/* * X.509v3 certificate parsing and processing (RFC 3280 profile) * Copyright (c) 2006-2015, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "includes.h" #include "common.h" #include "crypto/crypto.h" #include "asn1.h" #include "x509v3.h" void x509_free_name(struct x509_name *name) { size_t i; for (i = 0; i < name->num_attr; i++) { os_free(name->attr[i].value); name->attr[i].value = NULL; name->attr[i].type = X509_NAME_ATTR_NOT_USED; } name->num_attr = 0; os_free(name->email); name->email = NULL; os_free(name->alt_email); os_free(name->dns); os_free(name->uri); os_free(name->ip); name->alt_email = name->dns = name->uri = NULL; name->ip = NULL; name->ip_len = 0; os_memset(&name->rid, 0, sizeof(name->rid)); } /** * x509_certificate_free - Free an X.509 certificate * @cert: Certificate to be freed */ void x509_certificate_free(struct x509_certificate *cert) { if (cert == NULL) return; if (cert->next) { wpa_printf(MSG_DEBUG, "X509: x509_certificate_free: cer=%p " "was still on a list (next=%p)\n", cert, cert->next); } x509_free_name(&cert->issuer); x509_free_name(&cert->subject); os_free(cert->public_key); os_free(cert->sign_value); os_free(cert->subject_dn); os_free(cert); } /** * x509_certificate_free - Free an X.509 certificate chain * @cert: Pointer to the first certificate in the chain */ void x509_certificate_chain_free(struct x509_certificate *cert) { struct x509_certificate *next; while (cert) { next = cert->next; cert->next = NULL; x509_certificate_free(cert); cert = next; } } static int x509_whitespace(char c) { return c == ' ' || c == '\t'; } static void x509_str_strip_whitespace(char *a) { char *ipos, *opos; int remove_whitespace = 1; ipos = opos = a; while (*ipos) { if (remove_whitespace && x509_whitespace(*ipos)) ipos++; else { remove_whitespace = x509_whitespace(*ipos); *opos++ = *ipos++; } } *opos-- = '\0'; if (opos > a && x509_whitespace(*opos)) *opos = '\0'; } static int x509_str_compare(const char *a, const char *b) { char *aa, *bb; int ret; if (!a && b) return -1; if (a && !b) return 1; if (!a && !b) return 0; aa = os_strdup(a); bb = os_strdup(b); if (aa == NULL || bb == NULL) { os_free(aa); os_free(bb); return os_strcasecmp(a, b); } x509_str_strip_whitespace(aa); x509_str_strip_whitespace(bb); ret = os_strcasecmp(aa, bb); os_free(aa); os_free(bb); return ret; } /** * x509_name_compare - Compare X.509 certificate names * @a: Certificate name * @b: Certificate name * Returns: <0, 0, or >0 based on whether a is less than, equal to, or * greater than b */ int x509_name_compare(struct x509_name *a, struct x509_name *b) { int res; size_t i; if (!a && b) return -1; if (a && !b) return 1; if (!a && !b) return 0; if (a->num_attr < b->num_attr) return -1; if (a->num_attr > b->num_attr) return 1; for (i = 0; i < a->num_attr; i++) { if (a->attr[i].type < b->attr[i].type) return -1; if (a->attr[i].type > b->attr[i].type) return -1; res = x509_str_compare(a->attr[i].value, b->attr[i].value); if (res) return res; } res = x509_str_compare(a->email, b->email); if (res) return res; return 0; } int x509_parse_algorithm_identifier(const u8 *buf, size_t len, struct x509_algorithm_identifier *id, const u8 **next) { struct asn1_hdr hdr; const u8 *pos, *end; /* * AlgorithmIdentifier ::= SEQUENCE { * algorithm OBJECT IDENTIFIER, * parameters ANY DEFINED BY algorithm OPTIONAL * } */ if (asn1_get_next(buf, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(AlgorithmIdentifier) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } if (hdr.length > buf + len - hdr.payload) return -1; pos = hdr.payload; end = pos + hdr.length; *next = end; if (asn1_get_oid(pos, end - pos, &id->oid, &pos)) return -1; /* TODO: optional parameters */ return 0; } static int x509_parse_public_key(const u8 *buf, size_t len, struct x509_certificate *cert, const u8 **next) { struct asn1_hdr hdr; const u8 *pos, *end; /* * SubjectPublicKeyInfo ::= SEQUENCE { * algorithm AlgorithmIdentifier, * subjectPublicKey BIT STRING * } */ pos = buf; end = buf + len; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(SubjectPublicKeyInfo) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } pos = hdr.payload; if (hdr.length > end - pos) return -1; end = pos + hdr.length; *next = end; if (x509_parse_algorithm_identifier(pos, end - pos, &cert->public_key_alg, &pos)) return -1; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_BITSTRING) { wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING " "(subjectPublicKey) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } if (hdr.length < 1) return -1; pos = hdr.payload; if (*pos) { wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits", *pos); /* * TODO: should this be rejected? X.509 certificates are * unlikely to use such a construction. Now we would end up * including the extra bits in the buffer which may also be * ok. */ } os_free(cert->public_key); cert->public_key = os_memdup(pos + 1, hdr.length - 1); if (cert->public_key == NULL) { wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for " "public key"); return -1; } cert->public_key_len = hdr.length - 1; wpa_hexdump(MSG_MSGDUMP, "X509: subjectPublicKey", cert->public_key, cert->public_key_len); return 0; } int x509_parse_name(const u8 *buf, size_t len, struct x509_name *name, const u8 **next) { struct asn1_hdr hdr; const u8 *pos, *end, *set_pos, *set_end, *seq_pos, *seq_end; struct asn1_oid oid; char *val; /* * Name ::= CHOICE { RDNSequence } * RDNSequence ::= SEQUENCE OF RelativeDistinguishedName * RelativeDistinguishedName ::= SET OF AttributeTypeAndValue * AttributeTypeAndValue ::= SEQUENCE { * type AttributeType, * value AttributeValue * } * AttributeType ::= OBJECT IDENTIFIER * AttributeValue ::= ANY DEFINED BY AttributeType */ if (asn1_get_next(buf, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(Name / RDNSequencer) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } pos = hdr.payload; if (hdr.length > buf + len - pos) return -1; end = *next = pos + hdr.length; while (pos < end) { enum x509_name_attr_type type; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SET) { wpa_printf(MSG_DEBUG, "X509: Expected SET " "(RelativeDistinguishedName) - found class " "%d tag 0x%x", hdr.class, hdr.tag); x509_free_name(name); return -1; } set_pos = hdr.payload; pos = set_end = hdr.payload + hdr.length; if (asn1_get_next(set_pos, set_end - set_pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(AttributeTypeAndValue) - found class %d " "tag 0x%x", hdr.class, hdr.tag); x509_free_name(name); return -1; } seq_pos = hdr.payload; seq_end = hdr.payload + hdr.length; if (asn1_get_oid(seq_pos, seq_end - seq_pos, &oid, &seq_pos)) { x509_free_name(name); return -1; } if (asn1_get_next(seq_pos, seq_end - seq_pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL) { wpa_printf(MSG_DEBUG, "X509: Failed to parse " "AttributeValue"); x509_free_name(name); return -1; } /* RFC 3280: * MUST: country, organization, organizational-unit, * distinguished name qualifier, state or province name, * common name, serial