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review.trustedfirmware.org / mirror / mbed-tls.git / 800c7c61951197020fb4cb629f0d1386afdfd159 / . / library / pkparse.c
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/*
* Public Key layer for parsing key files and structures
*
* Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
*
* This file is part of mbed TLS (https://tls.mbed.org)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#if !defined(POLARSSL_CONFIG_FILE)
#include "polarssl/config.h"
#else
#include POLARSSL_CONFIG_FILE
#endif
#if defined(POLARSSL_PK_PARSE_C)
#include "polarssl/pk.h"
#include "polarssl/asn1.h"
#include "polarssl/oid.h"
#include <string.h>
#if defined(POLARSSL_RSA_C)
#include "polarssl/rsa.h"
#endif
#if defined(POLARSSL_ECP_C)
#include "polarssl/ecp.h"
#endif
#if defined(POLARSSL_ECDSA_C)
#include "polarssl/ecdsa.h"
#endif
#if defined(POLARSSL_PEM_PARSE_C)
#include "polarssl/pem.h"
#endif
#if defined(POLARSSL_PKCS5_C)
#include "polarssl/pkcs5.h"
#endif
#if defined(POLARSSL_PKCS12_C)
#include "polarssl/pkcs12.h"
#endif
#if defined(POLARSSL_PLATFORM_C)
#include "polarssl/platform.h"
#else
#include <stdlib.h>
#define polarssl_malloc malloc
#define polarssl_free free
#endif
#if defined(POLARSSL_FS_IO)
/* Implementation that should never be optimized out by the compiler */
static void polarssl_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/*
* Load all data from a file into a given buffer.
*/
int pk_load_file( const char *path, unsigned char **buf, size_t *n )
{
FILE *f;
long size;
if( ( f = fopen( path, "rb" ) ) == NULL )
return( POLARSSL_ERR_PK_FILE_IO_ERROR );
fseek( f, 0, SEEK_END );
if( ( size = ftell( f ) ) == -1 )
{
fclose( f );
return( POLARSSL_ERR_PK_FILE_IO_ERROR );
}
fseek( f, 0, SEEK_SET );
*n = (size_t) size;
if( *n + 1 == 0 ||
( *buf = polarssl_malloc( *n + 1 ) ) == NULL )
{
fclose( f );
return( POLARSSL_ERR_PK_MALLOC_FAILED );
}
if( fread( *buf, 1, *n, f ) != *n )
{
fclose( f );
polarssl_free( *buf );
return( POLARSSL_ERR_PK_FILE_IO_ERROR );
}
fclose( f );
(*buf)[*n] = '\0';
return( 0 );
}
/*
* Load and parse a private key
*/
int pk_parse_keyfile( pk_context *ctx,
const char *path, const char *pwd )
{
int ret;
size_t n;
unsigned char *buf;
if( ( ret = pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
if( pwd == NULL )
ret = pk_parse_key( ctx, buf, n, NULL, 0 );
else
ret = pk_parse_key( ctx, buf, n,
(const unsigned char *) pwd, strlen( pwd ) );
polarssl_zeroize( buf, n + 1 );
polarssl_free( buf );
return( ret );
}
/*
* Load and parse a public key
*/
int pk_parse_public_keyfile( pk_context *ctx, const char *path )
{
int ret;
size_t n;
unsigned char *buf;
if( ( ret = pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
ret = pk_parse_public_key( ctx, buf, n );
polarssl_zeroize( buf, n + 1 );
polarssl_free( buf );
return( ret );
}
#endif /* POLARSSL_FS_IO */
#if defined(POLARSSL_ECP_C)
/* Minimally parse an ECParameters buffer to and asn1_buf
*
* ECParameters ::= CHOICE {
* namedCurve OBJECT IDENTIFIER
* specifiedCurve SpecifiedECDomain -- = SEQUENCE { ... }
* -- implicitCurve NULL
* }
*/
static int pk_get_ecparams( unsigned char **p, const unsigned char *end,
asn1_buf *params )
{
int ret;
/* Tag may be either OID or SEQUENCE */
params->tag = **p;
if( params->tag != ASN1_OID
#if defined(POLARSSL_PK_PARSE_EC_EXTENDED)
&& params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE )
#endif
)
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
}
if( ( ret = asn1_get_tag( p, end, &params->len, params->tag ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
params->p = *p;
*p += params->len;
if( *p != end )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
#if defined(POLARSSL_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 asn1_buf *params, ecp_group *grp )
{
int ret;
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 = asn1_get_int( &p, end, &ver ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ver < 1 || ver > 3 )
