mbedtls/library/x509_crl.c
Gilles Peskine 71f4fa13bb
Merge pull request #721 from gilles-peskine-arm/x509parse_crl-empty_entry-development
Fix buffer overflow in x509_get_entries (oss-fuzz 24123)
2020-08-14 23:22:31 +02:00

771 lines
21 KiB
C

/*
* X.509 Certidicate Revocation List (CRL) parsing
*
* 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)
*/
/*
* The ITU-T X.509 standard defines a certificate format for PKI.
*
* http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
* http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
* http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
*
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
*/
#include "common.h"
#if defined(MBEDTLS_X509_CRL_PARSE_C)
#include "mbedtls/x509_crl.h"
#include "mbedtls/error.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#include <stdio.h>
#define mbedtls_free free
#define mbedtls_calloc calloc
#define mbedtls_snprintf snprintf
#endif
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
#include <windows.h>
#else
#include <time.h>
#endif
#if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32)
#include <stdio.h>
#endif
/*
* Version ::= INTEGER { v1(0), v2(1) }
*/
static int x509_crl_get_version( unsigned char **p,
const unsigned char *end,
int *ver )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
{
*ver = 0;
return( 0 );
}
return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
}
return( 0 );
}
/*
* X.509 CRL v2 extensions
*
* We currently don't parse any extension's content, but we do check that the
* list of extensions is well-formed and abort on critical extensions (that
* are unsupported as we don't support any extension so far)
*/
static int x509_get_crl_ext( unsigned char **p,
const unsigned char *end,
mbedtls_x509_buf *ext )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( *p == end )
return( 0 );
/*
* crlExtensions [0] EXPLICIT Extensions OPTIONAL
* -- if present, version MUST be v2
*/
if( ( ret = mbedtls_x509_get_ext( p, end, ext, 0 ) ) != 0 )
return( ret );
end = ext->p + ext->len;
while( *p < end )
{
/*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING }
*/
int is_critical = 0;
const unsigned char *end_ext_data;
size_t len;
/* Get enclosing sequence tag */
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
end_ext_data = *p + len;
/* Get OID (currently ignored) */
if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
MBEDTLS_ASN1_OID ) ) != 0 )
{
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
}
*p += len;
/* Get optional critical */
if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data,
&is_critical ) ) != 0 &&
( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
{
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
}
/* Data should be octet string type */
if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
/* Ignore data so far and just check its length */
*p += len;
if( *p != end_ext_data )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
/* Abort on (unsupported) critical extensions */
if( is_critical )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
}
if( *p != end )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
/*
* X.509 CRL v2 entry extensions (no extensions parsed yet.)
*/
static int x509_get_crl_entry_ext( unsigned char **p,
const unsigned char *end,
mbedtls_x509_buf *ext )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
/* OPTIONAL */
if( end <= *p )
return( 0 );
ext->tag = **p;
ext->p = *p;
/*
* Get CRL-entry extension sequence header
* crlEntryExtensions Extensions OPTIONAL -- if present, MUST be v2
*/
if( ( ret = mbedtls_asn1_get_tag( p, end, &ext->len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
{
ext->p = NULL;
return( 0 );
}
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
}
end = *p + ext->len;
if( end != *p + ext->len )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
while( *p < end )
{
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
*p += len;
}
if( *p != end )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
/*
* X.509 CRL Entries
*/
static int x509_get_entries( unsigned char **p,
const unsigned char *end,
mbedtls_x509_crl_entry *entry )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t entry_len;
mbedtls_x509_crl_entry *cur_entry = entry;
if( *p == end )
return( 0 );
if( ( ret = mbedtls_asn1_get_tag( p, end, &entry_len,
MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
return( 0 );
return( ret );
}
end = *p + entry_len;
while( *p < end )
{
size_t len2;
const unsigned char *end2;
cur_entry->raw.tag = **p;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len2,
MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED ) ) != 0 )
{
return( ret );
}
cur_entry->raw.p = *p;
cur_entry->raw.len = len2;
end2 = *p + len2;
if( ( ret = mbedtls_x509_get_serial( p, end2, &cur_entry->serial ) ) != 0 )
return( ret );
if( ( ret = mbedtls_x509_get_time( p, end2,
&cur_entry->revocation_date ) ) != 0 )
return( ret );
if( ( ret = x509_get_crl_entry_ext( p, end2,
&cur_entry->entry_ext ) ) != 0 )
return( ret );
if( *p < end )
{
cur_entry->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl_entry ) );
if( cur_entry->next == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
cur_entry = cur_entry->next;
}
}
return( 0 );
}
/*
* Parse one CRLs in DER format and append it to the chained list
*/
int mbedtls_x509_crl_parse_der( mbedtls_x509_crl *chain,
const unsigned char *buf, size_t buflen )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
unsigned char *p = NULL, *end = NULL;
mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
mbedtls_x509_crl *crl = chain;
/*
* Check for valid input
*/
if( crl == NULL || buf == NULL )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
/*
* Add new CRL on the end of the chain if needed.
