/* Support of X.509 certificates * Copyright (C) 2000 Andreas Hess, Patric Lichtsteiner, Roger Wegmann * Copyright (C) 2001 Marco Bertossa, Andreas Schleiss * Copyright (C) 2002 Mario Strasser * Copyright (C) 2000-2004 Andreas Steffen, Zuercher Hochschule Winterthur * * 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. See . * * 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. * * RCSID $Id: x509.c,v 1.36 2006/04/10 16:08:33 as Exp $ */ #include #include #include #include #include #include #include #include #include #include "constants.h" #include "defs.h" #include "mp_defs.h" #include "log.h" #include "id.h" #include "asn1.h" #include "oid.h" #include "pkcs1.h" #include "x509.h" #include "crl.h" #include "ca.h" #include "certs.h" #include "keys.h" #include "whack.h" #include "fetch.h" #include "ocsp.h" #include "sha1.h" /* chained lists of X.509 end certificates */ static x509cert_t *x509certs = NULL; /* ASN.1 definition of a basicConstraints extension */ static const asn1Object_t basicConstraintsObjects[] = { { 0, "basicConstraints", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ { 1, "CA", ASN1_BOOLEAN, ASN1_DEF | ASN1_BODY }, /* 1 */ { 1, "pathLenConstraint", ASN1_INTEGER, ASN1_OPT | ASN1_BODY }, /* 2 */ { 1, "end opt", ASN1_EOC, ASN1_END } /* 3 */ }; #define BASIC_CONSTRAINTS_CA 1 #define BASIC_CONSTRAINTS_ROOF 4 /* ASN.1 definition of time */ static const asn1Object_t timeObjects[] = { { 0, "utcTime", ASN1_UTCTIME, ASN1_OPT | ASN1_BODY }, /* 0 */ { 0, "end opt", ASN1_EOC, ASN1_END }, /* 1 */ { 0, "generalizeTime", ASN1_GENERALIZEDTIME, ASN1_OPT | ASN1_BODY }, /* 2 */ { 0, "end opt", ASN1_EOC, ASN1_END } /* 3 */ }; #define TIME_UTC 0 #define TIME_GENERALIZED 2 #define TIME_ROOF 4 /* ASN.1 definition of a keyIdentifier */ static const asn1Object_t keyIdentifierObjects[] = { { 0, "keyIdentifier", ASN1_OCTET_STRING, ASN1_BODY } /* 0 */ }; /* ASN.1 definition of a authorityKeyIdentifier extension */ static const asn1Object_t authorityKeyIdentifierObjects[] = { { 0, "authorityKeyIdentifier", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ { 1, "keyIdentifier", ASN1_CONTEXT_S_0, ASN1_OPT | ASN1_OBJ }, /* 1 */ { 1, "end opt", ASN1_EOC, ASN1_END }, /* 2 */ { 1, "authorityCertIssuer", ASN1_CONTEXT_C_1, ASN1_OPT | ASN1_OBJ }, /* 3 */ { 1, "end opt", ASN1_EOC, ASN1_END }, /* 4 */ { 1, "authorityCertSerialNumber", ASN1_CONTEXT_S_2, ASN1_OPT | ASN1_BODY }, /* 5 */ { 1, "end opt", ASN1_EOC, ASN1_END } /* 6 */ }; #define AUTH_KEY_ID_KEY_ID 1 #define AUTH_KEY_ID_CERT_ISSUER 3 #define AUTH_KEY_ID_CERT_SERIAL 5 #define AUTH_KEY_ID_ROOF 7 /* ASN.1 definition of a authorityInfoAccess extension */ static const asn1Object_t authorityInfoAccessObjects[] = { { 0, "authorityInfoAccess", ASN1_SEQUENCE, ASN1_LOOP }, /* 0 */ { 1, "accessDescription", ASN1_SEQUENCE, ASN1_NONE }, /* 1 */ { 2, "accessMethod", ASN1_OID, ASN1_BODY }, /* 2 */ { 2, "accessLocation", ASN1_EOC, ASN1_RAW }, /* 3 */ { 0, "end loop", ASN1_EOC, ASN1_END } /* 4 */ }; #define AUTH_INFO_ACCESS_METHOD 2 #define AUTH_INFO_ACCESS_LOCATION 3 #define AUTH_INFO_ACCESS_ROOF 5 /* ASN.1 definition of a extendedKeyUsage extension */ static const asn1Object_t extendedKeyUsageObjects[] = { { 0, "extendedKeyUsage", ASN1_SEQUENCE, ASN1_LOOP }, /* 0 */ { 1, "keyPurposeID", ASN1_OID, ASN1_BODY }, /* 1 */ { 0, "end loop", ASN1_EOC, ASN1_END }, /* 2 */ }; #define EXT_KEY_USAGE_PURPOSE_ID 1 #define EXT_KEY_USAGE_ROOF 3 /* ASN.1 definition of generalNames */ static const asn1Object_t generalNamesObjects[] = { { 0, "generalNames", ASN1_SEQUENCE, ASN1_LOOP }, /* 0 */ { 1, "generalName", ASN1_EOC, ASN1_RAW }, /* 1 */ { 0, "end loop", ASN1_EOC, ASN1_END } /* 2 */ }; #define GENERAL_NAMES_GN 1 #define GENERAL_NAMES_ROOF 3 /* ASN.1 definition of generalName */ static const asn1Object_t generalNameObjects[] = { { 0, "otherName", ASN1_CONTEXT_C_0, ASN1_OPT | ASN1_BODY }, /* 0 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 1 */ { 0, "rfc822Name", ASN1_CONTEXT_S_1, ASN1_OPT | ASN1_BODY }, /* 2 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 3 */ { 0, "dnsName", ASN1_CONTEXT_S_2, ASN1_OPT | ASN1_BODY }, /* 4 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 5 */ { 0, "x400Address", ASN1_CONTEXT_S_3, ASN1_OPT | ASN1_BODY }, /* 6 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 7 */ { 0, "directoryName", ASN1_CONTEXT_C_4, ASN1_OPT | ASN1_BODY }, /* 8 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 9 */ { 0, "ediPartyName", ASN1_CONTEXT_C_5, ASN1_OPT | ASN1_BODY }, /* 10 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 11 */ { 0, "uniformResourceIdentifier", ASN1_CONTEXT_S_6, ASN1_OPT | ASN1_BODY }, /* 12 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 13 */ { 0, "ipAddress", ASN1_CONTEXT_S_7, ASN1_OPT | ASN1_BODY }, /* 14 */ { 0, "end choice", ASN1_EOC, ASN1_END }, /* 15 */ { 0, "registeredID", ASN1_CONTEXT_S_8, ASN1_OPT | ASN1_BODY }, /* 16 */ { 0, "end choice", ASN1_EOC, ASN1_END } /* 17 */ }; #define GN_OBJ_OTHER_NAME 0 #define GN_OBJ_RFC822_NAME 2 #define GN_OBJ_DNS_NAME 4 #define GN_OBJ_X400_ADDRESS 6 #define GN_OBJ_DIRECTORY_NAME 8 #define GN_OBJ_EDI_PARTY_NAME 10 #define GN_OBJ_URI 12 #define GN_OBJ_IP_ADDRESS 14 #define GN_OBJ_REGISTERED_ID 16 #define GN_OBJ_ROOF 18 /* ASN.1 definition of otherName */ static const asn1Object_t otherNameObjects[] = { {0, "type-id", ASN1_OID, ASN1_BODY }, /* 0 */ {0, "value", ASN1_CONTEXT_C_0, ASN1_BODY } /* 1 */ }; #define ON_OBJ_ID_TYPE 0 #define ON_OBJ_VALUE 1 #define ON_OBJ_ROOF 2 /* ASN.1 definition of crlDistributionPoints */ static const asn1Object_t crlDistributionPointsObjects[] = { { 0, "crlDistributionPoints", ASN1_SEQUENCE, ASN1_LOOP }, /* 0 */ { 1, "DistributionPoint", ASN1_SEQUENCE, ASN1_NONE }, /* 1 */ { 2, "distributionPoint", ASN1_CONTEXT_C_0, ASN1_OPT | ASN1_LOOP }, /* 2 */ { 3, "fullName", ASN1_CONTEXT_C_0, ASN1_OPT | ASN1_OBJ }, /* 3 */ { 3, "end choice", ASN1_EOC, ASN1_END }, /* 4 */ { 3, "nameRelativeToCRLIssuer", ASN1_CONTEXT_C_1, ASN1_OPT | ASN1_BODY }, /* 5 */ { 3, "end choice", ASN1_EOC, ASN1_END }, /* 6 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 7 */ { 2, "reasons", ASN1_CONTEXT_C_1, ASN1_OPT | ASN1_BODY }, /* 8 