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pkparse.c
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/*
* Public Key layer for parsing key files and structures
*
* Copyright The Mbed TLS Contributors
* 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.
*/
#include "common.h"
#if defined(MBEDTLS_PK_PARSE_C)
#include "mbedtls/pk.h"
#include "mbedtls/asn1.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/ecp.h"
#endif
#if defined(MBEDTLS_ECDSA_C)
#include "mbedtls/ecdsa.h"
#endif
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_PKCS5_C)
#include "mbedtls/pkcs5.h"
#endif
#if defined(MBEDTLS_PKCS12_C)
#include "mbedtls/pkcs12.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_FS_IO)
/*
* Load all data from a file into a given buffer.
*
* The file is expected to contain either PEM or DER encoded data.
* A terminating null byte is always appended. It is included in the announced
* length only if the data looks like it is PEM encoded.
*/
int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n )
{
FILE *f;
long size;
PK_VALIDATE_RET( path != NULL );
PK_VALIDATE_RET( buf != NULL );
PK_VALIDATE_RET( n != NULL );
if( ( f = fopen( path, "rb" ) ) == NULL )
return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
fseek( f, 0, SEEK_END );
if( ( size = ftell( f ) ) == -1 )
{
fclose( f );
return( MBEDTLS_ERR_PK_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_PK_ALLOC_FAILED );
}
if( fread( *buf, 1, *n, f ) != *n )
{
fclose( f );
mbedtls_platform_zeroize( *buf, *n );
mbedtls_free( *buf );
return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
}
fclose( f );
(*buf)[*n] = '\0';
if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
++*n;
return( 0 );
}
/*
* Load and parse a private key
*/
int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
const char *path, const char *pwd,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( path != NULL );
if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
if( pwd == NULL )
ret = mbedtls_pk_parse_key( ctx, buf, n, NULL, 0, f_rng, p_rng );
else
ret = mbedtls_pk_parse_key( ctx, buf, n,
(const unsigned char *) pwd, strlen( pwd ), f_rng, p_rng );
mbedtls_platform_zeroize( buf, n );
mbedtls_free( buf );
return( ret );
}
/*
* Load and parse a public key
*/
int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( path != NULL );
if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
ret = mbedtls_pk_parse_public_key( ctx, buf, n );
mbedtls_platform_zeroize( buf, n );
mbedtls_free( buf );
return( ret );
}
#endif /* MBEDTLS_FS_IO */
#if defined(MBEDTLS_ECP_C)
/* Minimally parse an ECParameters buffer to and mbedtls_asn1_buf
*
* ECParameters ::= CHOICE {
* namedCurve OBJECT IDENTIFIER
* specifiedCurve SpecifiedECDomain -- = SEQUENCE { ... }
* -- implicitCurve NULL
* }
*/
static int pk_get_ecparams( unsigned char **p, const unsigned char *end,
mbedtls_asn1_buf *params )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if ( end - *p < 1 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_OUT_OF_DATA ) );
/* Tag may be either OID or SEQUENCE */
params->tag = **p;
if( params->tag != MBEDTLS_ASN1_OID
#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
&& params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE )
#endif
)
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
}
if( ( ret = mbedtls_asn1_get_tag( p, end, ¶ms->len, params->tag ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
params->p = *p;
*p += params->len;
if( *p != end )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
return( 0 );
}
#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
/*
* Parse a SpecifiedECDomain (SEC 1 C.2) and (mostly) fill the group with it.
* WARNING: the resulting group should only be used with
* pk_group_id_from_specified(), since its base point may not be set correctly
* if it was encoded compressed.
*
* SpecifiedECDomain ::= SEQUENCE {
* version SpecifiedECDomainVersion(ecdpVer1 | ecdpVer2 | ecdpVer3, ...),
* fieldID FieldID {{FieldTypes}},
* curve Curve,
* base ECPoint,
* order INTEGER,
* cofactor INTEGER OPTIONAL,
* hash HashAlgorithm OPTIONAL,
* ...
* }
*
* We only support prime-field as field type, and ignore hash and cofactor.
