Commit 15162a05 authored by Paul Bakker's avatar Paul Bakker
Browse files

Writing of X509v3 extensions supported

Standard extensions already in: basicConstraints, subjectKeyIdentifier
and authorityKeyIdentifier
parent 329def30
......@@ -291,6 +291,60 @@ void x509write_crt_set_issuer_key( x509write_cert *ctx, rsa_context *rsa );
*/
void x509write_crt_set_md_alg( x509write_cert *ctx, md_type_t md_alg );
/**
* \brief Generic function to add to or replace an extension in the
* CRT
*
* \param ctx CRT context to use
* \param oid OID of the extension
* \param oid_len length of the OID
* \param critical if the extension is critical (per the RFC's definition)
* \param val value of the extension OCTET STRING
* \param val_len length of the value data
*
* \return 0 if successful, or a POLARSSL_ERR_X509WRITE_MALLOC_FAILED
*/
int x509write_crt_set_extension( x509write_cert *ctx,
const char *oid, size_t oid_len,
int critical,
const unsigned char *val, size_t val_len );
/**
* \brief Set the basicConstraints extension for a CRT
*
* \param ctx CRT context to use
* \param is_ca is this a CA certificate
* \param max_pathlen maximum length of certificate chains below this
* certificate (only for CA certificates, -1 is
* inlimited)
*
* \return 0 if successful, or a POLARSSL_ERR_X509WRITE_MALLOC_FAILED
*/
int x509write_crt_set_basic_constraints( x509write_cert *ctx,
int is_ca, int max_pathlen );
/**
* \brief Set the subjectKeyIdentifier extension for a CRT
* Requires that x509write_crt_set_subject_key() has been
* called before
*
* \param ctx CRT context to use
*
* \return 0 if successful, or a POLARSSL_ERR_X509WRITE_MALLOC_FAILED
*/
int x509write_crt_set_subject_key_identifier( x509write_cert *ctx );
/**
* \brief Set the authorityKeyIdentifier extension for a CRT
* Requires that x509write_crt_set_issuer_key() has been
* called before
*
* \param ctx CRT context to use
*
* \return 0 if successful, or a POLARSSL_ERR_X509WRITE_MALLOC_FAILED
*/
int x509write_crt_set_authority_key_identifier( x509write_cert *ctx );
/**
* \brief Free the contents of a CRT write context
*
......
......@@ -33,6 +33,8 @@
#include "polarssl/md.h"
#include "polarssl/oid.h"
#include "polarssl/sha1.h"
#if defined(POLARSSL_BASE64_C)
#include "polarssl/base64.h"
#endif
......@@ -124,6 +126,27 @@ exit:
return( ret );
}
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int x509_write_rsa_pubkey( unsigned char **p, unsigned char *start,
rsa_context *rsa )
{
int ret;
size_t len = 0;
ASN1_CHK_ADD( len, asn1_write_mpi( p, start, &rsa->E ) );
ASN1_CHK_ADD( len, asn1_write_mpi( p, start, &rsa->N ) );
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 );
}
void x509write_csr_init( x509_csr *ctx )
{
memset( ctx, 0, sizeof(x509_csr) );
......@@ -165,14 +188,17 @@ int x509write_csr_set_subject_name( x509_csr *ctx, char *subject_name )
return x509write_string_to_names( &ctx->subject, subject_name );
}
int x509write_csr_set_extension( x509_csr *ctx,
const char *oid, size_t oid_len,
const unsigned char *val, size_t val_len )
/* The first byte of the value in the asn1_named_data structure is reserved
* to store the critical boolean for us
*/
static 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_find_named_data( ctx->extensions, oid,
oid_len ) ) == NULL )
if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
{
cur = polarssl_malloc( sizeof(asn1_named_data) );
if( cur == NULL )
......@@ -188,8 +214,8 @@ int x509write_csr_set_extension( x509_csr *ctx,
return( POLARSSL_ERR_X509WRITE_MALLOC_FAILED );
}
cur->val.len = val_len;
cur->val.p = polarssl_malloc( val_len );
cur->val.len = val_len + 1;
cur->val.p = polarssl_malloc( val_len + 1 );
if( cur->val.p == NULL )
{
polarssl_free( cur->oid.p );
......@@ -199,16 +225,16 @@ int x509write_csr_set_extension( x509_csr *ctx,
memcpy( cur->oid.p, oid, oid_len );
cur->next = ctx->extensions;
ctx->extensions = cur;
cur->next = *head;
*head = cur;
}
if( cur->val.len != val_len )
if( cur->val.len != val_len + 1 )
{
polarssl_free( cur->val.p );
cur->val.len = val_len;
cur->val.p = polarssl_malloc( val_len );
cur->val.len = val_len + 1;
cur->val.p = polarssl_malloc( val_len + 1);
if( cur->val.p == NULL )
{
polarssl_free( cur->oid.p );
......@@ -217,11 +243,20 @@ int x509write_csr_set_extension( x509_csr *ctx,
}
}
memcpy( cur->val.p, val, val_len );
cur->val.p[0] = critical;
memcpy( cur->val.p + 1, val, val_len );
return( 0 );
}
int x509write_csr_set_extension( x509_csr *ctx,
const char *oid, size_t oid_len,
const unsigned char *val, size_t val_len )
{
return x509_set_extension( &ctx->extensions, oid, oid_len,
0, val, val_len );
}
int x509write_csr_set_key_usage( x509_csr *ctx, unsigned char key_usage )
