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Don't use fixed len for RSA computation

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NIIBE Yutaka
2014-12-12 11:19:24 +09:00
parent f82206e7d5
commit 0d59d31230
3 changed files with 39 additions and 34 deletions
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9
ChangeLog
View File

@@ -1,3 +1,12 @@
2014-09-16 Niibe Yutaka <gniibe@fsij.org>
* src/gnuk.h (MAX_PRVKEY_LEN): New.
(KEY_CONTENT_LEN): Remove.
* src/call-rsa.c (RSA_SIGNATURE_LENGTH): Remove.
(rsa_sign, rsa_verify, rsa_genkey): Add new arg: PUBKEY_LEN.
(rsa_decrypt): Don't use KEY_CONTENT_LEN.
2014-06-19 Niibe Yutaka <gniibe@fsij.org>
* src/ecc-mont.c (compute_nQ): Add comment.

50
src/call-rsa.c
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@@ -32,29 +32,25 @@
#include "polarssl/config.h"
#include "polarssl/rsa.h"
#define RSA_SIGNATURE_LENGTH KEY_CONTENT_LEN
/* 256 byte == 2048-bit */
/* 128 byte == 1024-bit */
static rsa_context rsa_ctx;
int
rsa_sign (const uint8_t *raw_message, uint8_t *output, int msg_len,
struct key_data *kd)
struct key_data *kd, int pubkey_len)
{
mpi P1, Q1, H;
int ret = 0;
unsigned char temp[RSA_SIGNATURE_LENGTH];
unsigned char temp[pubkey_len];
rsa_init (&rsa_ctx, RSA_PKCS_V15, 0);
mpi_init (&P1); mpi_init (&Q1); mpi_init (&H);
rsa_ctx.len = KEY_CONTENT_LEN;
rsa_ctx.len = pubkey_len;
MPI_CHK( mpi_lset (&rsa_ctx.E, 0x10001) );
MPI_CHK( mpi_read_binary (&rsa_ctx.P, &kd->data[0], rsa_ctx.len / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.Q, &kd->data[KEY_CONTENT_LEN/2],
rsa_ctx.len / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.P, &kd->data[0], pubkey_len / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.Q, &kd->data[pubkey_len / 2],
pubkey_len / 2) );
#if 0
MPI_CHK( mpi_mul_mpi (&rsa_ctx.N, &rsa_ctx.P, &rsa_ctx.Q) );
#endif
@@ -74,7 +70,7 @@ rsa_sign (const uint8_t *raw_message, uint8_t *output, int msg_len,
ret = rsa_rsassa_pkcs1_v15_sign (&rsa_ctx, NULL, NULL,
RSA_PRIVATE, SIG_RSA_RAW,
msg_len, raw_message, temp);
memcpy (output, temp, RSA_SIGNATURE_LENGTH);
memcpy (output, temp, pubkey_len);
}
rsa_free (&rsa_ctx);
@@ -86,7 +82,7 @@ rsa_sign (const uint8_t *raw_message, uint8_t *output, int msg_len,
}
else
{
res_APDU_size = RSA_SIGNATURE_LENGTH;
res_APDU_size = pubkey_len;
DEBUG_INFO ("done.\r\n");
GPG_SUCCESS ();
return 0;
@@ -139,9 +135,8 @@ rsa_decrypt (const uint8_t *input, uint8_t *output, int msg_len,
DEBUG_WORD (msg_len);
MPI_CHK( mpi_lset (&rsa_ctx.E, 0x10001) );
MPI_CHK( mpi_read_binary (&rsa_ctx.P, &kd->data[0], KEY_CONTENT_LEN / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.Q, &kd->data[KEY_CONTENT_LEN/2],
KEY_CONTENT_LEN / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.P, &kd->data[0], msg_len / 2) );
MPI_CHK( mpi_read_binary (&rsa_ctx.Q, &kd->data[msg_len / 2], msg_len / 2) );
#if 0
MPI_CHK( mpi_mul_mpi (&rsa_ctx.N, &rsa_ctx.P, &rsa_ctx.Q) );
#endif
@@ -179,14 +174,15 @@ rsa_decrypt (const uint8_t *input, uint8_t *output, int msg_len,
}
int
rsa_verify (const uint8_t *pubkey, const uint8_t *hash, const uint8_t *sig)
rsa_verify (const uint8_t *pubkey, int pubkey_len,
const uint8_t *hash, const uint8_t *sig)
{
int ret;
rsa_init (&rsa_ctx, RSA_PKCS_V15, 0);
rsa_ctx.len = KEY_CONTENT_LEN;
rsa_ctx.len = pubkey_len;
MPI_CHK( mpi_lset (&rsa_ctx.E, 0x10001) );
MPI_CHK( mpi_read_binary (&rsa_ctx.N, pubkey, KEY_CONTENT_LEN) );
MPI_CHK( mpi_read_binary (&rsa_ctx.N, pubkey, pubkey_len) );
DEBUG_INFO ("RSA verify...");
@@ -212,14 +208,14 @@ rsa_verify (const uint8_t *pubkey, const uint8_t *hash, const uint8_t *sig)
#ifdef KEYGEN_SUPPORT
uint8_t *
rsa_genkey (void)
rsa_genkey (int pubkey_len)
{
int ret;
uint8_t index = 0;
uint8_t *p_q_modulus = (uint8_t *)malloc (KEY_CONTENT_LEN*2);
uint8_t *p_q_modulus = (uint8_t *)malloc (pubkey_len * 2);
uint8_t *p = p_q_modulus;
uint8_t *q = p_q_modulus + KEY_CONTENT_LEN/2;
uint8_t *modulus = p_q_modulus + KEY_CONTENT_LEN;
uint8_t *q = p_q_modulus + pubkey_len / 2;
uint8_t *modulus = p_q_modulus + pubkey_len;
extern int prng_seed (int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng);
extern void neug_flush (void);
@@ -231,8 +227,8 @@ rsa_genkey (void)
prng_seed (random_gen, &index);
rsa_init (&rsa_ctx, RSA_PKCS_V15, 0);
MPI_CHK( rsa_gen_key (&rsa_ctx, random_gen, &index,
KEY_CONTENT_LEN * 8, RSA_EXPONENT) );
MPI_CHK( rsa_gen_key (&rsa_ctx, random_gen, &index, pubkey_len * 8,
RSA_EXPONENT) );
if (ret != 0)
{
free (p_q_modulus);
@@ -240,9 +236,9 @@ rsa_genkey (void)
return NULL;
}
MPI_CHK( mpi_write_binary (&rsa_ctx.P, p, KEY_CONTENT_LEN/2) );
MPI_CHK( mpi_write_binary (&rsa_ctx.Q, q, KEY_CONTENT_LEN/2) );
MPI_CHK( mpi_write_binary (&rsa_ctx.N, modulus, KEY_CONTENT_LEN) );
MPI_CHK( mpi_write_binary (&rsa_ctx.P, p, pubkey_len / 2) );
MPI_CHK( mpi_write_binary (&rsa_ctx.Q, q, pubkey_len / 2) );
MPI_CHK( mpi_write_binary (&rsa_ctx.N, modulus, pubkey_len) );
cleanup:
rsa_free (&rsa_ctx);