*/
static int pk_group_from_specified( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *p = params->p;
const unsigned char * const end = params->p + params->len;
const unsigned char *end_field, *end_curve;
size_t len;
int ver;
/* SpecifiedECDomainVersion ::= INTEGER { 1, 2, 3 } */
if( ( ret = mbedtls_asn1_get_int( &p, end, &ver ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
if( ver < 1 || ver > 3 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
/*
* FieldID { FIELD-ID:IOSet } ::= SEQUENCE { -- Finite field
* fieldType FIELD-ID.&id({IOSet}),
* parameters FIELD-ID.&Type({IOSet}{@fieldType})
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_field = p + len;
/*
* FIELD-ID ::= TYPE-IDENTIFIER
* FieldTypes FIELD-ID ::= {
* { Prime-p IDENTIFIED BY prime-field } |
* { Characteristic-two IDENTIFIED BY characteristic-two-field }
* }
* prime-field OBJECT IDENTIFIER ::= { id-fieldType 1 }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end_field, &len, MBEDTLS_ASN1_OID ) ) != 0 )
return( ret );
if( len != MBEDTLS_OID_SIZE( MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD ) ||
memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
{
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
}
p += len;
/* Prime-p ::= INTEGER -- Field of size p. */
if( ( ret = mbedtls_asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
grp->pbits = mbedtls_mpi_bitlen( &grp->P );
if( p != end_field )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
/*
* Curve ::= SEQUENCE {
* a FieldElement,
* b FieldElement,
* seed BIT STRING OPTIONAL
* -- Shall be present if used in SpecifiedECDomain
* -- with version equal to ecdpVer2 or ecdpVer3
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_curve = p + len;
/*
* FieldElement ::= OCTET STRING
* containing an integer in the case of a prime field
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
( ret = mbedtls_mpi_read_binary( &grp->A, p, len ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
p += len;
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
( ret = mbedtls_mpi_read_binary( &grp->B, p, len ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
p += len;
/* Ignore seed BIT STRING OPTIONAL */
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_BIT_STRING ) ) == 0 )
p += len;
if( p != end_curve )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
/*
* ECPoint ::= OCTET STRING
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
if( ( ret = mbedtls_ecp_point_read_binary( grp, &grp->G,
( const unsigned char *) p, len ) ) != 0 )
{
/*
* If we can't read the point because it's compressed, cheat by
* reading only the X coordinate and the parity bit of Y.
*/
if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE ||
( p[0] != 0x02 && p[0] != 0x03 ) ||
len != mbedtls_mpi_size( &grp->P ) + 1 ||
mbedtls_mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
mbedtls_mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
mbedtls_mpi_lset( &grp->G.Z, 1 ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
}
}
p += len;
/*
* order INTEGER
*/
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
grp->nbits = mbedtls_mpi_bitlen( &grp->N );
/*
* Allow optional elements by purposefully not enforcing p == end here.
*/
return( 0 );
}
/*
* Find the group id associated with an (almost filled) group as generated by
* pk_group_from_specified(), or return an error if unknown.
