#include "common.h"
#if defined(MBEDTLS_DHM_C)
#include "mbedtls/dhm.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include <string.h>
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_ASN1_PARSE_C)
#include "mbedtls/asn1.h"
#endif
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_DHM_ALT)
static int dhm_read_bignum(mbedtls_mpi *X,
unsigned char **p,
const unsigned char *end)
{
int ret, n;
if (end - *p < 2) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
n = MBEDTLS_GET_UINT16_BE(*p, 0);
(*p) += 2;
if ((size_t) (end - *p) < (size_t) n) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if ((ret = mbedtls_mpi_read_binary(X, *p, n)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PARAMS_FAILED, ret);
}
(*p) += n;
return 0;
}
static int dhm_check_range(const mbedtls_mpi *param, const mbedtls_mpi *P)
{
mbedtls_mpi U;
int ret = 0;
mbedtls_mpi_init(&U);
MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&U, P, 2));
if (mbedtls_mpi_cmp_int(param, 2) < 0 ||
mbedtls_mpi_cmp_mpi(param, &U) > 0) {
ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
cleanup:
mbedtls_mpi_free(&U);
return ret;
}
void mbedtls_dhm_init(mbedtls_dhm_context *ctx)
{
memset(ctx, 0, sizeof(mbedtls_dhm_context));
}
size_t mbedtls_dhm_get_bitlen(const mbedtls_dhm_context *ctx)
{
return mbedtls_mpi_bitlen(&ctx->P);
}
size_t mbedtls_dhm_get_len(const mbedtls_dhm_context *ctx)
{
return mbedtls_mpi_size(&ctx->P);
}
int mbedtls_dhm_get_value(const mbedtls_dhm_context *ctx,
mbedtls_dhm_parameter param,
mbedtls_mpi *dest)
{
const mbedtls_mpi *src = NULL;
switch (param) {
case MBEDTLS_DHM_PARAM_P:
src = &ctx->P;
break;
case MBEDTLS_DHM_PARAM_G:
src = &ctx->G;
break;
case MBEDTLS_DHM_PARAM_X:
src = &ctx->X;
break;
case MBEDTLS_DHM_PARAM_GX:
src = &ctx->GX;
break;
case MBEDTLS_DHM_PARAM_GY:
src = &ctx->GY;
break;
case MBEDTLS_DHM_PARAM_K:
src = &ctx->K;
break;
default:
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
return mbedtls_mpi_copy(dest, src);
}
int mbedtls_dhm_read_params(mbedtls_dhm_context *ctx,
unsigned char **p,
const unsigned char *end)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if ((ret = dhm_read_bignum(&ctx->P, p, end)) != 0 ||
(ret = dhm_read_bignum(&ctx->G, p, end)) != 0 ||
(ret = dhm_read_bignum(&ctx->GY, p, end)) != 0) {
return ret;
}
if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
return ret;
}
return 0;
}
static int dhm_random_below(mbedtls_mpi *R, const mbedtls_mpi *M,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
int ret;
MBEDTLS_MPI_CHK(mbedtls_mpi_random(R, 3, M, f_rng, p_rng));
MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(R, R, 1));
cleanup:
return ret;
}
static int dhm_make_common(mbedtls_dhm_context *ctx, int x_size,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
int ret = 0;
if (mbedtls_mpi_cmp_int(&ctx->P, 0) == 0) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if (x_size < 0) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if ((unsigned) x_size < mbedtls_mpi_size(&ctx->P)) {
MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&ctx->X, x_size, f_rng, p_rng));
} else {
ret = dhm_random_below(&ctx->X, &ctx->P, f_rng, p_rng);
if (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) {
return MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED;
}
if (ret != 0) {
return ret;
}
}
MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->GX, &ctx->G, &ctx->X,
&ctx->P, &ctx->RP));
if ((ret = dhm_check_range(&ctx->GX, &ctx->P)) != 0) {
return ret;
}
cleanup:
return ret;
}
int mbedtls_dhm_make_params(mbedtls_dhm_context *ctx, int x_size,
unsigned char *output, size_t *olen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
int ret;
size_t n1, n2, n3;
unsigned char *p;
ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
if (ret != 0) {
goto cleanup;
}
#define DHM_MPI_EXPORT …
n1 = mbedtls_mpi_size(&ctx->P);
n2 = mbedtls_mpi_size(&ctx->G);
n3 = mbedtls_mpi_size(&ctx->GX);
p = output;
DHM_MPI_EXPORT(&ctx->P, n1);
DHM_MPI_EXPORT(&ctx->G, n2);
DHM_MPI_EXPORT(&ctx->GX, n3);
*olen = (size_t) (p - output);
cleanup:
if (ret != 0 && ret > -128) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED, ret);
}
return ret;
}
