blob: b9ddcf1d8d13aa6e9438bb775be1d9b6db67686c [file] [log] [blame]
/*
* Public Key layer for writing key files and structures
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#include "common.h"
#if defined(MBEDTLS_PK_WRITE_C)
#include "mbedtls/pk.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "pk_internal.h"
#include <string.h>
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/bignum.h"
#include "mbedtls/ecp.h"
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
#include "pk_internal.h"
#endif
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PK_HAVE_ECC_KEYS)
#include "pkwrite.h"
#endif
#if defined(MBEDTLS_PEM_WRITE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_RSA_C)
#include "rsa_internal.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "psa_util_internal.h"
#endif
#include "mbedtls/platform.h"
/* Helpers for properly sizing buffers aimed at holding public keys or
* key-pairs based on build symbols. */
#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
#define PK_MAX_EC_PUBLIC_KEY_SIZE PSA_EXPORT_PUBLIC_KEY_MAX_SIZE
#define PK_MAX_EC_KEY_PAIR_SIZE MBEDTLS_PSA_MAX_EC_KEY_PAIR_LENGTH
#elif defined(MBEDTLS_USE_PSA_CRYPTO)
#define PK_MAX_EC_PUBLIC_KEY_SIZE PSA_EXPORT_PUBLIC_KEY_MAX_SIZE
#define PK_MAX_EC_KEY_PAIR_SIZE MBEDTLS_PSA_MAX_EC_KEY_PAIR_LENGTH
#else
#define PK_MAX_EC_PUBLIC_KEY_SIZE MBEDTLS_ECP_MAX_PT_LEN
#define PK_MAX_EC_KEY_PAIR_SIZE MBEDTLS_ECP_MAX_BYTES
#endif
/******************************************************************************
* Internal functions for RSA keys.
******************************************************************************/
#if defined(MBEDTLS_RSA_C)
static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
const mbedtls_pk_context *pk)
{
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
uint8_t tmp[PSA_EXPORT_KEY_PAIR_MAX_SIZE];
size_t len = 0, tmp_len = 0;
if (psa_export_key(pk->priv_id, tmp, sizeof(tmp), &tmp_len) != PSA_SUCCESS) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
*p -= tmp_len;
memcpy(*p, tmp, tmp_len);
len += tmp_len;
mbedtls_platform_zeroize(tmp, sizeof(tmp));
return (int) len;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
return mbedtls_rsa_write_key(mbedtls_pk_rsa(*pk), buf, p);
}
#endif /* MBEDTLS_RSA_C */
/******************************************************************************
* Internal functions for EC keys.
******************************************************************************/
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *pk)
{
size_t len = 0;
uint8_t buf[PK_MAX_EC_PUBLIC_KEY_SIZE];
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
if (psa_export_public_key(pk->priv_id, buf, sizeof(buf), &len) != PSA_SUCCESS) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
} else {
len = pk->pub_raw_len;
memcpy(buf, pk->pub_raw, len);
}
if (*p < start || (size_t) (*p - start) < len) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*p -= len;
memcpy(*p, buf, len);
return (int) len;
}
#else /* MBEDTLS_PK_USE_PSA_EC_DATA */
static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *pk)
{
size_t len = 0;
unsigned char buf[PK_MAX_EC_PUBLIC_KEY_SIZE];
mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*pk);
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
if (psa_export_public_key(pk->priv_id, buf, sizeof(buf), &len) != PSA_SUCCESS) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
*p -= len;
memcpy(*p, buf, len);
return (int) len;
} else
#endif /* MBEDTLS_USE_PSA_CRYPTO */
{
if ((ret = mbedtls_ecp_point_write_binary(&ec->grp, &ec->Q,
MBEDTLS_ECP_PF_UNCOMPRESSED,
&len, buf, sizeof(buf))) != 0) {
return ret;
}
}
if (*p < start || (size_t) (*p - start) < len) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*p -= len;
memcpy(*p, buf, len);
return (int) len;
}
#endif /* MBEDTLS_PK_USE_PSA_EC_DATA */
/*
* privateKey OCTET STRING -- always of length ceil(log2(n)/8)
*/
#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
static int pk_write_ec_private(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *pk)
{
size_t byte_length;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char tmp[PK_MAX_EC_KEY_PAIR_SIZE];
psa_status_t status;
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
if (status != PSA_SUCCESS) {
ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
return ret;
}
} else {
status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
if (status != PSA_SUCCESS) {
ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
goto exit;
}
}
ret = mbedtls_asn1_write_octet_string(p, start, tmp, byte_length);
exit:
mbedtls_platform_zeroize(tmp, sizeof(tmp));
return ret;
}
#else /* MBEDTLS_PK_USE_PSA_EC_DATA */
static int pk_write_ec_private(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *pk)
{
size_t byte_length;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char tmp[PK_MAX_EC_KEY_PAIR_SIZE];
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_status_t status;
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
if (status != PSA_SUCCESS) {
ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
return ret;
}
} else
#endif /* MBEDTLS_USE_PSA_CRYPTO */
{
mbedtls_ecp_keypair *ec = mbedtls_pk_ec_rw(*pk);
byte_length = (ec->grp.pbits + 7) / 8;
ret = mbedtls_ecp_write_key(ec, tmp, byte_length);
if (ret != 0) {
goto exit;
}
}
ret = mbedtls_asn1_write_octet_string(p, start, tmp, byte_length);
exit:
mbedtls_platform_zeroize(tmp, sizeof(tmp));
return ret;
}
#endif /* MBEDTLS_PK_USE_PSA_EC_DATA */
/*
* ECParameters ::= CHOICE {
* namedCurve OBJECT IDENTIFIER
* }
*/
static int pk_write_ec_param(unsigned char **p, unsigned char *start,
mbedtls_ecp_group_id grp_id)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
const char *oid;
size_t oid_len;
if ((ret = mbedtls_oid_get_oid_by_ec_grp(grp_id, &oid, &oid_len)) != 0) {
return ret;
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
return (int) len;
}
#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
/*
* RFC8410 section 7
*
* OneAsymmetricKey ::= SEQUENCE {
* version Version,
* privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
* privateKey PrivateKey,
* attributes [0] IMPLICIT Attributes OPTIONAL,
* ...,
* [[2: publicKey [1] IMPLICIT PublicKey OPTIONAL ]],
* ...
* }
* ...
* CurvePrivateKey ::= OCTET STRING
*/
static int pk_write_ec_rfc8410_der(unsigned char **p, unsigned char *buf,
const mbedtls_pk_context *pk)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
size_t oid_len = 0;
const char *oid;
mbedtls_ecp_group_id grp_id;
/* privateKey */
MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(p, buf, pk));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_OCTET_STRING));
grp_id = mbedtls_pk_get_ec_group_id(pk);
/* privateKeyAlgorithm */
if ((ret = mbedtls_oid_get_oid_by_ec_grp_algid(grp_id, &oid, &oid_len)) != 0) {
return ret;
}
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_algorithm_identifier_ext(p, buf, oid, oid_len, 0, 0));
/* version */
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 0));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
return (int) len;
}
#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
/*
* RFC 5915, or SEC1 Appendix C.4
*
* ECPrivateKey ::= SEQUENCE {
* version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
* privateKey OCTET STRING,
* parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
* publicKey [1] BIT STRING OPTIONAL
* }
*/
static int pk_write_ec_der(unsigned char **p, unsigned char *buf,
const mbedtls_pk_context *pk)
{
size_t len = 0;
int ret;
size_t pub_len = 0, par_len = 0;
mbedtls_ecp_group_id grp_id;
/* publicKey */
MBEDTLS_ASN1_CHK_ADD(pub_len, pk_write_ec_pubkey(p, buf, pk));
if (*p - buf < 1) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
(*p)--;
**p = 0;
pub_len += 1;
MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(p, buf, pub_len));
MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_BIT_STRING));
MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(p, buf, pub_len));
MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(p, buf,
MBEDTLS_ASN1_CONTEXT_SPECIFIC |
MBEDTLS_ASN1_CONSTRUCTED | 1));
len += pub_len;
/* parameters */
grp_id = mbedtls_pk_get_ec_group_id(pk);
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(p, buf, grp_id));
MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_len(p, buf, par_len));
MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_tag(p, buf,
MBEDTLS_ASN1_CONTEXT_SPECIFIC |
MBEDTLS_ASN1_CONSTRUCTED | 0));
len += par_len;
/* privateKey */
MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(p, buf, pk));
/* version */
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 1));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
return (int) len;
}
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
/******************************************************************************
* Internal functions for Opaque keys.
