}
if( ( ret = rsa_pkcs1_sign( &rsa, RSA_PRIVATE, SIG_RSA_SHA1,
20, hash, buf ) ) != 0 )
{
printf( " failed\n ! rsa_pkcs1_sign returned %d\n\n", ret );
goto exit;
}
/*
* Write the signature into <filename>-sig.txt
*/
memcpy( argv[1] + strlen( argv[1] ), ".sig", 5 );
if( ( f = fopen( argv[1], "wb+" ) ) == NULL )
{
ret = 1;
printf( " failed\n ! Could not create %s\n\n", argv[1] );
goto exit;
}
for( i = 0; i < rsa.len; i++ )
fprintf( f, "%02X%s", buf[i],
( i + 1 ) % 16 == 0 ? "\r\n" : " " );
fclose( f );
printf( "\n . Done (created \"%s\")\n\n", argv[1] );
exit:
#ifdef WIN32
printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
int main( int argc, char *argv[] )
{
FILE *f;
int ret, c;
size_t i;
rsa_context rsa;
entropy_context entropy;
ctr_drbg_context ctr_drbg;
unsigned char result[1024];
unsigned char buf[512];
const char *pers = "rsa_decrypt";
((void) argv);
memset(result, 0, sizeof( result ) );
ret = 1;
if( argc != 1 )
{
polarssl_printf( "usage: rsa_decrypt\n" );
#if defined(_WIN32)
polarssl_printf( "\n" );
#endif
goto exit;
}
polarssl_printf( "\n . Seeding the random number generator..." );
fflush( stdout );
entropy_init( &entropy );
if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
polarssl_printf( " failed\n ! ctr_drbg_init returned %d\n", ret );
goto exit;
}
polarssl_printf( "\n . Reading private key from rsa_priv.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_priv.txt", "rb" ) ) == NULL )
{
polarssl_printf( " failed\n ! Could not open rsa_priv.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
rsa_init( &rsa, RSA_PKCS_V15, 0 );
if( ( ret = mpi_read_file( &rsa.N , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.E , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.D , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.P , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.Q , 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.DP, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.DQ, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.QP, 16, f ) ) != 0 )
{
polarssl_printf( " failed\n ! mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* Extract the RSA encrypted value from the text file
*/
ret = 1;
if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
{
polarssl_printf( "\n ! Could not open %s\n\n", "result-enc.txt" );
goto exit;
}
i = 0;
while( fscanf( f, "%02X", &c ) > 0 &&
i < (int) sizeof( buf ) )
buf[i++] = (unsigned char) c;
fclose( f );
if( i != rsa.len )
{
polarssl_printf( "\n ! Invalid RSA signature format\n\n" );
goto exit;
}
/*
* Decrypt the encrypted RSA data and print the result.
*/
polarssl_printf( "\n . Decrypting the encrypted data" );
fflush( stdout );
if( ( ret = rsa_pkcs1_decrypt( &rsa, ctr_drbg_random, &ctr_drbg,
RSA_PRIVATE, &i, buf, result,
1024 ) ) != 0 )
{
polarssl_printf( " failed\n ! rsa_pkcs1_decrypt returned %d\n\n", ret );
goto exit;
}
polarssl_printf( "\n . OK\n\n" );
polarssl_printf( "The decrypted result is: '%s'\n\n", result );
ret = 0;
exit:
ctr_drbg_free( &ctr_drbg );
entropy_free( &entropy );
#if defined(_WIN32)
polarssl_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
int main( int argc, char *argv[] )
{
FILE *f;
int ret, i, c;
rsa_context rsa;
unsigned char hash[20];
unsigned char buf[512];
ret = 1;
if( argc != 2 )
{
printf( "usage: rsa_verify <filename>\n" );
#ifdef WIN32
printf( "\n" );
#endif
goto exit;
}
printf( "\n . Reading public key from rsa_pub.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
{
printf( " failed\n ! Could not open rsa_pub.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
rsa_init( &rsa, RSA_PKCS_V15, 0, NULL, NULL );
if( ( ret = mpi_read_file( &rsa.N, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.E, 16, f ) ) != 0 )
{
printf( " failed\n ! mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* Extract the RSA signature from the text file
*/
ret = 1;
i = strlen( argv[1] );
memcpy( argv[1] + i, ".sig", 5 );
if( ( f = fopen( argv[1], "rb" ) ) == NULL )
{
printf( "\n ! Could not open %s\n\n", argv[1] );
goto exit;
}
argv[1][i] = '\0', i = 0;
while( fscanf( f, "%02X", &c ) > 0 &&
i < (int) sizeof( buf ) )
buf[i++] = (unsigned char) c;
fclose( f );
if( i != rsa.len )
{
printf( "\n ! Invalid RSA signature format\n\n" );
goto exit;
}
/*
* Compute the SHA-1 hash of the input file and compare
* it with the hash decrypted from the RSA signature.