return( POLARSSL_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 = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | 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 = asn1_get_tag( &p, end_field, &len, ASN1_OID ) ) != 0 )
return( ret );
if( len != OID_SIZE( OID_ANSI_X9_62_PRIME_FIELD ) ||
memcmp( p, OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
{
return( POLARSSL_ERR_PK_FEATURE_UNAVAILABLE );
}
p += len;
/* Prime-p ::= INTEGER -- Field of size p. */
if( ( ret = asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->pbits = mpi_msb( &grp->P );
if( p != end_field )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_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 = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_curve = p + len;
/*
* FieldElement ::= OCTET STRING
* containing an integer in the case of a prime field
*/
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_OCTET_STRING ) ) != 0 ||
( ret = mpi_read_binary( &grp->A, p, len ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_OCTET_STRING ) ) != 0 ||
( ret = mpi_read_binary( &grp->B, p, len ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
/* Ignore seed BIT STRING OPTIONAL */
if( ( ret = asn1_get_tag( &p, end_curve, &len, ASN1_BIT_STRING ) ) == 0 )
p += len;
if( p != end_curve )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
/*
* ECPoint ::= OCTET STRING
*/
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = 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 != POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE ||
( p[0] != 0x02 && p[0] != 0x03 ) ||
len != mpi_size( &grp->P ) + 1 ||
mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
mpi_lset( &grp->G.Z, 1 ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
}
}
p += len;
/*
* order INTEGER
*/
if( ( ret = asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->nbits = mpi_msb( &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 ecp_group *grp, ecp_group_id *grp_id )
{
int ret = 0;
ecp_group ref;
const ecp_group_id *id;
ecp_group_init( &ref );
for( id = ecp_grp_id_list(); *id != POLARSSL_ECP_DP_NONE; id++ )
{
/* Load the group associated to that id */
ecp_group_free( &ref );
MPI_CHK( ecp_use_known_dp( &ref, *id ) );
/* Compare to the group we were given, starting with easy tests */
if( grp->pbits == ref.pbits && grp->nbits == ref.nbits &&
mpi_cmp_mpi( &grp->P, &ref.P ) == 0 &&
mpi_cmp_mpi( &grp->A, &ref.A ) == 0 &&
mpi_cmp_mpi( &grp->B, &ref.B ) == 0 &&
mpi_cmp_mpi( &grp->N, &ref.N ) == 0 &&
mpi_cmp_mpi( &grp->G.X, &ref.G.X ) == 0 &&
mpi_cmp_mpi( &grp->G.Z, &ref.G.Z ) == 0 &&
/* For Y we may only know the parity bit, so compare only that */
mpi_get_bit( &grp->G.Y, 0 ) == mpi_get_bit( &ref.G.Y, 0 ) )
{
break;
}
}
cleanup:
ecp_group_free( &ref );
*grp_id = *id;
if( ret == 0 && *id == POLARSSL_ECP_DP_NONE )
ret = POLARSSL_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 asn1_buf *params,
ecp_group_id *grp_id )
{
int ret;
ecp_group grp;
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:
ecp_group_free( &grp );
return( ret );
}
#endif /* POLARSSL_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 asn1_buf *params, ecp_group *grp )
{
int ret;
ecp_group_id grp_id;
if( params->tag == ASN1_OID )
{
if( oid_get_ec_grp( params, &grp_id ) != 0 )
return( POLARSSL_ERR_PK_UNKNOWN_NAMED_CURVE );
}
else
{
#if defined(POLARSSL_PK_PARSE_EC_EXTENDED)
if( ( ret = pk_group_id_from_specified( params, &grp_id ) ) != 0 )
return( ret );
#else
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
#endif
}
/*
* grp may already be initilialized; if so, make sure IDs match
*/
if( grp->id != POLARSSL_ECP_DP_NONE && grp->id != grp_id )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
if( ( ret = ecp_use_known_dp( 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 ecp_point_read_binary() and leave p in a usable state.
