mbedtls/library/x509_csr.c
Hanno Becker 83cd8676fa Remove sig_oid parameter from mbedtls_x509_sig_alg_gets()
The function `mbedtls_x509_sig_alg_gets()` previously needed the
raw ASN.1 OID string even though it is implicit in the PK and MD
parameters.

This commit modifies `mbedtls_x509_sig_alg_gets()` to infer the OID
and remove it from the parameters.

This will be needed for the new X.509 CRT structure which will
likely not store the signature OID.

Care has to be taken to handle the case of RSASSA-PSS correctly,
where the hash algorithm in the OID list is set to MBEDTLS_MD_NONE
because it's only determined by the algorithm parameters.
2019-06-25 09:06:26 +01:00

422 lines
11 KiB
C

/*
* X.509 Certificate Signing Request (CSR) parsing
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* The ITU-T X.509 standard defines a certificate format for PKI.
*
* http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
* http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
* http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
*
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_X509_CSR_PARSE_C)
#include "mbedtls/x509_csr.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#include <stdio.h>
#define mbedtls_free free
#define mbedtls_calloc calloc
#define mbedtls_snprintf snprintf
#endif
#if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32)
#include <stdio.h>
#endif
/*
* Version ::= INTEGER { v1(0) }
*/
static int x509_csr_get_version( unsigned char **p,
const unsigned char *end,
int *ver )
{
int ret;
if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
{
*ver = 0;
return( 0 );
}
return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
}
return( 0 );
}
/*
* Parse a CSR in DER format
*/
int mbedtls_x509_csr_parse_der( mbedtls_x509_csr *csr,
const unsigned char *buf, size_t buflen )
{
int ret;
size_t len;
unsigned char *p, *end;
mbedtls_x509_buf sig_params;
memset( &sig_params, 0, sizeof( mbedtls_x509_buf ) );
/*
* Check for valid input
*/
if( csr == NULL || buf == NULL || buflen == 0 )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
mbedtls_x509_csr_init( csr );
/*
* first copy the raw DER data
*/
p = mbedtls_calloc( 1, len = buflen );
if( p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
memcpy( p, buf, buflen );
csr->raw.p = p;
csr->raw.len = len;
end = p + len;
/*
* CertificationRequest ::= SEQUENCE {
* certificationRequestInfo CertificationRequestInfo,
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
}
if( len != (size_t) ( end - p ) )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
/*
* CertificationRequestInfo ::= SEQUENCE {
*/
csr->cri.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
end = p + len;
csr->cri.len = end - csr->cri.p;
/*
* Version ::= INTEGER { v1(0) }
*/
if( ( ret = x509_csr_get_version( &p, end, &csr->version ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( csr->version != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
}
csr->version++;
/*
* subject Name
*/
csr->subject_raw.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
if( ( ret = mbedtls_x509_get_name( &p, p + len, &csr->subject ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
csr->subject_raw.len = p - csr->subject_raw.p;
/*
* subjectPKInfo SubjectPublicKeyInfo
*/
if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &csr->pk ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
/*
* attributes [0] Attributes
*
* The list of possible attributes is open-ended, though RFC 2985
* (PKCS#9) defines a few in section 5.4. We currently don't support any,
* so we just ignore them. This is a safe thing to do as the worst thing
* that could happen is that we issue a certificate that does not match
* the requester's expectations - this cannot cause a violation of our
* signature policies.
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
p += len;
end = csr->raw.p + csr->raw.len;
/*