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 9 */ { 2, "crlIssuer", ASN1_CONTEXT_C_2, ASN1_OPT | ASN1_BODY }, /* 10 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 11 */ { 0, "end loop", ASN1_EOC, ASN1_END }, /* 12 */ }; #define CRL_DIST_POINTS_FULLNAME 3 #define CRL_DIST_POINTS_ROOF 13 /* ASN.1 definition of an X.509v3 certificate */ static const asn1Object_t certObjects[] = { { 0, "certificate", ASN1_SEQUENCE, ASN1_OBJ }, /* 0 */ { 1, "tbsCertificate", ASN1_SEQUENCE, ASN1_OBJ }, /* 1 */ { 2, "DEFAULT v1", ASN1_CONTEXT_C_0, ASN1_DEF }, /* 2 */ { 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 3 */ { 2, "serialNumber", ASN1_INTEGER, ASN1_BODY }, /* 4 */ { 2, "signature", ASN1_EOC, ASN1_RAW }, /* 5 */ { 2, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 6 */ { 2, "validity", ASN1_SEQUENCE, ASN1_NONE }, /* 7 */ { 3, "notBefore", ASN1_EOC, ASN1_RAW }, /* 8 */ { 3, "notAfter", ASN1_EOC, ASN1_RAW }, /* 9 */ { 2, "subject", ASN1_SEQUENCE, ASN1_OBJ }, /* 10 */ { 2, "subjectPublicKeyInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 11 */ { 3, "algorithm", ASN1_EOC, ASN1_RAW }, /* 12 */ { 3, "subjectPublicKey", ASN1_BIT_STRING, ASN1_NONE }, /* 13 */ { 4, "RSAPublicKey", ASN1_SEQUENCE, ASN1_OBJ }, /* 14 */ { 5, "modulus", ASN1_INTEGER, ASN1_BODY }, /* 15 */ { 5, "publicExponent", ASN1_INTEGER, ASN1_BODY }, /* 16 */ { 2, "issuerUniqueID", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 17 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 18 */ { 2, "subjectUniqueID", ASN1_CONTEXT_C_2, ASN1_OPT }, /* 19 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 20 */ { 2, "optional extensions", ASN1_CONTEXT_C_3, ASN1_OPT }, /* 21 */ { 3, "extensions", ASN1_SEQUENCE, ASN1_LOOP }, /* 22 */ { 4, "extension", ASN1_SEQUENCE, ASN1_NONE }, /* 23 */ { 5, "extnID", ASN1_OID, ASN1_BODY }, /* 24 */ { 5, "critical", ASN1_BOOLEAN, ASN1_DEF | ASN1_BODY }, /* 25 */ { 5, "extnValue", ASN1_OCTET_STRING, ASN1_BODY }, /* 26 */ { 3, "end loop", ASN1_EOC, ASN1_END }, /* 27 */ { 2, "end opt", ASN1_EOC, ASN1_END }, /* 28 */ { 1, "signatureAlgorithm", ASN1_EOC, ASN1_RAW }, /* 29 */ { 1, "signatureValue", ASN1_BIT_STRING, ASN1_BODY } /* 30 */ }; #define X509_OBJ_CERTIFICATE 0 #define X509_OBJ_TBS_CERTIFICATE 1 #define X509_OBJ_VERSION 3 #define X509_OBJ_SERIAL_NUMBER 4 #define X509_OBJ_SIG_ALG 5 #define X509_OBJ_ISSUER 6 #define X509_OBJ_NOT_BEFORE 8 #define X509_OBJ_NOT_AFTER 9 #define X509_OBJ_SUBJECT 10 #define X509_OBJ_SUBJECT_PUBLIC_KEY_ALGORITHM 12 #define X509_OBJ_SUBJECT_PUBLIC_KEY 13 #define X509_OBJ_RSA_PUBLIC_KEY 14 #define X509_OBJ_MODULUS 15 #define X509_OBJ_PUBLIC_EXPONENT 16 #define X509_OBJ_EXTN_ID 24 #define X509_OBJ_CRITICAL 25 #define X509_OBJ_EXTN_VALUE 26 #define X509_OBJ_ALGORITHM 29 #define X509_OBJ_SIGNATURE 30 #define X509_OBJ_ROOF 31 const x509cert_t empty_x509cert = { NULL , /* *next */ UNDEFINED_TIME, /* installed */ 0 , /* count */ FALSE , /* smartcard */ AUTH_NONE , /* authority_flags */ { NULL, 0 } , /* certificate */ { NULL, 0 } , /* tbsCertificate */ 1 , /* version */ { NULL, 0 } , /* serialNumber */ OID_UNKNOWN , /* sigAlg */ { NULL, 0 } , /* issuer */ /* validity */ 0 , /* notBefore */ 0 , /* notAfter */ { NULL, 0 } , /* subject */ /* subjectPublicKeyInfo */ OID_UNKNOWN , /* subjectPublicKeyAlgorithm */ { NULL, 0 } , /* subjectPublicKey */ { NULL, 0 } , /* modulus */ { NULL, 0 } , /* publicExponent */ /* issuerUniqueID */ /* subjectUniqueID */ /* extensions */ /* extension */ /* extnID */ /* critical */ /* extnValue */ FALSE , /* isCA */ FALSE , /* isOcspSigner */ { NULL, 0 } , /* subjectKeyID */ { NULL, 0 } , /* authKeyID */ { NULL, 0 } , /* authKeySerialNumber */ { NULL, 0 } , /* accessLocation */ NULL , /* subjectAltName */ NULL , /* crlDistributionPoints */ OID_UNKNOWN , /* algorithm */ { NULL, 0 } /* signature */ }; /* coding of X.501 distinguished name */ typedef struct { const u_char *name; chunk_t oid; u_char type; } x501rdn_t; /* X.501 acronyms for well known object identifiers (OIDs) */ static u_char oid_ND[] = {0x02, 0x82, 0x06, 0x01, 0x0A, 0x07, 0x14}; static u_char oid_UID[] = {0x09, 0x92, 0x26, 0x89, 0x93, 0xF2, 0x2C, 0x64, 0x01, 0x01}; static u_char oid_DC[] = {0x09, 0x92, 0x26, 0x89, 0x93, 0xF2, 0x2C, 0x64, 0x01, 0x19}; static u_char oid_CN[] = {0x55, 0x04, 0x03}; static u_char oid_S[] = {0x55, 0x04, 0x04}; static u_char oid_SN[] = {0x55, 0x04, 0x05}; static u_char oid_C[] = {0x55, 0x04, 0x06}; static u_char oid_L[] = {0x55, 0x04, 0x07}; static u_char oid_ST[] = {0x55, 0x04, 0x08}; static u_char oid_O[] = {0x55, 0x04, 0x0A}; static u_char oid_OU[] = {0x55, 0x04, 0x0B}; static u_char oid_T[] = {0x55, 0x04, 0x0C}; static u_char oid_D[] = {0x55, 0x04, 0x0D}; static u_char oid_N[] = {0x55, 0x04, 0x29}; static u_char oid_G[] = {0x55, 0x04, 0x2A}; static u_char oid_I[] = {0x55, 0x04, 0x2B}; static u_char oid_ID[] = {0x55, 0x04, 0x2D}; static u_char oid_EN[] = {0x60, 0x86, 0x48, 0x01, 0x86, 0xF8, 0x42, 0x03, 0x01, 0x03}; static u_char oid_E[] = {0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x09, 0x01}; static u_char oid_UN[] = {0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x09, 0x02}; static u_char oid_TCGID[] = {0x2B, 0x06, 0x01, 0x04, 0x01, 0x89, 0x31, 0x01, 0x01, 0x02, 0x02, 0x4B}; static const x501rdn_t x501rdns[] = { {"ND" , {oid_ND, 7}, ASN1_PRINTABLESTRING}, {"UID" , {oid_UID, 10}, ASN1_PRINTABLESTRING}, {"DC" , {oid_DC, 10}, ASN1_PRINTABLESTRING}, {"CN" , {oid_CN, 3}, ASN1_PRINTABLESTRING}, {"S" , {oid_S, 3}, ASN1_PRINTABLESTRING}, {"SN" , {oid_SN, 3}, ASN1_PRINTABLESTRING}, {"serialNumber" , {oid_SN, 3}, ASN1_PRINTABLESTRING}, {"C" , {oid_C, 3}, ASN1_PRINTABLESTRING}, {"L" , {oid_L, 3}, ASN1_PRINTABLESTRING}, {"ST" , {oid_ST, 3}, ASN1_PRINTABLESTRING}, {"O" , {oid_O, 3}, ASN1_PRINTABLESTRING}, {"OU" , {oid_OU, 3}, ASN1_PRINTABLESTRING}, {"T" , {oid_T, 3}, ASN1_PRINTABLESTRING}, {"D" , {oid_D, 3}, ASN1_PRINTABLESTRING}, {"N" , {oid_N, 3}, ASN1_PRINTABLESTRING}, {"G" , {oid_G, 3}, ASN1_PRINTABLESTRING}, {"I" , {oid_I, 3}, ASN1_PRINTABLESTRING}, {"ID" , {oid_ID, 3}, ASN1_PRINTABLESTRING}, {"EN" , {oid_EN, 10}, ASN1_PRINTABLESTRING}, {"employeeNumber" , {oid_EN, 10}, ASN1_PRINTABLESTRING}, {"E" , {oid_E, 9}, ASN1_IA5STRING}, {"Email" , {oid_E, 