*/
static int pk_group_id_from_group( const mbedtls_ecp_group *grp, mbedtls_ecp_group_id *grp_id )
{
int ret = 0;
mbedtls_ecp_group ref;
const mbedtls_ecp_group_id *id;
mbedtls_ecp_group_init( &ref );
for( id = mbedtls_ecp_grp_id_list(); *id != MBEDTLS_ECP_DP_NONE; id++ )
{
/* Load the group associated to that id */
mbedtls_ecp_group_free( &ref );
MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &ref, *id ) );
/* Compare to the group we were given, starting with easy tests */
if( grp->pbits == ref.pbits && grp->nbits == ref.nbits &&
mbedtls_mpi_cmp_mpi( &grp->P, &ref.P ) == 0 &&
mbedtls_mpi_cmp_mpi( &grp->A, &ref.A ) == 0 &&
mbedtls_mpi_cmp_mpi( &grp->B, &ref.B ) == 0 &&
mbedtls_mpi_cmp_mpi( &grp->N, &ref.N ) == 0 &&
mbedtls_mpi_cmp_mpi( &grp->G.X, &ref.G.X ) == 0 &&
mbedtls_mpi_cmp_mpi( &grp->G.Z, &ref.G.Z ) == 0 &&
/* For Y we may only know the parity bit, so compare only that */
mbedtls_mpi_get_bit( &grp->G.Y, 0 ) == mbedtls_mpi_get_bit( &ref.G.Y, 0 ) )
{
break;
}
}
cleanup:
mbedtls_ecp_group_free( &ref );
*grp_id = *id;
if( ret == 0 && *id == MBEDTLS_ECP_DP_NONE )
ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
return( ret );
}
/*
* Parse a SpecifiedECDomain (SEC 1 C.2) and find the associated group ID
*/
static int pk_group_id_from_specified( const mbedtls_asn1_buf *params,
mbedtls_ecp_group_id *grp_id )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ecp_group grp;
mbedtls_ecp_group_init( &grp );
if( ( ret = pk_group_from_specified( params, &grp ) ) != 0 )
goto cleanup;
ret = pk_group_id_from_group( &grp, grp_id );
cleanup:
mbedtls_ecp_group_free( &grp );
return( ret );
}
#endif /* MBEDTLS_PK_PARSE_EC_EXTENDED */
/*
* Use EC parameters to initialise an EC group
*
* ECParameters ::= CHOICE {
* namedCurve OBJECT IDENTIFIER
* specifiedCurve SpecifiedECDomain -- = SEQUENCE { ... }
* -- implicitCurve NULL
*/
static int pk_use_ecparams( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ecp_group_id grp_id;
if( params->tag == MBEDTLS_ASN1_OID )
{
if( mbedtls_oid_get_ec_grp( params, &grp_id ) != 0 )
return( MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE );
}
else
{
#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
if( ( ret = pk_group_id_from_specified( params, &grp_id ) ) != 0 )
return( ret );
#else
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
#endif
}
/*
* grp may already be initilialized; if so, make sure IDs match
*/
if( grp->id != MBEDTLS_ECP_DP_NONE && grp->id != grp_id )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
if( ( ret = mbedtls_ecp_group_load( grp, grp_id ) ) != 0 )
return( ret );
return( 0 );
}
/*
* EC public key is an EC point
*
* The caller is responsible for clearing the structure upon failure if
* desired. Take care to pass along the possible ECP_FEATURE_UNAVAILABLE
* return code of mbedtls_ecp_point_read_binary() and leave p in a usable state.
*/
static int pk_get_ecpubkey( unsigned char **p, const unsigned char *end,
mbedtls_ecp_keypair *key )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ( ret = mbedtls_ecp_point_read_binary( &key->grp, &key->Q,
(const unsigned char *) *p, end - *p ) ) == 0 )
{
ret = mbedtls_ecp_check_pubkey( &key->grp, &key->Q );
}
/*
* We know mbedtls_ecp_point_read_binary consumed all bytes or failed
*/
*p = (unsigned char *) end;
return( ret );
}
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_RSA_C)
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int pk_get_rsapubkey( unsigned char **p,
const unsigned char *end,
mbedtls_rsa_context *rsa )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
if( *p + len != end )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
/* Import N */
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
if( ( ret = mbedtls_rsa_import_raw( rsa, *p, len, NULL, 0, NULL, 0,
NULL, 0, NULL, 0 ) ) != 0 )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
*p += len;
/* Import E */
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
if( ( ret = mbedtls_rsa_import_raw( rsa, NULL, 0, NULL, 0, NULL, 0,
NULL, 0, *p, len ) ) != 0 )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
*p += len;
if( mbedtls_rsa_complete( rsa ) != 0 ||
mbedtls_rsa_check_pubkey( rsa ) != 0 )
{
return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
}
if( *p != end )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
return( 0 );
}
#endif /* MBEDTLS_RSA_C */
/* Get a PK algorithm identifier
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL }
*/
static int pk_get_pk_alg( unsigned char **p,
const unsigned char *end,
