godot/thirdparty/mbedtls/library/pk_wrap.c

1094 lines
32 KiB
C

/*
* Public Key abstraction layer: wrapper functions
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#include "common.h"
#if defined(MBEDTLS_PK_C)
#include "mbedtls/pk_internal.h"
#include "mbedtls/error.h"
/* Even if RSA not activated, for the sake of RSA-alt */
#include "mbedtls/rsa.h"
#include <string.h>
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/ecp.h"
#endif
#if defined(MBEDTLS_ECDSA_C)
#include "mbedtls/ecdsa.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "mbedtls/asn1write.h"
#endif
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#include "mbedtls/asn1.h"
#endif
#include "mbedtls/platform.h"
#include <limits.h>
#include <stdint.h>
#if defined(MBEDTLS_RSA_C)
static int rsa_can_do(mbedtls_pk_type_t type)
{
return type == MBEDTLS_PK_RSA ||
type == MBEDTLS_PK_RSASSA_PSS;
}
static size_t rsa_get_bitlen(const void *ctx)
{
const mbedtls_rsa_context *rsa = (const mbedtls_rsa_context *) ctx;
/* Unfortunately, the rsa.h interface does not have a direct way
* to access the bit-length that works with MBEDTLS_RSA_ALT.
* So we have to do a little work here.
*/
mbedtls_mpi N;
mbedtls_mpi_init(&N);
int ret = mbedtls_rsa_export(rsa, &N, NULL, NULL, NULL, NULL);
/* If the export fails for some reason (e.g. the RSA_ALT implementation
* does not support export, or there is not enough memory),
* we have no way of returning an error from this function.
* As a fallback, return the byte-length converted in bits, which is
* the correct value if the modulus size is a multiple of 8 bits, which
* is very often the case in practice. */
size_t bitlen = (ret == 0 ? mbedtls_mpi_bitlen(&N) :
8 * mbedtls_rsa_get_len(rsa));
mbedtls_mpi_free(&N);
return bitlen;
}
static int rsa_verify_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_rsa_context *rsa = (mbedtls_rsa_context *) ctx;
size_t rsa_len = mbedtls_rsa_get_len(rsa);
#if SIZE_MAX > UINT_MAX
if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
#endif /* SIZE_MAX > UINT_MAX */
if (sig_len < rsa_len) {
return MBEDTLS_ERR_RSA_VERIFY_FAILED;
}
if ((ret = mbedtls_rsa_pkcs1_verify(rsa, NULL, NULL,
MBEDTLS_RSA_PUBLIC, md_alg,
(unsigned int) hash_len, hash, sig)) != 0) {
return ret;
}
/* The buffer contains a valid signature followed by extra data.
* We have a special error code for that so that so that callers can
* use mbedtls_pk_verify() to check "Does the buffer start with a
* valid signature?" and not just "Does the buffer contain a valid
* signature?". */
if (sig_len > rsa_len) {
return MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
}
return 0;
}
static int rsa_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
mbedtls_rsa_context *rsa = (mbedtls_rsa_context *) ctx;
#if SIZE_MAX > UINT_MAX
if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
#endif /* SIZE_MAX > UINT_MAX */
*sig_len = mbedtls_rsa_get_len(rsa);
return mbedtls_rsa_pkcs1_sign(rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
md_alg, (unsigned int) hash_len, hash, sig);
}
static int rsa_decrypt_wrap(void *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
mbedtls_rsa_context *rsa = (mbedtls_rsa_context *) ctx;
if (ilen != mbedtls_rsa_get_len(rsa)) {
return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
}
return mbedtls_rsa_pkcs1_decrypt(rsa, f_rng, p_rng,
MBEDTLS_RSA_PRIVATE, olen, input, output, osize);
}
static int rsa_encrypt_wrap(void *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
mbedtls_rsa_context *rsa = (mbedtls_rsa_context *) ctx;
*olen = mbedtls_rsa_get_len(rsa);
if (*olen > osize) {
return MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
}
return mbedtls_rsa_pkcs1_encrypt(rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
