x509_create.c

00001 /*
00002  *  X.509 base functions for creating certificates / CSRs
00003  *
00004  *  Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
00005  *
00006  *  This file is part of mbed TLS (https://tls.mbed.org)
00007  *
00008  *  This program is free software; you can redistribute it and/or modify
00009  *  it under the terms of the GNU General Public License as published by
00010  *  the Free Software Foundation; either version 2 of the License, or
00011  *  (at your option) any later version.
00012  *
00013  *  This program is distributed in the hope that it will be useful,
00014  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  *  GNU General Public License for more details.
00017  *
00018  *  You should have received a copy of the GNU General Public License along
00019  *  with this program; if not, write to the Free Software Foundation, Inc.,
00020  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00021  */
00022 
00023 #if !defined(POLARSSL_CONFIG_FILE)
00024 #include "polarssl/config.h"
00025 #else
00026 #include POLARSSL_CONFIG_FILE
00027 #endif
00028 
00029 #if defined(POLARSSL_X509_CREATE_C)
00030 
00031 #include "polarssl/x509.h"
00032 #include "polarssl/asn1write.h"
00033 #include "polarssl/oid.h"
00034 
00035 #include <string.h>
00036 
00037 #if defined(_MSC_VER) && !defined strncasecmp && !defined(EFIX64) && \
00038     !defined(EFI32)
00039 #define strncasecmp _strnicmp
00040 #endif
00041 
00042 typedef struct {
00043     const char *name;
00044     size_t name_len;
00045     const char*oid;
00046 } x509_attr_descriptor_t;
00047 
00048 #define ADD_STRLEN( s )     s, sizeof( s ) - 1
00049 
00050 static const x509_attr_descriptor_t x509_attrs[] =
00051 {
00052     { ADD_STRLEN( "CN" ),                       OID_AT_CN },
00053     { ADD_STRLEN( "commonName" ),               OID_AT_CN },
00054     { ADD_STRLEN( "C" ),                        OID_AT_COUNTRY },
00055     { ADD_STRLEN( "countryName" ),              OID_AT_COUNTRY },
00056     { ADD_STRLEN( "O" ),                        OID_AT_ORGANIZATION },
00057     { ADD_STRLEN( "organizationName" ),         OID_AT_ORGANIZATION },
00058     { ADD_STRLEN( "L" ),                        OID_AT_LOCALITY },
00059     { ADD_STRLEN( "locality" ),                 OID_AT_LOCALITY },
00060     { ADD_STRLEN( "R" ),                        OID_PKCS9_EMAIL },
00061     { ADD_STRLEN( "OU" ),                       OID_AT_ORG_UNIT },
00062     { ADD_STRLEN( "organizationalUnitName" ),   OID_AT_ORG_UNIT },
00063     { ADD_STRLEN( "ST" ),                       OID_AT_STATE },
00064     { ADD_STRLEN( "stateOrProvinceName" ),      OID_AT_STATE },
00065     { ADD_STRLEN( "emailAddress" ),             OID_PKCS9_EMAIL },
00066     { ADD_STRLEN( "serialNumber" ),             OID_AT_SERIAL_NUMBER },
00067     { ADD_STRLEN( "postalAddress" ),            OID_AT_POSTAL_ADDRESS },
00068     { ADD_STRLEN( "postalCode" ),               OID_AT_POSTAL_CODE },
00069     { ADD_STRLEN( "dnQualifier" ),              OID_AT_DN_QUALIFIER },
00070     { ADD_STRLEN( "title" ),                    OID_AT_TITLE },
00071     { ADD_STRLEN( "surName" ),                  OID_AT_SUR_NAME },
00072     { ADD_STRLEN( "SN" ),                       OID_AT_SUR_NAME },
00073     { ADD_STRLEN( "givenName" ),                OID_AT_GIVEN_NAME },
00074     { ADD_STRLEN( "GN" ),                       OID_AT_GIVEN_NAME },
00075     { ADD_STRLEN( "initials" ),                 OID_AT_INITIALS },
00076     { ADD_STRLEN( "pseudonym" ),                OID_AT_PSEUDONYM },
00077     { ADD_STRLEN( "generationQualifier" ),      OID_AT_GENERATION_QUALIFIER },
00078     { ADD_STRLEN( "domainComponent" ),          OID_DOMAIN_COMPONENT },
00079     { ADD_STRLEN( "DC" ),                       OID_DOMAIN_COMPONENT },
00080     { NULL, 0, NULL }
00081 };
00082 
00083 static const char *x509_at_oid_from_name( const char *name, size_t name_len )
00084 {
00085     const x509_attr_descriptor_t *cur;
00086 
00087     for( cur = x509_attrs; cur->name != NULL; cur++ )
00088         if( cur->name_len == name_len &&
00089             strncasecmp( cur->name, name, name_len ) == 0 )
00090             break;
00091 
00092     return( cur->oid );
00093 }
00094 
00095 int x509_string_to_names( asn1_named_data **head, const char *name )
