blob: 2e167ae8f153d42d0f49176d43e5c67769ed3c31 [file] [log] [blame]
/*
* Copyright (c) 2023, Christian Huitema
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifdef _WINDOWS
#include "wincompat.h"
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <picotls.h>
#include <mbedtls/mbedtls_config.h>
#include <mbedtls/build_info.h>
#include <mbedtls/pk.h>
#include <mbedtls/pem.h>
#include <mbedtls/error.h>
#include <psa/crypto.h>
#include <psa/crypto_struct.h>
#include <psa/crypto_values.h>
#include "ptls_mbedtls.h"
typedef struct st_ptls_mbedtls_signature_scheme_t {
uint16_t scheme_id;
psa_algorithm_t hash_algo;
} ptls_mbedtls_signature_scheme_t;
typedef struct st_ptls_mbedtls_sign_certificate_t {
ptls_sign_certificate_t super;
mbedtls_svc_key_id_t key_id;
psa_key_attributes_t attributes;
const ptls_mbedtls_signature_scheme_t *schemes;
} ptls_mbedtls_sign_certificate_t;
static const unsigned char ptls_mbedtls_oid_ec_key[] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01};
static const unsigned char ptls_mbedtls_oid_rsa_key[] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01};
static const unsigned char ptls_mbedtls_oid_ed25519[] = {0x2b, 0x65, 0x70};
static const ptls_mbedtls_signature_scheme_t rsa_signature_schemes[] = {{PTLS_SIGNATURE_RSA_PSS_RSAE_SHA256, PSA_ALG_SHA_256},
{PTLS_SIGNATURE_RSA_PSS_RSAE_SHA384, PSA_ALG_SHA_384},
{PTLS_SIGNATURE_RSA_PSS_RSAE_SHA512, PSA_ALG_SHA_512},
{UINT16_MAX, PSA_ALG_NONE}};
static const ptls_mbedtls_signature_scheme_t secp256r1_signature_schemes[] = {
{PTLS_SIGNATURE_ECDSA_SECP256R1_SHA256, PSA_ALG_SHA_256}, {UINT16_MAX, PSA_ALG_NONE}};
static const ptls_mbedtls_signature_scheme_t secp384r1_signature_schemes[] = {
{PTLS_SIGNATURE_ECDSA_SECP384R1_SHA384, PSA_ALG_SHA_384}, {UINT16_MAX, PSA_ALG_NONE}};
static const ptls_mbedtls_signature_scheme_t secp521r1_signature_schemes[] = {
{PTLS_SIGNATURE_ECDSA_SECP521R1_SHA512, PSA_ALG_SHA_512}, {UINT16_MAX, PSA_ALG_NONE}};
static const ptls_mbedtls_signature_scheme_t ed25519_signature_schemes[] = {{PTLS_SIGNATURE_ED25519, PSA_ALG_NONE},
{UINT16_MAX, PSA_ALG_NONE}};
#if defined(MBEDTLS_PEM_PARSE_C)
static int ptls_mbedtls_parse_der_length(const unsigned char *pem_buf, size_t pem_len, size_t *px, size_t *pl)
{
int ret = 0;
size_t x = *px;
size_t l = pem_buf[x++];
if (l > 128) {
size_t ll = l & 0x7F;
l = 0;
while (ll > 0 && x + l < pem_len) {
l *= 256;
l += pem_buf[x++];
ll--;
}
}
*pl = l;
*px = x;
return ret;
}
static int ptls_mbedtls_parse_ecdsa_field(const unsigned char *pem_buf, size_t pem_len, size_t *key_index, size_t *key_length)
{
int ret = 0;
int param_index_index = -1;
int param_length = 0;
size_t x = 0;
// const unsigned char head = { 0x30, l-2, 0x02, 0x01, 0x01, 0x04 }
if (pem_len < 16 || pem_buf[x++] != 0x30 /* type = sequence */) {
ret = -1;
} else {
size_t l = 0;
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l);
if (x + l != pem_len) {
ret = -1;
}
}
if (ret == 0) {
if (pem_buf[x++] != 0x02 /* type = int */ || pem_buf[x++] != 0x01 /* length of int = 1 */ ||
pem_buf[x++] != 0x01 /* version = 1 */ || pem_buf[x++] != 0x04 /*octet string */ || pem_buf[x] + x >= pem_len) {
ret = -1;
} else {
*key_index = x + 1;
*key_length = pem_buf[x];
x += 1 + pem_buf[x];
if (x < pem_len && pem_buf[x] == 0xa0) {
/* decode the EC parameters, identify the curve */
x++;
if (x + pem_buf[x] >= pem_len) {
/* EC parameters extend beyond buffer */
ret = -1;
} else {
x += pem_buf[x] + 1;
}
}
if (ret == 0 && x < pem_len) {
/* skip the public key parameter */
if (pem_buf[x++] != 0xa1 || x >= pem_len) {
ret = -1;
} else {
size_t l = 0;
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l);
x += l;
}
}
if (x != pem_len) {
ret = -1;
}
}
}
return ret;
}
/* On input, key_index points at the "key information" in a
* "private key" message. For EDDSA, this contains an
* octet string carrying the key itself. On return, key index
* and key length are updated to point at the key field.