ilen, input, output);
}
static int rsa_check_pair_wrap(const void *pub, const void *prv)
{
return mbedtls_rsa_check_pub_priv((const mbedtls_rsa_context *) pub,
(const mbedtls_rsa_context *) prv);
}
static void *rsa_alloc_wrap(void)
{
void *ctx = mbedtls_calloc(1, sizeof(mbedtls_rsa_context));
if (ctx != NULL) {
mbedtls_rsa_init((mbedtls_rsa_context *) ctx, 0, 0);
}
return ctx;
}
static void rsa_free_wrap(void *ctx)
{
mbedtls_rsa_free((mbedtls_rsa_context *) ctx);
mbedtls_free(ctx);
}
static void rsa_debug(const void *ctx, mbedtls_pk_debug_item *items)
{
items->type = MBEDTLS_PK_DEBUG_MPI;
items->name = "rsa.N";
items->value = &(((mbedtls_rsa_context *) ctx)->N);
items++;
items->type = MBEDTLS_PK_DEBUG_MPI;
items->name = "rsa.E";
items->value = &(((mbedtls_rsa_context *) ctx)->E);
}
const mbedtls_pk_info_t mbedtls_rsa_info = {
MBEDTLS_PK_RSA,
"RSA",
rsa_get_bitlen,
rsa_can_do,
rsa_verify_wrap,
rsa_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_decrypt_wrap,
rsa_encrypt_wrap,
rsa_check_pair_wrap,
rsa_alloc_wrap,
rsa_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_debug,
};
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
/*
* Generic EC key
*/
static int eckey_can_do(mbedtls_pk_type_t type)
{
return type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECKEY_DH ||
type == MBEDTLS_PK_ECDSA;
}
static size_t eckey_get_bitlen(const void *ctx)
{
return ((mbedtls_ecp_keypair *) ctx)->grp.pbits;
}
#if defined(MBEDTLS_ECDSA_C)
/* Forward declarations */
static int ecdsa_verify_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len);
static int ecdsa_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
static int eckey_verify_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ecdsa_context ecdsa;
mbedtls_ecdsa_init(&ecdsa);
if ((ret = mbedtls_ecdsa_from_keypair(&ecdsa, ctx)) == 0) {
ret = ecdsa_verify_wrap(&ecdsa, md_alg, hash, hash_len, sig, sig_len);
}
mbedtls_ecdsa_free(&ecdsa);
return ret;
}
static int eckey_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ecdsa_context ecdsa;
mbedtls_ecdsa_init(&ecdsa);
if ((ret = mbedtls_ecdsa_from_keypair(&ecdsa, ctx)) == 0) {
ret = ecdsa_sign_wrap(&ecdsa, md_alg, hash, hash_len, sig, sig_len,
f_rng, p_rng);
}
mbedtls_ecdsa_free(&ecdsa);
return ret;
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
/* Forward declarations */
static int ecdsa_verify_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx);
static int ecdsa_sign_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
void *rs_ctx);
/*
* Restart context for ECDSA operations with ECKEY context
*
* We need to store an actual ECDSA context, as we need to pass the same to
* the underlying ecdsa function, so we can't create it on the fly every time.
*/
typedef struct {
mbedtls_ecdsa_restart_ctx ecdsa_rs;
mbedtls_ecdsa_context ecdsa_ctx;
} eckey_restart_ctx;
static void *eckey_rs_alloc(void)
{
eckey_restart_ctx *rs_ctx;
void *ctx = mbedtls_calloc(1, sizeof(eckey_restart_ctx));
if (ctx != NULL) {
rs_ctx = ctx;
mbedtls_ecdsa_restart_init(&rs_ctx->ecdsa_rs);
mbedtls_ecdsa_init(&rs_ctx->ecdsa_ctx);
}
return ctx;
}
static void eckey_rs_free(void *ctx)
{
eckey_restart_ctx *rs_ctx;
if (ctx == NULL) {
return;
}
rs_ctx = ctx;
mbedtls_ecdsa_restart_free(&rs_ctx->ecdsa_rs);
mbedtls_ecdsa_free(&rs_ctx->ecdsa_ctx);
mbedtls_free(ctx);
}
static int eckey_verify_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
eckey_restart_ctx *rs = rs_ctx;
/* Should never happen */
if (rs == NULL) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
/* set up our own sub-context if needed (that is, on first run) */
if (rs->ecdsa_ctx.grp.pbits == 0) {
MBEDTLS_MPI_CHK(mbedtls_ecdsa_from_keypair(&rs->ecdsa_ctx, ctx));
}