9}, ASN1_IA5STRING}, {"emailAddress" , {oid_E, 9}, ASN1_IA5STRING}, {"UN" , {oid_UN, 9}, ASN1_IA5STRING}, {"unstructuredName", {oid_UN, 9}, ASN1_IA5STRING}, {"TCGID" , {oid_TCGID, 12}, ASN1_PRINTABLESTRING} }; #define X501_RDN_ROOF 26 static u_char ASN1_subjectAltName_oid_str[] = { 0x06, 0x03, 0x55, 0x1D, 0x11 }; static const chunk_t ASN1_subjectAltName_oid = strchunk(ASN1_subjectAltName_oid_str); static void update_chunk(chunk_t *ch, int n) { n = (n > -1 && n < (int)ch->len)? n : (int)ch->len-1; ch->ptr += n; ch->len -= n; } /* * Pointer is set to the first RDN in a DN */ static err_t init_rdn(chunk_t dn, chunk_t *rdn, chunk_t *attribute, bool *next) { *rdn = empty_chunk; *attribute = empty_chunk; /* a DN is a SEQUENCE OF RDNs */ if (*dn.ptr != ASN1_SEQUENCE) { return "DN is not a SEQUENCE"; } rdn->len = asn1_length(&dn); if (rdn->len == ASN1_INVALID_LENGTH) return "Invalid RDN length"; rdn->ptr = dn.ptr; /* are there any RDNs ? */ *next = rdn->len > 0; return NULL; } /* * Fetches the next RDN in a DN */ static err_t get_next_rdn(chunk_t *rdn, chunk_t * attribute, chunk_t *oid, chunk_t *value , asn1_t *type, bool *next) { chunk_t body; /* initialize return values */ *oid = empty_chunk; *value = empty_chunk; /* if all attributes have been parsed, get next rdn */ if (attribute->len <= 0) { /* an RDN is a SET OF attributeTypeAndValue */ if (*rdn->ptr != ASN1_SET) return "RDN is not a SET"; attribute->len = asn1_length(rdn); if (attribute->len == ASN1_INVALID_LENGTH) return "Invalid attribute length"; attribute->ptr = rdn->ptr; /* advance to start of next RDN */ rdn->ptr += attribute->len; rdn->len -= attribute->len; } /* an attributeTypeAndValue is a SEQUENCE */ if (*attribute->ptr != ASN1_SEQUENCE) return "attributeTypeAndValue is not a SEQUENCE"; /* extract the attribute body */ body.len = asn1_length(attribute); if (body.len == ASN1_INVALID_LENGTH) return "Invalid attribute body length"; body.ptr = attribute->ptr; /* advance to start of next attribute */ attribute->ptr += body.len; attribute->len -= body.len; /* attribute type is an OID */ if (*body.ptr != ASN1_OID) return "attributeType is not an OID"; /* extract OID */ oid->len = asn1_length(&body); if (oid->len == ASN1_INVALID_LENGTH) return "Invalid attribute OID length"; oid->ptr = body.ptr; /* advance to the attribute value */ body.ptr += oid->len; body.len -= oid->len; /* extract string type */ *type = *body.ptr; /* extract string value */ value->len = asn1_length(&body); if (value->len == ASN1_INVALID_LENGTH) return "Invalid attribute string length"; value->ptr = body.ptr; /* are there any RDNs left? */ *next = rdn->len > 0 || attribute->len > 0; return NULL; } /* * Parses an ASN.1 distinguished name int its OID/value pairs */ static err_t dn_parse(chunk_t dn, chunk_t *str) { chunk_t rdn, oid, attribute, value; asn1_t type; int oid_code; bool next; bool first = TRUE; err_t ugh = init_rdn(dn, &rdn, &attribute, &next); if (ugh != NULL) /* a parsing error has occured */ return ugh; while (next) { ugh = get_next_rdn(&rdn, &attribute, &oid, &value, &type, &next); if (ugh != NULL) /* a parsing error has occured */ return ugh; if (first) /* first OID/value pair */ first = FALSE; else /* separate OID/value pair by a comma */ update_chunk(str, snprintf(str->ptr,str->len,", ")); /* print OID */ oid_code = known_oid(oid); if (oid_code == OID_UNKNOWN) /* OID not found in list */ hex_str(oid, str); else update_chunk(str, snprintf(str->ptr,str->len,"%s", oid_names[oid_code].name)); /* print value */ update_chunk(str, snprintf(str->ptr,str->len,"=%.*s", (int)value.len,value.ptr)); } return NULL; } /* * Count the number of wildcard RDNs in a distinguished name */ int dn_count_wildcards(chunk_t dn) { chunk_t rdn, attribute, oid, value; asn1_t type; bool next; int wildcards = 0; err_t ugh = init_rdn(dn, &rdn, &attribute, &next); if (ugh != NULL) /* a parsing error has occured */ return -1; while (next) { ugh = get_next_rdn(&rdn, &attribute, &oid, &value, &type, &next); if (ugh != NULL) /* a parsing error has occured */ return -1; if (value.len == 1 && *value.ptr == '*') wildcards++; /* we have found a wildcard RDN */ } return wildcards; } /* * Prints a binary string in hexadecimal form */ void hex_str(chunk_t bin, chunk_t *str) { u_int i; update_chunk(str, snprintf(str->ptr,str->len,"0x")); for (i=0; i < bin.len; i++) update_chunk(str, snprintf(str->ptr,str->len,"%02X",*bin.ptr++)); } /* Converts a binary DER-encoded ASN.1 distinguished name * into LDAP-style human-readable ASCII format */ int dntoa(char *dst, size_t dstlen, chunk_t dn) { err_t ugh = NULL; chunk_t str; str.ptr = dst; str.len = dstlen; ugh = dn_parse(dn, &str); if (ugh != NULL) /* error, print DN as hex string */ { DBG(DBG_PARSING, DBG_log("error in DN parsing: %s", ugh) ) str.ptr = dst; str.len = dstlen; hex_str(dn, &str); } return (int)(dstlen - str.len); } /* * Same as dntoa but prints a special string for a null dn */ int dntoa_or_null(char *dst, size_t dstlen, chunk_t dn, const char* null_dn) { if (dn.ptr == NULL) return snprintf(dst, dstlen, "%s", null_dn); else return dntoa(dst, dstlen, dn); } /* Converts an LDAP-style human-readable ASCII-encoded * ASN.1 distinguished name into binary DER-encoded format */ err_t atodn(char *src, chunk_t *dn) { /* finite state machine for atodn */ typedef enum { SEARCH_OID = 0, READ_OID = 1, SEARCH_NAME = 2, READ_NAME = 3, UNKNOWN_OID = 4 } state_t; u_char oid_len_buf[3]; u_char name_len_buf[3]; u_char rdn_seq_len_buf[3]; u_char rdn_set_len_buf[3]; u_char dn_seq_len_buf[3]; chunk_t asn1_oid_len = { oid_len_buf, 0 }; chunk_t asn1_name_len = { name_len_buf, 0 }; chunk_t asn1_rdn_seq_len = { rdn_seq_len_buf, 0 }; chunk_t asn1_rdn_set_len = { rdn_set_len_buf, 0 }; chunk_t asn1_dn_seq_len = { dn_seq_len_buf, 0 }; chunk_t oid = empty_chunk; chunk_t name = empty_chunk; int whitespace = 0; int rdn_seq_len = 0; int rdn_set_len = 0; int dn_seq_len = 0; int pos = 0; err_t ugh = NULL; u_char *dn_ptr = dn->ptr + 4; state_t state = SEARCH_OID; do { switch (state) { case SEARCH_OID: if (*src != ' ' && *src != '/' && *src != ',') { oid.ptr = src; oid.len = 1; state = READ_OID; } break; case READ_OID: if (*src != ' ' && *src != '=') oid.len++; else { for (pos = 