*/
static int ptls_mbedtls_parse_eddsa_key(const unsigned char *pem_buf, size_t pem_len, size_t *key_index, size_t *key_length)
{
int ret = 0;
size_t x = *key_index;
size_t l_key = 0;
if (*key_length < 2 || pem_buf[x++] != 0x04) {
ret = -1;
} else {
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l_key);
if (x + l_key != *key_index + *key_length) {
ret = -1;
} else {
*key_index = x;
*key_length = l_key;
}
}
return ret;
}
/* If using PKCS8 encoding, the "private key" field contains the
* same "ecdsa field" found in PEM "EC PRIVATE KEY" files. We
* use the same parser, but we need to reset indices so they
* reflect the unwrapped key.
*/
int ptls_mbedtls_parse_ec_private_key(const unsigned char *pem_buf, size_t pem_len, size_t *key_index, size_t *key_length)
{
size_t x_offset = 0;
size_t x_len = 0;
int ret = ptls_mbedtls_parse_ecdsa_field(pem_buf + *key_index, *key_length, &x_offset, &x_len);
if (ret == 0) {
*key_index += x_offset;
*key_length = x_len;
}
return ret;
}
int test_parse_private_key_field(const unsigned char *pem_buf, size_t pem_len, size_t *oid_index, size_t *oid_length,
size_t *key_index, size_t *key_length)
{
int ret = 0;
size_t l_oid = 0;
size_t x_oid = 0;
size_t l_key = 0;
size_t x_key = 0;
size_t x = 0;
/* const unsigned char head = {0x30, l - 2, 0x02, 0x01, 0x00} */
if (pem_len < 16 || pem_buf[x++] != 0x30 /* type = sequence */) {
ret = -1;
} else {
size_t l = 0;
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l);
if (x + l != pem_len) {
ret = -1;
}
}
if (ret == 0) {
if (pem_buf[x++] != 0x02 /* type = int */ || pem_buf[x++] != 0x01 /* length of int = 1 */ ||
pem_buf[x++] != 0x00 /* version = 0 */ || pem_buf[x++] != 0x30 /* sequence */) {
ret = -1;
} else {
/* the sequence contains the OID and optional key attributes,
* which we ignore for now.
*/
size_t l_seq = 0;
size_t x_seq;
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l_seq);
x_seq = x;
if (x + l_seq >= pem_len || pem_buf[x++] != 0x06) {
ret = -1;
} else {
l_oid = pem_buf[x++];
x_oid = x;
if (x + l_oid > x_seq + l_seq) {
ret = -1;
} else {
x = x_seq + l_seq;
}
}
}
}
if (ret == 0) {
/* At that point the oid has been identified.
* The next parameter is an octet string containing the key info.
