#include "mbedtls/x509_csr.h"
#include "mbedtls/oid.h"
#include "mbedtls/asn1write.h"
+#include "mbedtls/platform_util.h"
#include <string.h>
#include <stdlib.h>
#include "mbedtls/pem.h"
#endif
-/* Implementation that should never be optimized out by the compiler */
-static void mbedtls_zeroize( void *v, size_t n ) {
- volatile unsigned char *p = v; while( n-- ) *p++ = 0;
-}
-
/*
* For the currently used signature algorithms the buffer to store any signature
* must be at least of size MAX(MBEDTLS_ECDSA_MAX_LEN, MBEDTLS_MPI_MAX_SIZE)
#define SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
#endif
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc calloc
+#define mbedtls_free free
+#endif
+
void mbedtls_x509write_csr_init( mbedtls_x509write_csr *ctx )
{
memset( ctx, 0, sizeof( mbedtls_x509write_csr ) );
mbedtls_asn1_free_named_data_list( &ctx->subject );
mbedtls_asn1_free_named_data_list( &ctx->extensions );
- mbedtls_zeroize( ctx, sizeof( mbedtls_x509write_csr ) );
+ mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_csr ) );
}
void mbedtls_x509write_csr_set_md_alg( mbedtls_x509write_csr *ctx, mbedtls_md_type_t md_alg )
return( 0 );
}
-int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size,
- int (*f_rng)(void *, unsigned char *, size_t),
- void *p_rng )
+static int x509write_csr_der_internal( mbedtls_x509write_csr *ctx,
+ unsigned char *buf,
+ size_t size,
+ unsigned char *sig,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng )
{
int ret;
const char *sig_oid;
size_t sig_oid_len = 0;
unsigned char *c, *c2;
unsigned char hash[64];
- unsigned char sig[SIGNATURE_MAX_SIZE];
- unsigned char tmp_buf[2048];
size_t pub_len = 0, sig_and_oid_len = 0, sig_len;
size_t len = 0;
mbedtls_pk_type_t pk_alg;
- /*
- * Prepare data to be signed in tmp_buf
- */
- c = tmp_buf + sizeof( tmp_buf );
+ /* Write the CSR backwards starting from the end of buf */
+ c = buf + size;
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, buf,
+ ctx->extensions ) );
if( len )
{
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SEQUENCE ) );
-
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SET ) );
-
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( &c, tmp_buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
- MBEDTLS_OID_SIZE( MBEDTLS_OID_PKCS9_CSR_EXT_REQ ) ) );
-
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SEQUENCE ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SET ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_oid(
+ &c, buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
+ MBEDTLS_OID_SIZE( MBEDTLS_OID_PKCS9_CSR_EXT_REQ ) ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
}
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_CONTEXT_SPECIFIC ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) );
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->key,
- tmp_buf, c - tmp_buf ) );
+ buf, c - buf ) );
c -= pub_len;
len += pub_len;
/*
* Subject ::= Name
*/
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, buf,
+ ctx->subject ) );
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, tmp_buf, 0 ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 0 ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SEQUENCE ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
/*
- * Prepare signature
+ * Sign the written CSR data into the sig buffer
+ * Note: hash errors can happen only after an internal error
*/
ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash );
if( ret != 0 )
return( MBEDTLS_ERR_X509_INVALID_ALG );
if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
- &sig_oid, &sig_oid_len ) ) != 0 )
+ &sig_oid, &sig_oid_len ) ) != 0 )
{
return( ret );
}
/*
- * Write data to output buffer
+ * Move the written CSR data to the start of buf to create space for
+ * writing the signature into buf.
*/
- c2 = buf + size;
- MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf,
- sig_oid, sig_oid_len, sig, sig_len ) );
+ memmove( buf, c, len );
- if( len > (size_t)( c2 - buf ) )
- return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+ /*
+ * Write sig and its OID into buf backwards from the end of buf.
+ * Note: mbedtls_x509_write_sig will check for c2 - ( buf + len ) < sig_len
+ * and return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL if needed.
+ */
+ c2 = buf + size;
+ MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len,
+ mbedtls_x509_write_sig( &c2, buf + len, sig_oid, sig_oid_len,
+ sig, sig_len ) );
+ /*
+ * Compact the space between the CSR data and signature by moving the
+ * CSR data to the start of the signature.
+ */
c2 -= len;
- memcpy( c2, c, len );
+ memmove( c2, buf, len );
+ /* ASN encode the total size and tag the CSR data with it. */
len += sig_and_oid_len;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c2, buf, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c2, buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SEQUENCE ) );
+ MBEDTLS_ASN1_CHK_ADD( len,
+ mbedtls_asn1_write_tag(
+ &c2, buf,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
+
+ /* Zero the unused bytes at the start of buf */
+ memset( buf, 0, c2 - buf);
return( (int) len );
}
+int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf,
+ size_t size,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng )
+{
+ int ret;
+ unsigned char *sig;
+
+ if( ( sig = mbedtls_calloc( 1, SIGNATURE_MAX_SIZE ) ) == NULL )
+ {
+ return( MBEDTLS_ERR_X509_ALLOC_FAILED );
+ }
+
+ ret = x509write_csr_der_internal( ctx, buf, size, sig, f_rng, p_rng );
+
+ mbedtls_free( sig );
+
+ return( ret );
+}
+
#define PEM_BEGIN_CSR "-----BEGIN CERTIFICATE REQUEST-----\n"
#define PEM_END_CSR "-----END CERTIFICATE REQUEST-----\n"
projects / reactos.git / blobdiff