*/
while( crl->version != 0 && crl->next != NULL )
crl = crl->next;
if( crl->version != 0 && crl->next == NULL )
{
crl->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl ) );
if( crl->next == NULL )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
}
mbedtls_x509_crl_init( crl->next );
crl = crl->next;
}
/*
* Copy raw DER-encoded CRL
*/
if( buflen == 0 )
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
p = mbedtls_calloc( 1, buflen );
if( p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
memcpy( p, buf, buflen );
crl->raw.p = p;
crl->raw.len = buflen;
end = p + buflen;
/*
* CertificateList ::= SEQUENCE {
* tbsCertList TBSCertList,
* signatureAlgorithm AlgorithmIdentifier,
* signatureValue BIT STRING }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
}
if( len != (size_t) ( end - p ) )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
/*
* TBSCertList ::= SEQUENCE {
*/
crl->tbs.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
end = p + len;
crl->tbs.len = end - crl->tbs.p;
/*
* Version ::= INTEGER OPTIONAL { v1(0), v2(1) }
* -- if present, MUST be v2
*
* signature AlgorithmIdentifier
*/
if( ( ret = x509_crl_get_version( &p, end, &crl->version ) ) != 0 ||
( ret = mbedtls_x509_get_alg( &p, end, &crl->sig_oid, &sig_params1 ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
if( crl->version < 0 || crl->version > 1 )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
}
crl->version++;
if( ( ret = mbedtls_x509_get_sig_alg( &crl->sig_oid, &sig_params1,
&crl->sig_md, &crl->sig_pk,
&crl->sig_opts ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG );
}
/*
* issuer Name
*/
crl->issuer_raw.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
if( ( ret = mbedtls_x509_get_name( &p, p + len, &crl->issuer ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
crl->issuer_raw.len = p - crl->issuer_raw.p;
/*
* thisUpdate Time
* nextUpdate Time OPTIONAL
*/
if( ( ret = mbedtls_x509_get_time( &p, end, &crl->this_update ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
if( ( ret = mbedtls_x509_get_time( &p, end, &crl->next_update ) ) != 0 )
{
if( ret != ( MBEDTLS_ERR_X509_INVALID_DATE +
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) &&
ret != ( MBEDTLS_ERR_X509_INVALID_DATE +
MBEDTLS_ERR_ASN1_OUT_OF_DATA ) )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
}
/*
* revokedCertificates SEQUENCE OF SEQUENCE {
* userCertificate CertificateSerialNumber,
* revocationDate Time,
* crlEntryExtensions Extensions OPTIONAL
* -- if present, MUST be v2
* } OPTIONAL
*/
if( ( ret = x509_get_entries( &p, end, &crl->entry ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
/*
* crlExtensions EXPLICIT Extensions OPTIONAL
* -- if present, MUST be v2
*/
if( crl->version == 2 )
{
ret = x509_get_crl_ext( &p, end, &crl->crl_ext );
if( ret != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
}
if( p != end )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
end = crl->raw.p + crl->raw.len;
/*
* signatureAlgorithm AlgorithmIdentifier,
* signatureValue BIT STRING
*/
if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
if( crl->sig_oid.len != sig_oid2.len ||
memcmp( crl->sig_oid.p, sig_oid2.p, crl->sig_oid.len ) != 0 ||
sig_params1.len != sig_params2.len ||
( sig_params1.len != 0 &&
memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_SIG_MISMATCH );
}
if( ( ret = mbedtls_x509_get_sig( &p, end, &crl->sig ) ) != 0 )
{
mbedtls_x509_crl_free( crl );
return( ret );
}
if( p != end )
{
mbedtls_x509_crl_free( crl );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
return( 0 );
}
/*
* Parse one or more CRLs and add them to the chained list
*/
int mbedtls_x509_crl_parse( mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen )
{
#if defined(MBEDTLS_PEM_PARSE_C)
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t use_len = 0;
mbedtls_pem_context pem;
int is_pem = 0;
if( chain == NULL || buf == NULL )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
do
{
mbedtls_pem_init( &pem );
// Avoid calling mbedtls_pem_read_buffer() on non-null-terminated
// string
if( buflen == 0 || buf[buflen - 1] != '\0' )
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
else
ret = mbedtls_pem_read_buffer( &pem,
"-----BEGIN X509 CRL-----",
"-----END X509 CRL-----",
buf, NULL, 0, &use_len );
if( ret == 0 )
{
/*
* Was PEM encoded
*/
is_pem = 1;
buflen -= use_len;
buf += use_len;
if( ( ret = mbedtls_x509_crl_parse_der( chain,
pem.buf, pem.buflen ) ) != 0 )
{
mbedtls_pem_free( &pem );
return( ret );
}
}
else if( is_pem )
{
mbedtls_pem_free( &pem );
return( ret );
}
mbedtls_pem_free( &pem );
}
/* In the PEM case, buflen is 1 at the end, for the terminated NULL byte.