mbedtls_pk_type_t *pk_alg, mbedtls_asn1_buf *params )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_asn1_buf alg_oid;
memset( params, 0, sizeof(mbedtls_asn1_buf) );
if( ( ret = mbedtls_asn1_get_alg( p, end, &alg_oid, params ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_ALG, ret ) );
if( mbedtls_oid_get_pk_alg( &alg_oid, pk_alg ) != 0 )
return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
/*
* No parameters with RSA (only for EC)
*/
if( *pk_alg == MBEDTLS_PK_RSA &&
( ( params->tag != MBEDTLS_ASN1_NULL && params->tag != 0 ) ||
params->len != 0 ) )
{
return( MBEDTLS_ERR_PK_INVALID_ALG );
}
return( 0 );
}
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
mbedtls_pk_context *pk )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
mbedtls_asn1_buf alg_params;
mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
const mbedtls_pk_info_t *pk_info;
PK_VALIDATE_RET( p != NULL );
PK_VALIDATE_RET( *p != NULL );
PK_VALIDATE_RET( end != NULL );
PK_VALIDATE_RET( pk != NULL );
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
end = *p + len;
if( ( ret = pk_get_pk_alg( p, end, &pk_alg, &alg_params ) ) != 0 )
return( ret );
if( ( ret = mbedtls_asn1_get_bitstring_null( p, end, &len ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
if( *p + len != end )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
if( ( pk_info = mbedtls_pk_info_from_type( pk_alg ) ) == NULL )
return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 )
return( ret );
#if defined(MBEDTLS_RSA_C)
if( pk_alg == MBEDTLS_PK_RSA )
{
ret = pk_get_rsapubkey( p, end, mbedtls_pk_rsa( *pk ) );
} else
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
if( pk_alg == MBEDTLS_PK_ECKEY_DH || pk_alg == MBEDTLS_PK_ECKEY )
{
ret = pk_use_ecparams( &alg_params, &mbedtls_pk_ec( *pk )->grp );
if( ret == 0 )
ret = pk_get_ecpubkey( p, end, mbedtls_pk_ec( *pk ) );
} else
#endif /* MBEDTLS_ECP_C */
ret = MBEDTLS_ERR_PK_UNKNOWN_PK_ALG;
if( ret == 0 && *p != end )
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
if( ret != 0 )
mbedtls_pk_free( pk );
return( ret );
}
#if defined(MBEDTLS_RSA_C)
/*
* Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
*
* The value zero is:
* - never a valid value for an RSA parameter
* - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
*
* Since values can't be omitted in PKCS#1, passing a zero value to
* rsa_complete() would be incorrect, so reject zero values early.
*/
static int asn1_get_nonzero_mpi( unsigned char **p,
const unsigned char *end,
mbedtls_mpi *X )
{
int ret;
ret = mbedtls_asn1_get_mpi( p, end, X );
if( ret != 0 )
return( ret );
if( mbedtls_mpi_cmp_int( X, 0 ) == 0 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
return( 0 );
}
/*
* Parse a PKCS#1 encoded private RSA key
*/
static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
const unsigned char *key,
size_t keylen )
{
int ret, version;
size_t len;
unsigned char *p, *end;
mbedtls_mpi T;
mbedtls_mpi_init( &T );
p = (unsigned char *) key;
end = p + keylen;
/*
* This function parses the RSAPrivateKey (PKCS#1)
*
* RSAPrivateKey ::= SEQUENCE {
* version Version,
* 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
* otherPrimeInfos OtherPrimeInfos OPTIONAL
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
end = p + len;
if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
if( version != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
}
/* Import N */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_rsa_import( rsa, &T, NULL, NULL,
NULL, NULL ) ) != 0 )
goto cleanup;
/* Import E */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_rsa_import( rsa, NULL, NULL, NULL,
NULL, &T ) ) != 0 )
goto cleanup;
/* Import D */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_rsa_import( rsa, NULL, NULL, NULL,
&T, NULL ) ) != 0 )
goto cleanup;
/* Import P */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_rsa_import( rsa, NULL, &T, NULL,
NULL, NULL ) ) != 0 )
goto cleanup;
/* Import Q */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_rsa_import( rsa, NULL, NULL, &T,
NULL, NULL ) ) != 0 )
goto cleanup;
#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
/*
* The RSA CRT parameters DP, DQ and QP are nominally redundant, in
* that they can be easily recomputed from D, P and Q. However by
* parsing them from the PKCS1 structure it is possible to avoid
* recalculating them which both reduces the overhead of loading
* RSA private keys into memory and also avoids side channels which
* can arise when computing those values, since all of D, P, and Q
* are secret. See https://eprint.iacr.org/2020/055 for a
* description of one such attack.
