mbedtls/library/x509.c
2013-09-18 14:32:52 +02:00

765 lines
18 KiB
C

/*
* X.509 certificate and private key decoding
*
* Copyright (C) 2006-2013, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* 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.
*/
/*
* The ITU-T X.509 standard defines a certificate format for PKI.
*
* http://www.ietf.org/rfc/rfc3279.txt
* http://www.ietf.org/rfc/rfc3280.txt
*
* ftp://ftp.rsasecurity.com/pub/pkcs/ascii/pkcs-1v2.asc
*
* 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 "polarssl/config.h"
#if defined(POLARSSL_X509_USE_C)
#include "polarssl/x509.h"
#include "polarssl/asn1.h"
#include "polarssl/oid.h"
#if defined(POLARSSL_PEM_PARSE_C)
#include "polarssl/pem.h"
#endif
#if defined(POLARSSL_MEMORY_C)
#include "polarssl/memory.h"
#else
#define polarssl_malloc malloc
#define polarssl_free free
#endif
#include <string.h>
#include <stdlib.h>
#if defined(_WIN32)
#include <windows.h>
#else
#include <time.h>
#endif
#if defined(POLARSSL_FS_IO)
#include <stdio.h>
#if !defined(_WIN32)
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#endif
#endif
/*
* CertificateSerialNumber ::= INTEGER
*/
int x509_get_serial( unsigned char **p, const unsigned char *end,
x509_buf *serial )
{
int ret;
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_SERIAL +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( **p != ( ASN1_CONTEXT_SPECIFIC | ASN1_PRIMITIVE | 2 ) &&
**p != ASN1_INTEGER )
return( POLARSSL_ERR_X509_INVALID_SERIAL +
POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
serial->tag = *(*p)++;
if( ( ret = asn1_get_len( p, end, &serial->len ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_SERIAL + ret );
serial->p = *p;
*p += serial->len;
return( 0 );
}
/* Get an algorithm identifier without parameters (eg for signatures)
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL }
*/
int x509_get_alg_null( unsigned char **p, const unsigned char *end,
x509_buf *alg )
{
int ret;
if( ( ret = asn1_get_alg_null( p, end, alg ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_ALG + ret );
return( 0 );
}
/*
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue }
*
* AttributeType ::= OBJECT IDENTIFIER
*
* AttributeValue ::= ANY DEFINED BY AttributeType
*/
static int x509_get_attr_type_value( unsigned char **p,
const unsigned char *end,
x509_name *cur )
{
int ret;
size_t len;
x509_buf *oid;
x509_buf *val;
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_NAME + ret );
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_NAME +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
oid = &cur->oid;
oid->tag = **p;
if( ( ret = asn1_get_tag( p, end, &oid->len, ASN1_OID ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_NAME + ret );
oid->p = *p;
*p += oid->len;
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_NAME +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( **p != ASN1_BMP_STRING && **p != ASN1_UTF8_STRING &&
**p != ASN1_T61_STRING && **p != ASN1_PRINTABLE_STRING &&
**p != ASN1_IA5_STRING && **p != ASN1_UNIVERSAL_STRING )
return( POLARSSL_ERR_X509_INVALID_NAME +
POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
val = &cur->val;
val->tag = *(*p)++;
if( ( ret = asn1_get_len( p, end, &val->len ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_NAME + ret );
val->p = *p;
*p += val->len;
cur->next = NULL;
return( 0 );
}
/*
* RelativeDistinguishedName ::=
* SET OF AttributeTypeAndValue
*
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue }
*
* AttributeType ::= OBJECT IDENTIFIER
*
* AttributeValue ::= ANY DEFINED BY AttributeType
*/
int x509_get_name( unsigned char **p, const unsigned char *end,