{
unsigned char buf[4];
......@@ -350,26 +385,102 @@ int x509write_crt_set_validity( x509write_cert *ctx, char *not_before,
return( 0 );
}
int x509write_pubkey_der( rsa_context *rsa, unsigned char *buf, size_t size )
int x509write_crt_set_extension( x509write_cert *ctx,
const char *oid, size_t oid_len,
int critical,
const unsigned char *val, size_t val_len )
{
return x509_set_extension( &ctx->extensions, oid, oid_len,
critical, val, val_len );
}
int x509write_crt_set_basic_constraints( x509write_cert *ctx,
int is_ca, int max_pathlen )
{
int ret;
unsigned char *c;
unsigned char buf[9];
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
c = buf + size - 1;
memset( buf, 0, sizeof(buf) );
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->E ) );
ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->N ) );
if( is_ca && max_pathlen > 127 )
return( POLARSSL_ERR_X509WRITE_BAD_INPUT_DATA );
if( is_ca )
{
if( max_pathlen >= 0 )
{
ASN1_CHK_ADD( len, asn1_write_int( &c, buf, max_pathlen ) );
}
ASN1_CHK_ADD( len, asn1_write_bool( &c, buf, 1 ) );
}
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
return x509write_crt_set_extension( ctx, OID_BASIC_CONSTRAINTS,
OID_SIZE( OID_BASIC_CONSTRAINTS ),
0, buf + sizeof(buf) - len, len );
}
int x509write_crt_set_subject_key_identifier( x509write_cert *ctx )
{
int ret;
unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
memset( buf, 0, sizeof(buf));
ASN1_CHK_ADD( len, x509_write_rsa_pubkey( &c, buf, ctx->subject_key ) );
sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
c = buf + sizeof(buf) - 20;
len = 20;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_OCTET_STRING ) );
return x509write_crt_set_extension( ctx, OID_SUBJECT_KEY_IDENTIFIER,
OID_SIZE( OID_SUBJECT_KEY_IDENTIFIER ),
0, buf + sizeof(buf) - len, len );
}
int x509write_crt_set_authority_key_identifier( x509write_cert *ctx )
{
int ret;
unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
memset( buf, 0, sizeof(buf));
ASN1_CHK_ADD( len, x509_write_rsa_pubkey( &c, buf, ctx->issuer_key ) );
sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
c = buf + sizeof(buf) - 20;
len = 20;
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONTEXT_SPECIFIC | 0 ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
return x509write_crt_set_extension( ctx, OID_AUTHORITY_KEY_IDENTIFIER,
OID_SIZE( OID_AUTHORITY_KEY_IDENTIFIER ),
0, buf + sizeof(buf) - len, len );
}
int x509write_pubkey_der( rsa_context *rsa, unsigned char *buf, size_t size )
{
int ret;
unsigned char *c;
size_t len = 0;
c = buf + size - 1;
ASN1_CHK_ADD( len, x509_write_rsa_pubkey( &c, buf, rsa ) );
if( c - buf < 1 )
return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
......@@ -541,6 +652,59 @@ static int x509_write_time( unsigned char **p, unsigned char *start,
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
* }
*/
static 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 );
}
int x509write_csr_der( x509_csr *ctx, unsigned char *buf, size_t size )
{
int ret;
......@@ -551,31 +715,10 @@ int x509write_csr_der( x509_csr *ctx, unsigned char *buf, size_t size )
unsigned char tmp_buf[2048];
size_t pub_len = 0, sig_len = 0;
size_t len = 0;
asn1_named_data *cur_ext = ctx->extensions;
c = tmp_buf + 2048 - 1;
while( cur_ext != NULL )
{
size_t ext_len = 0;
ASN1_CHK_ADD( ext_len, asn1_write_raw_buffer( &c, tmp_buf, cur_ext->val.p,
cur_ext->val.len ) );
ASN1_CHK_ADD( ext_len, asn1_write_len( &c, tmp_buf, cur_ext->val.len ) );
ASN1_CHK_ADD( ext_len, asn1_write_tag( &c, tmp_buf, ASN1_OCTET_STRING ) );
ASN1_CHK_ADD( ext_len, asn1_write_raw_buffer( &c, tmp_buf, cur_ext->oid.p,
cur_ext->oid.len ) );
ASN1_CHK_ADD( ext_len, asn1_write_len( &c, tmp_buf, cur_ext->oid.len ) );
ASN1_CHK_ADD( ext_len, asn1_write_tag( &c, tmp_buf, ASN1_OID ) );
ASN1_CHK_ADD( ext_len, asn1_write_len( &c, tmp_buf, ext_len ) );
ASN1_CHK_ADD( ext_len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
cur_ext = cur_ext->next;
len += ext_len;
}
ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
if( len )
{
......@@ -664,7 +807,6 @@ int x509write_crt_der( x509write_cert *ctx, unsigned char *buf, size_t size )
unsigned char tmp_buf[2048];
size_t sub_len = 0, pub_len = 0, sig_len = 0;
size_t len = 0;
asn1_named_data *cur_ext = ctx->extensions;
c = tmp_buf + 2048 - 1;
......@@ -674,6 +816,14 @@ int x509write_crt_der( x509write_cert *ctx, unsigned char *buf, size_t size )
if( ret != 0 )
return( ret );
/*
* Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
*/
ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 3 ) );
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
......