*/
static int pk_get_ecpubkey( unsigned char **p, const unsigned char *end,
ecp_keypair *key )
{
int ret;
if( ( ret = ecp_point_read_binary( &key->grp, &key->Q,
(const unsigned char *) *p, end - *p ) ) == 0 )
{
ret = ecp_check_pubkey( &key->grp, &key->Q );
}
/*
* We know ecp_point_read_binary consumed all bytes or failed
*/
*p = (unsigned char *) end;
return( ret );
}
#endif /* POLARSSL_ECP_C */
#if defined(POLARSSL_RSA_C)
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int pk_get_rsapubkey( unsigned char **p,
const unsigned char *end,
rsa_context *rsa )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_PUBKEY + ret );
if( *p + len != end )
return( POLARSSL_ERR_PK_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( ( ret = asn1_get_mpi( p, end, &rsa->N ) ) != 0 ||
( ret = asn1_get_mpi( p, end, &rsa->E ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_PUBKEY + ret );
if( *p != end )
return( POLARSSL_ERR_PK_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( ( ret = rsa_check_pubkey( rsa ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_PUBKEY );
rsa->len = mpi_size( &rsa->N );
return( 0 );
}
#endif /* POLARSSL_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,
pk_type_t *pk_alg, asn1_buf *params )
{
int ret;
asn1_buf alg_oid;
memset( params, 0, sizeof(asn1_buf) );
if( ( ret = asn1_get_alg( p, end, &alg_oid, params ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_ALG + ret );
if( oid_get_pk_alg( &alg_oid, pk_alg ) != 0 )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
/*
* No parameters with RSA (only for EC)
*/
if( *pk_alg == POLARSSL_PK_RSA &&
( ( params->tag != ASN1_NULL && params->tag != 0 ) ||
params->len != 0 ) )
{
return( POLARSSL_ERR_PK_INVALID_ALG );
}
return( 0 );
}
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
int pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
pk_context *pk )
{
int ret;
size_t len;
asn1_buf alg_params;
pk_type_t pk_alg = POLARSSL_PK_NONE;
const pk_info_t *pk_info;
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_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 = asn1_get_bitstring_null( p, end, &len ) ) != 0 )
return( POLARSSL_ERR_PK_INVALID_PUBKEY + ret );
if( *p + len != end )
return( POLARSSL_ERR_PK_INVALID_PUBKEY +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
if( ( pk_info = pk_info_from_type( pk_alg ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 )
return( ret );
#if defined(POLARSSL_RSA_C)
if( pk_alg == POLARSSL_PK_RSA )
{
ret = pk_get_rsapubkey( p, end, pk_rsa( *pk ) );
} else
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
if( pk_alg == POLARSSL_PK_ECKEY_DH || pk_alg == POLARSSL_PK_ECKEY )
{
ret = pk_use_ecparams( &alg_params, &pk_ec( *pk )->grp );
if( ret == 0 )
ret = pk_get_ecpubkey( p, end, pk_ec( *pk ) );
} else
#endif /* POLARSSL_ECP_C */
ret = POLARSSL_ERR_PK_UNKNOWN_PK_ALG;
if( ret == 0 && *p != end )
ret = POLARSSL_ERR_PK_INVALID_PUBKEY
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
if( ret != 0 )
pk_free( pk );
return( ret );
}
#if defined(POLARSSL_RSA_C)
/*
* Parse a PKCS#1 encoded private RSA key
*/
static int pk_parse_key_pkcs1_der( rsa_context *rsa,
const unsigned char *key,
size_t keylen )
{
int ret;
size_t len;
unsigned char *p, *end;
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 = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = asn1_get_int( &p, end, &rsa->ver ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
if( rsa->ver != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_VERSION );
}
if( ( ret = asn1_get_mpi( &p, end, &rsa->N ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->E ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->D ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->P ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->Q ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->DP ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->DQ ) ) != 0 ||
( ret = asn1_get_mpi( &p, end, &rsa->QP ) ) != 0 )
{
rsa_free( rsa );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
rsa->len = mpi_size( &rsa->N );
if( p != end )
{
rsa_free( rsa );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
}
if( ( ret = rsa_check_privkey( rsa ) ) != 0 )
{
rsa_free( rsa );
return( ret );
}
return( 0 );
}
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
/*
* Parse a SEC1 encoded private EC key
*/
static int pk_parse_key_sec1_der( ecp_keypair *eck,
const unsigned char *key,
size_t keylen )
{
int ret;
int version, pubkey_done;
size_t len;
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 = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = asn1_get_int( &p, end, &version ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( version != 1 )
return( POLARSSL_ERR_PK_KEY_INVALID_VERSION );
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = mpi_read_binary( &eck->d, p, len ) ) != 0 )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
pubkey_done = 0;
if( p != end )
{
/*
* Is 'parameters' present?
