AuroraMiddleware/mbedtls
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
0af1560919
mbedtls/library/pkwrite.c
Gilles Peskine f65ed6f254 Change key types to a 16-bit encoding 
All key types now have an encoding on 32 bits where the bottom 16 bits
are zero. Change to using 16 bits only.

Keep 32 bits for key types in storage, but move the significant
half-word from the top to the bottom.

Likewise, change EC curve and DH group families from 32 bits out of
which the top 8 and bottom 16 bits are zero, to 8 bits only.

Reorder psa_core_key_attributes_t to avoid padding.
2020-01-31 10:24:21 +01:00

630 lines
20 KiB
C
Raw Blame History

/*
* Public Key layer for writing key files and structures
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#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 <string.h>
#if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h"
#endif
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/bignum.h"
#include "mbedtls/ecp.h"
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_ECDSA_C)
#include "mbedtls/ecdsa.h"
#endif
#if defined(MBEDTLS_PEM_WRITE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
/* Parameter validation macros based on platform_util.h */
#define PK_VALIDATE_RET( cond ) \
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
#define PK_VALIDATE( cond ) \
MBEDTLS_INTERNAL_VALIDATE( cond )
#if defined(MBEDTLS_RSA_C)
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
mbedtls_rsa_context *rsa )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
mbedtls_mpi T;
mbedtls_mpi_init( &T );
/* Export E */
if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &T ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export N */
if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL, NULL, NULL, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
goto end_of_export;
len += ret;
end_of_export:
mbedtls_mpi_free( &T );
if( ret < 0 )
return( ret );
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
/*
* EC public key is an EC point
*/
static int pk_write_ec_pubkey( unsigned char **p, unsigned char *start,
mbedtls_ecp_keypair *ec )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
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 );
}
/*
* ECParameters ::= CHOICE {
* namedCurve OBJECT IDENTIFIER
* }
*/
static int pk_write_ec_param( unsigned char **p, unsigned char *start,
mbedtls_ecp_keypair *ec )
{
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( ec->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 );
}
/*
* privateKey OCTET STRING -- always of length ceil(log2(n)/8)
*/
static int pk_write_ec_private( unsigned char **p, unsigned char *start,
mbedtls_ecp_keypair *ec )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t byte_length = ( ec->grp.pbits + 7 ) / 8;
unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
ret = mbedtls_mpi_write_binary( &ec->d, tmp, byte_length );
if( ret != 0 )
goto exit;
ret = mbedtls_asn1_write_octet_string( p, start, tmp, byte_length );
exit:
mbedtls_platform_zeroize( tmp, byte_length );
return( ret );
}
#endif /* MBEDTLS_ECP_C */
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;
PK_VALIDATE_RET( p != NULL );
PK_VALIDATE_RET( *p != NULL );
PK_VALIDATE_RET( start != NULL );
PK_VALIDATE_RET( key != NULL );
#if defined(MBEDTLS_RSA_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
MBEDTLS_ASN1_CHK_ADD( len, pk_write_rsa_pubkey( p, start, mbedtls_pk_rsa( *key ) ) );
else
#endif
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_pubkey( p, start, mbedtls_pk_ec( *key ) ) );
else
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_OPAQUE )
{
size_t buffer_size;
psa_key_handle_t* key_slot = (psa_key_handle_t*) key->pk_ctx;
if ( *p < start )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
buffer_size = (size_t)( *p - start );
if ( psa_export_public_key( *key_slot, start, buffer_size, &len )
!= PSA_SUCCESS )
{
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
}
else
{
*p -= len;
memmove( *p, start, len );
}
}
else
#endif /* MBEDTLS_USE_PSA_CRYPTO */
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
return( (int) len );
}
int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *c;
size_t len = 0, par_len = 0, oid_len;
mbedtls_pk_type_t pk_type;
const char *oid;
PK_VALIDATE_RET( key != NULL );