*/
printf( "\n . Verifying the RSA/SHA-1 signature" );
fflush( stdout );
if( ( ret = sha1_file( argv[1], hash ) ) != 0 )
{
printf( " failed\n ! Could not open or read %s\n\n", argv[1] );
goto exit;
}
if( ( ret = rsa_pkcs1_verify( &rsa, RSA_PUBLIC, RSA_SHA1,
20, hash, buf ) ) != 0 )
{
printf( " failed\n ! rsa_pkcs1_verify returned %d\n\n", ret );
goto exit;
}
printf( "\n . OK (the decrypted SHA-1 hash matches)\n\n" );
ret = 0;
exit:
#ifdef WIN32
printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
*/
int rsa_rsassa_pss_verify_ext( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
md_type_t md_alg,
unsigned int hashlen,
const unsigned char *hash,
md_type_t mgf1_hash_id,
int expected_salt_len,
const unsigned char *sig )
{
int ret;
size_t siglen;
unsigned char *p;
unsigned char buf[POLARSSL_MPI_MAX_SIZE];
unsigned char result[POLARSSL_MD_MAX_SIZE];
unsigned char zeros[8];
unsigned int hlen;
size_t slen, msb;
const md_info_t *md_info;
md_context_t md_ctx;
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
siglen = ctx->len;
if( siglen < 16 || siglen > sizeof( buf ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
ret = ( mode == RSA_PUBLIC )
? rsa_public( ctx, sig, buf )
: rsa_private( ctx, f_rng, p_rng, sig, buf );
if( ret != 0 )
return( ret );
p = buf;
if( buf[siglen - 1] != 0xBC )
return( POLARSSL_ERR_RSA_INVALID_PADDING );
if( md_alg != POLARSSL_MD_NONE )
{
// Gather length of hash to sign
//
md_info = md_info_from_type( md_alg );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hashlen = md_get_size( md_info );
}
md_info = md_info_from_type( mgf1_hash_id );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
slen = siglen - hlen - 1; /* Currently length of salt + padding */
memset( zeros, 0, 8 );
// Note: EMSA-PSS verification is over the length of N - 1 bits
//
msb = mpi_msb( &ctx->N ) - 1;
// Compensate for boundary condition when applying mask
//
if( msb % 8 == 0 )
{
p++;
siglen -= 1;
}
if( buf[0] >> ( 8 - siglen * 8 + msb ) )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
md_init( &md_ctx );
md_init_ctx( &md_ctx, md_info );
mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx );
buf[0] &= 0xFF >> ( siglen * 8 - msb );
while( p < buf + siglen && *p == 0 )
p++;
if( p == buf + siglen ||
*p++ != 0x01 )
{
md_free( &md_ctx );
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
/* Actual salt len */
slen -= p - buf;
if( expected_salt_len != RSA_SALT_LEN_ANY &&
slen != (size_t) expected_salt_len )
{
md_free( &md_ctx );
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
// Generate H = Hash( M' )
//
md_starts( &md_ctx );
md_update( &md_ctx, zeros, 8 );
md_update( &md_ctx, hash, hashlen );
md_update( &md_ctx, p, slen );
md_finish( &md_ctx, result );
md_free( &md_ctx );
if( memcmp( p + slen, result, hlen ) == 0 )
return( 0 );
else
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
}
int main( int argc, char *argv[] )
{
FILE *f;
int ret;
size_t n, buflen;
int server_fd = -1;
unsigned char *p, *end;
unsigned char buf[2048];
unsigned char hash[20];
const char *pers = "dh_client";
entropy_context entropy;
ctr_drbg_context ctr_drbg;
rsa_context rsa;
dhm_context dhm;
aes_context aes;
((void) argc);
