Split up X509 files into smaller modules
diff --git a/library/x509_create.c b/library/x509_create.c
new file mode 100644
index 0000000..6991161
--- /dev/null
+++ b/library/x509_create.c
@@ -0,0 +1,267 @@
+/*
+ *  X.509 base functions for creating certificates / CSRs
+ *
+ *  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.
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_X509_CREATE_C)
+
+#include "polarssl/x509.h"
+#include "polarssl/asn1write.h"
+#include "polarssl/oid.h"
+
+int x509write_string_to_names( asn1_named_data **head, char *name )
+{
+    int ret = 0;
+    char *s = name, *c = s;
+    char *end = s + strlen( s );
+    char *oid = NULL;
+    int in_tag = 1;
+    asn1_named_data *cur;
+
+    /* Clear existing chain if present */
+    asn1_free_named_data_list( head );
+
+    while( c <= end )
+    {
+        if( in_tag && *c == '=' )
+        {
+            if( memcmp( s, "CN", 2 ) == 0 && c - s == 2 )
+                oid = OID_AT_CN;
+            else if( memcmp( s, "C", 1 ) == 0 && c - s == 1 )
+                oid = OID_AT_COUNTRY;
+            else if( memcmp( s, "O", 1 ) == 0 && c - s == 1 )
+                oid = OID_AT_ORGANIZATION;
+            else if( memcmp( s, "L", 1 ) == 0 && c - s == 1 )
+                oid = OID_AT_LOCALITY;
+            else if( memcmp( s, "R", 1 ) == 0 && c - s == 1 )
+                oid = OID_PKCS9_EMAIL;
+            else if( memcmp( s, "OU", 2 ) == 0 && c - s == 2 )
+                oid = OID_AT_ORG_UNIT;
+            else if( memcmp( s, "ST", 2 ) == 0 && c - s == 2 )
+                oid = OID_AT_STATE;
+            else
+            {
+                ret = POLARSSL_ERR_X509WRITE_UNKNOWN_OID;
+                goto exit;
+            }
+
+            s = c + 1;
+            in_tag = 0;
+        }
+
+        if( !in_tag && ( *c == ',' || c == end ) )
+        {
+            if( ( cur = asn1_store_named_data( head, oid, strlen( oid ),
+                                               (unsigned char *) s,
+                                               c - s ) ) == NULL )
+            {
+                return( POLARSSL_ERR_X509WRITE_MALLOC_FAILED );
+            }
+
+            while( c < end && *(c + 1) == ' ' )
+                c++;
+
+            s = c + 1;
+            in_tag = 1;
+        }
+        c++;
+    }
+
+exit:
+
+    return( ret );
+}
+
+/* The first byte of the value in the asn1_named_data structure is reserved
+ * to store the critical boolean for us
+ */
+int x509_set_extension( asn1_named_data **head, const char *oid, size_t oid_len,
+                        int critical, const unsigned char *val, size_t val_len )
+{
+    asn1_named_data *cur;
+
+    if( ( cur = asn1_store_named_data( head, oid, oid_len,
+                                       NULL, val_len + 1 ) ) == NULL )
+    {
+        return( POLARSSL_ERR_X509WRITE_MALLOC_FAILED );
+    }
+
+    cur->val.p[0] = critical;
+    memcpy( cur->val.p + 1, val, val_len );
+
+    return( 0 );
+}
+
+/*
+ *  RelativeDistinguishedName ::=
+ *    SET OF AttributeTypeAndValue
+ *
+ *  AttributeTypeAndValue ::= SEQUENCE {
+ *    type     AttributeType,
+ *    value    AttributeValue }
+ *
+ *  AttributeType ::= OBJECT IDENTIFIER
+ *
+ *  AttributeValue ::= ANY DEFINED BY AttributeType
+ */
+static int x509_write_name( unsigned char **p, unsigned char *start,
+                            const char *oid, size_t oid_len,
+                            const unsigned char *name, size_t name_len )
+{
+    int ret;
+    size_t len = 0;
+
+    // Write PrintableString for all except OID_PKCS9_EMAIL
+    //
+    if( OID_SIZE( OID_PKCS9_EMAIL ) == oid_len &&
+        memcmp( oid, OID_PKCS9_EMAIL, oid_len ) == 0 )
+    {
+        ASN1_CHK_ADD( len, asn1_write_ia5_string( p, start,
+                                                  (const char *) name,
+                                                  name_len ) );
+    }
+    else
+    {
+        ASN1_CHK_ADD( len, asn1_write_printable_string( p, start,
+                                                        (const char *) name,
+                                                        name_len ) );
+    }
+
+    // Write OID
+    //
+    ASN1_CHK_ADD( len, asn1_write_oid( p, start, oid, oid_len ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SET ) );
+
+    return( len );
+}
+
+int x509_write_names( unsigned char **p, unsigned char *start,
+                      asn1_named_data *first )
+{
+    int ret;
+    size_t len = 0;
+    asn1_named_data *cur = first;
+
+    while( cur != NULL )
+    {
+        ASN1_CHK_ADD( len, x509_write_name( p, start, (char *) cur->oid.p,
+                                            cur->oid.len,
+                                            cur->val.p, cur->val.len ) );
+        cur = cur->next;
+    }
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    return( len );
+}
+
+int x509_write_sig( unsigned char **p, unsigned char *start,
+                    const char *oid, size_t oid_len,
+                    unsigned char *sig, size_t size )
+{
+    int ret;
+    size_t len = 0;
+
+    if( *p - start < (int) size + 1 )
+        return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
+
+    len = size;
+    (*p) -= len;
+    memcpy( *p, sig, len );
+
+    *--(*p) = 0;
+    len += 1;
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );
+
+    // Write OID
+    //
+    ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( p, start, oid,
+                                                        oid_len, 0 ) );
+
+    return( len );
+}
+
+static int x509_write_extension( unsigned char **p, unsigned char *start,
+                                 asn1_named_data *ext )
+{
+    int ret;
+    size_t len = 0;
+
+    ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, ext->val.p + 1,
+                                              ext->val.len - 1 ) );
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, ext->val.len - 1 ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OCTET_STRING ) );
+
+    if( ext->val.p[0] != 0 )
+    {
+        ASN1_CHK_ADD( len, asn1_write_bool( p, start, 1 ) );
+    }
+
+    ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, ext->oid.p,
+                                              ext->oid.len ) );
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, ext->oid.len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OID ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    return( len );
+}
+
+/*
+ * Extension  ::=  SEQUENCE  {
+ *     extnID      OBJECT IDENTIFIER,
+ *     critical    BOOLEAN DEFAULT FALSE,
+ *     extnValue   OCTET STRING
+ *                 -- contains the DER encoding of an ASN.1 value
+ *                 -- corresponding to the extension type identified
+ *                 -- by extnID
+ *     }
+ */
+int x509_write_extensions( unsigned char **p, unsigned char *start,
+                           asn1_named_data *first )
+{
+    int ret;
+    size_t len = 0;
+    asn1_named_data *cur_ext = first;
+
+    while( cur_ext != NULL )
+    {
+        ASN1_CHK_ADD( len, x509_write_extension( p, start, cur_ext ) );
+        cur_ext = cur_ext->next;
+    }
+
+    return( len );
+}
+
+#endif /* POLARSSL_X509_CREATE_C */