int mbedtls_dhm_set_group(mbedtls_dhm_context *ctx,
const mbedtls_mpi *P,
const mbedtls_mpi *G)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if ((ret = mbedtls_mpi_copy(&ctx->P, P)) != 0 ||
(ret = mbedtls_mpi_copy(&ctx->G, G)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_SET_GROUP_FAILED, ret);
}
return 0;
}
int mbedtls_dhm_read_public(mbedtls_dhm_context *ctx,
const unsigned char *input, size_t ilen)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (ilen < 1 || ilen > mbedtls_dhm_get_len(ctx)) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if ((ret = mbedtls_mpi_read_binary(&ctx->GY, input, ilen)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED, ret);
}
return 0;
}
int mbedtls_dhm_make_public(mbedtls_dhm_context *ctx, int x_size,
unsigned char *output, size_t olen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
int ret;
if (olen < 1 || olen > mbedtls_dhm_get_len(ctx)) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
if (ret == MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED) {
return MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED;
}
if (ret != 0) {
goto cleanup;
}
MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->GX, output, olen));
cleanup:
if (ret != 0 && ret > -128) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED, ret);
}
return ret;
}
static int dhm_update_blinding(mbedtls_dhm_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
int ret;
mbedtls_mpi R;
mbedtls_mpi_init(&R);
if (mbedtls_mpi_cmp_mpi(&ctx->X, &ctx->pX) != 0) {
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&ctx->pX, &ctx->X));
MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vi, 1));
MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vf, 1));
return 0;
}
if (mbedtls_mpi_cmp_int(&ctx->Vi, 1) != 0) {
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &ctx->Vi));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &ctx->Vf));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
return 0;
}
MBEDTLS_MPI_CHK(dhm_random_below(&ctx->Vi, &ctx->P, f_rng, p_rng));
MBEDTLS_MPI_CHK(dhm_random_below(&R, &ctx->P, f_rng, p_rng));
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vi, &R));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&ctx->Vf, &ctx->Vf, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &R));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP));
cleanup:
mbedtls_mpi_free(&R);
return ret;
}
int mbedtls_dhm_calc_secret(mbedtls_dhm_context *ctx,
unsigned char *output, size_t output_size, size_t *olen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi GYb;
if (f_rng == NULL) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if (output_size < mbedtls_dhm_get_len(ctx)) {
return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
}
if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
return ret;
}
mbedtls_mpi_init(&GYb);
MBEDTLS_MPI_CHK(dhm_update_blinding(ctx, f_rng, p_rng));
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&GYb, &ctx->GY, &ctx->Vi));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&GYb, &GYb, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->K, &GYb, &ctx->X,
&ctx->P, &ctx->RP));
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->K, &ctx->K, &ctx->Vf));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->K, &ctx->K, &ctx->P));
*olen = mbedtls_mpi_size(&ctx->K);
MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->K, output, *olen));
cleanup:
mbedtls_mpi_free(&GYb);
if (ret != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_CALC_SECRET_FAILED, ret);
}
return 0;
}
void mbedtls_dhm_free(mbedtls_dhm_context *ctx)
{
if (ctx == NULL) {
return;
}
mbedtls_mpi_free(&ctx->pX);
mbedtls_mpi_free(&ctx->Vf);
mbedtls_mpi_free(&ctx->Vi);
mbedtls_mpi_free(&ctx->RP);
mbedtls_mpi_free(&ctx->K);
mbedtls_mpi_free(&ctx->GY);
mbedtls_mpi_free(&ctx->GX);
mbedtls_mpi_free(&ctx->X);
mbedtls_mpi_free(&ctx->G);
mbedtls_mpi_free(&ctx->P);
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_dhm_context));
}
#if defined(MBEDTLS_ASN1_PARSE_C)
int mbedtls_dhm_parse_dhm(mbedtls_dhm_context *dhm, const unsigned char *dhmin,
size_t dhminlen)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
unsigned char *p, *end;