*/
size_t l = 0;
if (x + 2 > pem_len || pem_buf[x++] != 0x04) {
ret = -1;
} else {
ret = ptls_mbedtls_parse_der_length(pem_buf, pem_len, &x, &l_key);
x_key = x;
x += l_key;
if (x > pem_len) {
ret = -1;
}
}
}
*oid_index = x_oid;
*oid_length = l_oid;
*key_index = x_key;
*key_length = l_key;
return ret;
}
int ptls_mbedtls_get_der_key(mbedtls_pem_context *pem, mbedtls_pk_type_t *pk_type, const unsigned char *key, size_t keylen,
const unsigned char *pwd, size_t pwdlen, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
#if defined(MBEDTLS_PEM_PARSE_C)
size_t len;
#endif
if (keylen == 0) {
return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
mbedtls_pem_init(pem);
#if defined(MBEDTLS_RSA_C)
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if (key[keylen - 1] != '\0') {
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
} else {
ret = mbedtls_pem_read_buffer(pem, "-----BEGIN RSA PRIVATE KEY-----", "-----END RSA PRIVATE KEY-----", key, pwd, pwdlen,
&len);
}
if (ret == 0) {
*pk_type = MBEDTLS_PK_RSA;
return ret;
} else if (ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH) {
return MBEDTLS_ERR_PK_PASSWORD_MISMATCH;
} else if (ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED) {
return MBEDTLS_ERR_PK_PASSWORD_REQUIRED;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
return ret;
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if (key[keylen - 1] != '\0') {
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
} else {
ret =
mbedtls_pem_read_buffer(pem, "-----BEGIN EC PRIVATE KEY-----", "-----END EC PRIVATE KEY-----", key, pwd, pwdlen, &len);
}
if (ret == 0) {
*pk_type = MBEDTLS_PK_ECKEY;
return ret;
} else if (ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH) {
return MBEDTLS_ERR_PK_PASSWORD_MISMATCH;
} else if (ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED) {
return MBEDTLS_ERR_PK_PASSWORD_REQUIRED;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
return ret;
}
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if (key[keylen - 1] != '\0') {
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
} else {
ret = mbedtls_pem_read_buffer(pem, "-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----", key, NULL, 0, &len);
if (ret == 0) {
/* info is unknown */
return ret;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
return ret;
}
}
#if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if (key[keylen - 1] != '\0') {
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
} else {
ret = mbedtls_pem_read_buffer(pem, "-----BEGIN ENCRYPTED PRIVATE KEY-----", "-----END ENCRYPTED PRIVATE KEY-----", key,
NULL, 0, &len);
}
if (ret == 0) {
/* infor is unknown */
return ret;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
return ret;
}
#endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
#endif
const ptls_mbedtls_signature_scheme_t *ptls_mbedtls_select_signature_scheme(const ptls_mbedtls_signature_scheme_t *available,
const uint16_t *algorithms, size_t num_algorithms)
{
const ptls_mbedtls_signature_scheme_t *scheme;
/* select the algorithm, driven by server-isde preference of `available` */
for (scheme = available; scheme->scheme_id != UINT16_MAX; ++scheme) {
for (size_t i = 0; i != num_algorithms; ++i) {
if (algorithms[i] == scheme->scheme_id) {
return scheme;
}
}
}
return NULL;
}
int ptls_mbedtls_set_available_schemes(ptls_mbedtls_sign_certificate_t *signer)
{
int ret = 0;
psa_algorithm_t algo = psa_get_key_algorithm(&signer->attributes);
size_t nb_bits = psa_get_key_bits(&signer->attributes);
switch (algo) {
case PSA_ALG_RSA_PKCS1V15_SIGN_RAW:
signer->schemes = rsa_signature_schemes;
break;
case PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_256):
signer->schemes = secp256r1_signature_schemes;
break;
case PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_384):
signer->schemes = secp384r1_signature_schemes;
break;
case PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_512):
signer->schemes = secp521r1_signature_schemes;
break;
case PSA_ALG_ECDSA_BASE:
switch (nb_bits) {
case 521:
signer->schemes = secp521r1_signature_schemes;
break;
case 384:
signer->schemes = secp384r1_signature_schemes;
break;
case 256:
signer->schemes = secp256r1_signature_schemes;
break;
default:
signer->schemes = secp256r1_signature_schemes;
ret = -1;
break;
}
break;
case PSA_ALG_ED25519PH:
signer->schemes = ed25519_signature_schemes;
break;
default:
printf("Unknown algo: %x\n", algo);
ret = -1;
}
return ret;
}
/*
* Sign a certificate
* - step1, selected a signature algorithm compatible with the public key algorithm
* and with the list specified by the application.