((void) argv);
memset( &rsa, 0, sizeof( rsa ) );
memset( &dhm, 0, sizeof( dhm ) );
/*
* 1. Setup the RNG
*/
printf( "\n . Seeding the random number generator" );
fflush( stdout );
entropy_init( &entropy );
if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
printf( " failed\n ! ctr_drbg_init returned %d\n", ret );
goto exit;
}
/*
* 2. Read the server's public RSA key
*/
printf( "\n . Reading public key from rsa_pub.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
{
ret = 1;
printf( " failed\n ! Could not open rsa_pub.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
rsa_init( &rsa, RSA_PKCS_V15, 0 );
if( ( ret = mpi_read_file( &rsa.N, 16, f ) ) != 0 ||
( ret = mpi_read_file( &rsa.E, 16, f ) ) != 0 )
{
printf( " failed\n ! mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mpi_msb( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* 3. Initiate the connection
*/
printf( "\n . Connecting to tcp/%s/%d", SERVER_NAME,
SERVER_PORT );
fflush( stdout );
if( ( ret = net_connect( &server_fd, SERVER_NAME,
SERVER_PORT ) ) != 0 )
{
printf( " failed\n ! net_connect returned %d\n\n", ret );
goto exit;
}
/*
* 4a. First get the buffer length
*/
printf( "\n . Receiving the server's DH parameters" );
fflush( stdout );
memset( buf, 0, sizeof( buf ) );
if( ( ret = net_recv( &server_fd, buf, 2 ) ) != 2 )
{
printf( " failed\n ! net_recv returned %d\n\n", ret );
goto exit;
}
n = buflen = ( buf[0] << 8 ) | buf[1];
if( buflen < 1 || buflen > sizeof( buf ) )
{
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 = net_recv( &server_fd, buf, n ) ) != (int) n )
{
printf( " failed\n ! net_recv returned %d\n\n", ret );
goto exit;
}
p = buf, end = buf + buflen;
if( ( ret = dhm_read_params( &dhm, &p, end ) ) != 0 )
{
printf( " failed\n ! dhm_read_params returned %d\n\n", ret );
goto exit;
}
if( dhm.len < 64 || dhm.len > 512 )
{
ret = 1;
printf( " failed\n ! Invalid DHM modulus size\n\n" );
goto exit;
}
/*
* 5. Check that the server's RSA signature matches
* the SHA-1 hash of (P,G,Ys)
*/
printf( "\n . Verifying the server's RSA signature" );
fflush( stdout );
p += 2;
if( ( n = (size_t) ( end - p ) ) != rsa.len )
{
ret = 1;
printf( " failed\n ! Invalid RSA signature size\n\n" );
goto exit;
}
sha1( buf, (int)( p - 2 - buf ), hash );
if( ( ret = rsa_pkcs1_verify( &rsa, RSA_PUBLIC, SIG_RSA_SHA1,
0, hash, p ) ) != 0 )
{
printf( " failed\n ! rsa_pkcs1_verify returned %d\n\n", ret );
goto exit;
}
/*
* 6. Send our public value: Yc = G ^ Xc mod P
*/
printf( "\n . Sending own public value to server" );
fflush( stdout );
n = dhm.len;
if( ( ret = dhm_make_public( &dhm, dhm.len, buf, n,
ctr_drbg_random, &ctr_drbg ) ) != 0 )
{
printf( " failed\n ! dhm_make_public returned %d\n\n", ret );
goto exit;
}
if( ( ret = net_send( &server_fd, buf, n ) ) != (int) n )
{
printf( " failed\n ! net_send returned %d\n\n", ret );
goto exit;
}
/*
* 7. Derive the shared secret: K = Ys ^ Xc mod P
*/
printf( "\n . Shared secret: " );
fflush( stdout );
n = dhm.len;
if( ( ret = dhm_calc_secret( &dhm, buf, &n ) ) != 0 )
{
printf( " failed\n ! dhm_calc_secret returned %d\n\n", ret );
goto exit;
}
for( n = 0; n < 16; n++ )
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.