number. * SHOULD: locality, title, surname, given name, initials, * pseudonym, generation qualifier. * MUST: domainComponent (RFC 2247). */ type = X509_NAME_ATTR_NOT_USED; if (oid.len == 4 && oid.oid[0] == 2 && oid.oid[1] == 5 && oid.oid[2] == 4) { /* id-at ::= 2.5.4 */ switch (oid.oid[3]) { case 3: /* commonName */ type = X509_NAME_ATTR_CN; break; case 6: /* countryName */ type = X509_NAME_ATTR_C; break; case 7: /* localityName */ type = X509_NAME_ATTR_L; break; case 8: /* stateOrProvinceName */ type = X509_NAME_ATTR_ST; break; case 10: /* organizationName */ type = X509_NAME_ATTR_O; break; case 11: /* organizationalUnitName */ type = X509_NAME_ATTR_OU; break; } } else if (oid.len == 7 && oid.oid[0] == 1 && oid.oid[1] == 2 && oid.oid[2] == 840 && oid.oid[3] == 113549 && oid.oid[4] == 1 && oid.oid[5] == 9 && oid.oid[6] == 1) { /* 1.2.840.113549.1.9.1 - e-mailAddress */ os_free(name->email); name->email = os_malloc(hdr.length + 1); if (name->email == NULL) { x509_free_name(name); return -1; } os_memcpy(name->email, hdr.payload, hdr.length); name->email[hdr.length] = '\0'; continue; } else if (oid.len == 7 && oid.oid[0] == 0 && oid.oid[1] == 9 && oid.oid[2] == 2342 && oid.oid[3] == 19200300 && oid.oid[4] == 100 && oid.oid[5] == 1 && oid.oid[6] == 25) { /* 0.9.2342.19200300.100.1.25 - domainComponent */ type = X509_NAME_ATTR_DC; } if (type == X509_NAME_ATTR_NOT_USED) { wpa_hexdump(MSG_DEBUG, "X509: Unrecognized OID", (u8 *) oid.oid, oid.len * sizeof(oid.oid[0])); wpa_hexdump_ascii(MSG_MSGDUMP, "X509: Attribute Data", hdr.payload, hdr.length); continue; } if (name->num_attr == X509_MAX_NAME_ATTRIBUTES) { wpa_printf(MSG_INFO, "X509: Too many Name attributes"); x509_free_name(name); return -1; } val = dup_binstr(hdr.payload, hdr.length); if (val == NULL) { x509_free_name(name); return -1; } if (os_strlen(val) != hdr.length) { wpa_printf(MSG_INFO, "X509: Reject certificate with " "embedded NUL byte in a string (%s[NUL])", val); os_free(val); x509_free_name(name); return -1; } name->attr[name->num_attr].type = type; name->attr[name->num_attr].value = val; name->num_attr++; } return 0; } static char * x509_name_attr_str(enum x509_name_attr_type type) { switch (type) { case X509_NAME_ATTR_NOT_USED: return "[N/A]"; case X509_NAME_ATTR_DC: return "DC"; case X509_NAME_ATTR_CN: return "CN"; case X509_NAME_ATTR_C: return "C"; case X509_NAME_ATTR_L: return "L"; case X509_NAME_ATTR_ST: return "ST"; case X509_NAME_ATTR_O: return "O"; case X509_NAME_ATTR_OU: return "OU"; } return "?"; } /** * x509_name_string - Convert an X.509 certificate name into a string * @name: Name to convert * @buf: Buffer for the string * @len: Maximum buffer length */ void x509_name_string(struct x509_name *name, char *buf, size_t len) { char *pos, *end; int ret; size_t i; if (len == 0) return; pos = buf; end = buf + len; for (i = 0; i < name->num_attr; i++) { ret = os_snprintf(pos, end - pos, "%s=%s, ", x509_name_attr_str(name->attr[i].type), name->attr[i].value); if (os_snprintf_error(end - pos, ret)) goto done; pos += ret; } if (pos > buf + 1 && pos[-1] == ' ' && pos[-2] == ',') { pos--; *pos = '\0'; pos--; *pos = '\0'; } if (name->email) { ret = os_snprintf(pos, end - pos, "/emailAddress=%s", name->email); if (os_snprintf_error(end - pos, ret)) goto done; pos += ret; } done: if (pos < end) *pos = '\0'; end[-1] = '\0'; } static int parse_uint2(const char *pos, size_t len) { char buf[3]; int ret; if (len < 2) return -1; buf[0] = pos[0]; buf[1] = pos[1]; buf[2] = 0x00; if (sscanf(buf, "%2d", &ret) != 