if( size == 0 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
PK_VALIDATE_RET( buf != NULL );
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 = mbedtls_pk_get_type( key );
#if defined(MBEDTLS_ECP_C)
if( pk_type == MBEDTLS_PK_ECKEY )
{
MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
}
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( pk_type == MBEDTLS_PK_OPAQUE )
{
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_key_type_t key_type;
psa_key_handle_t handle;
psa_ecc_curve_t curve;
size_t bits;
handle = *((psa_key_handle_t*) key->pk_ctx );
if( PSA_SUCCESS != psa_get_key_attributes( handle, &attributes ) )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
key_type = psa_get_key_type( &attributes );
bits = psa_get_key_bits( &attributes );
psa_reset_key_attributes( &attributes );
curve = PSA_KEY_TYPE_GET_CURVE( key_type );
if( curve == 0 )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
ret = mbedtls_psa_get_ecc_oid_from_id( curve, bits, &oid, &oid_len );
if( ret != 0 )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
/* Write EC algorithm parameters; that's akin
* to pk_write_ec_param() above. */
MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_oid( &c, buf,
oid, oid_len ) );
/* The rest of the function works as for legacy EC contexts. */
pk_type = MBEDTLS_PK_ECKEY;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
if( ( ret = mbedtls_oid_get_oid_by_pk_alg( pk_type, &oid,
&oid_len ) ) != 0 )
{
return( ret );
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
par_len ) );
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( mbedtls_pk_context *key, unsigned char *buf, size_t size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *c;
size_t len = 0;
PK_VALIDATE_RET( key != NULL );
if( size == 0 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
PK_VALIDATE_RET( buf != NULL );
c = buf + size;
#if defined(MBEDTLS_RSA_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
{
mbedtls_mpi T; /* Temporary holding the exported parameters */
mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key );
/*
* Export the parameters one after another to avoid simultaneous copies.
*/
mbedtls_mpi_init( &T );
/* Export QP */
if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, NULL, &T ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export DQ */
if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, &T, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export DP */
if( ( ret = mbedtls_rsa_export_crt( rsa, &T, NULL, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export Q */
if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
&T, NULL, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export P */
if ( ( ret = mbedtls_rsa_export( rsa, NULL, &T,
NULL, NULL, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export D */
if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
NULL, &T, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export E */
if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
NULL, NULL, &T ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
/* Export N */
if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL,
NULL, NULL, NULL ) ) != 0 ||
( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
goto end_of_export;
len += ret;
end_of_export:
mbedtls_mpi_free( &T );
if( ret < 0 )
return( ret );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 0 ) );
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 ) );
}
else
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
{
mbedtls_ecp_keypair *ec = mbedtls_pk_ec( *key );
size_t pub_len = 0, par_len = 0;
/*
* 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
* }
*/
/* publicKey */
MBEDTLS_ASN1_CHK_ADD( pub_len, pk_write_ec_pubkey( &c, buf, ec ) );
if( c - buf < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--c = 0;
pub_len += 1;
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) );
len += pub_len;
/* parameters */
MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, ec ) );
MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_len( &c, buf, par_len ) );
MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_tag( &c, buf,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
len += par_len;
/* privateKey */
MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_private( &c, buf, ec ) );
/* version */