* - step2, compute the hash with the specified algorithm.
* - step3, compute the signature of the hash using psa_sign_hash.
*
* In the case of RSA, we use the algorithm PSA_ALG_RSA_PKCS1V15_SIGN_RAW, which
* pads the hash according to PKCS1V15 before doing the private key operation.
* The implementation of RSA/PKCS1V15 also includes a verification step to protect
* against key attacks through partial faults.
*
* MBEDTLS has a "psa_sign_message" that combines step2 and step3. However, it
* requires specifying an algorithm type that exactly specifies the signature
* algorithm, such as "RSA with SHA384". This is not compatible with the
* "RSA sign raw" algorithm. Instead, we decompose the operation in two steps.
* There is no performance penalty doing so, as "psa_sign_message" is only
* a convenience API.
*/
int ptls_mbedtls_sign_certificate(ptls_sign_certificate_t *_self, ptls_t *tls, ptls_async_job_t **async,
uint16_t *selected_algorithm, ptls_buffer_t *outbuf, ptls_iovec_t input,
const uint16_t *algorithms, size_t num_algorithms)
{
int ret = 0;
ptls_mbedtls_sign_certificate_t *self =
(ptls_mbedtls_sign_certificate_t *)(((unsigned char *)_self) - offsetof(struct st_ptls_mbedtls_sign_certificate_t, super));
/* First, find the set of compatible algorithms */
const ptls_mbedtls_signature_scheme_t *scheme = ptls_mbedtls_select_signature_scheme(self->schemes, algorithms, num_algorithms);
if (scheme == NULL) {
ret = PTLS_ERROR_INCOMPATIBLE_KEY;
} else {
/* First prepare the hash */
unsigned char hash_buffer[PTLS_MAX_DIGEST_SIZE];
unsigned char *hash_value = NULL;
size_t hash_length = 0;
if (scheme->hash_algo == PSA_ALG_NONE) {
hash_value = input.base;
hash_length = input.len;
} else {
if (psa_hash_compute(scheme->hash_algo, input.base, input.len, hash_buffer, PTLS_MAX_DIGEST_SIZE, &hash_length) !=
PSA_SUCCESS) {
ret = PTLS_ERROR_NOT_AVAILABLE;
} else {
hash_value = hash_buffer;
}
}
if (ret == 0) {
psa_algorithm_t sign_algo = psa_get_key_algorithm(&self->attributes);
size_t nb_bits = psa_get_key_bits(&self->attributes);
size_t nb_bytes = (nb_bits + 7) / 8;
if (nb_bits == 0) {
if (sign_algo == PSA_ALG_RSA_PKCS1V15_SIGN_RAW) {
/* assume at most 4096 bit key */
nb_bytes = 512;
} else {
/* Max size assumed, secp521r1 */
nb_bytes = 124;
}
} else if (sign_algo != PSA_ALG_RSA_PKCS1V15_SIGN_RAW) {
nb_bytes *= 2;
}
if ((ret = ptls_buffer_reserve(outbuf, nb_bytes)) == 0) {
size_t signature_length = 0;
if (psa_sign_hash(self->key_id, sign_algo, hash_value, hash_length, outbuf->base + outbuf->off, nb_bytes,
&signature_length) != 0) {
ret = PTLS_ERROR_INCOMPATIBLE_KEY;
} else {
outbuf->off += signature_length;
}
}
}
}
return ret;
}
void ptls_mbedtls_dispose_sign_certificate(ptls_sign_certificate_t *_self)
{
if (_self != NULL) {
ptls_mbedtls_sign_certificate_t *self =
(ptls_mbedtls_sign_certificate_t *)(((unsigned char *)_self) -
offsetof(struct st_ptls_mbedtls_sign_certificate_t, super));
/* Destroy the key */
psa_destroy_key(self->key_id);
psa_reset_key_attributes(&self->attributes);
memset(self, 0, sizeof(ptls_mbedtls_sign_certificate_t));
free(self);
}
}
/*
* An RSa key is encoded in DER as:
* RSAPrivateKey ::= SEQUENCE {
* version INTEGER, -- must be 0
* 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
* }
*
* The number of key bits is the size in bits of the integer N.