MBEDTLS_MPI_CHK(ecdsa_verify_rs_wrap(&rs->ecdsa_ctx,
md_alg, hash, hash_len,
sig, sig_len, &rs->ecdsa_rs));
cleanup:
return ret;
}
static int eckey_sign_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
void *rs_ctx)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
eckey_restart_ctx *rs = rs_ctx;
/* Should never happen */
if (rs == NULL) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
/* set up our own sub-context if needed (that is, on first run) */
if (rs->ecdsa_ctx.grp.pbits == 0) {
MBEDTLS_MPI_CHK(mbedtls_ecdsa_from_keypair(&rs->ecdsa_ctx, ctx));
}
MBEDTLS_MPI_CHK(ecdsa_sign_rs_wrap(&rs->ecdsa_ctx, md_alg,
hash, hash_len, sig, sig_len,
f_rng, p_rng, &rs->ecdsa_rs));
cleanup:
return ret;
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
#endif /* MBEDTLS_ECDSA_C */
static int eckey_check_pair(const void *pub, const void *prv)
{
return mbedtls_ecp_check_pub_priv((const mbedtls_ecp_keypair *) pub,
(const mbedtls_ecp_keypair *) prv);
}
static void *eckey_alloc_wrap(void)
{
void *ctx = mbedtls_calloc(1, sizeof(mbedtls_ecp_keypair));
if (ctx != NULL) {
mbedtls_ecp_keypair_init(ctx);
}
return ctx;
}
static void eckey_free_wrap(void *ctx)
{
mbedtls_ecp_keypair_free((mbedtls_ecp_keypair *) ctx);
mbedtls_free(ctx);
}
static void eckey_debug(const void *ctx, mbedtls_pk_debug_item *items)
{
items->type = MBEDTLS_PK_DEBUG_ECP;
items->name = "eckey.Q";
items->value = &(((mbedtls_ecp_keypair *) ctx)->Q);
}
const mbedtls_pk_info_t mbedtls_eckey_info = {
MBEDTLS_PK_ECKEY,
"EC",
eckey_get_bitlen,
eckey_can_do,
#if defined(MBEDTLS_ECDSA_C)
eckey_verify_wrap,
eckey_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
eckey_verify_rs_wrap,
eckey_sign_rs_wrap,
#endif
#else /* MBEDTLS_ECDSA_C */
NULL,
NULL,
#endif /* MBEDTLS_ECDSA_C */
NULL,
NULL,
eckey_check_pair,
eckey_alloc_wrap,
eckey_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
eckey_rs_alloc,
eckey_rs_free,
#endif
eckey_debug,
};
/*
* EC key restricted to ECDH
*/
static int eckeydh_can_do(mbedtls_pk_type_t type)
{
return type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECKEY_DH;
}
const mbedtls_pk_info_t mbedtls_eckeydh_info = {
MBEDTLS_PK_ECKEY_DH,
"EC_DH",
eckey_get_bitlen, /* Same underlying key structure */
eckeydh_can_do,
NULL,
NULL,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
NULL,
NULL,
eckey_check_pair,
eckey_alloc_wrap, /* Same underlying key structure */
eckey_free_wrap, /* Same underlying key structure */
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
eckey_debug, /* Same underlying key structure */
};
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_ECDSA_C)
static int ecdsa_can_do(mbedtls_pk_type_t type)
{
return type == MBEDTLS_PK_ECDSA;
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/*
* An ASN.1 encoded signature is a sequence of two ASN.1 integers. Parse one of
* those integers and convert it to the fixed-length encoding expected by PSA.
*/
static int extract_ecdsa_sig_int(unsigned char **from, const unsigned char *end,
unsigned char *to, size_t to_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t unpadded_len, padding_len;
if ((ret = mbedtls_asn1_get_tag(from, end, &unpadded_len,
MBEDTLS_ASN1_INTEGER)) != 0) {
return ret;
}
while (unpadded_len > 0 && **from == 0x00) {
(*from)++;
unpadded_len--;
}
if (unpadded_len > to_len || unpadded_len == 0) {
return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
}
padding_len = to_len - unpadded_len;
memset(to, 0x00, padding_len);
memcpy(to + padding_len, *from, unpadded_len);
(*from) += unpadded_len;
return 0;
}
/*
* Convert a signature from an ASN.1 sequence of two integers
* to a raw {r,s} buffer. Note: the provided sig buffer must be at least
* twice as big as int_size.