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
*/
if( ( ret = mbedtls_x509_get_alg( &p, end, &csr->sig_oid, &sig_params ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( ( ret = mbedtls_x509_get_sig_alg( &csr->sig_oid, &sig_params,
&csr->sig_md, &csr->sig_pk,
&csr->sig_opts ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG );
}
if( ( ret = mbedtls_x509_get_sig( &p, end, &csr->sig ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( p != end )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
return( 0 );
}
/*
* Parse a CSR, allowing for PEM or raw DER encoding
*/
int mbedtls_x509_csr_parse( mbedtls_x509_csr *csr, const unsigned char *buf, size_t buflen )
{
#if defined(MBEDTLS_PEM_PARSE_C)
int ret;
size_t use_len;
mbedtls_pem_context pem;
#endif
/*
* Check for valid input
*/
if( csr == NULL || buf == NULL || buflen == 0 )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
#if defined(MBEDTLS_PEM_PARSE_C)
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if( buf[buflen - 1] == '\0' )
{
mbedtls_pem_init( &pem );
ret = mbedtls_pem_read_buffer( &pem,
"-----BEGIN CERTIFICATE REQUEST-----",
"-----END CERTIFICATE REQUEST-----",
buf, NULL, 0, &use_len );
if( ret == MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
{
ret = mbedtls_pem_read_buffer( &pem,
"-----BEGIN NEW CERTIFICATE REQUEST-----",
"-----END NEW CERTIFICATE REQUEST-----",
buf, NULL, 0, &use_len );
}
if( ret == 0 )
{
/*
* Was PEM encoded, parse the result
*/
ret = mbedtls_x509_csr_parse_der( csr, pem.buf, pem.buflen );
}
mbedtls_pem_free( &pem );
if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
return( ret );
}
#endif /* MBEDTLS_PEM_PARSE_C */
return( mbedtls_x509_csr_parse_der( csr, buf, buflen ) );
}
#if defined(MBEDTLS_FS_IO)
/*
* Load a CSR into the structure
*/
int mbedtls_x509_csr_parse_file( mbedtls_x509_csr *csr, const char *path )
{
int ret;
size_t n;
unsigned char *buf;
if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
return( ret );
ret = mbedtls_x509_csr_parse( csr, buf, n );
mbedtls_platform_zeroize( buf, n );
mbedtls_free( buf );
return( ret );
}
#endif /* MBEDTLS_FS_IO */
#if !defined(MBEDTLS_X509_REMOVE_INFO)
#define BEFORE_COLON 14
#define BC "14"
/*
* Return an informational string about the CSR.
*/
int mbedtls_x509_csr_info( char *buf, size_t size, const char *prefix,
const mbedtls_x509_csr *csr )
{
int ret;
size_t n;
char *p;
char key_size_str[BEFORE_COLON];
p = buf;
n = size;
ret = mbedtls_snprintf( p, n, "%sCSR version : %d",
prefix, csr->version );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_dn_gets( p, n, &csr->subject );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_sig_alg_gets( p, n, csr->sig_pk,
csr->sig_md, csr->sig_opts );
MBEDTLS_X509_SAFE_SNPRINTF;
if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
mbedtls_pk_get_name( &csr->pk ) ) ) != 0 )
{
return( ret );
}
ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits\n", prefix, key_size_str,
(int) mbedtls_pk_get_bitlen( &csr->pk ) );
MBEDTLS_X509_SAFE_SNPRINTF;
return( (int) ( size - n ) );
}
#endif /* !MBEDTLS_X509_REMOVE_INFO */
/*
* Initialize a CSR
*/
void mbedtls_x509_csr_init( mbedtls_x509_csr *csr )
{
memset( csr, 0, sizeof(mbedtls_x509_csr) );
}
/*
* Unallocate all CSR data
*/
void mbedtls_x509_csr_free( mbedtls_x509_csr *csr )
{
mbedtls_x509_name *name_cur;
mbedtls_x509_name *name_prv;
if( csr == NULL )
return;
mbedtls_pk_free( &csr->pk );
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
mbedtls_free( csr->sig_opts );
#endif
name_cur = csr->subject.next;
while( name_cur != NULL )
{
name_prv = name_cur;
name_cur = name_cur->next;
mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
mbedtls_free( name_prv );
}
if( csr->raw.p != NULL )
{
mbedtls_platform_zeroize( csr->raw.p, csr->raw.len );
mbedtls_free( csr->raw.p );
}
mbedtls_platform_zeroize( csr, sizeof( mbedtls_x509_csr ) );
}
#endif /* MBEDTLS_X509_CSR_PARSE_C */