0; pos < X501_RDN_ROOF; pos++) { if (strlen(x501rdns[pos].name) == oid.len && strncasecmp(x501rdns[pos].name, oid.ptr, oid.len) == 0) break; /* found a valid OID */ } if (pos == X501_RDN_ROOF) { ugh = "unknown OID in distinguished name"; state = UNKNOWN_OID; break; } code_asn1_length(x501rdns[pos].oid.len, &asn1_oid_len); /* reset oid and change state */ oid = empty_chunk; state = SEARCH_NAME; } break; case SEARCH_NAME: if (*src != ' ' && *src != '=') { name.ptr = src; name.len = 1; whitespace = 0; state = READ_NAME; } break; case READ_NAME: if (*src != ',' && *src != '/' && *src != '\0') { name.len++; if (*src == ' ') whitespace++; else whitespace = 0; } else { name.len -= whitespace; code_asn1_length(name.len, &asn1_name_len); /* compute the length of the relative distinguished name sequence */ rdn_seq_len = 1 + asn1_oid_len.len + x501rdns[pos].oid.len + 1 + asn1_name_len.len + name.len; code_asn1_length(rdn_seq_len, &asn1_rdn_seq_len); /* compute the length of the relative distinguished name set */ rdn_set_len = 1 + asn1_rdn_seq_len.len + rdn_seq_len; code_asn1_length(rdn_set_len, &asn1_rdn_set_len); /* encode the relative distinguished name */ *dn_ptr++ = ASN1_SET; chunkcpy(dn_ptr, asn1_rdn_set_len); *dn_ptr++ = ASN1_SEQUENCE; chunkcpy(dn_ptr, asn1_rdn_seq_len); *dn_ptr++ = ASN1_OID; chunkcpy(dn_ptr, asn1_oid_len); chunkcpy(dn_ptr, x501rdns[pos].oid); /* encode the ASN.1 character string type of the name */ *dn_ptr++ = (x501rdns[pos].type == ASN1_PRINTABLESTRING && !is_printablestring(name))? ASN1_T61STRING : x501rdns[pos].type; chunkcpy(dn_ptr, asn1_name_len); chunkcpy(dn_ptr, name); /* accumulate the length of the distinguished name sequence */ dn_seq_len += 1 + asn1_rdn_set_len.len + rdn_set_len; /* reset name and change state */ name = empty_chunk; state = SEARCH_OID; } break; case UNKNOWN_OID: break; } } while (*src++ != '\0'); /* complete the distinguished name sequence*/ code_asn1_length(dn_seq_len, &asn1_dn_seq_len); dn->ptr += 3 - asn1_dn_seq_len.len; dn->len = 1 + asn1_dn_seq_len.len + dn_seq_len; dn_ptr = dn->ptr; *dn_ptr++ = ASN1_SEQUENCE; chunkcpy(dn_ptr, asn1_dn_seq_len); return ugh; } /* compare two distinguished names by * comparing the individual RDNs */ bool same_dn(chunk_t a, chunk_t b) { chunk_t rdn_a, rdn_b, attribute_a, attribute_b; chunk_t oid_a, oid_b, value_a, value_b; asn1_t type_a, type_b; bool next_a, next_b; /* same lengths for the DNs */ if (a.len != b.len) return FALSE; /* try a binary comparison first */ if (memcmp(a.ptr, b.ptr, b.len) == 0) return TRUE; /* initialize DN parsing */ if (init_rdn(a, &rdn_a, &attribute_a, &next_a) != NULL || init_rdn(b, &rdn_b, &attribute_b, &next_b) != NULL) return FALSE; /* fetch next RDN pair */ while (next_a && next_b) { /* parse next RDNs and check for errors */ if (get_next_rdn(&rdn_a, &attribute_a, &oid_a, &value_a, &type_a, &next_a) != NULL || get_next_rdn(&rdn_b, &attribute_b, &oid_b, &value_b, &type_b, &next_b) != NULL) { return FALSE; } /* OIDs must agree */ if (oid_a.len != oid_b.len || memcmp(oid_a.ptr, oid_b.ptr, oid_b.len) != 0) return FALSE; /* same lengths for values */ if (value_a.len != value_b.len) return FALSE; /* printableStrings and email RDNs require uppercase comparison */ if (type_a == type_b && (type_a == ASN1_PRINTABLESTRING || (type_a == ASN1_IA5STRING && known_oid(oid_a) == OID_PKCS9_EMAIL))) { if (strncasecmp(value_a.ptr, value_b.ptr, value_b.len) != 0) return FALSE; } else { if (strncmp(value_a.ptr, value_b.ptr, value_b.len) != 0) return FALSE; } } /* both DNs must have same number of RDNs */ if (next_a || next_b) return FALSE; /* the two DNs are equal! */ return TRUE; } /* compare two distinguished names by comparing the individual RDNs. * A single'*' character designates a wildcard RDN in DN b. */ bool match_dn(chunk_t a, chunk_t b, int *wildcards) { chunk_t rdn_a, rdn_b, attribute_a, attribute_b; chunk_t oid_a, oid_b, value_a, value_b; asn1_t type_a, type_b; bool next_a, next_b; /* initialize wildcard counter */ *wildcards = 0; /* initialize DN parsing */ if (init_rdn(a, &rdn_a, &attribute_a, &next_a) != NULL || init_rdn(b, &rdn_b, &attribute_b, &next_b) != NULL) return FALSE; /* fetch next RDN pair */ while (next_a && next_b) { /* parse next RDNs and check for errors */ if (get_next_rdn(&rdn_a, &attribute_a, &oid_a, &value_a, &type_a, &next_a) != NULL || get_next_rdn(&rdn_b, &attribute_b, &oid_b, &value_b, &type_b, &next_b) != NULL) { return FALSE; } /* OIDs must agree */ if (oid_a.len != oid_b.len || memcmp(oid_a.ptr, oid_b.ptr, oid_b.len) != 0) return FALSE; /* does rdn_b contain a wildcard? */ if (value_b.len == 1 && *value_b.ptr == '*') { (*wildcards)++; continue; } /* same lengths for values */ if (value_a.len != value_b.len) return FALSE; /* printableStrings and email RDNs require uppercase comparison */ if (type_a == type_b && (type_a == ASN1_PRINTABLESTRING || (type_a == ASN1_IA5STRING && known_oid(oid_a) == OID_PKCS9_EMAIL))) { if (strncasecmp(value_a.ptr, value_b.ptr, value_b.len) != 0) return FALSE; } else { if (strncmp(value_a.ptr, value_b.ptr, value_b.len) != 0) return FALSE; } } /* both DNs must have same number of RDNs */ if (next_a || next_b) return FALSE; /* the two DNs match! */ return TRUE; } /* * compare two X.509 certificates by comparing their signatures */ bool same_x509cert(const x509cert_t *a, const x509cert_t *b) { return same_chunk(a->signature, b->signature); } /* for each link pointing to the certificate " increase the count by one */ void share_x509cert(x509cert_t *cert) { if (cert != NULL) cert->count++; } /* * add a X.509 user/host certificate to the chained list */ x509cert_t* add_x509cert(x509cert_t *cert) { x509cert_t *c = x509certs; while (c != NULL) { if (same_x509cert(c, cert)) /* already in chain, free cert */ { free_x509cert(cert); return c; } c = c->next; } /* insert new cert at the root of the chain */ lock_certs_and_keys("add_x509cert"); cert->next = x509certs; x509certs = cert; DBG(DBG_CONTROL | DBG_PARSING, DBG_log(" x509 cert inserted") ) unlock_certs_and_keys("add_x509cert"); return cert; } /* * choose either subject DN or a subjectAltName as connection end ID */ void select_x509cert_id(x509cert_t *cert, struct id *end_id) { bool copy_subject_dn = TRUE; /* ID is subject DN */ if (end_id->kind != ID_NONE) /* check for matching subjectAltName */ { generalName_t *gn = cert->subjectAltName; while (gn != NULL) { struct id id = empty_id; gntoid(&id, gn); if (same_id(&id, end_id)) { copy_subject_dn = FALSE; /* take subjectAltName instead */ break; } gn = gn->next; } } if (copy_subject_dn) { if (end_id->kind != ID_NONE && end_id->kind != ID_DER_ASN1_DN) { char buf[BUF_LEN]; idtoa(end_id, buf, BUF_LEN); plog(" no subjectAltName matches ID '%s', replaced by subject DN", buf); } end_id->kind = ID_DER_ASN1_DN; end_id->name.len = cert->subject.len; end_id->name.ptr = temporary_cyclic_buffer(); memcpy(end_id->name.ptr, cert->subject.ptr, cert->subject.len); } } /* * check for equality between two key identifiers */ bool same_keyid(chunk_t a, chunk_t b) { if (a.ptr == NULL || b.ptr == NULL) return FALSE; return same_chunk(a, b); } /* * check for equality between two serial numbers */ bool same_serial(chunk_t a, chunk_t b) { /* do not compare serial numbers if one of them is not defined */ if (a.ptr == NULL || b.ptr == NULL) return TRUE; return same_chunk(a, b); } /* * get a X.509 certificate with a given issuer found at a certain position */ x509cert_t* get_x509cert(chunk_t issuer, chunk_t serial, chunk_t keyid, x509cert_t *chain) { x509cert_t *cert = (chain != NULL)? chain->next : x509certs; while (cert != NULL) { if ((keyid.ptr != NULL) ? same_keyid(keyid, cert->authKeyID) : (same_dn(issuer, cert->issuer) && same_serial(serial, cert->authKeySerialNumber))) { return cert; } cert = cert->next; } return NULL; } /* * encode a linked list of subjectAltNames */ chunk_t build_subjectAltNames(generalName_t *subjectAltNames) { u_char *pos; chunk_t names; size_t len = 0; generalName_t *gn = subjectAltNames; /* compute the total size of the ASN.1 attributes object */ while (gn != NULL) { len += gn->name.len; gn = gn->next; } pos = build_asn1_object(&names, ASN1_SEQUENCE, len); gn = subjectAltNames; while (gn != NULL) { chunkcpy(pos, gn->name); gn = gn->next; } return asn1_wrap(ASN1_SEQUENCE, "cm" , ASN1_subjectAltName_oid , asn1_wrap(ASN1_OCTET_STRING, "m", names)); } /* * build a to-be-signed X.509 certificate body */ static chunk_t build_tbs_x509cert(x509cert_t *cert, const RSA_public_key_t *rsa) { /* version is always X.509v3 */ chunk_t version = asn1_simple_object(ASN1_CONTEXT_C_0, ASN1_INTEGER_2); chunk_t extensions = empty_chunk; if (cert->subjectAltName != NULL) { extensions = asn1_wrap(ASN1_CONTEXT_C_3, "m" , asn1_wrap(ASN1_SEQUENCE, "m" , build_subjectAltNames(cert->subjectAltName))); } return asn1_wrap(ASN1_SEQUENCE, "mmccmcmm" , version , asn1_simple_object(ASN1_INTEGER, cert->serialNumber) , asn1_algorithmIdentifier(cert->sigAlg) , cert->issuer , asn1_wrap(ASN1_SEQUENCE, "mm" , timetoasn1(&cert->notBefore, ASN1_UTCTIME) , timetoasn1(&cert->notAfter, ASN1_UTCTIME) ) , cert->subject , pkcs1_build_publicKeyInfo(rsa) , extensions ); } /* * build a DER-encoded X.509 certificate */ void build_x509cert(x509cert_t *cert, const RSA_public_key_t *cert_key , const RSA_private_key_t *signer_key) { chunk_t tbs_cert = build_tbs_x509cert(cert, cert_key); chunk_t signature = pkcs1_build_signature(tbs_cert, cert->sigAlg , signer_key, TRUE); cert->certificate = asn1_wrap(ASN1_SEQUENCE, "mcm" , tbs_cert , asn1_algorithmIdentifier(cert->sigAlg) , signature); } /* * free the dynamic memory used to store generalNames */ void free_generalNames(generalName_t* gn, bool free_name) { while (gn != NULL) { generalName_t *gn_top = gn; if (free_name) { pfree(gn->name.ptr); } gn = gn->next; pfree(gn_top); } } /* * free a X.509 certificate */ void free_x509cert(x509cert_t *cert) { if (cert != NULL) { free_generalNames(cert->subjectAltName, FALSE); free_generalNames(cert->crlDistributionPoints, FALSE); pfreeany(cert->certificate.ptr); pfree(cert); cert = NULL; } } /* release of a certificate decreases the count by one " the certificate is freed when the counter reaches zero */ void release_x509cert(x509cert_t *cert) { if (cert != NULL && --cert->count == 0) { x509cert_t **pp = &x509certs; while (*pp != cert) pp = &(*pp)->next; *pp = cert->next; free_x509cert(cert); } } /* * stores a chained list of end certs and CA certs */ void store_x509certs(x509cert_t **firstcert, bool strict) { x509cert_t *cacerts = NULL; x509cert_t **pp = firstcert; /* first extract CA certs, discarding root CA certs */ while (*pp != NULL) { x509cert_t *cert = *pp; if (cert->isCA) { *pp = cert->next; /* we don't accept self-signed CA certs */ if (same_dn(cert->issuer, cert->subject)) { plog("self-signed cacert rejected"); free_x509cert(cert); } else { /* insertion into temporary chain of candidate CA certs */ cert->next = cacerts; cacerts = cert; } } else pp = &cert->next; } /* now verify the candidate CA certs */ while (cacerts != NULL) { x509cert_t *cert = cacerts; cacerts = cacerts->next; if (trust_authcert_candidate(cert, cacerts)) { add_authcert(cert, AUTH_CA); } else { plog("intermediate cacert rejected"); free_x509cert(cert); } } /* now verify the end certificates */ pp = firstcert; while (*pp != NULL) { time_t valid_until; x509cert_t *cert = *pp; if (verify_x509cert(cert, strict, &valid_until)) { DBG(DBG_CONTROL | DBG_PARSING, DBG_log("public key validated") ) add_x509_public_key(cert, valid_until, DAL_SIGNED); } else { plog("X.509 certificate rejected"); } *pp = cert->next; free_x509cert(cert); } } /* * decrypts an RSA signature using the issuer's certificate */ static bool decrypt_sig(chunk_t sig, int alg, const x509cert_t *issuer_cert, chunk_t *digest) { switch (alg) { chunk_t decrypted; case OID_RSA_ENCRYPTION: case OID_MD2_WITH_RSA: case OID_MD5_WITH_RSA: case OID_SHA1_WITH_RSA: case OID_SHA1_WITH_RSA_OIW: case OID_SHA256_WITH_RSA: case OID_SHA384_WITH_RSA: case OID_SHA512_WITH_RSA: { mpz_t s; RSA_public_key_t rsa; init_RSA_public_key(&rsa, issuer_cert->publicExponent , issuer_cert->modulus); /* decrypt the signature s = s^e mod n */ n_to_mpz(s, sig.ptr, sig.len); mpz_powm(s, s, &rsa.e, &rsa.n); /* convert back to bytes */ decrypted = mpz_to_n(s, rsa.k); DBG(DBG_PARSING, DBG_dump_chunk(" decrypted signature: ", decrypted) ) /* copy the least significant bits of decrypted signature * into the digest string */ memcpy(digest->ptr, decrypted.ptr + decrypted.len - digest->len, digest->len); /* free memory */ free_RSA_public_content(&rsa); pfree(decrypted.ptr); mpz_clear(s); return TRUE; } default: digest->len = 0; return FALSE; } } /* * Check if a signature over binary blob is genuine */ bool check_signature(chunk_t tbs, chunk_t sig, int digest_alg, int enc_alg , const x509cert_t *issuer_cert) { u_char digest_buf[MAX_DIGEST_LEN]; u_char decrypted_buf[MAX_DIGEST_LEN]; chunk_t digest = {digest_buf, MAX_DIGEST_LEN}; chunk_t decrypted = {decrypted_buf, MAX_DIGEST_LEN}; DBG(DBG_PARSING, if (digest_alg != OID_UNKNOWN) DBG_log("signature digest algorithm: '%s'",oid_names[digest_alg].name); else DBG_log("unknown signature digest algorithm"); ) if (!compute_digest(tbs, digest_alg, &digest)) { plog(" digest algorithm not supported"); return FALSE; } DBG(DBG_PARSING, DBG_dump_chunk(" digest:", digest) ) decrypted.len = digest.len; /* we want the same digest length */ DBG(DBG_PARSING, if (enc_alg != OID_UNKNOWN) DBG_log("signature encryption algorithm: '%s'",oid_names[enc_alg].name); else DBG_log("unknown signature encryption algorithm"); ) if (!decrypt_sig(sig, enc_alg, issuer_cert, &decrypted)) { plog(" decryption algorithm not supported"); return FALSE; } /* check if digests are equal */ return !memcmp(decrypted.ptr, digest.ptr, digest.len); } /* * extracts the basicConstraints extension */ static bool parse_basicConstraints(chunk_t blob, int level0) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; bool isCA = FALSE; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < BASIC_CONSTRAINTS_ROOF) { if (!extract_object(basicConstraintsObjects, &objectID, &object,&level, &ctx)) break; if (objectID == BASIC_CONSTRAINTS_CA) { isCA = object.len && *object.ptr; DBG(DBG_PARSING, DBG_log(" %s",(isCA)?"TRUE":"FALSE"); ) } objectID++; } return isCA; } /* * Converts a X.500 generalName into an ID */ void gntoid(struct id *id, const generalName_t *gn) { switch(gn->kind) { case GN_DNS_NAME: /* ID type: ID_FQDN */ id->kind = ID_FQDN; id->name = gn->name; break; case GN_IP_ADDRESS: /* ID type: ID_IPV4_ADDR */ { const struct af_info *afi = &af_inet4_info; err_t ugh = NULL; id->kind = afi->id_addr; ugh = initaddr(gn->name.ptr, gn->name.len, afi->af, &id->ip_addr); } break; case GN_RFC822_NAME: /* ID type: ID_USER_FQDN */ id->kind = ID_USER_FQDN; id->name = gn->name; break; default: id->kind = ID_NONE; id->name = empty_chunk; } } /* compute the subjectKeyIdentifier according to section 4.2.1.2 of RFC 3280 * as the 160 bit SHA-1 hash of the public key */ void compute_subjectKeyID(x509cert_t *cert, chunk_t subjectKeyID) { SHA1_CTX context; SHA1Init(&context); SHA1Update(&context , cert->subjectPublicKey.ptr , cert->subjectPublicKey.len); SHA1Final(subjectKeyID.ptr, &context); subjectKeyID.len = SHA1_DIGEST_SIZE; } /* * extracts an otherName */ static bool parse_otherName(chunk_t blob, int level0) { asn1_ctx_t ctx; chunk_t object; int objectID = 0; u_int level; int oid = OID_UNKNOWN; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < ON_OBJ_ROOF) { if (!extract_object(otherNameObjects, &objectID, &object, &level, &ctx)) return FALSE; switch (objectID) { case ON_OBJ_ID_TYPE: oid = known_oid(object); break; case ON_OBJ_VALUE: if (oid == OID_XMPP_ADDR) { if (!parse_asn1_simple_object(&object, ASN1_UTF8STRING , level + 1, "xmppAddr")) { return FALSE; } } break; default: break; } objectID++; } return TRUE; } /* * extracts a generalName */ static generalName_t* parse_generalName(chunk_t blob, int level0) { u_char buf[BUF_LEN]; asn1_ctx_t ctx; chunk_t object; int objectID = 0; u_int level; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < GN_OBJ_ROOF) { bool valid_gn = FALSE; if (!extract_object(generalNameObjects, &objectID, &object, &level, &ctx)) return NULL; switch (objectID) { case GN_OBJ_RFC822_NAME: case GN_OBJ_DNS_NAME: case GN_OBJ_URI: DBG(DBG_PARSING, DBG_log(" '%.*s'", (int)object.len, object.ptr); ) valid_gn = TRUE; break; case GN_OBJ_DIRECTORY_NAME: DBG(DBG_PARSING, dntoa(buf, BUF_LEN, object); DBG_log(" '%s'", buf) ) valid_gn = TRUE; break; case GN_OBJ_IP_ADDRESS: DBG(DBG_PARSING, DBG_log(" '%d.%d.%d.%d'", *object.ptr, *(object.ptr+1), *(object.ptr+2), *(object.ptr+3)); ) valid_gn = TRUE; break; case GN_OBJ_OTHER_NAME: if (!parse_otherName(object, level + 1)) return NULL; break; case GN_OBJ_X400_ADDRESS: case GN_OBJ_EDI_PARTY_NAME: case GN_OBJ_REGISTERED_ID: break; default: break; } if (valid_gn) { generalName_t *gn = alloc_thing(generalName_t, "generalName"); gn->kind = (objectID - GN_OBJ_OTHER_NAME) / 2; gn->name = object; gn->next = NULL; return gn; } objectID++; } return NULL; } /* * extracts one or several GNs and puts them into a chained list */ static generalName_t* parse_generalNames(chunk_t blob, int level0, bool implicit) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; generalName_t *top_gn = NULL; asn1_init(&ctx, blob, level0, implicit, DBG_RAW); while (objectID < GENERAL_NAMES_ROOF) { if (!extract_object(generalNamesObjects, &objectID, &object, &level, &ctx)) return NULL; if (objectID == GENERAL_NAMES_GN) { generalName_t *gn = parse_generalName(object, level+1); if (gn != NULL) { gn->next = top_gn; top_gn = gn; } } objectID++; } return top_gn; } /* * returns a directoryName */ chunk_t get_directoryName(chunk_t blob, int level, bool implicit) { chunk_t name = empty_chunk; generalName_t * gn = parse_generalNames(blob, level, implicit); if (gn != NULL && gn->kind == GN_DIRECTORY_NAME) name= gn->name; free_generalNames(gn, FALSE); return name; } /* * extracts and converts a UTCTIME or GENERALIZEDTIME object */ time_t parse_time(chunk_t blob, int level0) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < TIME_ROOF) { if (!extract_object(timeObjects, &objectID, &object, &level, &ctx)) return UNDEFINED_TIME; if (objectID == TIME_UTC || objectID == TIME_GENERALIZED) { return asn1totime(&object, (objectID == TIME_UTC) ? ASN1_UTCTIME : ASN1_GENERALIZEDTIME); } objectID++; } return UNDEFINED_TIME; } /* * extracts a keyIdentifier */ static chunk_t parse_keyIdentifier(chunk_t blob, int level0, bool