/* * X.509 certificate and private key decoding * * Copyright (C) 2006-2013, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* * The ITU-T X.509 standard defines a certificate format for PKI. * * http://www.ietf.org/rfc/rfc3279.txt * http://www.ietf.org/rfc/rfc3280.txt * * ftp://ftp.rsasecurity.com/pub/pkcs/ascii/pkcs-1v2.asc * * 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 */ #include "polarssl/config.h" #if defined(POLARSSL_X509_CRT_PARSE_C) #include "polarssl/x509_crt.h" #include "polarssl/oid.h" #if defined(POLARSSL_PEM_PARSE_C) #include "polarssl/pem.h" #endif #if defined(POLARSSL_MEMORY_C) #include "polarssl/memory.h" #else #define polarssl_malloc malloc #define polarssl_free free #endif #include #include #if defined(_WIN32) #include #else #include #endif #if defined(POLARSSL_FS_IO) #include #if !defined(_WIN32) #include #include #include #endif #endif /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ static int x509_get_version( unsigned char **p, const unsigned char *end, int *ver ) { int ret; size_t len; if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) { *ver = 0; return( 0 ); } return( ret ); } end = *p + len; if( ( ret = asn1_get_int( p, end, ver ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_VERSION + ret ); if( *p != end ) return( POLARSSL_ERR_X509_INVALID_VERSION + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } */ static int x509_get_dates( unsigned char **p, const unsigned char *end, x509_time *from, x509_time *to ) { int ret; size_t len; if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_DATE + ret ); end = *p + len; if( ( ret = x509_get_time( p, end, from ) ) != 0 ) return( ret ); if( ( ret = x509_get_time( p, end, to ) ) != 0 ) return( ret ); if( *p != end ) return( POLARSSL_ERR_X509_INVALID_DATE + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * X.509 v2/v3 unique identifier (not parsed) */ static int x509_get_uid( unsigned char **p, const unsigned char *end, x509_buf *uid, int n ) { int ret; if( *p == end ) return( 0 ); uid->tag = **p; if( ( ret = asn1_get_tag( p, end, &uid->len, ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | n ) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } uid->p = *p; *p += uid->len; return( 0 ); } static int x509_get_basic_constraints( unsigned char **p, const unsigned char *end, int *ca_istrue, int *max_pathlen ) { int ret; size_t len; /* * BasicConstraints ::= SEQUENCE { * cA BOOLEAN DEFAULT FALSE, * pathLenConstraint INTEGER (0..MAX) OPTIONAL } */ *ca_istrue = 0; /* DEFAULT FALSE */ *max_pathlen = 0; /* endless */ if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( *p == end ) return 0; if( ( ret = asn1_get_bool( p, end, ca_istrue ) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) ret = asn1_get_int( p, end, ca_istrue ); if( ret != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( *ca_istrue != 0 ) *ca_istrue = 1; } if( *p == end ) return 0; if( ( ret = asn1_get_int( p, end, max_pathlen ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( *p != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); (*max_pathlen)++; return 0; } static int x509_get_ns_cert_type( unsigned char **p, const unsigned char *end, unsigned char *ns_cert_type) { int ret; x509_bitstring bs = { 0, 0, NULL }; if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( bs.len != 1 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_INVALID_LENGTH ); /* Get actual bitstring */ *ns_cert_type = *bs.p; return 0; } static int x509_get_key_usage( unsigned char **p, const unsigned char *end, unsigned char *key_usage) { int ret; x509_bitstring bs = { 0, 0, NULL }; if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( bs.len < 1 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_INVALID_LENGTH ); /* Get actual bitstring */ *key_usage = *bs.p; return 0; } /* * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId * * KeyPurposeId ::= OBJECT IDENTIFIER */ static int x509_get_ext_key_usage( unsigned char **p, const unsigned char *end, x509_sequence *ext_key_usage) { int ret; if( ( ret = asn1_get_sequence_of( p, end, ext_key_usage, ASN1_OID ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); /* Sequence length must be >= 1 */ if( ext_key_usage->buf.p == NULL ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_INVALID_LENGTH ); return 0; } /* * SubjectAltName ::= GeneralNames * * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName * * GeneralName ::= CHOICE { * otherName [0] OtherName, * rfc822Name [1] IA5String, * dNSName [2] IA5String, * x400Address [3] ORAddress, * directoryName [4] Name, * ediPartyName [5] EDIPartyName, * uniformResourceIdentifier [6] IA5String, * iPAddress [7] OCTET STRING, * registeredID [8] OBJECT IDENTIFIER } * * OtherName ::= SEQUENCE { * type-id OBJECT IDENTIFIER, * value [0] EXPLICIT ANY DEFINED BY type-id } * * EDIPartyName ::= SEQUENCE { * nameAssigner [0] DirectoryString OPTIONAL, * partyName [1] DirectoryString } * * NOTE: PolarSSL only parses and uses dNSName at this point. */ static int x509_get_subject_alt_name( unsigned char **p, const unsigned char *end, x509_sequence *subject_alt_name ) { int ret; size_t len, tag_len; asn1_buf *buf; unsigned char tag; asn1_sequence *cur = subject_alt_name; /* Get main sequence tag */ if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( *p + len != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); while( *p < end ) { if( ( end - *p ) < 1 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_OUT_OF_DATA ); tag = **p; (*p)++; if( ( ret = asn1_get_len( p, end, &tag_len ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); if( ( tag & ASN1_CONTEXT_SPECIFIC ) != ASN1_CONTEXT_SPECIFIC ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_UNEXPECTED_TAG ); if( tag != ( ASN1_CONTEXT_SPECIFIC | 2 ) ) { *p += tag_len; continue; } buf = &(cur->buf); buf->tag = tag; buf->p = *p; buf->len = tag_len; *p += buf->len; /* Allocate and assign next pointer */ if (*p < end) { cur->next = (asn1_sequence *) polarssl_malloc( sizeof( asn1_sequence ) ); if( cur->next == NULL ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_MALLOC_FAILED ); memset( cur->next, 0, sizeof( asn1_sequence ) ); cur = cur->next; } } /* Set final sequence entry's next pointer to NULL */ cur->next = NULL; if( *p != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * X.509 v3 extensions * * TODO: Perform all of the basic constraints tests required by the RFC * TODO: Set values for undetected extensions to a sane default? * */ static int x509_get_crt_ext( unsigned char **p, const unsigned char *end, x509_crt *crt ) { int ret; size_t len; unsigned char *end_ext_data, *end_ext_octet; if( ( ret = x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } while( *p < end ) { /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ x509_buf extn_oid = {0, 0, NULL}; int is_critical = 0; /* DEFAULT FALSE */ int ext_type = 0; if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_data = *p + len; /* Get extension ID */ extn_oid.tag = **p; if( ( ret = asn1_get_tag( p, end, &extn_oid.len, ASN1_OID ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); extn_oid.p = *p; *p += extn_oid.len; if( ( end - *p ) < 1 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_OUT_OF_DATA ); /* Get optional critical */ if( ( ret = asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 && ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); /* Data should be octet string type */ if( ( ret = asn1_get_tag( p, end_ext_data, &len, ASN1_OCTET_STRING ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_octet = *p + len; if( end_ext_octet != end_ext_data ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); /* * Detect supported extensions */ ret = oid_get_x509_ext_type( &extn_oid, &ext_type ); if( ret != 0 ) { /* No parser found, skip extension */ *p = end_ext_octet; #if !defined(POLARSSL_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION) if( is_critical ) { /* Data is marked as critical: fail */ return ( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_UNEXPECTED_TAG ); } #endif continue; } crt->ext_types |= ext_type; switch( ext_type ) { case EXT_BASIC_CONSTRAINTS: /* Parse basic constraints */ if( ( ret = x509_get_basic_constraints( p, end_ext_octet, &crt->ca_istrue, &crt->max_pathlen ) ) != 0 ) return ( ret ); break; case EXT_KEY_USAGE: /* Parse key usage */ if( ( ret = x509_get_key_usage( p, end_ext_octet, &crt->key_usage ) ) != 0 ) return ( ret ); break; case EXT_EXTENDED_KEY_USAGE: /* Parse extended key usage */ if( ( ret = x509_get_ext_key_usage( p, end_ext_octet, &crt->ext_key_usage ) ) != 0 ) return ( ret ); break; case EXT_SUBJECT_ALT_NAME: /* Parse subject alt name */ if( ( ret = x509_get_subject_alt_name( p, end_ext_octet, &crt->subject_alt_names ) ) != 0 ) return ( ret ); break; case EXT_NS_CERT_TYPE: /* Parse netscape certificate type */ if( ( ret = x509_get_ns_cert_type( p, end_ext_octet, &crt->ns_cert_type ) ) != 0 ) return ( ret ); break; default: return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE ); } } if( *p != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } /* * Parse and fill a single X.509 certificate in DER format */ static int x509_crt_parse_der_core( x509_crt *crt, const unsigned char *buf, size_t buflen ) { int ret; size_t len; unsigned char *p, *end, *crt_end; /* * Check for valid input */ if( crt == NULL || buf == NULL ) return( POLARSSL_ERR_X509_BAD_INPUT_DATA ); p = (unsigned char *) polarssl_malloc( len = buflen ); if( p == NULL ) return( POLARSSL_ERR_X509_MALLOC_FAILED ); memcpy( p, buf, buflen ); buflen = 0; crt->raw.p = p; crt->raw.len = len; end = p + len; /* * Certificate ::= SEQUENCE { * tbsCertificate TBSCertificate, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING } */ if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT ); } if( len > (size_t) ( end - p ) ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); } crt_end = p + len; /* * TBSCertificate ::= SEQUENCE { */ crt->tbs.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + ret ); } end = p + len; crt->tbs.len = end - crt->tbs.p; /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } * * CertificateSerialNumber ::= INTEGER * * signature AlgorithmIdentifier */ if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 || ( ret = x509_get_serial( &p, end, &crt->serial ) ) != 0 || ( ret = x509_get_alg_null( &p, end, &crt->sig_oid1 ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } crt->version++; if( crt->version > 3 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_UNKNOWN_VERSION ); } if( ( ret = x509_get_sig_alg( &crt->sig_oid1, &crt->sig_md, &crt->sig_pk ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } /* * issuer Name */ crt->issuer_raw.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + ret ); } if( ( ret = x509_get_name( &p, p + len, &crt->issuer ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } crt->issuer_raw.len = p - crt->issuer_raw.p; /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } * */ if( ( ret = x509_get_dates( &p, end, &crt->valid_from, &crt->valid_to ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } /* * subject Name */ crt->subject_raw.