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_context pem;
#endif
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_init(&pem);
if (dhminlen == 0 || dhmin[dhminlen - 1] != '\0') {
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
} else {
ret = mbedtls_pem_read_buffer(&pem,
"-----BEGIN DH PARAMETERS-----",
"-----END DH PARAMETERS-----",
dhmin, NULL, 0, &dhminlen);
}
if (ret == 0) {
dhminlen = pem.buflen;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
goto exit;
}
p = (ret == 0) ? pem.buf : (unsigned char *) dhmin;
#else
p = (unsigned char *) dhmin;
#endif
end = p + dhminlen;
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
goto exit;
}
end = p + len;
if ((ret = mbedtls_asn1_get_mpi(&p, end, &dhm->P)) != 0 ||
(ret = mbedtls_asn1_get_mpi(&p, end, &dhm->G)) != 0) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
goto exit;
}
if (p != end) {
mbedtls_mpi rec;
mbedtls_mpi_init(&rec);
ret = mbedtls_asn1_get_mpi(&p, end, &rec);
mbedtls_mpi_free(&rec);
if (ret != 0) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
goto exit;
}
if (p != end) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
goto exit;
}
}
ret = 0;
exit:
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_free(&pem);
#endif
if (ret != 0) {
mbedtls_dhm_free(dhm);
}
return ret;
}
#if defined(MBEDTLS_FS_IO)
static int load_file(const char *path, unsigned char **buf, size_t *n)
{
FILE *f;
long size;
if ((f = fopen(path, "rb")) == NULL) {
return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
}
fseek(f, 0, SEEK_END);
if ((size = ftell(f)) == -1) {
fclose(f);
return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
}
fseek(f, 0, SEEK_SET);
*n = (size_t) size;
if (*n + 1 == 0 ||
(*buf = mbedtls_calloc(1, *n + 1)) == NULL) {
fclose(f);
return MBEDTLS_ERR_DHM_ALLOC_FAILED;
}
if (fread(*buf, 1, *n, f) != *n) {
fclose(f);
mbedtls_zeroize_and_free(*buf, *n + 1);
return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
}
fclose(f);
(*buf)[*n] = '\0';
if (strstr((const char *) *buf, "-----BEGIN ") != NULL) {
++*n;
}
return 0;
}
int mbedtls_dhm_parse_dhmfile(mbedtls_dhm_context *dhm, const char *path)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
if ((ret = load_file(path, &buf, &n)) != 0) {
return ret;
}
ret = mbedtls_dhm_parse_dhm(dhm, buf, n);
mbedtls_zeroize_and_free(buf, n);
return ret;
}
#endif
#endif
#endif
#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_PEM_PARSE_C)
static const char mbedtls_test_dhm_params[] =
"-----BEGIN DH PARAMETERS-----\r\n"
"MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
"1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
"9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
"-----END DH PARAMETERS-----\r\n";
#else
static const char mbedtls_test_dhm_params[] = {
0x30, 0x81, 0x87, 0x02, 0x81, 0x81, 0x00, 0x9e, 0x35, 0xf4, 0x30, 0x44,
0x3a, 0x09, 0x90, 0x4f, 0x3a, 0x39, 0xa9, 0x79, 0x79, 0x7d, 0x07, 0x0d,
0xf5, 0x33, 0x78, 0xe7, 0x9c, 0x24, 0x38, 0xbe, 0xf4, 0xe7, 0x61, 0xf3,
0xc7, 0x14, 0x55, 0x33, 0x28, 0x58, 0x9b, 0x04, 0x1c, 0x80, 0x9b, 0xe1,
0xd6, 0xc6, 0xb5, 0xf1, 0xfc, 0x9f, 0x47, 0xd3, 0xa2, 0x54, 0x43, 0x18,
0x82, 0x53, 0xa9, 0x92, 0xa5, 0x68, 0x18, 0xb3, 0x7b, 0xa9, 0xde, 0x5a,
0x40, 0xd3, 0x62, 0xe5, 0x6e, 0xff, 0x0b, 0xe5, 0x41, 0x74, 0x74, 0xc1,
0x25, 0xc1, 0x99, 0x27, 0x2c, 0x8f, 0xe4, 0x1d, 0xea, 0x73, 0x3d, 0xf6,
0xf6, 0x62, 0xc9, 0x2a, 0xe7, 0x65, 0x56, 0xe7, 0x55, 0xd1, 0x0c, 0x64,
0xe6, 0xa5, 0x09, 0x68, 0xf6, 0x7f, 0xc6, 0xea, 0x73, 0xd0, 0xdc, 0xa8,
0x56, 0x9b, 0xe2, 0xba, 0x20, 0x4e, 0x23, 0x58, 0x0d, 0x8b, 0xca, 0x2f,
0x49, 0x75, 0xb3, 0x02, 0x01, 0x02
};
#endif
static const size_t mbedtls_test_dhm_params_len = sizeof(mbedtls_test_dhm_params);
int mbedtls_dhm_self_test(int verbose)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_dhm_context dhm;
mbedtls_dhm_init(&dhm);
if (verbose != 0) {
mbedtls_printf(" DHM parameter load: ");
}
if ((ret = mbedtls_dhm_parse_dhm(&dhm,
(const unsigned char *) mbedtls_test_dhm_params,
mbedtls_test_dhm_params_len)) != 0) {
if (verbose != 0) {
mbedtls_printf("failed\n");
}
ret = 1;
goto exit;
}
if (verbose != 0) {
mbedtls_printf("passed\n\n");
}
exit:
mbedtls_dhm_free(&dhm);
return ret;
}
#endif
#endif