*/
static int extract_ecdsa_sig(unsigned char **p, const unsigned char *end,
unsigned char *sig, size_t int_size)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t tmp_size;
if ((ret = mbedtls_asn1_get_tag(p, end, &tmp_size,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return ret;
}
/* Extract r */
if ((ret = extract_ecdsa_sig_int(p, end, sig, int_size)) != 0) {
return ret;
}
/* Extract s */
if ((ret = extract_ecdsa_sig_int(p, end, sig + int_size, int_size)) != 0) {
return ret;
}
return 0;
}
static int ecdsa_verify_wrap(void *ctx_arg, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len)
{
mbedtls_ecdsa_context *ctx = ctx_arg;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_key_id_t key_id = 0;
psa_status_t status;
mbedtls_pk_context key;
int key_len;
/* see ECP_PUB_DER_MAX_BYTES in pkwrite.c */
unsigned char buf[30 + 2 * MBEDTLS_ECP_MAX_BYTES];
unsigned char *p;
mbedtls_pk_info_t pk_info = mbedtls_eckey_info;
psa_algorithm_t psa_sig_md = PSA_ALG_ECDSA_ANY;
size_t curve_bits;
psa_ecc_family_t curve =
mbedtls_ecc_group_to_psa(ctx->grp.id, &curve_bits);
const size_t signature_part_size = (ctx->grp.nbits + 7) / 8;
((void) md_alg);
if (curve == 0) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
/* mbedtls_pk_write_pubkey() expects a full PK context;
* re-construct one to make it happy */
key.pk_info = &pk_info;
key.pk_ctx = ctx;
p = buf + sizeof(buf);
key_len = mbedtls_pk_write_pubkey(&p, buf, &key);
if (key_len <= 0) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
psa_set_key_type(&attributes, PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve));
psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_VERIFY_HASH);
psa_set_key_algorithm(&attributes, psa_sig_md);
status = psa_import_key(&attributes,
buf + sizeof(buf) - key_len, key_len,
&key_id);
if (status != PSA_SUCCESS) {
ret = mbedtls_psa_err_translate_pk(status);
goto cleanup;
}
/* We don't need the exported key anymore and can
* reuse its buffer for signature extraction. */
if (2 * signature_part_size > sizeof(buf)) {
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
p = (unsigned char *) sig;
if ((ret = extract_ecdsa_sig(&p, sig + sig_len, buf,
signature_part_size)) != 0) {
goto cleanup;
}
if (psa_verify_hash(key_id, psa_sig_md,
hash, hash_len,
buf, 2 * signature_part_size)
!= PSA_SUCCESS) {
ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
goto cleanup;
}
if (p != sig + sig_len) {
ret = MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
goto cleanup;
}
ret = 0;
cleanup:
psa_destroy_key(key_id);
return ret;
}
#else /* MBEDTLS_USE_PSA_CRYPTO */
static int ecdsa_verify_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((void) md_alg);
ret = mbedtls_ecdsa_read_signature((mbedtls_ecdsa_context *) ctx,
hash, hash_len, sig, sig_len);
if (ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH) {
return MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
}
return ret;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
static int ecdsa_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
return mbedtls_ecdsa_write_signature((mbedtls_ecdsa_context *) ctx,
md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng);
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
static int ecdsa_verify_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((void) md_alg);
ret = mbedtls_ecdsa_read_signature_restartable(
(mbedtls_ecdsa_context *) ctx,
hash, hash_len, sig, sig_len,
(mbedtls_ecdsa_restart_ctx *) rs_ctx);
if (ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH) {
return MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
}
return ret;
}
static int ecdsa_sign_rs_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
void *rs_ctx)
{
return mbedtls_ecdsa_write_signature_restartable(
(mbedtls_ecdsa_context *) ctx,
md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng,
(mbedtls_ecdsa_restart_ctx *) rs_ctx);
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
static void *ecdsa_alloc_wrap(void)
{
void *ctx = mbedtls_calloc(1, sizeof(mbedtls_ecdsa_context));
if (ctx != NULL) {
mbedtls_ecdsa_init((mbedtls_ecdsa_context *) ctx);
}
return ctx;
}
static void ecdsa_free_wrap(void *ctx)
{
mbedtls_ecdsa_free((mbedtls_ecdsa_context *) ctx);
mbedtls_free(ctx);
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
static void *ecdsa_rs_alloc(void)
{
void *ctx = mbedtls_calloc(1, sizeof(mbedtls_ecdsa_restart_ctx));
if (ctx != NULL) {
mbedtls_ecdsa_restart_init(ctx);