x509_name *cur )
{
int ret;
size_t len;
const unsigned char *end2;
x509_name *use;
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SET ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_NAME + ret );
end2 = end;
end = *p + len;
use = cur;
do
{
if( ( ret = x509_get_attr_type_value( p, end, use ) ) != 0 )
return( ret );
if( *p != end )
{
use->next = (x509_name *) polarssl_malloc(
sizeof( x509_name ) );
if( use->next == NULL )
return( POLARSSL_ERR_X509_MALLOC_FAILED );
memset( use->next, 0, sizeof( x509_name ) );
use = use->next;
}
}
while( *p != end );
/*
* recurse until end of SEQUENCE is reached
*/
if( *p == end2 )
return( 0 );
cur->next = (x509_name *) polarssl_malloc(
sizeof( x509_name ) );
if( cur->next == NULL )
return( POLARSSL_ERR_X509_MALLOC_FAILED );
memset( cur->next, 0, sizeof( x509_name ) );
return( x509_get_name( p, end2, cur->next ) );
}
/*
* Time ::= CHOICE {
* utcTime UTCTime,
* generalTime GeneralizedTime }
*/
int x509_get_time( unsigned char **p, const unsigned char *end,
x509_time *time )
{
int ret;
size_t len;
char date[64];
unsigned char tag;
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_DATE +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
tag = **p;
if ( tag == ASN1_UTC_TIME )
{
(*p)++;
ret = asn1_get_len( p, end, &len );
if( ret != 0 )
return( POLARSSL_ERR_X509_INVALID_DATE + ret );
memset( date, 0, sizeof( date ) );
memcpy( date, *p, ( len < sizeof( date ) - 1 ) ?
len : sizeof( date ) - 1 );
if( sscanf( date, "%2d%2d%2d%2d%2d%2d",
&time->year, &time->mon, &time->day,
&time->hour, &time->min, &time->sec ) < 5 )
return( POLARSSL_ERR_X509_INVALID_DATE );
time->year += 100 * ( time->year < 50 );
time->year += 1900;
*p += len;
return( 0 );
}
else if ( tag == ASN1_GENERALIZED_TIME )
{
(*p)++;
ret = asn1_get_len( p, end, &len );
if( ret != 0 )
return( POLARSSL_ERR_X509_INVALID_DATE + ret );
memset( date, 0, sizeof( date ) );
memcpy( date, *p, ( len < sizeof( date ) - 1 ) ?
len : sizeof( date ) - 1 );
if( sscanf( date, "%4d%2d%2d%2d%2d%2d",
&time->year, &time->mon, &time->day,
&time->hour, &time->min, &time->sec ) < 5 )
return( POLARSSL_ERR_X509_INVALID_DATE );
*p += len;
return( 0 );
}
else
return( POLARSSL_ERR_X509_INVALID_DATE +
POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
}
int x509_get_sig( unsigned char **p, const unsigned char *end, x509_buf *sig )
{
int ret;
size_t len;
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_X509_INVALID_SIGNATURE +
POLARSSL_ERR_ASN1_OUT_OF_DATA );
sig->tag = **p;
if( ( ret = asn1_get_bitstring_null( p, end, &len ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_SIGNATURE + ret );
sig->len = len;
sig->p = *p;
*p += len;
return( 0 );
}
int x509_get_sig_alg( const x509_buf *sig_oid, md_type_t *md_alg,
pk_type_t *pk_alg )
{
int ret = oid_get_sig_alg( sig_oid, md_alg, pk_alg );
if( ret != 0 )
return( POLARSSL_ERR_X509_UNKNOWN_SIG_ALG + ret );
return( 0 );
}
/*
* X.509 Extensions (No parsing of extensions, pointer should
* be either manually updated or extensions should be parsed!
*/
int x509_get_ext( unsigned char **p, const unsigned char *end,
x509_buf *ext, int tag )
{
int ret;
size_t len;
if( *p == end )
return( 0 );
ext->tag = **p;
if( ( ret = asn1_get_tag( p, end, &ext->len,
ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | tag ) ) != 0 )
return( ret );
ext->p = *p;
end = *p + ext->len;
/*
* Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING }
*/
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
if( end != *p + len )
return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
#if defined(POLARSSL_FS_IO)
/*
* Load all data from a file into a given buffer.