14
src/gnuk.h
View File

@@ -144,13 +144,14 @@ extern int flash_write_binary (uint8_t file_id, const uint8_t *data, uint16_t le
extern uint8_t ch_certificate_start;
extern uint8_t random_bits_start;
#define KEY_CONTENT_LEN 256 /* p and q */
#define INITIAL_VECTOR_SIZE 16
#define DATA_ENCRYPTION_KEY_SIZE 16
#define MAX_PRVKEY_LEN 512 /* Maximum is the case for RSA 4096-bit. */
struct key_data {
uint8_t *key_addr; /* Pointer to encrypted data, and public */
uint8_t data[KEY_CONTENT_LEN]; /* decrypted data content */
const uint8_t *pubkey; /* Pointer to public key*/
uint8_t data[MAX_PRVKEY_LEN]; /* decrypted private key data content */
};
struct key_data_internal {
@@ -241,12 +242,11 @@ extern void put_binary (const char *s, int len);
#define DEBUG_BINARY(s,len)
#endif
extern int rsa_sign (const uint8_t *, uint8_t *, int, struct key_data *);
extern int rsa_sign (const uint8_t *, uint8_t *, int, struct key_data *, int);
extern uint8_t *modulus_calc (const uint8_t *, int);
extern int rsa_decrypt (const uint8_t *, uint8_t *, int, struct key_data *);
extern int rsa_verify (const uint8_t *pubkey, const uint8_t *hash,
const uint8_t *signature);
extern uint8_t *rsa_genkey (void);
extern int rsa_verify (const uint8_t *, int, const uint8_t *, const uint8_t *);
extern uint8_t *rsa_genkey (int);
extern int ecdsa_sign_p256r1 (const uint8_t *hash, uint8_t *output,
const uint8_t *key_data);