}
return ctx;
}
static void ecdsa_rs_free(void *ctx)
{
mbedtls_ecdsa_restart_free(ctx);
mbedtls_free(ctx);
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
const mbedtls_pk_info_t mbedtls_ecdsa_info = {
MBEDTLS_PK_ECDSA,
"ECDSA",
eckey_get_bitlen, /* Compatible key structures */
ecdsa_can_do,
ecdsa_verify_wrap,
ecdsa_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
ecdsa_verify_rs_wrap,
ecdsa_sign_rs_wrap,
#endif
NULL,
NULL,
eckey_check_pair, /* Compatible key structures */
ecdsa_alloc_wrap,
ecdsa_free_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
ecdsa_rs_alloc,
ecdsa_rs_free,
#endif
eckey_debug, /* Compatible key structures */
};
#endif /* MBEDTLS_ECDSA_C */
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/*
* Support for alternative RSA-private implementations
*/
static int rsa_alt_can_do(mbedtls_pk_type_t type)
{
return type == MBEDTLS_PK_RSA;
}
static size_t rsa_alt_get_bitlen(const void *ctx)
{
const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
return 8 * rsa_alt->key_len_func(rsa_alt->key);
}
static int rsa_alt_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
#if SIZE_MAX > UINT_MAX
if (UINT_MAX < hash_len) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
#endif /* SIZE_MAX > UINT_MAX */
*sig_len = rsa_alt->key_len_func(rsa_alt->key);
if (*sig_len > MBEDTLS_PK_SIGNATURE_MAX_SIZE) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
return rsa_alt->sign_func(rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
md_alg, (unsigned int) hash_len, hash, sig);
}
static int rsa_alt_decrypt_wrap(void *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
((void) f_rng);
((void) p_rng);
if (ilen != rsa_alt->key_len_func(rsa_alt->key)) {
return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
}
return rsa_alt->decrypt_func(rsa_alt->key,
MBEDTLS_RSA_PRIVATE, olen, input, output, osize);
}
#if defined(MBEDTLS_RSA_C)
static int rsa_alt_check_pair(const void *pub, const void *prv)
{
unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
unsigned char hash[32];
size_t sig_len = 0;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (rsa_alt_get_bitlen(prv) != rsa_get_bitlen(pub)) {
return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
memset(hash, 0x2a, sizeof(hash));
if ((ret = rsa_alt_sign_wrap((void *) prv, MBEDTLS_MD_NONE,
hash, sizeof(hash),
sig, &sig_len, NULL, NULL)) != 0) {
return ret;
}
if (rsa_verify_wrap((void *) pub, MBEDTLS_MD_NONE,
hash, sizeof(hash), sig, sig_len) != 0) {
return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
return 0;
}
#endif /* MBEDTLS_RSA_C */
static void *rsa_alt_alloc_wrap(void)
{
void *ctx = mbedtls_calloc(1, sizeof(mbedtls_rsa_alt_context));
if (ctx != NULL) {
memset(ctx, 0, sizeof(mbedtls_rsa_alt_context));
}
return ctx;
}
static void rsa_alt_free_wrap(void *ctx)
{
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_rsa_alt_context));
mbedtls_free(ctx);
}
const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
MBEDTLS_PK_RSA_ALT,
"RSA-alt",
rsa_alt_get_bitlen,
rsa_alt_can_do,
NULL,
rsa_alt_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_alt_decrypt_wrap,
NULL,
#if defined(MBEDTLS_RSA_C)
rsa_alt_check_pair,
#else
NULL,
#endif
rsa_alt_alloc_wrap,
rsa_alt_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
NULL,
};
#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
#if defined(MBEDTLS_USE_PSA_CRYPTO)
static void *pk_opaque_alloc_wrap(void)
{
void *ctx = mbedtls_calloc(1, sizeof(psa_key_id_t));
/* no _init() function to call, as calloc() already zeroized */
return ctx;
}
static void pk_opaque_free_wrap(void *ctx)
{
mbedtls_platform_zeroize(ctx, sizeof(psa_key_id_t));
mbedtls_free(ctx);
}
static size_t pk_opaque_get_bitlen(const void *ctx)
{
const psa_key_id_t *key = (const psa_key_id_t *) ctx;
size_t bits;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
if (PSA_SUCCESS != psa_get_key_attributes(*key, &attributes)) {
return 0;
}
bits = psa_get_key_bits(&attributes);
psa_reset_key_attributes(&attributes);
return bits;
}
static int pk_opaque_can_do(mbedtls_pk_type_t type)
{
/* For now opaque PSA keys can only wrap ECC keypairs,
* as checked by setup_psa().
* Also, ECKEY_DH does not really make sense with the current API. */
return type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECDSA;
}
#if defined(MBEDTLS_ECDSA_C)
/*
* Simultaneously convert and move raw MPI from the beginning of a buffer
* to an ASN.1 MPI at the end of the buffer.