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) == 0 )
{
if( ( ret = pk_get_ecparams( &p, p + len, &params) ) != 0 ||
( ret = pk_use_ecparams( &params, &eck->grp ) ) != 0 )
{
ecp_keypair_free( eck );
return( ret );
}
}
else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
/*
* 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 = asn1_get_tag( &p, end, &len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 1 ) ) == 0 )
{
end2 = p + len;
if( ( ret = asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( p + len != end2 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_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 != POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
}
}
else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
}
if( ! pubkey_done &&
( ret = ecp_mul( &eck->grp, &eck->Q, &eck->d, &eck->grp.G,
NULL, NULL ) ) != 0 )
{
ecp_keypair_free( eck );
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
if( ( ret = ecp_check_privkey( &eck->grp, &eck->d ) ) != 0 )
{
ecp_keypair_free( eck );
return( ret );
}
return( 0 );
}
#endif /* POLARSSL_ECP_C */
/*
* Parse an unencrypted PKCS#8 encoded private key
*/
static int pk_parse_key_pkcs8_unencrypted_der(
pk_context *pk,
const unsigned char* key,
size_t keylen )
{
int ret, version;
size_t len;
asn1_buf params;
unsigned char *p = (unsigned char *) key;
unsigned char *end = p + keylen;
pk_type_t pk_alg = POLARSSL_PK_NONE;
const pk_info_t *pk_info;
/*
* This function parses the PrivatKeyInfo object (PKCS#8 v1.2 = RFC 5208)
*
* PrivateKeyInfo ::= SEQUENCE {
* version Version,
* privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
* privateKey PrivateKey,
* attributes [0] IMPLICIT Attributes OPTIONAL }
*
* Version ::= INTEGER
* PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
* PrivateKey ::= OCTET STRING
*
* The PrivateKey OCTET STRING is a SEC1 ECPrivateKey
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = asn1_get_int( &p, end, &version ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( version != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_VERSION + ret );
if( ( ret = pk_get_pk_alg( &p, end, &pk_alg, &params ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( len < 1 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( ( pk_info = pk_info_from_type( pk_alg ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 )
return( ret );
#if defined(POLARSSL_RSA_C)
if( pk_alg == POLARSSL_PK_RSA )
{
if( ( ret = pk_parse_key_pkcs1_der( pk_rsa( *pk ), p, len ) ) != 0 )
{
pk_free( pk );
return( ret );
}
} else
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
if( pk_alg == POLARSSL_PK_ECKEY || pk_alg == POLARSSL_PK_ECKEY_DH )
{
if( ( ret = pk_use_ecparams( &params, &pk_ec( *pk )->grp ) ) != 0 ||
( ret = pk_parse_key_sec1_der( pk_ec( *pk ), p, len ) ) != 0 )
{
pk_free( pk );
return( ret );
}
} else
#endif /* POLARSSL_ECP_C */
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
return( 0 );
}
/*
* Parse an encrypted PKCS#8 encoded private key
*/
#if defined(POLARSSL_PKCS12_C) || defined(POLARSSL_PKCS5_C)
static int pk_parse_key_pkcs8_encrypted_der(
pk_context *pk,
const unsigned char *key, size_t keylen,
const unsigned char *pwd, size_t pwdlen )
{
int ret, decrypted = 0;
size_t len;
unsigned char buf[2048];
unsigned char *p, *end;
asn1_buf pbe_alg_oid, pbe_params;
#if defined(POLARSSL_PKCS12_C)
cipher_type_t cipher_alg;
