Diff: source/x509_csr.c

Revision:

1:24750b9ad5ef

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/x509_csr.c	Fri Jan 22 16:44:49 2016 -0600
@@ -0,0 +1,417 @@
+/*
+ *  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 <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
+
+/* 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;
+}
+
+/*
+ *  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 )
+        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 );
+    }
+
+    csr->version++;
+
+    if( csr->version != 1 )
+    {
+        mbedtls_x509_csr_free( csr );
+        return( MBEDTLS_ERR_X509_UNKNOWN_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
+     */
+    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 );
+    }
+    // TODO Parse Attributes / extension requests
+
+    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 )
+{
+    int ret;
+#if defined(MBEDTLS_PEM_PARSE_C)
+    size_t use_len;
+    mbedtls_pem_context pem;
+#endif
+
+    /*
+     * Check for valid input
+     */
+    if( csr == NULL || buf == NULL )
+        return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_pem_init( &pem );
+
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( buflen == 0 || buf[buflen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                               "-----BEGIN CERTIFICATE REQUEST-----",
+                               "-----END CERTIFICATE REQUEST-----",
+                               buf, NULL, 0, &use_len );
+
+    if( ret == 0 )
+    {
+        /*
+         * Was PEM encoded, parse the result
+         */
+        if( ( ret = mbedtls_x509_csr_parse_der( csr, pem.buf, pem.buflen ) ) != 0 )
+            return( ret );
+
+        mbedtls_pem_free( &pem );
+        return( 0 );
+    }
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+    {
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    else
+#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_zeroize( buf, n );
+    mbedtls_free( buf );
+
+    return( ret );
+}
+#endif /* MBEDTLS_FS_IO */
+
+#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_oid, 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 ) );
+}
+
+/*
+ * 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_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
+        mbedtls_free( name_prv );
+    }
+
+    if( csr->raw.p != NULL )
+    {
+        mbedtls_zeroize( csr->raw.p, csr->raw.len );
+        mbedtls_free( csr->raw.p );
+    }
+
+    mbedtls_zeroize( csr, sizeof( mbedtls_x509_csr ) );
+}
+
+#endif /* MBEDTLS_X509_CSR_PARSE_C */