* See also mbedtls_asn1_write_mpi().
*
* p: pointer to the end of the output buffer
* start: start of the output buffer, and also of the mpi to write at the end
* n_len: length of the mpi to read from start
*/
static int asn1_write_mpibuf(unsigned char **p, unsigned char *start,
size_t n_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
if ((size_t) (*p - start) < n_len) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
len = n_len;
*p -= len;
memmove(*p, start, len);
/* ASN.1 DER encoding requires minimal length, so skip leading 0s.
* Neither r nor s should be 0, but as a failsafe measure, still detect
* that rather than overflowing the buffer in case of a PSA error. */
while (len > 0 && **p == 0x00) {
++(*p);
--len;
}
/* this is only reached if the signature was invalid */
if (len == 0) {
return MBEDTLS_ERR_PK_HW_ACCEL_FAILED;
}
/* if the msb is 1, ASN.1 requires that we prepend a 0.
* Neither r nor s can be 0, so we can assume len > 0 at all times. */
if (**p & 0x80) {
if (*p - start < 1) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = 0x00;
len += 1;
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
MBEDTLS_ASN1_INTEGER));
return (int) len;
}
/* Transcode signature from PSA format to ASN.1 sequence.
* See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
* MPIs, and in-place.
*
* [in/out] sig: the signature pre- and post-transcoding
* [in/out] sig_len: signature length pre- and post-transcoding
* [int] buf_len: the available size the in/out buffer
*/
static int pk_ecdsa_sig_asn1_from_psa(unsigned char *sig, size_t *sig_len,
size_t buf_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
const size_t rs_len = *sig_len / 2;
unsigned char *p = sig + buf_len;
MBEDTLS_ASN1_CHK_ADD(len, asn1_write_mpibuf(&p, sig + rs_len, rs_len));
MBEDTLS_ASN1_CHK_ADD(len, asn1_write_mpibuf(&p, sig, rs_len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&p, sig, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&p, sig,
MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
memmove(sig, p, len);
*sig_len = len;
return 0;
}
#endif /* MBEDTLS_ECDSA_C */
static int pk_opaque_sign_wrap(void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
#if !defined(MBEDTLS_ECDSA_C)
((void) ctx);
((void) md_alg);
((void) hash);
((void) hash_len);
((void) sig);
((void) sig_len);
((void) f_rng);
((void) p_rng);
return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
#else /* !MBEDTLS_ECDSA_C */
const psa_key_id_t *key = (const psa_key_id_t *) ctx;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_algorithm_t alg = PSA_ALG_ECDSA(mbedtls_psa_translate_md(md_alg));
size_t buf_len;
psa_status_t status;
/* PSA has its own RNG */
(void) f_rng;
(void) p_rng;
/* PSA needs an output buffer of known size, but our API doesn't provide
* that information. Assume that the buffer is large enough for a
* maximal-length signature with that key (otherwise the application is
* buggy anyway). */
status = psa_get_key_attributes(*key, &attributes);
if (status != PSA_SUCCESS) {
return mbedtls_psa_err_translate_pk(status);
}
buf_len = MBEDTLS_ECDSA_MAX_SIG_LEN(psa_get_key_bits(&attributes));
psa_reset_key_attributes(&attributes);
if (buf_len > MBEDTLS_PK_SIGNATURE_MAX_SIZE) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
/* make the signature */
status = psa_sign_hash(*key, alg, hash, hash_len,
sig, buf_len, sig_len);
if (status != PSA_SUCCESS) {
return mbedtls_psa_err_translate_pk(status);
}
/* transcode it to ASN.1 sequence */
return pk_ecdsa_sig_asn1_from_psa(sig, sig_len, buf_len);
#endif /* !MBEDTLS_ECDSA_C */
}
const mbedtls_pk_info_t mbedtls_pk_opaque_info = {
MBEDTLS_PK_OPAQUE,
"Opaque",
pk_opaque_get_bitlen,
pk_opaque_can_do,
NULL, /* verify - will be done later */
pk_opaque_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL, /* restartable verify - not relevant */
NULL, /* restartable sign - not relevant */
#endif
NULL, /* decrypt - will be done later */
NULL, /* encrypt - will be done later */
NULL, /* check_pair - could be done later or left NULL */
pk_opaque_alloc_wrap,
pk_opaque_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL, /* restart alloc - not relevant */
NULL, /* restart free - not relevant */
#endif
NULL, /* debug - could be done later, or even left NULL */
};
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#endif /* MBEDTLS_PK_C */