* We must decode the length in octets of the integer representation,
* then subtract the number of zeros at the beginning of the data.
*/
int ptls_mbedtls_rsa_get_key_bits(const unsigned char *key_value, size_t key_length, size_t *p_nb_bits)
{
int ret = 0;
size_t nb_bytes = 0;
size_t nb_bits = 0;
size_t x = 0;
if (key_length > 16 && key_value[x++] == 0x30) {
/* get the length of the sequence. */
size_t l = 0;
ret = ptls_mbedtls_parse_der_length(key_value, key_length, &x, &l);
if (x + l != key_length) {
ret = -1;
}
}
if (ret == 0 && key_value[x] == 0x02 && key_value[x + 1] == 0x01 && key_value[x + 2] == 0x00 && key_value[x + 3] == 0x02) {
x += 4;
ret = ptls_mbedtls_parse_der_length(key_value, key_length, &x, &nb_bytes);
} else {
ret = -1;
}
if (ret == 0) {
unsigned char v = key_value[x];
nb_bits = 8 * nb_bytes;
if (v == 0) {
nb_bits -= 8;
} else {
while ((v & 0x80) == 0) {
nb_bits--;
v <<= 1;
}
}
}
*p_nb_bits = nb_bits;
return ret;
}
void ptls_mbedtls_set_rsa_key_attributes(ptls_mbedtls_sign_certificate_t *signer, const unsigned char *key_value, size_t key_length)
{
size_t nb_bits = 0;
psa_set_key_usage_flags(&signer->attributes, PSA_KEY_USAGE_SIGN_HASH);
psa_set_key_algorithm(&signer->attributes, PSA_ALG_RSA_PKCS1V15_SIGN_RAW);
psa_set_key_type(&signer->attributes, PSA_KEY_TYPE_RSA_KEY_PAIR);
if (ptls_mbedtls_rsa_get_key_bits(key_value, key_length, &nb_bits) == 0) {
psa_set_key_bits(&signer->attributes, nb_bits);
}
}
int ptls_mbedtls_set_ec_key_attributes(ptls_mbedtls_sign_certificate_t *signer, size_t key_length)
{
int ret = 0;
psa_set_key_usage_flags(&signer->attributes, PSA_KEY_USAGE_SIGN_HASH);
psa_set_key_algorithm(&signer->attributes, PSA_ALG_ECDSA_BASE);
psa_set_key_type(&signer->attributes, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_SECP_R1));
if (key_length == 32) {
psa_set_key_algorithm(&signer->attributes, PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_256));
psa_set_key_bits(&signer->attributes, 256);
} else if (key_length == 48) {
psa_set_key_algorithm(&signer->attributes, PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_384));
psa_set_key_bits(&signer->attributes, 384);
} else if (key_length == 66) {
psa_set_key_algorithm(&signer->attributes, PSA_ALG_DETERMINISTIC_ECDSA(PSA_ALG_SHA_512));
psa_set_key_bits(&signer->attributes, 521);
} else {
ret = -1;
}
return ret;
}
int ptls_mbedtls_load_private_key(ptls_context_t *ctx, char const *pem_fname)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
mbedtls_pem_context pem = {0};
mbedtls_pk_type_t pk_type = 0;
mbedtls_svc_key_id_t key_id = 0;
size_t key_length = 0;
size_t key_index = 0;
ptls_mbedtls_sign_certificate_t *signer = (ptls_mbedtls_sign_certificate_t *)malloc(sizeof(ptls_mbedtls_sign_certificate_t));
if (signer == NULL) {
return (PTLS_ERROR_NO_MEMORY);
}
memset(signer, 0, sizeof(ptls_mbedtls_sign_certificate_t));
signer->attributes = psa_key_attributes_init();
if ((ret = mbedtls_pk_load_file(pem_fname, &buf, &n)) != 0) {
if (ret == MBEDTLS_ERR_PK_ALLOC_FAILED) {
return (PTLS_ERROR_NO_MEMORY);
} else {
return (PTLS_ERROR_NOT_AVAILABLE);
}
}
ret = ptls_mbedtls_get_der_key(&pem, &pk_type, buf, n, NULL, 0, NULL, NULL);
/* We cannot use the platform API:
mbedtls_zeroize_and_free(buf, n);
so we do our own thing.