*/
int x509_load_file( const char *path, unsigned char **buf, size_t *n )
{
FILE *f;
long size;
if( ( f = fopen( path, "rb" ) ) == NULL )
return( POLARSSL_ERR_X509_FILE_IO_ERROR );
fseek( f, 0, SEEK_END );
if( ( size = ftell( f ) ) == -1 )
{
fclose( f );
return( POLARSSL_ERR_X509_FILE_IO_ERROR );
}
fseek( f, 0, SEEK_SET );
*n = (size_t) size;
if( *n + 1 == 0 ||
( *buf = (unsigned char *) polarssl_malloc( *n + 1 ) ) == NULL )
{
fclose( f );
return( POLARSSL_ERR_X509_MALLOC_FAILED );
}
if( fread( *buf, 1, *n, f ) != *n )
{
fclose( f );
polarssl_free( *buf );
return( POLARSSL_ERR_X509_FILE_IO_ERROR );
}
fclose( f );
(*buf)[*n] = '\0';
return( 0 );
}
#endif /* POLARSSL_FS_IO */
#if defined _MSC_VER && !defined snprintf
#include <stdarg.h>
#if !defined vsnprintf
#define vsnprintf _vsnprintf
#endif // vsnprintf
/*
* Windows _snprintf and _vsnprintf are not compatible to linux versions.
* Result value is not size of buffer needed, but -1 if no fit is possible.
*
* This fuction tries to 'fix' this by at least suggesting enlarging the
* size by 20.
*/
static int compat_snprintf(char *str, size_t size, const char *format, ...)
{
va_list ap;
int res = -1;
va_start( ap, format );
res = vsnprintf( str, size, format, ap );
va_end( ap );
// No quick fix possible
if ( res < 0 )
return( (int) size + 20 );
return res;
}
#define snprintf compat_snprintf
#endif
#define POLARSSL_ERR_DEBUG_BUF_TOO_SMALL -2
#define SAFE_SNPRINTF() \
{ \
if( ret == -1 ) \
return( -1 ); \
\
if ( (unsigned int) ret > n ) { \
p[n - 1] = '\0'; \
return POLARSSL_ERR_DEBUG_BUF_TOO_SMALL;\
} \
\
n -= (unsigned int) ret; \
p += (unsigned int) ret; \
}
/*
* Store the name in printable form into buf; no more
* than size characters will be written
*/
int x509_dn_gets( char *buf, size_t size, const x509_name *dn )
{
int ret;
size_t i, n;
unsigned char c;
const x509_name *name;
const char *short_name = NULL;
char s[128], *p;
memset( s, 0, sizeof( s ) );
name = dn;
p = buf;
n = size;
while( name != NULL )
{
if( !name->oid.p )
{
name = name->next;
continue;
}
if( name != dn )
{
ret = snprintf( p, n, ", " );
SAFE_SNPRINTF();
}
ret = oid_get_attr_short_name( &name->oid, &short_name );
if( ret == 0 )
ret = snprintf( p, n, "%s=", short_name );
else
ret = snprintf( p, n, "\?\?=" );
SAFE_SNPRINTF();
for( i = 0; i < name->val.len; i++ )
{
if( i >= sizeof( s ) - 1 )
break;
c = name->val.p[i];
if( c < 32 || c == 127 || ( c > 128 && c < 160 ) )
s[i] = '?';
else s[i] = c;
}
s[i] = '\0';
ret = snprintf( p, n, "%s", s );
SAFE_SNPRINTF();
name = name->next;
}
return( (int) ( size - n ) );
}
/*
* Store the serial in printable form into buf; no more
* than size characters will be written
*/
int x509_serial_gets( char *buf, size_t size, const x509_buf *serial )
{
int ret;
size_t i, n, nr;
char *p;
p = buf;
n = size;
nr = ( serial->len <= 32 )
? serial->len : 28;
for( i = 0; i < nr; i++ )
{
if( i == 0 && nr > 1 && serial->p[i] == 0x0 )
continue;
ret = snprintf( p, n, "%02X%s",
serial->p[i], ( i < nr - 1 ) ? ":" : "" );
SAFE_SNPRINTF();
}
if( nr != serial->len )
{
ret = snprintf( p, n, "...." );
SAFE_SNPRINTF();
}
return( (int) ( size - n ) );
}
/*
* Helper for writing "RSA key size", "EC key size", etc
*/
int x509_key_size_helper( char *buf, size_t size, const char *name )
{
char *p = buf;
size_t n = size;
int ret;
if( strlen( name ) + sizeof( " key size" ) > size )
return POLARSSL_ERR_DEBUG_BUF_TOO_SMALL;
ret = snprintf( p, n, "%s key size", name );
SAFE_SNPRINTF();
return( 0 );
}
/*
* Return an informational string describing the given OID
*/
const char *x509_oid_get_description( x509_buf *oid )
{
const char *desc = NULL;
int ret;
ret = oid_get_extended_key_usage( oid, &desc );
if( ret != 0 )
return( NULL );
return( desc );
}
/* Return the x.y.z.... style numeric string for the given OID */
int x509_oid_get_numeric_string( char *buf, size_t size, x509_buf *oid )
{
return oid_get_numeric_string( buf, size, oid );
}
/*
* Return 0 if the x509_time is still valid, or 1 otherwise.