* And a valid CRL cannot be less than 1 byte anyway. */
while( is_pem && buflen > 1 );
if( is_pem )
return( 0 );
else
#endif /* MBEDTLS_PEM_PARSE_C */
return( mbedtls_x509_crl_parse_der( chain, buf, buflen ) );
}
#if defined(MBEDTLS_FS_IO)
/*
* Load one or more CRLs and add them to the chained list
*/
int mbedtls_x509_crl_parse_file( mbedtls_x509_crl *chain, const char *path )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
ret = mbedtls_x509_crl_parse( chain, buf, n );
mbedtls_platform_zeroize( buf, n );
mbedtls_free( buf );
return( ret );
}
#endif /* MBEDTLS_FS_IO */
/*
* Return an informational string about the certificate.
*/
#define BEFORE_COLON 14
#define BC "14"
/*
* Return an informational string about the CRL.
*/
int mbedtls_x509_crl_info( char *buf, size_t size, const char *prefix,
const mbedtls_x509_crl *crl )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
char *p;
const mbedtls_x509_crl_entry *entry;
p = buf;
n = size;
ret = mbedtls_snprintf( p, n, "%sCRL version : %d",
prefix, crl->version );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_dn_gets( p, n, &crl->issuer );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n%sthis update : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
crl->this_update.year, crl->this_update.mon,
crl->this_update.day, crl->this_update.hour,
crl->this_update.min, crl->this_update.sec );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n%snext update : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
crl->next_update.year, crl->next_update.mon,
crl->next_update.day, crl->next_update.hour,
crl->next_update.min, crl->next_update.sec );
MBEDTLS_X509_SAFE_SNPRINTF;
entry = &crl->entry;
ret = mbedtls_snprintf( p, n, "\n%sRevoked certificates:",
prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
while( entry != NULL && entry->raw.len != 0 )
{
ret = mbedtls_snprintf( p, n, "\n%sserial number: ",
prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_serial_gets( p, n, &entry->serial );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, " revocation date: " \
"%04d-%02d-%02d %02d:%02d:%02d",
entry->revocation_date.year, entry->revocation_date.mon,
entry->revocation_date.day, entry->revocation_date.hour,
entry->revocation_date.min, entry->revocation_date.sec );
MBEDTLS_X509_SAFE_SNPRINTF;
entry = entry->next;
}
ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_sig_alg_gets( p, n, &crl->sig_oid, crl->sig_pk, crl->sig_md,
crl->sig_opts );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n" );
MBEDTLS_X509_SAFE_SNPRINTF;
return( (int) ( size - n ) );
}
/*
* Initialize a CRL chain
*/
void mbedtls_x509_crl_init( mbedtls_x509_crl *crl )
{
memset( crl, 0, sizeof(mbedtls_x509_crl) );
}
/*
* Unallocate all CRL data
*/
void mbedtls_x509_crl_free( mbedtls_x509_crl *crl )
{
mbedtls_x509_crl *crl_cur = crl;
mbedtls_x509_crl *crl_prv;
mbedtls_x509_name *name_cur;
mbedtls_x509_name *name_prv;
mbedtls_x509_crl_entry *entry_cur;
mbedtls_x509_crl_entry *entry_prv;
if( crl == NULL )
return;
do
{
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
mbedtls_free( crl_cur->sig_opts );
#endif
name_cur = crl_cur->issuer.next;
while( name_cur != NULL )
{
name_prv = name_cur;
name_cur = name_cur->next;
mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
mbedtls_free( name_prv );
}
entry_cur = crl_cur->entry.next;
while( entry_cur != NULL )
{
entry_prv = entry_cur;
entry_cur = entry_cur->next;
mbedtls_platform_zeroize( entry_prv,
sizeof( mbedtls_x509_crl_entry ) );
mbedtls_free( entry_prv );
}
if( crl_cur->raw.p != NULL )
{
mbedtls_platform_zeroize( crl_cur->raw.p, crl_cur->raw.len );
mbedtls_free( crl_cur->raw.p );
}
crl_cur = crl_cur->next;
}
while( crl_cur != NULL );
crl_cur = crl;
do
{
crl_prv = crl_cur;
crl_cur = crl_cur->next;
mbedtls_platform_zeroize( crl_prv, sizeof( mbedtls_x509_crl ) );
if( crl_prv != crl )
mbedtls_free( crl_prv );
}
while( crl_cur != NULL );
}
#endif /* MBEDTLS_X509_CRL_PARSE_C */