00096 {
00097     int ret = 0;
00098     const char *s = name, *c = s;
00099     const char *end = s + strlen( s );
00100     const char *oid = NULL;
00101     int in_tag = 1;
00102     char data[X509_MAX_DN_NAME_SIZE];
00103     char *d = data;
00104 
00105     /* Clear existing chain if present */
00106     asn1_free_named_data_list( head );
00107 
00108     while( c <= end )
00109     {
00110         if( in_tag && *c == '=' )
00111         {
00112             if( ( oid = x509_at_oid_from_name( s, c - s ) ) == NULL )
00113             {
00114                 ret = POLARSSL_ERR_X509_UNKNOWN_OID;
00115                 goto exit;
00116             }
00117 
00118             s = c + 1;
00119             in_tag = 0;
00120             d = data;
00121         }
00122 
00123         if( !in_tag && *c == '\\' && c != end )
00124         {
00125             c++;
00126 
00127             /* Check for valid escaped characters */
00128             if( c == end || *c != ',' )
00129             {
00130                 ret = POLARSSL_ERR_X509_INVALID_NAME;
00131                 goto exit;
00132             }
00133         }
00134         else if( !in_tag && ( *c == ',' || c == end ) )
00135         {
00136             if( asn1_store_named_data( head, oid, strlen( oid ),
00137                                        (unsigned char *) data,
00138                                        d - data ) == NULL )
00139             {
00140                 return( POLARSSL_ERR_X509_MALLOC_FAILED );
00141             }
00142 
00143             while( c < end && *(c + 1) == ' ' )
00144                 c++;
00145 
00146             s = c + 1;
00147             in_tag = 1;
00148         }
00149 
00150         if( !in_tag && s != c + 1 )
00151         {
00152             *(d++) = *c;
00153 
00154             if( d - data == X509_MAX_DN_NAME_SIZE )
00155             {
00156                 ret = POLARSSL_ERR_X509_INVALID_NAME;
00157                 goto exit;
00158             }
00159         }
00160 
00161         c++;
00162     }
00163 
00164 exit:
00165 
00166     return( ret );
00167 }
00168 
00169 /* The first byte of the value in the asn1_named_data structure is reserved
00170  * to store the critical boolean for us
00171  */
00172 int x509_set_extension( asn1_named_data **head, const char *oid, size_t oid_len,
00173                         int critical, const unsigned char *val, size_t val_len )
00174 {
00175     asn1_named_data *cur;
00176 
00177     if( ( cur = asn1_store_named_data( head, oid, oid_len,
00178                                        NULL, val_len + 1 ) ) == NULL )
00179     {
00180         return( POLARSSL_ERR_X509_MALLOC_FAILED );
00181     }
00182 
00183     cur->val.p[0] = critical;
00184     memcpy( cur->val.p + 1, val, val_len );
00185 
00186     return( 0 );
00187 }
00188 
00189 /*
00190  *  RelativeDistinguishedName ::=
00191  *    SET OF AttributeTypeAndValue
00192  *
00193  *  AttributeTypeAndValue ::= SEQUENCE {
00194  *    type     AttributeType,
00195  *    value    AttributeValue }
00196  *
00197  *  AttributeType ::= OBJECT IDENTIFIER
00198  *
00199  *  AttributeValue ::= ANY DEFINED BY AttributeType
00200  */
00201 static int x509_write_name( unsigned char **p, unsigned char *start,
00202                             const char *oid, size_t oid_len,
00203                             const unsigned char *name, size_t name_len )
00204 {
00205     int ret;
00206     size_t len = 0;
00207 
00208     // Write PrintableString for all except OID_PKCS9_EMAIL
00209     //
00210     if( OID_SIZE( OID_PKCS9_EMAIL ) == oid_len &&
00211         memcmp( oid, OID_PKCS9_EMAIL, oid_len ) == 0 )
00212     {
00213         ASN1_CHK_ADD( len, asn1_write_ia5_string( p, start,
00214                                                   (const char *) name,
00215                                                   name_len ) );
00216     }
00217     else
00218     {
00219         ASN1_CHK_ADD( len, asn1_write_printable_string( p, start,
00220                                                         (const char *) name,
00221                                                         name_len ) );
00222     }
00223 
00224     // Write OID
00225     //
00226     ASN1_CHK_ADD( len, asn1_write_oid( p, start, oid, oid_len ) );