******************************************************************************/
#if defined(MBEDTLS_USE_PSA_CRYPTO)
static int pk_write_opaque_pubkey(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *pk)
{
size_t buffer_size;
size_t len = 0;
if (*p < start) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
buffer_size = (size_t) (*p - start);
if (psa_export_public_key(pk->priv_id, start, buffer_size,
&len) != PSA_SUCCESS) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
*p -= len;
memmove(*p, start, len);
return (int) len;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/******************************************************************************
* Generic helpers
******************************************************************************/
/* Extend the public mbedtls_pk_get_type() by getting key type also in case of
* opaque keys. */
static mbedtls_pk_type_t pk_get_type_ext(const mbedtls_pk_context *pk)
{
mbedtls_pk_type_t pk_type = mbedtls_pk_get_type(pk);
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (pk_type == MBEDTLS_PK_OPAQUE) {
psa_key_attributes_t opaque_attrs = PSA_KEY_ATTRIBUTES_INIT;
psa_key_type_t opaque_key_type;
if (psa_get_key_attributes(pk->priv_id, &opaque_attrs) != PSA_SUCCESS) {
return MBEDTLS_PK_NONE;
}
opaque_key_type = psa_get_key_type(&opaque_attrs);
psa_reset_key_attributes(&opaque_attrs);
if (PSA_KEY_TYPE_IS_ECC(opaque_key_type)) {
return MBEDTLS_PK_ECKEY;
} else if (PSA_KEY_TYPE_IS_RSA(opaque_key_type)) {
return MBEDTLS_PK_RSA;
} else {
return MBEDTLS_PK_NONE;
}
} else
#endif
return pk_type;
}
/******************************************************************************
* Public functions for writing private/public DER keys.
******************************************************************************/
int mbedtls_pk_write_pubkey(unsigned char **p, unsigned char *start,
const mbedtls_pk_context *key)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
#if defined(MBEDTLS_RSA_C)
if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_rsa_write_pubkey(mbedtls_pk_rsa(*key), start, p));
} else
#endif
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_pubkey(p, start, key));
} else
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (mbedtls_pk_get_type(key) == MBEDTLS_PK_OPAQUE) {
MBEDTLS_ASN1_CHK_ADD(len, pk_write_opaque_pubkey(p, start, key));
} else
#endif /* MBEDTLS_USE_PSA_CRYPTO */
return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
return (int) len;
}
int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *c;
int has_par = 1;
size_t len = 0, par_len = 0, oid_len = 0;
mbedtls_pk_type_t pk_type;
const char *oid = NULL;
if (size == 0) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
c = buf + size;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_pk_write_pubkey(&c, buf, key));
if (c - buf < 1) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
*--c = 0;
len += 1;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_BIT_STRING));
pk_type = pk_get_type_ext(key);
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
if (pk_get_type_ext(key) == MBEDTLS_PK_ECKEY) {
mbedtls_ecp_group_id ec_grp_id = mbedtls_pk_get_ec_group_id(key);
if (MBEDTLS_PK_IS_RFC8410_GROUP_ID(ec_grp_id)) {
ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec_grp_id, &oid, &oid_len);
if (ret != 0) {
return ret;
}
has_par = 0;
} else {
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec_grp_id));
}
}
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
/* At this point oid_len is not null only for EC Montgomery keys. */
if (oid_len == 0) {
ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid, &oid_len);
if (ret != 0) {
return ret;
}
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier_ext(&c, buf, oid, oid_len,
par_len, has_par));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
return (int) len;
}
int mbedtls_pk_write_key_der(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
{
unsigned char *c;
if (size == 0) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
c = buf + size;
#if defined(MBEDTLS_RSA_C)
if (pk_get_type_ext(key) == MBEDTLS_PK_RSA) {
return pk_write_rsa_der(&c, buf, key);
} else
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
if (pk_get_type_ext(key) == MBEDTLS_PK_ECKEY) {
#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
if (mbedtls_pk_is_rfc8410(key)) {
return pk_write_ec_rfc8410_der(&c, buf, key);
}
#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
return pk_write_ec_der(&c, buf, key);
} else
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
}
/******************************************************************************
* Public functions for wrinting private/public PEM keys.