*/
memset(buf, 0, n);
free(buf);
if (ret == 0) {
if (pk_type == MBEDTLS_PK_RSA) {
key_length = pem.private_buflen;
ptls_mbedtls_set_rsa_key_attributes(signer, pem.private_buf, key_length);
} else if (pk_type == MBEDTLS_PK_ECKEY) {
ret = ptls_mbedtls_parse_ecdsa_field(pem.private_buf, pem.private_buflen, &key_index, &key_length);
if (ret == 0) {
ret = ptls_mbedtls_set_ec_key_attributes(signer, key_length);
}
} else if (pk_type == MBEDTLS_PK_NONE) {
/* TODO: not clear whether MBDED TLS supports ED25519 yet. Probably not. */
/* Should have option to encode RSA or ECDSA using PKCS8 */
size_t oid_index = 0;
size_t oid_length = 0;
psa_set_key_usage_flags(&signer->attributes, PSA_KEY_USAGE_SIGN_HASH);
ret =
test_parse_private_key_field(pem.private_buf, pem.private_buflen, &oid_index, &oid_length, &key_index, &key_length);
if (ret == 0) {
/* need to parse the OID in order to set the parameters */
if (oid_length == sizeof(ptls_mbedtls_oid_ec_key) &&
memcmp(pem.private_buf + oid_index, ptls_mbedtls_oid_ec_key, sizeof(ptls_mbedtls_oid_ec_key)) == 0) {
ret = ptls_mbedtls_parse_ec_private_key(pem.private_buf, pem.private_buflen, &key_index, &key_length);
if (ret == 0) {
ret = ptls_mbedtls_set_ec_key_attributes(signer, key_length);
}
} else if (oid_length == sizeof(ptls_mbedtls_oid_ed25519) &&
memcmp(pem.private_buf + oid_index, ptls_mbedtls_oid_ed25519, sizeof(ptls_mbedtls_oid_ed25519)) == 0) {
/* We recognized ED25519 -- PSA_ECC_FAMILY_TWISTED_EDWARDS -- PSA_ALG_ED25519PH */
psa_set_key_algorithm(&signer->attributes, PSA_ALG_PURE_EDDSA);
psa_set_key_type(&signer->attributes, PSA_ECC_FAMILY_TWISTED_EDWARDS);
ret = ptls_mbedtls_parse_eddsa_key(pem.private_buf, pem.private_buflen, &key_index, &key_length);
psa_set_key_bits(&signer->attributes, 256);
} else if (oid_length == sizeof(ptls_mbedtls_oid_rsa_key) &&
memcmp(pem.private_buf + oid_index, ptls_mbedtls_oid_rsa_key, sizeof(ptls_mbedtls_oid_rsa_key)) == 0) {
/* We recognized RSA */
key_length = pem.private_buflen;
ptls_mbedtls_set_rsa_key_attributes(signer, pem.private_buf, key_length);
} else {
ret = PTLS_ERROR_NOT_AVAILABLE;
}
}
} else {
ret = -1;
}
if (ret == 0) {
/* Now that we have the DER or bytes for the key, try import into PSA */
psa_status_t status = psa_import_key(&signer->attributes, pem.private_buf + key_index, key_length, &signer->key_id);
if (status != PSA_SUCCESS) {
ret = -1;
} else {
ret = ptls_mbedtls_set_available_schemes(signer);
}
}
/* Free the PEM buffer */
mbedtls_pem_free(&pem);
}
if (ret == 0) {
signer->super.cb = ptls_mbedtls_sign_certificate;
ctx->sign_certificate = &signer->super;
} else {
/* Dispose of what we have allocated. */
ptls_mbedtls_dispose_sign_certificate(&signer->super);
}
return ret;
}