00227 
00228     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
00229     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED |
00230                                                  ASN1_SEQUENCE ) );
00231 
00232     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
00233     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED |
00234                                                  ASN1_SET ) );
00235 
00236     return( (int) len );
00237 }
00238 
00239 int x509_write_names( unsigned char **p, unsigned char *start,
00240                       asn1_named_data *first )
00241 {
00242     int ret;
00243     size_t len = 0;
00244     asn1_named_data *cur = first;
00245 
00246     while( cur != NULL )
00247     {
00248         ASN1_CHK_ADD( len, x509_write_name( p, start, (char *) cur->oid.p,
00249                                             cur->oid.len,
00250                                             cur->val.p, cur->val.len ) );
00251         cur = cur->next;
00252     }
00253 
00254     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
00255     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED |
00256                                                  ASN1_SEQUENCE ) );
00257 
00258     return( (int) len );
00259 }
00260 
00261 int x509_write_sig( unsigned char **p, unsigned char *start,
00262                     const char *oid, size_t oid_len,
00263                     unsigned char *sig, size_t size )
00264 {
00265     int ret;
00266     size_t len = 0;
00267 
00268     if( *p - start < (int) size + 1 )
00269         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
00270 
00271     len = size;
00272     (*p) -= len;
00273     memcpy( *p, sig, len );
00274 
00275     *--(*p) = 0;
00276     len += 1;
00277 
00278     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
00279     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );
00280 
00281     // Write OID
00282     //
00283     ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( p, start, oid,
00284                                                         oid_len, 0 ) );
00285 
00286     return( (int) len );
00287 }
00288 
00289 static int x509_write_extension( unsigned char **p, unsigned char *start,
00290                                  asn1_named_data *ext )
00291 {
00292     int ret;
00293     size_t len = 0;
00294 
00295     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, ext->val.p + 1,
00296                                               ext->val.len - 1 ) );
00297     ASN1_CHK_ADD( len, asn1_write_len( p, start, ext->val.len - 1 ) );
00298     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OCTET_STRING ) );
00299 
00300     if( ext->val.p[0] != 0 )
00301     {
00302         ASN1_CHK_ADD( len, asn1_write_bool( p, start, 1 ) );
00303     }
00304 
00305     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, ext->oid.p,
00306                                               ext->oid.len ) );
00307     ASN1_CHK_ADD( len, asn1_write_len( p, start, ext->oid.len ) );
00308     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OID ) );
00309 
00310     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
00311     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED |
00312                                                  ASN1_SEQUENCE ) );
00313 
00314     return( (int) len );
00315 }
00316 
00317 /*
00318  * Extension  ::=  SEQUENCE  {
00319  *     extnID      OBJECT IDENTIFIER,
00320  *     critical    BOOLEAN DEFAULT FALSE,
00321  *     extnValue   OCTET STRING
00322  *                 -- contains the DER encoding of an ASN.1 value
00323  *                 -- corresponding to the extension type identified
00324  *                 -- by extnID
00325  *     }
00326  */
00327 int x509_write_extensions( unsigned char **p, unsigned char *start,
00328                            asn1_named_data *first )
00329 {
00330     int ret;
00331     size_t len = 0;
00332     asn1_named_data *cur_ext = first;
00333 
00334     while( cur_ext != NULL )
00335     {
00336         ASN1_CHK_ADD( len, x509_write_extension( p, start, cur_ext ) );
00337         cur_ext = cur_ext->next;
00338     }
00339 
00340     return( (int) len );
00341 }
00342 
00343 #endif /* POLARSSL_X509_CREATE_C */
00344