*/
printf( "...\n . Receiving and decrypting the ciphertext" );
fflush( stdout );
aes_setkey_dec( &aes, buf, 256 );
memset( buf, 0, sizeof( buf ) );
if( ( ret = net_recv( &server_fd, buf, 16 ) ) != 16 )
{
printf( " failed\n ! net_recv returned %d\n\n", ret );
goto exit;
}
aes_crypt_ecb( &aes, AES_DECRYPT, buf, buf );
buf[16] = '\0';
printf( "\n . Plaintext is \"%s\"\n\n", (char *) buf );
exit:
net_close( server_fd );
rsa_free( &rsa );
dhm_free( &dhm );
#if defined(_WIN32)
printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
/*
* Do an RSA operation to sign the message digest
*/
int rsa_pkcs1_sign( rsa_context *ctx,
int (*f_rng)(void *),
void *p_rng,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
size_t nb_pad, olen;
unsigned char *p = sig;
#if defined(POLARSSL_PKCS1_V21)
unsigned char salt[POLARSSL_MD_MAX_SIZE];
unsigned int i, slen, hlen, offset = 0;
size_t msb;
const md_info_t *md_info;
md_context_t md_ctx;
#else
(void) f_rng;
(void) p_rng;
#endif
olen = ctx->len;
switch( ctx->padding )
{
case RSA_PKCS_V15:
switch( hash_id )
{
case SIG_RSA_RAW:
nb_pad = olen - 3 - hashlen;
break;
case SIG_RSA_MD2:
case SIG_RSA_MD4:
case SIG_RSA_MD5:
nb_pad = olen - 3 - 34;
break;
case SIG_RSA_SHA1:
nb_pad = olen - 3 - 35;
break;
case SIG_RSA_SHA224:
nb_pad = olen - 3 - 47;
break;
case SIG_RSA_SHA256:
nb_pad = olen - 3 - 51;
break;
case SIG_RSA_SHA384:
nb_pad = olen - 3 - 67;
break;
case SIG_RSA_SHA512:
nb_pad = olen - 3 - 83;
break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
if( nb_pad < 8 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
*p++ = 0;
*p++ = RSA_SIGN;
memset( p, 0xFF, nb_pad );
p += nb_pad;
*p++ = 0;
switch( hash_id )
{
case SIG_RSA_RAW:
memcpy( p, hash, hashlen );
break;
case SIG_RSA_MD2:
memcpy( p, ASN1_HASH_MDX, 18 );
memcpy( p + 18, hash, 16 );
p[13] = 2; break;
case SIG_RSA_MD4:
memcpy( p, ASN1_HASH_MDX, 18 );
memcpy( p + 18, hash, 16 );
p[13] = 4; break;
case SIG_RSA_MD5:
memcpy( p, ASN1_HASH_MDX, 18 );
memcpy( p + 18, hash, 16 );
p[13] = 5; break;
case SIG_RSA_SHA1:
memcpy( p, ASN1_HASH_SHA1, 15 );
memcpy( p + 15, hash, 20 );
break;
case SIG_RSA_SHA224:
memcpy( p, ASN1_HASH_SHA2X, 19 );
memcpy( p + 19, hash, 28 );
p[1] += 28; p[14] = 4; p[18] += 28; break;
case SIG_RSA_SHA256:
memcpy( p, ASN1_HASH_SHA2X, 19 );
memcpy( p + 19, hash, 32 );
p[1] += 32; p[14] = 1; p[18] += 32; break;
case SIG_RSA_SHA384:
memcpy( p, ASN1_HASH_SHA2X, 19 );
memcpy( p + 19, hash, 48 );
p[1] += 48; p[14] = 2; p[18] += 48; break;
case SIG_RSA_SHA512:
memcpy( p, ASN1_HASH_SHA2X, 19 );
memcpy( p + 19, hash, 64 );
p[1] += 64; p[14] = 3; p[18] += 64; break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
break;
#if defined(POLARSSL_PKCS1_V21)
case RSA_PKCS_V21:
if( f_rng == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
switch( hash_id )
{
case SIG_RSA_MD2:
case SIG_RSA_MD4:
case SIG_RSA_MD5:
hashlen = 16;
break;
case SIG_RSA_SHA1:
hashlen = 20;
break;
case SIG_RSA_SHA224:
hashlen = 28;
break;
case SIG_RSA_SHA256:
hashlen = 32;
break;
case SIG_RSA_SHA384:
hashlen = 48;
break;
case SIG_RSA_SHA512:
hashlen = 64;
break;
default:
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
}
md_info = md_info_from_type( ctx->hash_id );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
slen = hlen;
memset( sig, 0, olen );
memset( &md_ctx, 0, sizeof( md_context_t ) );
md_init_ctx( &md_ctx, md_info );
msb = mpi_msb( &ctx->N ) - 1;
// Generate salt of length slen
//
for( i = 0; i < slen; ++i )
salt[i] = (unsigned char) f_rng( p_rng );
// Note: EMSA-PSS encoding is over the length of N - 1 bits
//
msb = mpi_msb( &ctx->N ) - 1;
p += olen - hlen * 2 - 2;
*p++ = 0x01;
memcpy( p, salt, slen );
p += slen;
// Generate H = Hash( M' )
//
md_starts( &md_ctx );
md_update( &md_ctx, p, 8 );
md_update( &md_ctx, hash, hashlen );
md_update( &md_ctx, salt, slen );
md_finish( &md_ctx, p );
// Compensate for boundary condition when applying mask
//
if( msb % 8 == 0 )
offset = 1;
// maskedDB: Apply dbMask to DB
//
mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx );
msb = mpi_msb( &ctx->N ) - 1;
sig[0] &= 0xFF >> ( olen * 8 - msb );
p += hlen;
*p++ = 0xBC;
break;
#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
return( ( mode == RSA_PUBLIC )
? rsa_public( ctx, sig, sig )
: rsa_private( ctx, sig, sig ) );
}