1) return -1; return ret; } static int parse_uint4(const char *pos, size_t len) { char buf[5]; int ret; if (len < 4) return -1; buf[0] = pos[0]; buf[1] = pos[1]; buf[2] = pos[2]; buf[3] = pos[3]; buf[4] = 0x00; if (sscanf(buf, "%4d", &ret) != 1) return -1; return ret; } int x509_parse_time(const u8 *buf, size_t len, u8 asn1_tag, os_time_t *val) { const char *pos, *end; int year, month, day, hour, min, sec; /* * Time ::= CHOICE { * utcTime UTCTime, * generalTime GeneralizedTime * } * * UTCTime: YYMMDDHHMMSSZ * GeneralizedTime: YYYYMMDDHHMMSSZ */ pos = (const char *) buf; end = pos + len; switch (asn1_tag) { case ASN1_TAG_UTCTIME: if (len != 13 || buf[12] != 'Z') { wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized " "UTCTime format", buf, len); return -1; } year = parse_uint2(pos, end - pos); if (year < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse " "UTCTime year", buf, len); return -1; } if (year < 50) year += 2000; else year += 1900; pos += 2; break; case ASN1_TAG_GENERALIZEDTIME: if (len != 15 || buf[14] != 'Z') { wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized " "GeneralizedTime format", buf, len); return -1; } year = parse_uint4(pos, end - pos); if (year < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse " "GeneralizedTime year", buf, len); return -1; } pos += 4; break; default: wpa_printf(MSG_DEBUG, "X509: Expected UTCTime or " "GeneralizedTime - found tag 0x%x", asn1_tag); return -1; } month = parse_uint2(pos, end - pos); if (month < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time " "(month)", buf, len); return -1; } pos += 2; day = parse_uint2(pos, end - pos); if (day < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time " "(day)", buf, len); return -1; } pos += 2; hour = parse_uint2(pos, end - pos); if (hour < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time " "(hour)", buf, len); return -1; } pos += 2; min = parse_uint2(pos, end - pos); if (min < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time " "(min)", buf, len); return -1; } pos += 2; sec = parse_uint2(pos, end - pos); if (sec < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time " "(sec)", buf, len); return -1; } if (os_mktime(year, month, day, hour, min, sec, val) < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to convert Time", buf, len); if (year < 1970) { /* * At least some test certificates have been configured * to use dates prior to 1970. Set the date to * beginning of 1970 to handle these case. */ wpa_printf(MSG_DEBUG, "X509: Year=%d before epoch - " "assume epoch as the time", year); *val = 0; return 0; } return -1; } return 0; } static int x509_parse_validity(const u8 *buf, size_t len, struct x509_certificate *cert, const u8 **next) { struct asn1_hdr hdr; const u8 *pos; size_t plen; /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time * } * * RFC 3280, 4.1.2.5: * CAs conforming to this profile MUST always encode certificate * validity dates through the year 2049 as UTCTime; certificate * validity dates in 2050 or later MUST be encoded as GeneralizedTime. */ if (asn1_get_next(buf, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(Validity) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } pos = hdr.payload; plen = hdr.length; if (plen > (size_t) (buf + len - pos)) return -1; *next = pos + plen; if (asn1_get_next(pos, plen, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || x509_parse_time(hdr.payload, hdr.length, hdr.tag, &cert->not_before) < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notBefore " "Time", hdr.payload, hdr.length); return -1; } pos = hdr.payload + hdr.length; plen = *next - pos; if (asn1_get_next(pos, plen, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || x509_parse_time(hdr.payload, hdr.length, hdr.tag, &cert->not_after) < 0) { wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notAfter " "Time", hdr.payload, hdr.length); return -1; } wpa_printf(MSG_MSGDUMP, "X509: Validity: notBefore: %lu notAfter: %lu", (unsigned long) cert->not_before, (unsigned long) cert->not_after); return 0; } static int x509_id_ce_oid(struct asn1_oid *oid) { /* id-ce arc from X.509 for standard X.509v3 extensions */ return oid->len >= 4 && oid->oid[0] == 2 /* joint-iso-ccitt */ && oid->oid[1] == 5 /* ds */ && oid->oid[2] == 29 /* id-ce */; } static int x509_any_ext_key_usage_oid(struct asn1_oid *oid) { return oid->len == 6 && x509_id_ce_oid(oid) && oid->oid[3] == 37 /* extKeyUsage */ && oid->oid[4] == 0 /* anyExtendedKeyUsage */; } static int x509_parse_ext_key_usage(struct x509_certificate *cert, const u8 *pos, size_t len) { struct asn1_hdr hdr; /* * KeyUsage ::= BIT STRING { * digitalSignature (0), * nonRepudiation (1), * keyEncipherment (2), * dataEncipherment (3), * keyAgreement (4), * keyCertSign (5), * cRLSign (6), * encipherOnly (7), * decipherOnly (8) } */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_BITSTRING || hdr.length < 1) { wpa_printf(MSG_DEBUG, "X509: Expected BIT STRING in " "KeyUsage; found %d tag 0x%x len %d", hdr.class, hdr.tag, hdr.length); return -1; } cert->extensions_present |= X509_EXT_KEY_USAGE; cert->key_usage = asn1_bit_string_to_long(hdr.payload, hdr.length); wpa_printf(MSG_DEBUG, "X509: KeyUsage 0x%lx", cert->key_usage); return 0; } static int x509_parse_ext_basic_constraints(struct x509_certificate *cert, const u8 *pos, size_t len) { struct asn1_hdr hdr; unsigned long value; size_t left; /* * BasicConstraints ::= SEQUENCE { * cA BOOLEAN DEFAULT FALSE, * pathLenConstraint INTEGER (0..MAX) OPTIONAL } */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in " "BasicConstraints; found %d tag 0x%x", hdr.class, hdr.tag); return -1; } cert->extensions_present |= X509_EXT_BASIC_CONSTRAINTS; if (hdr.length == 0) return 0; if (asn1_get_next(hdr.payload, hdr.length, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL) { wpa_printf(MSG_DEBUG, "X509: Failed to parse " "BasicConstraints"); return -1; } if (hdr.tag == ASN1_TAG_BOOLEAN) { if (hdr.length != 1) { wpa_printf(MSG_DEBUG, "X509: Unexpected " "Boolean length (%u) in BasicConstraints", hdr.length); return -1; } cert->ca = hdr.payload[0]; if (hdr.length == pos + len - hdr.payload) { wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d", cert->ca); return 0; } if (asn1_get_next(hdr.payload + hdr.length, len - hdr.length, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL) { wpa_printf(MSG_DEBUG, "X509: Failed to parse " "BasicConstraints"); return -1; } } if (hdr.tag != ASN1_TAG_INTEGER) { wpa_printf(MSG_DEBUG, "X509: Expected INTEGER in " "BasicConstraints; found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } pos = hdr.payload; left = hdr.length; value = 0; while (left) { value <<= 8; value |= *pos++; left--; } cert->path_len_constraint = value; cert->extensions_present |= X509_EXT_PATH_LEN_CONSTRAINT; wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d " "pathLenConstraint=%lu", cert->ca, cert->path_len_constraint); return 0; } static int x509_parse_alt_name_rfc8222(struct x509_name *name, const