mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-11-22 17:15:38 +01:00
Merge pull request #3464 from CodeMonkeyLeet/csr_heap_alloc
Dynamically allocate requested CSR write buffer size
This commit is contained in:
Manuel Pégourié-Gonnard
GitHub
commit
d4d6ad0363
4
ChangeLog.d/x509write_csr_heap_alloc.txt
Normal file
4
ChangeLog.d/x509write_csr_heap_alloc.txt
Normal file
@ -0,0 +1,4 @@
|
||||
Changes
|
||||
* Reduce the stack consumption of mbedtls_x509write_csr_der() which
|
||||
previously could lead to stack overflow on constrained devices.
|
||||
Contributed by Doru Gucea and Simon Leet in #3464.
|
||||
@ -46,6 +46,14 @@
|
||||
#include "mbedtls/pem.h"
|
||||
#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 ) );
|
||||
@ -126,7 +134,10 @@ int mbedtls_x509write_csr_set_ns_cert_type( mbedtls_x509write_csr *ctx,
|
||||
return( 0 );
|
||||
}
|
||||
|
||||
int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size,
|
||||
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 )
|
||||
{
|
||||
@ -135,8 +146,6 @@ int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, s
|
||||
size_t sig_oid_len = 0;
|
||||
unsigned char *c, *c2;
|
||||
unsigned char hash[64];
|
||||
unsigned char sig[MBEDTLS_PK_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;
|
||||
@ -145,56 +154,69 @@ int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, s
|
||||
size_t hash_len;
|
||||
psa_algorithm_t hash_alg = mbedtls_psa_translate_md( ctx->md_alg );
|
||||
#endif /* MBEDTLS_USE_PSA_CRYPTO */
|
||||
/*
|
||||
* Prepare data to be signed in tmp_buf
|
||||
*/
|
||||
c = tmp_buf + sizeof( tmp_buf );
|
||||
|
||||
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
|
||||
/* Write the CSR backwards starting from the end of buf */
|
||||
c = buf + size;
|
||||
|
||||
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, 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_SET ) );
|
||||
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, tmp_buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
|
||||
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, 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, 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
|
||||
*/
|
||||
#if defined(MBEDTLS_USE_PSA_CRYPTO)
|
||||
@ -234,26 +256,62 @@ int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, s
|
||||
}
|
||||
|
||||
/*
|
||||
* Write data to output buffer
|
||||
* Move the written CSR data to the start of buf to create space for
|
||||
* writing the signature into buf.
|
||||
*/
|
||||
memmove( buf, c, len );
|
||||
|
||||
/*
|
||||
* 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,
|
||||
sig_oid, sig_oid_len, sig, sig_len ) );
|
||||
|
||||
if( len > (size_t)( c2 - buf ) )
|
||||
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
|
||||
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, MBEDTLS_PK_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"
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user