......@@ -63,6 +63,8 @@ int main( int argc, char *argv[] )
#define DFL_NOT_BEFORE "20010101000000"
#define DFL_NOT_AFTER "20301231235959"
#define DFL_SERIAL "1"
#define DFL_IS_CA 0
#define DFL_MAX_PATHLEN -1
#define DFL_KEY_USAGE 0
#define DFL_NS_CERT_TYPE 0
......@@ -81,6 +83,8 @@ struct options
char *not_before; /* validity period not before */
char *not_after; /* validity period not after */
char *serial; /* serial number string */
int is_ca; /* is a CA certificate */
int max_pathlen; /* maximum CA path length */
unsigned char key_usage; /* key usage flags */
unsigned char ns_cert_type; /* NS cert type */
} opt;
......@@ -122,6 +126,8 @@ int write_certificate( x509write_cert *crt, char *output_file )
" serial=%%s default: 1\n" \
" not_before=%%s default: 20010101000000\n"\
" not_after=%%s default: 20301231235959\n"\
" is_ca=%%d default: 0 (disabled)\n" \
" max_pathlen=%%d default: -1 (none)\n" \
" key_usage=%%s default: (empty)\n" \
" Comma-separated-list of values:\n" \
" digital_signature\n" \
......@@ -180,6 +186,8 @@ int main( int argc, char *argv[] )
opt.not_before = DFL_NOT_BEFORE;
opt.not_after = DFL_NOT_AFTER;
opt.serial = DFL_SERIAL;
opt.is_ca = DFL_IS_CA;
opt.max_pathlen = DFL_MAX_PATHLEN;
opt.key_usage = DFL_KEY_USAGE;
opt.ns_cert_type = DFL_NS_CERT_TYPE;
......@@ -228,6 +236,18 @@ int main( int argc, char *argv[] )
{
opt.serial = q;
}
else if( strcmp( p, "is_ca" ) == 0 )
{
opt.is_ca = atoi( q );
if( opt.is_ca < 0 || opt.is_ca > 1 )
goto usage;
}
else if( strcmp( p, "max_pathlen" ) == 0 )
{
opt.max_pathlen = atoi( q );
if( opt.max_pathlen < -1 || opt.max_pathlen > 127 )
goto usage;
}
else if( strcmp( p, "key_usage" ) == 0 )
{
while( q != NULL )
......@@ -389,6 +409,52 @@ int main( int argc, char *argv[] )
printf( " ok\n" );
printf( " . Adding the Basic Constraints extension ..." );
fflush( stdout );
ret = x509write_crt_set_basic_constraints( &crt, opt.is_ca,
opt.max_pathlen );
if( ret != 0 )
{
#ifdef POLARSSL_ERROR_C
error_strerror( ret, buf, 1024 );
#endif
printf( " failed\n ! x509write_crt_set_basic_contraints returned -0x%02x - %s\n\n", -ret, buf );
goto exit;
}
printf( " ok\n" );
printf( " . Adding the Subject Key Identifier ..." );
fflush( stdout );
ret = x509write_crt_set_subject_key_identifier( &crt );
if( ret != 0 )
{
#ifdef POLARSSL_ERROR_C
error_strerror( ret, buf, 1024 );
#endif
printf( " failed\n ! x509write_crt_set_subject_key_identifier returned -0x%02x - %s\n\n", -ret, buf );
goto exit;
}
printf( " ok\n" );
printf( " . Adding the Authority Key Identifier ..." );
fflush( stdout );
ret = x509write_crt_set_authority_key_identifier( &crt );
if( ret != 0 )
{
#ifdef POLARSSL_ERROR_C
error_strerror( ret, buf, 1024 );
#endif
printf( " failed\n ! x509write_crt_set_authority_key_identifier returned -0x%02x - %s\n\n", -ret, buf );
goto exit;
}
printf( " ok\n" );
/*
* 1.2. Writing the request
*/
......
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