u8 *pos, size_t len) { /* rfc822Name IA5String */ wpa_hexdump_ascii(MSG_MSGDUMP, "X509: altName - rfc822Name", pos, len); os_free(name->alt_email); name->alt_email = os_zalloc(len + 1); if (name->alt_email == NULL) return -1; os_memcpy(name->alt_email, pos, len); if (os_strlen(name->alt_email) != len) { wpa_printf(MSG_INFO, "X509: Reject certificate with " "embedded NUL byte in rfc822Name (%s[NUL])", name->alt_email); os_free(name->alt_email); name->alt_email = NULL; return -1; } return 0; } static int x509_parse_alt_name_dns(struct x509_name *name, const u8 *pos, size_t len) { /* dNSName IA5String */ wpa_hexdump_ascii(MSG_MSGDUMP, "X509: altName - dNSName", pos, len); os_free(name->dns); name->dns = os_zalloc(len + 1); if (name->dns == NULL) return -1; os_memcpy(name->dns, pos, len); if (os_strlen(name->dns) != len) { wpa_printf(MSG_INFO, "X509: Reject certificate with " "embedded NUL byte in dNSName (%s[NUL])", name->dns); os_free(name->dns); name->dns = NULL; return -1; } return 0; } static int x509_parse_alt_name_uri(struct x509_name *name, const u8 *pos, size_t len) { /* uniformResourceIdentifier IA5String */ wpa_hexdump_ascii(MSG_MSGDUMP, "X509: altName - uniformResourceIdentifier", pos, len); os_free(name->uri); name->uri = os_zalloc(len + 1); if (name->uri == NULL) return -1; os_memcpy(name->uri, pos, len); if (os_strlen(name->uri) != len) { wpa_printf(MSG_INFO, "X509: Reject certificate with " "embedded NUL byte in uniformResourceIdentifier " "(%s[NUL])", name->uri); os_free(name->uri); name->uri = NULL; return -1; } return 0; } static int x509_parse_alt_name_ip(struct x509_name *name, const u8 *pos, size_t len) { /* iPAddress OCTET STRING */ wpa_hexdump(MSG_MSGDUMP, "X509: altName - iPAddress", pos, len); os_free(name->ip); name->ip = os_memdup(pos, len); if (name->ip == NULL) return -1; name->ip_len = len; return 0; } static int x509_parse_alt_name_rid(struct x509_name *name, const u8 *pos, size_t len) { char buf[80]; /* registeredID OBJECT IDENTIFIER */ if (asn1_parse_oid(pos, len, &name->rid) < 0) return -1; asn1_oid_to_str(&name->rid, buf, sizeof(buf)); wpa_printf(MSG_MSGDUMP, "X509: altName - registeredID: %s", buf); return 0; } static int x509_parse_ext_alt_name(struct x509_name *name, const u8 *pos, size_t len) { struct asn1_hdr hdr; const u8 *p, *end; /* * 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 } */ for (p = pos, end = pos + len; p < end; p = hdr.payload + hdr.length) { int res; if (asn1_get_next(p, end - p, &hdr) < 0) { wpa_printf(MSG_DEBUG, "X509: Failed to parse " "SubjectAltName item"); return -1; } if (hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) continue; switch (hdr.tag) { case 1: res = x509_parse_alt_name_rfc8222(name, hdr.payload, hdr.length); break; case 2: res = x509_parse_alt_name_dns(name, hdr.payload, hdr.length); break; case 6: res = x509_parse_alt_name_uri(name, hdr.payload, hdr.length); break; case 7: res = x509_parse_alt_name_ip(name, hdr.payload, hdr.length); break; case 8: res = x509_parse_alt_name_rid(name, hdr.payload, hdr.length); break; case 0: /* TODO: otherName */ case 3: /* TODO: x500Address */ case 4: /* TODO: directoryName */ case 5: /* TODO: ediPartyName */ default: res = 0; break; } if (res < 0) return res; } return 0; } static int x509_parse_ext_subject_alt_name(struct x509_certificate *cert, const u8 *pos, size_t len) { struct asn1_hdr hdr; /* SubjectAltName ::= GeneralNames */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in " "SubjectAltName; found %d tag 