md_type_t md_alg;
#endif
memset( buf, 0, sizeof( buf ) );
p = (unsigned char *) key;
end = p + keylen;
if( pwdlen == 0 )
return( POLARSSL_ERR_PK_PASSWORD_REQUIRED );
/*
* This function parses the EncryptedPrivatKeyInfo object (PKCS#8)
*
* EncryptedPrivateKeyInfo ::= SEQUENCE {
* encryptionAlgorithm EncryptionAlgorithmIdentifier,
* encryptedData EncryptedData
* }
*
* EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
*
* EncryptedData ::= OCTET STRING
*
* The EncryptedData OCTET STRING is a PKCS#8 PrivateKeyInfo
*/
if( ( ret = asn1_get_tag( &p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
{
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = asn1_get_alg( &p, end, &pbe_alg_oid, &pbe_params ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT + ret );
if( len > sizeof( buf ) )
return( POLARSSL_ERR_PK_BAD_INPUT_DATA );
/*
* Decrypt EncryptedData with appropriate PDE
*/
#if defined(POLARSSL_PKCS12_C)
if( oid_get_pkcs12_pbe_alg( &pbe_alg_oid, &md_alg, &cipher_alg ) == 0 )
{
if( ( ret = pkcs12_pbe( &pbe_params, PKCS12_PBE_DECRYPT,
cipher_alg, md_alg,
pwd, pwdlen, p, len, buf ) ) != 0 )
{
if( ret == POLARSSL_ERR_PKCS12_PASSWORD_MISMATCH )
return( POLARSSL_ERR_PK_PASSWORD_MISMATCH );
return( ret );
}
decrypted = 1;
}
else if( OID_CMP( OID_PKCS12_PBE_SHA1_RC4_128, &pbe_alg_oid ) )
{
if( ( ret = pkcs12_pbe_sha1_rc4_128( &pbe_params,
PKCS12_PBE_DECRYPT,
pwd, pwdlen,
p, len, buf ) ) != 0 )
{
return( ret );
}
// Best guess for password mismatch when using RC4. If first tag is
// not ASN1_CONSTRUCTED | ASN1_SEQUENCE
//
if( *buf != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
return( POLARSSL_ERR_PK_PASSWORD_MISMATCH );
decrypted = 1;
}
else
#endif /* POLARSSL_PKCS12_C */
#if defined(POLARSSL_PKCS5_C)
if( OID_CMP( OID_PKCS5_PBES2, &pbe_alg_oid ) )
{
if( ( ret = pkcs5_pbes2( &pbe_params, PKCS5_DECRYPT, pwd, pwdlen,
p, len, buf ) ) != 0 )
{
if( ret == POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH )
return( POLARSSL_ERR_PK_PASSWORD_MISMATCH );
return( ret );
}
decrypted = 1;
}
else
#endif /* POLARSSL_PKCS5_C */
{
((void) pwd);
}
if( decrypted == 0 )
return( POLARSSL_ERR_PK_FEATURE_UNAVAILABLE );
return( pk_parse_key_pkcs8_unencrypted_der( pk, buf, len ) );
}
#endif /* POLARSSL_PKCS12_C || POLARSSL_PKCS5_C */
/*
* Parse a private key
*/
int pk_parse_key( pk_context *pk,
const unsigned char *key, size_t keylen,
const unsigned char *pwd, size_t pwdlen )
{
int ret;
const pk_info_t *pk_info;
#if defined(POLARSSL_PEM_PARSE_C)
size_t len;
pem_context pem;
pem_init( &pem );
#if defined(POLARSSL_RSA_C)
ret = pem_read_buffer( &pem,
"-----BEGIN RSA PRIVATE KEY-----",
"-----END RSA PRIVATE KEY-----",
key, pwd, pwdlen, &len );
if( ret == 0 )
{
if( ( pk_info = pk_info_from_type( POLARSSL_PK_RSA ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 ||
( ret = pk_parse_key_pkcs1_der( pk_rsa( *pk ),
pem.buf, pem.buflen ) ) != 0 )
{
pk_free( pk );
}
pem_free( &pem );
return( ret );
}
else if( ret == POLARSSL_ERR_PEM_PASSWORD_MISMATCH )
return( POLARSSL_ERR_PK_PASSWORD_MISMATCH );
else if( ret == POLARSSL_ERR_PEM_PASSWORD_REQUIRED )
return( POLARSSL_ERR_PK_PASSWORD_REQUIRED );
else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
return( ret );
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
ret = pem_read_buffer( &pem,
"-----BEGIN EC PRIVATE KEY-----",
"-----END EC PRIVATE KEY-----",
key, pwd, pwdlen, &len );
if( ret == 0 )
{