*/
#if defined(POLARSSL_HAVE_TIME)
int x509_time_expired( const x509_time *to )
{
int year, mon, day;
int hour, min, sec;
#if defined(_WIN32)
SYSTEMTIME st;
GetLocalTime(&st);
year = st.wYear;
mon = st.wMonth;
day = st.wDay;
hour = st.wHour;
min = st.wMinute;
sec = st.wSecond;
#else
struct tm *lt;
time_t tt;
tt = time( NULL );
lt = localtime( &tt );
year = lt->tm_year + 1900;
mon = lt->tm_mon + 1;
day = lt->tm_mday;
hour = lt->tm_hour;
min = lt->tm_min;
sec = lt->tm_sec;
#endif
if( year > to->year )
return( 1 );
if( year == to->year &&
mon > to->mon )
return( 1 );
if( year == to->year &&
mon == to->mon &&
day > to->day )
return( 1 );
if( year == to->year &&
mon == to->mon &&
day == to->day &&
hour > to->hour )
return( 1 );
if( year == to->year &&
mon == to->mon &&
day == to->day &&
hour == to->hour &&
min > to->min )
return( 1 );
if( year == to->year &&
mon == to->mon &&
day == to->day &&
hour == to->hour &&
min == to->min &&
sec > to->sec )
return( 1 );
return( 0 );
}
#else /* POLARSSL_HAVE_TIME */
int x509_time_expired( const x509_time *to )
{
((void) to);
return( 0 );
}
#endif /* POLARSSL_HAVE_TIME */
#if defined(POLARSSL_SELF_TEST)
#include "polarssl/x509_crt.h"
#include "polarssl/certs.h"
/*
* Checkup routine
*/
int x509_self_test( int verbose )
{
#if defined(POLARSSL_CERTS_C) && defined(POLARSSL_MD5_C)
int ret;
int flags;
x509_crt cacert;
x509_crt clicert;
if( verbose != 0 )
printf( " X.509 certificate load: " );
x509_crt_init( &clicert );
ret = x509_crt_parse( &clicert, (const unsigned char *) test_cli_crt,
strlen( test_cli_crt ) );
if( ret != 0 )
{
if( verbose != 0 )
printf( "failed\n" );
return( ret );
}
x509_crt_init( &cacert );
ret = x509_crt_parse( &cacert, (const unsigned char *) test_ca_crt,
strlen( test_ca_crt ) );
if( ret != 0 )
{
if( verbose != 0 )
printf( "failed\n" );
return( ret );
}
if( verbose != 0 )
printf( "passed\n X.509 signature verify: ");
ret = x509_crt_verify( &clicert, &cacert, NULL, NULL, &flags, NULL, NULL );
if( ret != 0 )
{
if( verbose != 0 )
printf( "failed\n" );
printf("ret = %d, &flags = %04x\n", ret, flags);
return( ret );
}
if( verbose != 0 )
printf( "passed\n\n");
x509_crt_free( &cacert );
x509_crt_free( &clicert );
return( 0 );
#else
((void) verbose);
return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
#endif
}
#endif
#endif /* POLARSSL_X509_USE_C */