0x%x", hdr.class, hdr.tag); return -1; } wpa_printf(MSG_DEBUG, "X509: SubjectAltName"); cert->extensions_present |= X509_EXT_SUBJECT_ALT_NAME; if (hdr.length == 0) return 0; return x509_parse_ext_alt_name(&cert->subject, hdr.payload, hdr.length); } static int x509_parse_ext_issuer_alt_name(struct x509_certificate *cert, const u8 *pos, size_t len) { struct asn1_hdr hdr; /* IssuerAltName ::= GeneralNames */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in " "IssuerAltName; found %d tag 0x%x", hdr.class, hdr.tag); return -1; } wpa_printf(MSG_DEBUG, "X509: IssuerAltName"); cert->extensions_present |= X509_EXT_ISSUER_ALT_NAME; if (hdr.length == 0) return 0; return x509_parse_ext_alt_name(&cert->issuer, hdr.payload, hdr.length); } static int x509_id_pkix_oid(struct asn1_oid *oid) { return oid->len >= 7 && oid->oid[0] == 1 /* iso */ && oid->oid[1] == 3 /* identified-organization */ && oid->oid[2] == 6 /* dod */ && oid->oid[3] == 1 /* internet */ && oid->oid[4] == 5 /* security */ && oid->oid[5] == 5 /* mechanisms */ && oid->oid[6] == 7 /* id-pkix */; } static int x509_id_kp_oid(struct asn1_oid *oid) { /* id-kp */ return oid->len >= 8 && x509_id_pkix_oid(oid) && oid->oid[7] == 3 /* id-kp */; } static int x509_id_kp_server_auth_oid(struct asn1_oid *oid) { /* id-kp */ return oid->len == 9 && x509_id_kp_oid(oid) && oid->oid[8] == 1 /* id-kp-serverAuth */; } static int x509_id_kp_client_auth_oid(struct asn1_oid *oid) { /* id-kp */ return oid->len == 9 && x509_id_kp_oid(oid) && oid->oid[8] == 2 /* id-kp-clientAuth */; } static int x509_id_kp_ocsp_oid(struct asn1_oid *oid) { /* id-kp */ return oid->len == 9 && x509_id_kp_oid(oid) && oid->oid[8] == 9 /* id-kp-OCSPSigning */; } static int x509_parse_ext_ext_key_usage(struct x509_certificate *cert, const u8 *pos, size_t len) { struct asn1_hdr hdr; const u8 *end; struct asn1_oid oid; /* * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId * * KeyPurposeId ::= OBJECT IDENTIFIER */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(ExtKeyUsageSyntax) - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } if (hdr.length > pos + len - hdr.payload) return -1; pos = hdr.payload; end = pos + hdr.length; wpa_hexdump(MSG_MSGDUMP, "X509: ExtKeyUsageSyntax", pos, end - pos); while (pos < end) { char buf[80]; if (asn1_get_oid(pos, end - pos, &oid, &pos)) return -1; if (x509_any_ext_key_usage_oid(&oid)) { os_strlcpy(buf, "anyExtendedKeyUsage", sizeof(buf)); cert->ext_key_usage |= X509_EXT_KEY_USAGE_ANY; } else if (x509_id_kp_server_auth_oid(&oid)) { os_strlcpy(buf, "id-kp-serverAuth", sizeof(buf)); cert->ext_key_usage |= X509_EXT_KEY_USAGE_SERVER_AUTH; } else if (x509_id_kp_client_auth_oid(&oid)) { os_strlcpy(buf, "id-kp-clientAuth", sizeof(buf)); cert->ext_key_usage |= X509_EXT_KEY_USAGE_CLIENT_AUTH; } else if (x509_id_kp_ocsp_oid(&oid)) { os_strlcpy(buf, "id-kp-OCSPSigning", sizeof(buf)); cert->ext_key_usage |= X509_EXT_KEY_USAGE_OCSP; } else { asn1_oid_to_str(&oid, buf, sizeof(buf)); } wpa_printf(MSG_DEBUG, "ExtKeyUsage KeyPurposeId: %s", buf); } cert->extensions_present |= X509_EXT_EXT_KEY_USAGE; return 0; } static int x509_parse_extension_data(struct x509_certificate *cert, struct asn1_oid *oid, const u8 *pos, size_t len) { if (!x509_id_ce_oid(oid)) return 1; /* TODO: add other extensions required by RFC 3280, Ch 4.2: * certificate policies (section 4.2.1.5) * name constraints (section 4.2.1.11) * policy constraints (section 4.2.1.12) * inhibit any-policy (section 4.2.1.15) */ switch (oid->oid[3]) { case 