******************************************************************************/
#if defined(MBEDTLS_PEM_WRITE_C)
#define PUB_DER_MAX_BYTES \
(MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES > MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES ? \
MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES : MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES)
#define PRV_DER_MAX_BYTES \
(MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES > MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES ? \
MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES : MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES)
int mbedtls_pk_write_pubkey_pem(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *output_buf = NULL;
output_buf = mbedtls_calloc(1, PUB_DER_MAX_BYTES);
if (output_buf == NULL) {
return MBEDTLS_ERR_PK_ALLOC_FAILED;
}
size_t olen = 0;
if ((ret = mbedtls_pk_write_pubkey_der(key, output_buf,
PUB_DER_MAX_BYTES)) < 0) {
goto cleanup;
}
if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_PUBLIC_KEY "\n", PEM_END_PUBLIC_KEY "\n",
output_buf + PUB_DER_MAX_BYTES - ret,
ret, buf, size, &olen)) != 0) {
goto cleanup;
}
ret = 0;
cleanup:
mbedtls_free(output_buf);
return ret;
}
int mbedtls_pk_write_key_pem(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *output_buf = NULL;
output_buf = mbedtls_calloc(1, PRV_DER_MAX_BYTES);
if (output_buf == NULL) {
return MBEDTLS_ERR_PK_ALLOC_FAILED;
}
const char *begin, *end;
size_t olen = 0;
if ((ret = mbedtls_pk_write_key_der(key, output_buf, PRV_DER_MAX_BYTES)) < 0) {
goto cleanup;
}
#if defined(MBEDTLS_RSA_C)
if (pk_get_type_ext(key) == MBEDTLS_PK_RSA) {
begin = PEM_BEGIN_PRIVATE_KEY_RSA "\n";
end = PEM_END_PRIVATE_KEY_RSA "\n";
} else
#endif
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
if (pk_get_type_ext(key) == MBEDTLS_PK_ECKEY) {
if (mbedtls_pk_is_rfc8410(key)) {
begin = PEM_BEGIN_PRIVATE_KEY_PKCS8 "\n";
end = PEM_END_PRIVATE_KEY_PKCS8 "\n";
} else {
begin = PEM_BEGIN_PRIVATE_KEY_EC "\n";
end = PEM_END_PRIVATE_KEY_EC "\n";
}
} else
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
{
ret = MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
goto cleanup;
}
if ((ret = mbedtls_pem_write_buffer(begin, end,
output_buf + PRV_DER_MAX_BYTES - ret,
ret, buf, size, &olen)) != 0) {
goto cleanup;
}
ret = 0;
cleanup:
mbedtls_zeroize_and_free(output_buf, PRV_DER_MAX_BYTES);
return ret;
}
#endif /* MBEDTLS_PEM_WRITE_C */
#endif /* MBEDTLS_PK_WRITE_C */