if( ( pk_info = pk_info_from_type( POLARSSL_PK_ECKEY ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 ||
( ret = pk_parse_key_sec1_der( pk_ec( *pk ),
pem.buf, pem.buflen ) ) != 0 )
{
pk_free( pk );
}
pem_free( &pem );
return( ret );
}
else if( ret == POLARSSL_ERR_PEM_PASSWORD_MISMATCH )
return( POLARSSL_ERR_PK_PASSWORD_MISMATCH );
else if( ret == POLARSSL_ERR_PEM_PASSWORD_REQUIRED )
return( POLARSSL_ERR_PK_PASSWORD_REQUIRED );
else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
return( ret );
#endif /* POLARSSL_ECP_C */
ret = pem_read_buffer( &pem,
"-----BEGIN PRIVATE KEY-----",
"-----END PRIVATE KEY-----",
key, NULL, 0, &len );
if( ret == 0 )
{
if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk,
pem.buf, pem.buflen ) ) != 0 )
{
pk_free( pk );
}
pem_free( &pem );
return( ret );
}
else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
return( ret );
#if defined(POLARSSL_PKCS12_C) || defined(POLARSSL_PKCS5_C)
ret = pem_read_buffer( &pem,
"-----BEGIN ENCRYPTED PRIVATE KEY-----",
"-----END ENCRYPTED PRIVATE KEY-----",
key, NULL, 0, &len );
if( ret == 0 )
{
if( ( ret = pk_parse_key_pkcs8_encrypted_der( pk,
pem.buf, pem.buflen,
pwd, pwdlen ) ) != 0 )
{
pk_free( pk );
}
pem_free( &pem );
return( ret );
}
else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
return( ret );
#endif /* POLARSSL_PKCS12_C || POLARSSL_PKCS5_C */
#else
((void) pwd);
((void) pwdlen);
#endif /* POLARSSL_PEM_PARSE_C */
/*
* At this point we only know it's not a PEM formatted key. Could be any
* of the known DER encoded private key formats
*
* We try the different DER format parsers to see if one passes without
* error
*/
#if defined(POLARSSL_PKCS12_C) || defined(POLARSSL_PKCS5_C)
if( ( ret = pk_parse_key_pkcs8_encrypted_der( pk, key, keylen,
pwd, pwdlen ) ) == 0 )
{
return( 0 );
}
pk_free( pk );
if( ret == POLARSSL_ERR_PK_PASSWORD_MISMATCH )
{
return( ret );
}
#endif /* POLARSSL_PKCS12_C || POLARSSL_PKCS5_C */
if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk, key, keylen ) ) == 0 )
return( 0 );
pk_free( pk );
#if defined(POLARSSL_RSA_C)
if( ( pk_info = pk_info_from_type( POLARSSL_PK_RSA ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 ||
( ret = pk_parse_key_pkcs1_der( pk_rsa( *pk ), key, keylen ) ) == 0 )
{
return( 0 );
}
pk_free( pk );
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
if( ( pk_info = pk_info_from_type( POLARSSL_PK_ECKEY ) ) == NULL )
return( POLARSSL_ERR_PK_UNKNOWN_PK_ALG );
if( ( ret = pk_init_ctx( pk, pk_info ) ) != 0 ||
( ret = pk_parse_key_sec1_der( pk_ec( *pk ), key, keylen ) ) == 0 )
{
return( 0 );
}
pk_free( pk );
#endif /* POLARSSL_ECP_C */
return( POLARSSL_ERR_PK_KEY_INVALID_FORMAT );
}
/*
* Parse a public key
*/
int pk_parse_public_key( pk_context *ctx,
const unsigned char *key, size_t keylen )
{
int ret;
unsigned char *p;
#if defined(POLARSSL_PEM_PARSE_C)
size_t len;
pem_context pem;
pem_init( &pem );
ret = pem_read_buffer( &pem,
"-----BEGIN PUBLIC KEY-----",
"-----END PUBLIC KEY-----",
key, NULL, 0, &len );
if( ret == 0 )
{
/*
* Was PEM encoded
*/
key = pem.buf;
keylen = pem.buflen;
}
else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
{
pem_free( &pem );
return( ret );
}
#endif /* POLARSSL_PEM_PARSE_C */
p = (unsigned char *) key;
ret = pk_parse_subpubkey( &p, p + keylen, ctx );
#if defined(POLARSSL_PEM_PARSE_C)
pem_free( &pem );
#endif
return( ret );
}
#endif /* POLARSSL_PK_PARSE_C */