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
}
else
#endif /* MBEDTLS_ECP_C */
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
return( (int) len );
}
#if defined(MBEDTLS_PEM_WRITE_C)
#define PEM_BEGIN_PUBLIC_KEY "-----BEGIN PUBLIC KEY-----\n"
#define PEM_END_PUBLIC_KEY "-----END PUBLIC KEY-----\n"
#define PEM_BEGIN_PRIVATE_KEY_RSA "-----BEGIN RSA PRIVATE KEY-----\n"
#define PEM_END_PRIVATE_KEY_RSA "-----END RSA PRIVATE KEY-----\n"
#define PEM_BEGIN_PRIVATE_KEY_EC "-----BEGIN EC PRIVATE KEY-----\n"
#define PEM_END_PRIVATE_KEY_EC "-----END EC PRIVATE KEY-----\n"
/*
* Max sizes of key per types. Shown as tag + len (+ content).
*/
#if defined(MBEDTLS_RSA_C)
/*
* RSA public keys:
* SubjectPublicKeyInfo ::= SEQUENCE { 1 + 3
* algorithm AlgorithmIdentifier, 1 + 1 (sequence)
* + 1 + 1 + 9 (rsa oid)
* + 1 + 1 (params null)
* subjectPublicKey BIT STRING } 1 + 3 + (1 + below)
* RSAPublicKey ::= SEQUENCE { 1 + 3
* modulus INTEGER, -- n 1 + 3 + MPI_MAX + 1
* publicExponent INTEGER -- e 1 + 3 + MPI_MAX + 1
* }
*/
#define RSA_PUB_DER_MAX_BYTES 38 + 2 * MBEDTLS_MPI_MAX_SIZE
/*
* RSA private keys:
* RSAPrivateKey ::= SEQUENCE { 1 + 3
* version Version, 1 + 1 + 1
* modulus INTEGER, 1 + 3 + MPI_MAX + 1
* publicExponent INTEGER, 1 + 3 + MPI_MAX + 1
* privateExponent INTEGER, 1 + 3 + MPI_MAX + 1
* prime1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
* prime2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
* exponent1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
* exponent2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
* coefficient INTEGER, 1 + 3 + MPI_MAX / 2 + 1
* otherPrimeInfos OtherPrimeInfos OPTIONAL 0 (not supported)
* }
*/
#define MPI_MAX_SIZE_2 MBEDTLS_MPI_MAX_SIZE / 2 + \
MBEDTLS_MPI_MAX_SIZE % 2
#define RSA_PRV_DER_MAX_BYTES 47 + 3 * MBEDTLS_MPI_MAX_SIZE \
+ 5 * MPI_MAX_SIZE_2
#else /* MBEDTLS_RSA_C */
#define RSA_PUB_DER_MAX_BYTES 0
#define RSA_PRV_DER_MAX_BYTES 0
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
/*
* EC public keys:
* SubjectPublicKeyInfo ::= SEQUENCE { 1 + 2
* algorithm AlgorithmIdentifier, 1 + 1 (sequence)
* + 1 + 1 + 7 (ec oid)
* + 1 + 1 + 9 (namedCurve oid)
* subjectPublicKey BIT STRING 1 + 2 + 1 [1]
* + 1 (point format) [1]
* + 2 * ECP_MAX (coords) [1]
* }
*/
#define ECP_PUB_DER_MAX_BYTES 30 + 2 * MBEDTLS_ECP_MAX_BYTES
/*
* EC private keys:
* ECPrivateKey ::= SEQUENCE { 1 + 2
* version INTEGER , 1 + 1 + 1
* privateKey OCTET STRING, 1 + 1 + ECP_MAX
* parameters [0] ECParameters OPTIONAL, 1 + 1 + (1 + 1 + 9)
* publicKey [1] BIT STRING OPTIONAL 1 + 2 + [1] above
* }
*/
#define ECP_PRV_DER_MAX_BYTES 29 + 3 * MBEDTLS_ECP_MAX_BYTES
#else /* MBEDTLS_ECP_C */
#define ECP_PUB_DER_MAX_BYTES 0
#define ECP_PRV_DER_MAX_BYTES 0
#endif /* MBEDTLS_ECP_C */
#define PUB_DER_MAX_BYTES RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES
#define PRV_DER_MAX_BYTES RSA_PRV_DER_MAX_BYTES > ECP_PRV_DER_MAX_BYTES ? \
RSA_PRV_DER_MAX_BYTES : ECP_PRV_DER_MAX_BYTES
int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char output_buf[PUB_DER_MAX_BYTES];
size_t olen = 0;
PK_VALIDATE_RET( key != NULL );
PK_VALIDATE_RET( buf != NULL || size == 0 );
if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
sizeof(output_buf) ) ) < 0 )
{
return( ret );
}
if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
output_buf + sizeof(output_buf) - ret,
ret, buf, size, &olen ) ) != 0 )
{
return( ret );
}
return( 0 );
}
int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char output_buf[PRV_DER_MAX_BYTES];
const char *begin, *end;
size_t olen = 0;
PK_VALIDATE_RET( key != NULL );
PK_VALIDATE_RET( buf != NULL || size == 0 );
if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
return( ret );
#if defined(MBEDTLS_RSA_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
{
begin = PEM_BEGIN_PRIVATE_KEY_RSA;
end = PEM_END_PRIVATE_KEY_RSA;
}
else
#endif
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
{
begin = PEM_BEGIN_PRIVATE_KEY_EC;
end = PEM_END_PRIVATE_KEY_EC;
}
else
#endif
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
if( ( ret = mbedtls_pem_write_buffer( begin, end,
output_buf + sizeof(output_buf) - ret,
ret, buf, size, &olen ) ) != 0 )
{
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_PEM_WRITE_C */
#endif /* MBEDTLS_PK_WRITE_C */
Reference in New Issue View Git Blame Copy Permalink