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + ret ); } if( len && ( ret = x509_get_name( &p, p + len, &crt->subject ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } crt->subject_raw.len = p - crt->subject_raw.p; /* * SubjectPublicKeyInfo */ if( ( ret = pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } /* * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * extensions [3] EXPLICIT Extensions OPTIONAL * -- If present, version shall be v3 */ if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->issuer_id, 1 ); if( ret != 0 ) { x509_crt_free( crt ); return( ret ); } } if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->subject_id, 2 ); if( ret != 0 ) { x509_crt_free( crt ); return( ret ); } } #if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3) if( crt->version == 3 ) { #endif ret = x509_get_crt_ext( &p, end, crt); if( ret != 0 ) { x509_crt_free( crt ); return( ret ); } #if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3) } #endif if( p != end ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); } end = crt_end; /* * } * -- end of TBSCertificate * * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING */ if( ( ret = x509_get_alg_null( &p, end, &crt->sig_oid2 ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } if( crt->sig_oid1.len != crt->sig_oid2.len || memcmp( crt->sig_oid1.p, crt->sig_oid2.p, crt->sig_oid1.len ) != 0 ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_SIG_MISMATCH ); } if( ( ret = x509_get_sig( &p, end, &crt->sig ) ) != 0 ) { x509_crt_free( crt ); return( ret ); } if( p != end ) { x509_crt_free( crt ); return( POLARSSL_ERR_X509_INVALID_FORMAT + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); } return( 0 ); } /* * Parse one X.509 certificate in DER format from a buffer and add them to a * chained list */ int x509_crt_parse_der( x509_crt *chain, const unsigned char *buf, size_t buflen ) { int ret; x509_crt *crt = chain, *prev = NULL; /* * Check for valid input */ if( crt == NULL || buf == NULL ) return( POLARSSL_ERR_X509_BAD_INPUT_DATA ); while( crt->version != 0 && crt->next != NULL ) { prev = crt; crt = crt->next; } /* * Add new certificate on the end of the chain if needed. */ if ( crt->version != 0 && crt->next == NULL) { crt->next = (x509_crt *) polarssl_malloc( sizeof( x509_crt ) ); if( crt->next == NULL ) return( POLARSSL_ERR_X509_MALLOC_FAILED ); prev = crt; crt = crt->next; x509_crt_init( crt ); } if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 ) { if( prev ) prev->next = NULL; if( crt != chain ) polarssl_free( crt ); return( ret ); } return( 0 ); } /* * Parse one or more PEM certificates from a buffer and add them to the chained list */ int x509_crt_parse( x509_crt *chain, const unsigned char *buf, size_t buflen ) { int success = 0, first_error = 0, total_failed = 0; int buf_format = X509_FORMAT_DER; /* * Check for valid input */ if( chain == NULL || buf == NULL ) return( POLARSSL_ERR_X509_BAD_INPUT_DATA ); /* * Determine buffer content. Buffer contains either one DER certificate or * one or more PEM certificates. */ #if defined(POLARSSL_PEM_PARSE_C) if( strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL ) buf_format = X509_FORMAT_PEM; #endif if( buf_format == X509_FORMAT_DER ) return x509_crt_parse_der( chain, buf, buflen ); #if defined(POLARSSL_PEM_PARSE_C) if( buf_format == X509_FORMAT_PEM ) { int ret; pem_context pem; while( buflen > 0 ) { size_t use_len; pem_init( &pem ); ret = pem_read_buffer( &pem, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----", buf, NULL, 0, &use_len ); if( ret == 0 ) { /* * Was PEM encoded */ buflen -= use_len; buf += use_len; } else if( ret == POLARSSL_ERR_PEM_BAD_INPUT_DATA ) { return( ret ); } else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT ) { pem_free( &pem ); /* * PEM header and footer were found */ buflen -= use_len; buf += use_len; if( first_error == 0 ) first_error = ret; continue; } else break; ret = x509_crt_parse_der( chain, pem.buf, pem.buflen ); pem_free( &pem ); if( ret != 0 ) { /* * Quit parsing on a memory error */ if( ret == POLARSSL_ERR_X509_MALLOC_FAILED ) return( ret ); if( first_error == 0 ) first_error = ret; total_failed++; continue; } success = 1; } } #endif if( success ) return( total_failed ); else if( first_error ) return( first_error ); else return( POLARSSL_ERR_X509_CERT_UNKNOWN_FORMAT ); } #if defined(POLARSSL_FS_IO) /* * Load one or more certificates and add them to the chained list */ int x509_crt_parse_file( x509_crt *chain, const char *path ) { int ret; size_t n; unsigned char *buf; if ( ( ret = x509_load_file( path, &buf, &n ) ) != 0 ) return( ret ); ret = x509_crt_parse( chain, buf, n ); memset( buf, 0, n + 1 ); polarssl_free( buf ); return( ret ); } int x509_crt_parse_path( x509_crt *chain, const char *path ) { int ret = 0; #if defined(_WIN32) int w_ret; WCHAR szDir[MAX_PATH]; char filename[MAX_PATH]; char *p; int len = (int) strlen( path ); WIN32_FIND_DATAW file_data; HANDLE hFind; if( len > MAX_PATH - 3 ) return( POLARSSL_ERR_X509_BAD_INPUT_DATA ); memset( szDir, 0, sizeof(szDir) ); memset( filename, 0, MAX_PATH ); memcpy( filename, path, len ); filename[len++] = '\\'; p = filename + len; filename[len++] = '*'; w_ret = MultiByteToWideChar( CP_ACP, 0, path, len, szDir, MAX_PATH - 3 ); hFind = FindFirstFileW( szDir, &file_data ); if (hFind == INVALID_HANDLE_VALUE) return( POLARSSL_ERR_X509_FILE_IO_ERROR ); len = MAX_PATH - len; do { memset( p, 0, len ); if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY ) continue; w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName, lstrlenW(file_data.cFileName), p, len - 1, NULL, NULL ); w_ret = x509_crt_parse_file( chain, filename ); if( w_ret < 0 ) ret++; else ret += w_ret; } while( FindNextFileW( hFind, &file_data ) != 0 ); if (GetLastError() != ERROR_NO_MORE_FILES) ret = POLARSSL_ERR_X509_FILE_IO_ERROR; FindClose( hFind ); #else int t_ret, i; struct stat sb; struct dirent entry, *result = NULL; char entry_name[255]; DIR *dir = opendir( path ); if( dir == NULL) return( POLARSSL_ERR_X509_FILE_IO_ERROR ); while( ( t_ret = readdir_r( dir, &entry, &result ) ) == 0 ) { if( result == NULL ) break; snprintf( entry_name, sizeof(entry_name), "%s/%s", path, entry.d_name ); i = stat( entry_name, &sb ); if( i == -1 ) { closedir( dir ); return( POLARSSL_ERR_X509_FILE_IO_ERROR ); } if( !S_ISREG( sb.st_mode ) ) continue; // Ignore parse errors // t_ret = x509_crt_parse_file( chain, entry_name ); if( t_ret < 0 ) ret++; else ret += t_ret; } closedir( dir ); #endif return( ret ); } #endif /* POLARSSL_FS_IO */ #if defined _MSC_VER && !defined snprintf #include #if !defined vsnprintf #define vsnprintf _vsnprintf #endif // vsnprintf /* * Windows _snprintf and _vsnprintf are not compatible to linux versions. * Result value is not size of buffer needed, but -1 if no fit is possible. * * This fuction tries to 'fix' this by at least suggesting enlarging the * size by 20. */ static int compat_snprintf(char *str, size_t size, const char *format, ...) { va_list ap; int res = -1; va_start( ap, format ); res = vsnprintf( str, size, format, ap ); va_end( ap ); // No quick fix possible if ( res < 0 ) return( (int) size + 20 ); return res; } #define snprintf compat_snprintf #endif #define POLARSSL_ERR_DEBUG_BUF_TOO_SMALL -2 #define SAFE_SNPRINTF() \ { \ if( ret == -1 ) \ return( -1 ); \ \ if ( (unsigned int) ret > n ) { \ p[n - 1] = '\0'; \ return POLARSSL_ERR_DEBUG_BUF_TOO_SMALL;\ } \ \ n -= (unsigned int) ret; \ p += (unsigned int) ret; \ } /* * Return an informational string about the certificate. */ #define BEFORE_COLON 14 #define BC "14" int x509_crt_info( char *buf, size_t size, const char *prefix, const x509_crt *crt ) { int ret; size_t n; char *p; const char *desc = NULL; char key_size_str[BEFORE_COLON]; p = buf; n = size; ret = snprintf( p, n, "%scert. version : %d\n", prefix, crt->version ); SAFE_SNPRINTF(); ret = snprintf( p, n, "%sserial number : ", prefix ); SAFE_SNPRINTF(); ret = x509_serial_gets( p, n, &crt->serial); SAFE_SNPRINTF(); ret = snprintf( p, n, "\n%sissuer name : ", prefix ); SAFE_SNPRINTF(); ret = x509_dn_gets( p, n, &crt->issuer ); SAFE_SNPRINTF(); ret = snprintf( p, n, "\n%ssubject name : ", prefix ); SAFE_SNPRINTF(); ret = x509_dn_gets( p, n, &crt->subject ); SAFE_SNPRINTF(); ret = snprintf( p, n, "\n%sissued on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_from.year, crt->valid_from.mon, crt->valid_from.day, crt->valid_from.hour, crt->valid_from.min, crt->valid_from.sec ); SAFE_SNPRINTF(); ret = snprintf( p, n, "\n%sexpires on : " \ "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_to.year, crt->valid_to.mon, crt->valid_to.day, crt->valid_to.hour, crt->valid_to.min, crt->valid_to.sec ); SAFE_SNPRINTF(); ret = snprintf( p, n, "\n%ssigned using : ", prefix ); SAFE_SNPRINTF(); ret = oid_get_sig_alg_desc( &crt->sig_oid1, &desc ); if( ret != 0 ) ret = snprintf( p, n, "???" ); else ret = snprintf( p, n, "%s", desc ); SAFE_SNPRINTF(); if( ( ret = x509_key_size_helper( key_size_str, BEFORE_COLON, pk_get_name( &crt->pk ) ) ) != 0 ) { return( ret ); } ret = snprintf( p, n, "\n%s%-" BC "s: %d bits\n", prefix, key_size_str, (int) pk_get_size( &crt->pk ) ); SAFE_SNPRINTF(); return( (int) ( size - n ) ); } #if defined(POLARSSL_X509_CRL_PARSE_C) /* * Return 1 if the certificate is revoked, or 0 otherwise. */ int x509_crt_revoked( const x509_crt *crt, const x509_crl *crl ) { const x509_crl_entry *cur = &crl->entry; while( cur != NULL && cur->serial.len != 0 ) { if( crt->serial.len == cur->serial.len && memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 ) { if( x509_time_expired( &cur->revocation_date ) ) return( 1 ); } cur = cur->next; } return( 0 ); } /* * Check that the given certificate is valid accoring to the CRL. */ static int x509_crt_verifycrl( x509_crt *crt, x509_crt *ca, x509_crl *crl_list) { int flags = 0; unsigned char hash[POLARSSL_MD_MAX_SIZE]; const md_info_t *md_info; if( ca == NULL ) return( flags ); /* * TODO: What happens if no CRL is present? * Suggestion: Revocation state should be unknown if no CRL is present. * For backwards compatibility this is not yet implemented. */ while( crl_list != NULL ) { if( crl_list->version == 0 || crl_list->issuer_raw.len != ca->subject_raw.len || memcmp( crl_list->issuer_raw.p, ca->subject_raw.p, crl_list->issuer_raw.len ) != 0 ) { crl_list = crl_list->next; continue; } /* * Check if CRL is correctly signed by the trusted CA */ md_info = md_info_from_type( crl_list->sig_md ); if( md_info == NULL ) { /* * Cannot check 'unknown' hash */ flags |= BADCRL_NOT_TRUSTED; break; } md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ); if( pk_can_do( &ca->pk, crl_list->sig_pk ) == 0 || pk_verify( &ca->pk, crl_list->sig_md, hash, md_info->size, crl_list->sig.p, crl_list->sig.len ) != 0 ) { flags |= BADCRL_NOT_TRUSTED; break; } /* * Check for validity of CRL (Do not drop out) */ if( x509_time_expired( &crl_list->next_update ) ) flags |= BADCRL_EXPIRED; /* * Check if certificate is revoked */ if( x509_crt_revoked(crt, crl_list) ) { flags |= BADCERT_REVOKED; break; } crl_list = crl_list->next; } return flags; } #endif /* POLARSSL_X509_CRL_PARSE_C */ // Equal == 0, inequal == 1 static int x509_name_cmp( const void *s1, const void *s2, size_t len ) { size_t i; unsigned char diff; const unsigned char *n1 = s1, *n2 = s2; for( i = 0; i < len; i++ ) { diff = n1[i] ^ n2[i]; if( ( n1[i] >= 'a' || n1[i] <= 'z' ) && ( diff == 0 || diff == 32 ) ) continue; if( ( n1[i] >= 'A' || n1[i] <= 'Z' ) && ( diff == 0 || diff == 32 ) ) continue; return( 1 ); } return( 0 ); } static int x509_wildcard_verify( const char *cn, x509_buf *name ) { size_t i; size_t cn_idx = 0; if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' ) return( 0 ); for( i = 0; i < strlen( cn ); ++i ) { if( cn[i] == '.' ) { cn_idx = i; break; } } if( cn_idx == 0 ) return( 0 ); if( strlen( cn ) - cn_idx == name->len - 1 && x509_name_cmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 ) { return( 1 ); } return( 0 ); } static int x509_crt_verify_top( x509_crt *child, x509_crt *trust_ca, x509_crl *ca_crl, int path_cnt, int *flags, int (*f_vrfy)(void *, x509_crt *, int, int *), void *p_vrfy ) { int ret; int ca_flags = 0, check_path_cnt = path_cnt + 1; unsigned char hash[POLARSSL_MD_MAX_SIZE]; const md_info_t *md_info; if( x509_time_expired( &child->valid_to ) ) *flags |= BADCERT_EXPIRED; /* * Child is the top of the chain. Check against the trust_ca list. */ *flags |= BADCERT_NOT_TRUSTED; md_info = md_info_from_type( child->sig_md ); if( md_info == NULL ) { /* * Cannot check 'unknown', no need to try any CA */ trust_ca = NULL; } else md( md_info, child->tbs.p, child->tbs.len, hash ); while( trust_ca != NULL ) { if( trust_ca->version == 0 || child->issuer_raw.len != trust_ca->subject_raw.len || memcmp( child->issuer_raw.p, trust_ca->subject_raw.p, child->issuer_raw.len ) != 0 ) { trust_ca = trust_ca->next; continue; } /* * Reduce path_len to check against if top of the chain is * the same as the trusted CA */ if( child->subject_raw.len == trust_ca->subject_raw.len && memcmp( child->subject_raw.p, trust_ca->subject_raw.p, child->issuer_raw.len ) == 0 ) { check_path_cnt--; } if( trust_ca->max_pathlen > 0 && trust_ca->max_pathlen < check_path_cnt ) { trust_ca = trust_ca->next; continue; } if( pk_can_do( &trust_ca->pk, child->sig_pk ) == 0 || pk_verify( &trust_ca->pk, child->sig_md, hash, md_info->size, child->sig.p, child->sig.len ) != 0 ) { trust_ca = trust_ca->next; continue; } /* * Top of chain is signed by a trusted CA */ *flags &= ~BADCERT_NOT_TRUSTED; break; } /* * If top of chain is not the same as the trusted CA send a verify request * to the callback for any issues with validity and CRL presence for the * trusted CA certificate. */ if( trust_ca != NULL && ( child->subject_raw.len != trust_ca->subject_raw.len || memcmp( child->subject_raw.p, trust_ca->subject_raw.p, child->issuer_raw.len ) != 0 ) ) { #if defined(POLARSSL_X509_CRL_PARSE_C) /* Check trusted CA's CRL for the chain's top crt */ *flags |= x509_crt_verifycrl( child, trust_ca, ca_crl ); #else ((void) ca_crl); #endif if( x509_time_expired( &trust_ca->valid_to ) ) ca_flags |= BADCERT_EXPIRED; if( NULL != f_vrfy ) { if( ( ret = f_vrfy( p_vrfy, trust_ca, path_cnt + 1, &ca_flags ) ) != 0 ) return( ret ); } } /* Call callback on top cert */ if( NULL != f_vrfy ) { if( ( ret = f_vrfy(p_vrfy, child, path_cnt, flags ) ) != 0 ) return( ret ); } *flags |= ca_flags; return( 0 ); } static int x509_crt_verify_child( x509_crt *child, x509_crt *parent, x509_crt *trust_ca, x509_crl *ca_crl, int path_cnt, int *flags, int (*f_vrfy)(void *, x509_crt *, int, int *), void *p_vrfy ) { int ret; int parent_flags = 0; unsigned char hash[POLARSSL_MD_MAX_SIZE]; x509_crt *grandparent; const md_info_t *md_info; if( x509_time_expired( &child->valid_to ) ) *flags |= BADCERT_EXPIRED; md_info = md_info_from_type( child->sig_md ); if( md_info == NULL ) { /* * Cannot check 'unknown' hash */ *flags |= BADCERT_NOT_TRUSTED; } else { md( md_info, child->tbs.p, child->tbs.len, hash ); if( pk_can_do( &parent->pk, child->sig_pk ) == 0 || pk_verify( &parent->pk, child->sig_md, hash, md_info->size, child->sig.p, child->sig.len ) != 0 ) { *flags |= BADCERT_NOT_TRUSTED; } } #if defined(POLARSSL_X509_CRL_PARSE_C) /* Check trusted CA's CRL for the given crt */ *flags |= x509_crt_verifycrl(child, parent, ca_crl); #endif grandparent = parent->next; while( grandparent != NULL ) { if( grandparent->version == 0 || grandparent->ca_istrue == 0 || parent->issuer_raw.len != grandparent->subject_raw.len || memcmp( parent->issuer_raw.p, grandparent->subject_raw.p, parent->issuer_raw.len ) != 0 ) { grandparent = grandparent->next; continue; } break; } if( grandparent != NULL ) { /* * Part of the chain */ ret = x509_crt_verify_child( parent, grandparent, trust_ca, ca_crl, path_cnt + 1, &parent_flags, f_vrfy, p_vrfy ); if( ret != 0 ) return( ret ); } else { ret = x509_crt_verify_top( parent, trust_ca, ca_crl, path_cnt + 1, &parent_flags, f_vrfy, p_vrfy ); if( ret != 0 ) return( ret ); } /* child is verified to be a child of the parent, call verify callback */ if( NULL != f_vrfy ) if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 ) return( ret ); *flags |= parent_flags; return( 0 ); } /* * Verify the certificate validity */ int x509_crt_verify( x509_crt *crt, x509_crt *trust_ca, x509_crl *ca_crl, const char *cn, int *flags, int (*f_vrfy)(void *, x509_crt *, int, int *), void *p_vrfy ) { size_t cn_len; int ret; int pathlen = 0; x509_crt *parent; x509_name *name; x509_sequence *cur = NULL; *flags = 0; if( cn != NULL ) { name = &crt->subject; cn_len = strlen( cn ); if( crt->ext_types & EXT_SUBJECT_ALT_NAME ) { cur = &crt->subject_alt_names; while( cur != NULL ) { if( cur->buf.len == cn_len && x509_name_cmp( cn, cur->buf.p, cn_len ) == 0 ) break; if( cur->buf.len > 2 && memcmp( cur->buf.p, "*.", 2 ) == 0 && x509_wildcard_verify( cn, &cur->buf ) ) break; cur = cur->next; } if( cur == NULL ) *flags |= BADCERT_CN_MISMATCH; } else { while( name != NULL ) { if( OID_CMP( OID_AT_CN, &name->oid ) ) { if( name->val.len == cn_len && x509_name_cmp( name->val.p, cn, cn_len ) == 0 ) break; if( name->val.len > 2 && memcmp( name->val.p, "*.", 2 ) == 0 && x509_wildcard_verify( cn, &name->val ) ) break; } name = name->next; } if( name == NULL ) *flags |= BADCERT_CN_MISMATCH; } } /* * Iterate upwards in the given cert chain, to find our crt parent. * Ignore any upper cert with CA != TRUE. */ parent = crt->next; while( parent != NULL && parent->version != 0 ) { if( parent->ca_istrue == 0 || crt->issuer_raw.len != parent->subject_raw.len || memcmp( crt->issuer_raw.p, parent->subject_raw.p, crt->issuer_raw.len ) != 0 ) { parent = parent->next; continue; } break; } if( parent != NULL ) { /* * Part of the chain */ ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl, pathlen, flags, f_vrfy, p_vrfy ); if( ret != 0 ) return( ret ); } else { ret = x509_crt_verify_top( crt, trust_ca, ca_crl, pathlen, flags, f_vrfy, p_vrfy ); if( ret != 0 ) return( ret ); } if( *flags != 0 ) return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED ); return( 0 ); } /* * Initialize a certificate chain */ void x509_crt_init( x509_crt *crt ) { memset( crt, 0, sizeof(x509_crt) ); } /* * Unallocate all certificate data */ void x509_crt_free( x509_crt *crt ) { x509_crt *cert_cur = crt; x509_crt *cert_prv; x509_name *name_cur; x509_name *name_prv; x509_sequence *seq_cur; x509_sequence *seq_prv; if( crt == NULL ) return; do { pk_free( &cert_cur->pk ); name_cur = cert_cur->issuer.next; while( name_cur != NULL ) { name_prv = name_cur; name_cur = name_cur->next; memset( name_prv, 0, sizeof( x509_name ) ); polarssl_free( name_prv ); } name_cur = cert_cur->subject.next; while( name_cur != NULL ) { name_prv = name_cur; name_cur = name_cur->next; memset( name_prv, 0, sizeof( x509_name ) ); polarssl_free( name_prv ); } seq_cur = cert_cur->ext_key_usage.next; while( seq_cur != NULL ) { seq_prv = seq_cur; seq_cur = seq_cur->next; memset( seq_prv, 0, sizeof( x509_sequence ) ); polarssl_free( seq_prv ); } seq_cur = cert_cur->subject_alt_names.next; while( seq_cur != NULL ) { seq_prv = seq_cur; seq_cur = seq_cur->next; memset( seq_prv, 0, sizeof( x509_sequence ) ); polarssl_free( seq_prv ); } if( cert_cur->raw.p != NULL ) { memset( cert_cur->raw.p, 0, cert_cur->raw.len ); polarssl_free( cert_cur->raw.p ); } cert_cur = cert_cur->next; } while( cert_cur != NULL ); cert_cur = crt; do { cert_prv = cert_cur; cert_cur = cert_cur->next; memset( cert_prv, 0, sizeof( x509_crt ) ); if( cert_prv != crt ) polarssl_free( cert_prv ); } while( cert_cur != NULL ); } #endif