implicit) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; asn1_init(&ctx, blob, level0, implicit, DBG_RAW); extract_object(keyIdentifierObjects, &objectID, &object, &level, &ctx); return object; } /* * extracts an authoritykeyIdentifier */ void parse_authorityKeyIdentifier(chunk_t blob, int level0 , chunk_t *authKeyID, chunk_t *authKeySerialNumber) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < AUTH_KEY_ID_ROOF) { if (!extract_object(authorityKeyIdentifierObjects, &objectID, &object, &level, &ctx)) return; switch (objectID) { case AUTH_KEY_ID_KEY_ID: *authKeyID = parse_keyIdentifier(object, level+1, TRUE); break; case AUTH_KEY_ID_CERT_ISSUER: { generalName_t * gn = parse_generalNames(object, level+1, TRUE); free_generalNames(gn, FALSE); } break; case AUTH_KEY_ID_CERT_SERIAL: *authKeySerialNumber = object; break; default: break; } objectID++; } } /* * extracts an authorityInfoAcess location */ static void parse_authorityInfoAccess(chunk_t blob, int level0, chunk_t *accessLocation) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; u_int accessMethod = OID_UNKNOWN; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < AUTH_INFO_ACCESS_ROOF) { if (!extract_object(authorityInfoAccessObjects, &objectID, &object, &level, &ctx)) return; switch (objectID) { case AUTH_INFO_ACCESS_METHOD: accessMethod = known_oid(object); break; case AUTH_INFO_ACCESS_LOCATION: { switch (accessMethod) { case OID_OCSP: if (*object.ptr == ASN1_CONTEXT_S_6) { if (asn1_length(&object) == ASN1_INVALID_LENGTH) return; DBG(DBG_PARSING, DBG_log(" '%.*s'",(int)object.len, object.ptr) ) /* only HTTP(S) URIs accepted */ if (strncasecmp(object.ptr, "http", 4) == 0) { *accessLocation = object; return; } } plog("warning: ignoring OCSP InfoAccessLocation with unkown protocol"); break; default: /* unkown accessMethod, ignoring */ break; } } break; default: break; } objectID++; } } /* * extracts extendedKeyUsage OIDs */ static bool parse_extendedKeyUsage(chunk_t blob, int level0) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < EXT_KEY_USAGE_ROOF) { if (!extract_object(extendedKeyUsageObjects, &objectID , &object, &level, &ctx)) return FALSE; if (objectID == EXT_KEY_USAGE_PURPOSE_ID && known_oid(object) == OID_OCSP_SIGNING) return TRUE; objectID++; } return FALSE; } /* extracts one or several crlDistributionPoints and puts them into * a chained list */ static generalName_t* parse_crlDistributionPoints(chunk_t blob, int level0) { asn1_ctx_t ctx; chunk_t object; u_int level; int objectID = 0; generalName_t *top_gn = NULL; /* top of the chained list */ generalName_t **tail_gn = &top_gn; /* tail of the chained list */ asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < CRL_DIST_POINTS_ROOF) { if (!extract_object(crlDistributionPointsObjects, &objectID, &object, &level, &ctx)) return NULL; if (objectID == CRL_DIST_POINTS_FULLNAME) { generalName_t *gn = parse_generalNames(object, level+1, TRUE); /* append extracted generalNames to existing chained list */ *tail_gn = gn; /* find new tail of the chained list */ while (gn != NULL) { tail_gn = &gn->next; gn = gn->next; } } objectID++; } return top_gn; } /* * Parses an X.509v3 certificate */ bool parse_x509cert(chunk_t blob, u_int level0, x509cert_t *cert) { u_char buf[BUF_LEN]; asn1_ctx_t ctx; bool critical; chunk_t object; u_int level; u_int extn_oid = OID_UNKNOWN; int objectID = 0; asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); while (objectID < X509_OBJ_ROOF) { if (!extract_object(certObjects, &objectID, &object, &level, &ctx)) return FALSE; /* those objects which will parsed further need the next higher level */ level++; switch (objectID) { case X509_OBJ_CERTIFICATE: cert->certificate = object; break; case X509_OBJ_TBS_CERTIFICATE: cert->tbsCertificate = object; break; case X509_OBJ_VERSION: cert->version = (object.len) ? (1+(u_int)*object.ptr) : 1; DBG(DBG_PARSING, DBG_log(" v%d", cert->version); ) break; case X509_OBJ_SERIAL_NUMBER: cert->serialNumber = object; break; case X509_OBJ_SIG_ALG: cert->sigAlg = parse_algorithmIdentifier(object, level, NULL); break; case X509_OBJ_ISSUER: cert->issuer = object; DBG(DBG_PARSING, dntoa(buf, BUF_LEN, object); DBG_log(" '%s'",buf) ) break; case X509_OBJ_NOT_BEFORE: cert->notBefore = parse_time(object, level); break; case X509_OBJ_NOT_AFTER: cert->notAfter = parse_time(object, level); break; case X509_OBJ_SUBJECT: cert->subject = object; DBG(DBG_PARSING, dntoa(buf, BUF_LEN, object); DBG_log(" '%s'",buf) ) break; case X509_OBJ_SUBJECT_PUBLIC_KEY_ALGORITHM: if (parse_algorithmIdentifier(object, level, NULL) == OID_RSA_ENCRYPTION) cert->subjectPublicKeyAlgorithm = PUBKEY_ALG_RSA; else { plog(" unsupported public key algorithm"); return FALSE; } break; case X509_OBJ_SUBJECT_PUBLIC_KEY: if (ctx.blobs[4].len > 0 && *ctx.blobs[4].ptr == 0x00) { /* skip initial bit string octet defining 0 unused bits */ ctx.blobs[4].ptr++; ctx.blobs[4].len--; } else { plog(" invalid RSA public key format"); return FALSE; } break; case X509_OBJ_RSA_PUBLIC_KEY: cert->subjectPublicKey = object; break; case X509_OBJ_MODULUS: if (object.len < RSA_MIN_OCTETS + 1) { plog(" " RSA_MIN_OCTETS_UGH); return FALSE; } if (object.len > RSA_MAX_OCTETS + (size_t)(*object.ptr == 0x00)) { plog(" " RSA_MAX_OCTETS_UGH); return FALSE; } cert->modulus = object; break; case X509_OBJ_PUBLIC_EXPONENT: cert->publicExponent = object; break; case X509_OBJ_EXTN_ID: extn_oid = known_oid(object); break; case X509_OBJ_CRITICAL: critical = object.len && *object.ptr; DBG(DBG_PARSING, DBG_log(" %s",(critical)?"TRUE":"FALSE"); ) break; case X509_OBJ_EXTN_VALUE: { switch (extn_oid) { case OID_SUBJECT_KEY_ID: cert->subjectKeyID = parse_keyIdentifier(object, level, FALSE); break; case OID_SUBJECT_ALT_NAME: cert->subjectAltName = parse_generalNames(object, level, FALSE); break; case OID_BASIC_CONSTRAINTS: cert->isCA = parse_basicConstraints(object, level); break; case OID_CRL_DISTRIBUTION_POINTS: cert->crlDistributionPoints = parse_crlDistributionPoints(object, level); break; case OID_AUTHORITY_KEY_ID: parse_authorityKeyIdentifier(object, level , &cert->authKeyID, &cert->authKeySerialNumber); break; case OID_AUTHORITY_INFO_ACCESS: parse_authorityInfoAccess(object, level, &cert->accessLocation); break; case OID_EXTENDED_KEY_USAGE: cert->isOcspSigner = parse_extendedKeyUsage(object, level); break; case OID_NS_REVOCATION_URL: case OID_NS_CA_REVOCATION_URL: case OID_NS_CA_POLICY_URL: case OID_NS_COMMENT: if (!parse_asn1_simple_object(&object, ASN1_IA5STRING , level, oid_names[extn_oid].name)) { return FALSE; } break; default: break; } } break; case X509_OBJ_ALGORITHM: cert->algorithm = parse_algorithmIdentifier(object, level, NULL); break; case X509_OBJ_SIGNATURE: cert->signature = object; break; default: break; } objectID++; } time(&cert->installed); return TRUE; } /* verify the validity of a certificate by * checking the notBefore and notAfter dates */ err_t check_validity(const x509cert_t *cert, time_t *until) { time_t current_time; time(¤t_time); DBG(DBG_CONTROL | DBG_PARSING , DBG_log(" not before : %s", timetoa(&cert->notBefore, TRUE)); DBG_log(" current time: %s", timetoa(¤t_time, TRUE)); DBG_log(" not after : %s", timetoa(&cert->notAfter, TRUE)); ) if (cert->notAfter < *until) *until = cert->notAfter; if (current_time < cert->notBefore) return "certificate is not valid yet"; if (current_time > cert->notAfter) return "certificate has expired"; else return NULL; } /* * verifies a X.509 certificate */ bool verify_x509cert(const x509cert_t *cert, bool strict, time_t *until) { int pathlen; *until = cert->notAfter; for (pathlen = 0; pathlen < MAX_CA_PATH_LEN; pathlen++) { x509cert_t *issuer_cert; u_char buf[BUF_LEN]; err_t ugh = NULL; DBG(DBG_CONTROL, dntoa(buf, BUF_LEN, cert->subject); DBG_log("subject: '%s'",buf); dntoa(buf, BUF_LEN, cert->issuer); DBG_log("issuer: '%s'",buf); if (cert->authKeyID.ptr != NULL) { datatot(cert->authKeyID.ptr, cert->authKeyID.len, ':' , buf, BUF_LEN); DBG_log("authkey: %s", buf); } ) ugh = check_validity(cert, until); if (ugh != NULL) { plog("%s", ugh); return FALSE; } DBG(DBG_CONTROL, DBG_log("certificate is valid") ) lock_authcert_list("verify_x509cert"); issuer_cert = get_authcert(cert->issuer, cert->authKeySerialNumber , cert->authKeyID, AUTH_CA); if (issuer_cert == NULL) { plog("issuer cacert not found"); unlock_authcert_list("verify_x509cert"); return FALSE; } DBG(DBG_CONTROL, DBG_log("issuer cacert found") ) if (!check_signature(cert->tbsCertificate, cert->signature , cert->algorithm, cert->algorithm, issuer_cert)) { plog("certificate signature is invalid"); unlock_authcert_list("verify_x509cert"); return FALSE; } DBG(DBG_CONTROL, DBG_log("certificate signature is valid") ) unlock_authcert_list("verify_x509cert"); /* check if cert is a self-signed root ca */ if (pathlen > 0 && same_dn(cert->issuer, cert->subject)) { DBG(DBG_CONTROL, DBG_log("reached self-signed root ca") ) return TRUE; } else { time_t nextUpdate = *until; time_t revocationDate = UNDEFINED_TIME; crl_reason_t revocationReason = REASON_UNSPECIFIED; /* first check certificate revocation using ocsp */ cert_status_t status = verify_by_ocsp(cert, &nextUpdate , &revocationDate, &revocationReason); /* if ocsp service is not available then fall back to crl */ if ((status == CERT_UNDEFINED) || (status == CERT_UNKNOWN && strict)) { status = verify_by_crl(cert, &nextUpdate, &revocationDate , &revocationReason); } switch (status) { case CERT_GOOD: /* if status information is stale */ if (strict && nextUpdate < time(NULL)) { DBG(DBG_CONTROL, DBG_log("certificate is good but status is stale") ) remove_x509_public_key(cert); return FALSE; } DBG(DBG_CONTROL, DBG_log("certificate is good") ) /* with strict crl policy the public key must have the same * lifetime as the validity of the ocsp status or crl lifetime */ if (strict && nextUpdate < *until) *until = nextUpdate; break; case CERT_REVOKED: plog("certificate was revoked on %s, reason: %s" , timetoa(&revocationDate, TRUE) , enum_name(&crl_reason_names, revocationReason)); remove_x509_public_key(cert); return FALSE; case CERT_UNKNOWN: case CERT_UNDEFINED: default: plog("certificate status unknown"); if (strict) { remove_x509_public_key(cert); return FALSE; } break; } } /* go up one step in the trust chain */ cert = issuer_cert; } plog("maximum ca path length of %d levels exceeded", MAX_CA_PATH_LEN); return FALSE; } /* * list all X.509 certs in a chained list */ void list_x509cert_chain(const char *caption, x509cert_t* cert, u_char auth_flags , bool utc) { bool first = TRUE; time_t now; /* determine the current time */ time(&now); while (cert != NULL) { if (auth_flags == AUTH_NONE || (auth_flags & cert->authority_flags)) { unsigned keysize; char keyid[KEYID_BUF]; u_char buf[BUF_LEN]; cert_t c; c.type = CERT_X509_SIGNATURE; c.u.x509 = cert; if (first) { whack_log(RC_COMMENT, " "); whack_log(RC_COMMENT, "List of X.509 %s Certificates:", caption); whack_log(RC_COMMENT, " "); first = FALSE; } whack_log(RC_COMMENT, "%s, count: %d", timetoa(&cert->installed, utc), cert->count); dntoa(buf, BUF_LEN, cert->subject); whack_log(RC_COMMENT, " subject: '%s'", buf); dntoa(buf, BUF_LEN, cert->issuer); whack_log(RC_COMMENT, " issuer: '%s'", buf); datatot(cert->serialNumber.ptr, cert->serialNumber.len, ':' , buf, BUF_LEN); whack_log(RC_COMMENT, " serial: %s", buf); form_keyid(cert->publicExponent, cert->modulus, keyid, &keysize); whack_log(RC_COMMENT, " pubkey: %4d RSA Key %s%s" , 8*keysize, keyid , cert->smartcard ? ", on smartcard" : (has_private_key(c)? ", has private key" : "")); whack_log(RC_COMMENT, " validity: not before %s %s", timetoa(&cert->notBefore, utc), (cert->notBefore < now)?"ok":"fatal (not valid yet)"); whack_log(RC_COMMENT, " not after %s %s", timetoa(&cert->notAfter, utc), check_expiry(cert->notAfter, CA_CERT_WARNING_INTERVAL, TRUE)); if (cert->subjectKeyID.ptr != NULL) { datatot(cert->subjectKeyID.ptr, cert->subjectKeyID.len, ':' , buf, BUF_LEN); whack_log(RC_COMMENT, " subjkey: %s", buf); } if (cert->authKeyID.ptr != NULL) { datatot(cert->authKeyID.ptr, cert->authKeyID.len, ':' , buf, BUF_LEN); whack_log(RC_COMMENT, " authkey: %s", buf); } if (cert->authKeySerialNumber.ptr != NULL) { datatot(cert->authKeySerialNumber.ptr, cert->authKeySerialNumber.len , ':', buf, BUF_LEN); whack_log(RC_COMMENT, " aserial: %s", buf); } } cert = cert->next; } } /* * list all X.509 end certificates in a chained list */ void list_x509_end_certs(bool utc) { list_x509cert_chain("End", x509certs, AUTH_NONE, utc); }