*/
/* Import DP */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_mpi_copy( &rsa->DP, &T ) ) != 0 )
goto cleanup;
/* Import DQ */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_mpi_copy( &rsa->DQ, &T ) ) != 0 )
goto cleanup;
/* Import QP */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = mbedtls_mpi_copy( &rsa->QP, &T ) ) != 0 )
goto cleanup;
#else
/* Verify existance of the CRT params */
if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 )
goto cleanup;
#endif
/* rsa_complete() doesn't complete anything with the default
* implementation but is still called:
* - for the benefit of alternative implementation that may want to
* pre-compute stuff beyond what's provided (eg Montgomery factors)
* - as is also sanity-checks the key
*
* Furthermore, we also check the public part for consistency with
* mbedtls_pk_parse_pubkey(), as it includes size minima for example.
*/
if( ( ret = mbedtls_rsa_complete( rsa ) ) != 0 ||
( ret = mbedtls_rsa_check_pubkey( rsa ) ) != 0 )
{
goto cleanup;
}
if( p != end )
{
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
cleanup:
mbedtls_mpi_free( &T );
if( ret != 0 )
{
/* Wrap error code if it's coming from a lower level */
if( ( ret & 0xff80 ) == 0 )
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret );
else
ret = MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
mbedtls_rsa_free( rsa );
}
return( ret );
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
/*
* Parse a SEC1 encoded private EC key
*/
static int pk_parse_key_sec1_der( mbedtls_ecp_keypair *eck,
const unsigned char *key, size_t keylen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
int version, pubkey_done;
size_t len;
mbedtls_asn1_buf params;
unsigned char *p = (unsigned char *) key;
unsigned char *end = p + keylen;
unsigned char *end2;
/*
* 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
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
end = p + len;
if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
if( version != 1 )
return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
if( ( ret = mbedtls_mpi_read_binary( &eck->d, p, len ) ) != 0 )
{
mbedtls_ecp_keypair_free( eck );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
p += len;
pubkey_done = 0;
if( p != end )
{
/*
* Is 'parameters' present?
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) == 0 )
{
if( ( ret = pk_get_ecparams( &p, p + len, ¶ms) ) != 0 ||
( ret = pk_use_ecparams( ¶ms, &eck->grp ) ) != 0 )
{
mbedtls_ecp_keypair_free( eck );
return( ret );
}
}
else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
{
mbedtls_ecp_keypair_free( eck );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
}
if( p != end )
{
/*
* Is 'publickey' present? If not, or if we can't read it (eg because it
* is compressed), create it from the private key.
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) == 0 )
{
end2 = p + len;
if( ( ret = mbedtls_asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
if( p + len != end2 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
pubkey_done = 1;
else
{
/*
* The only acceptable failure mode of pk_get_ecpubkey() above
* is if the point format is not recognized.
*/
if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
}
}
else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
{
mbedtls_ecp_keypair_free( eck );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
}
if( ! pubkey_done &&
( ret = mbedtls_ecp_mul( &eck->grp, &eck->Q, &eck->d, &eck->grp.G,
f_rng, p_rng ) ) != 0 )
{
mbedtls_ecp_keypair_free( eck );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
}
if( ( ret = mbedtls_ecp_check_privkey( &eck->grp, &eck->d ) ) != 0 )
{
mbedtls_ecp_keypair_free( eck );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_ECP_C */
/*
* Parse an unencrypted PKCS#8 encoded private key
*
* Notes:
*
* - This function does not own the key buffer. It is the
* responsibility of the caller to take care of zeroizing
* and freeing it after use.
*
* - The function is responsible for freeing the provided
* PK context on failure.
*
*/
static int pk_parse_key_pkcs8_unencrypted_der(