15: /* id-ce-keyUsage */ return x509_parse_ext_key_usage(cert, pos, len); case 17: /* id-ce-subjectAltName */ return x509_parse_ext_subject_alt_name(cert, pos, len); case 18: /* id-ce-issuerAltName */ return x509_parse_ext_issuer_alt_name(cert, pos, len); case 19: /* id-ce-basicConstraints */ return x509_parse_ext_basic_constraints(cert, pos, len); case 37: /* id-ce-extKeyUsage */ return x509_parse_ext_ext_key_usage(cert, pos, len); default: return 1; } } static int x509_parse_extension(struct x509_certificate *cert, const u8 *pos, size_t len, const u8 **next) { const u8 *end; struct asn1_hdr hdr; struct asn1_oid oid; int critical_ext = 0, res; char buf[80]; /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING * } */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in " "Extensions: class %d tag 0x%x; expected SEQUENCE", hdr.class, hdr.tag); return -1; } pos = hdr.payload; *next = end = pos + hdr.length; if (asn1_get_oid(pos, end - pos, &oid, &pos) < 0) { wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data for " "Extension (expected OID)"); return -1; } if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || (hdr.tag != ASN1_TAG_BOOLEAN && hdr.tag != ASN1_TAG_OCTETSTRING)) { wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in " "Extensions: class %d tag 0x%x; expected BOOLEAN " "or OCTET STRING", hdr.class, hdr.tag); return -1; } if (hdr.tag == ASN1_TAG_BOOLEAN) { if (hdr.length != 1) { wpa_printf(MSG_DEBUG, "X509: Unexpected " "Boolean length (%u)", hdr.length); return -1; } critical_ext = hdr.payload[0]; pos = hdr.payload; if (asn1_get_next(pos, end - pos, &hdr) < 0 || (hdr.class != ASN1_CLASS_UNIVERSAL && hdr.class != ASN1_CLASS_PRIVATE) || hdr.tag != ASN1_TAG_OCTETSTRING) { wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header " "in Extensions: class %d tag 0x%x; " "expected OCTET STRING", hdr.class, hdr.tag); return -1; } } asn1_oid_to_str(&oid, buf, sizeof(buf)); wpa_printf(MSG_DEBUG, "X509: Extension: extnID=%s critical=%d", buf, critical_ext); wpa_hexdump(MSG_MSGDUMP, "X509: extnValue", hdr.payload, hdr.length); res = x509_parse_extension_data(cert, &oid, hdr.payload, hdr.length); if (res < 0) return res; if (res == 1 && critical_ext) { wpa_printf(MSG_INFO, "X509: Unknown critical extension %s", buf); return -1; } return 0; } static int x509_parse_extensions(struct x509_certificate *cert, const u8 *pos, size_t len) { const u8 *end; struct asn1_hdr hdr; /* Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data " "for Extensions: class %d tag 0x%x; " "expected SEQUENCE", hdr.class, hdr.tag); return -1; } pos = hdr.payload; end = pos + hdr.length; while (pos < end) { if (x509_parse_extension(cert, pos, end - pos, &pos) < 0) return -1; } return 0; } static int x509_parse_tbs_certificate(const u8 *buf, size_t len, struct x509_certificate *cert, const u8 **next) { struct asn1_hdr hdr; const u8 *pos, *end; size_t left; char sbuf[128]; unsigned long value; const u8 *subject_dn; /* tbsCertificate TBSCertificate ::= SEQUENCE */ if (asn1_get_next(buf, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: tbsCertificate did not start " "with a valid SEQUENCE - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } pos = hdr.payload; end = *next = pos + hdr.length; /* * version [0] EXPLICIT Version DEFAULT v1 * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ if (asn1_get_next(pos, end - pos, &hdr) < 0) return -1; pos = hdr.payload; if (hdr.class == ASN1_CLASS_CONTEXT_SPECIFIC) { if (asn1_get_next(pos, end - pos, &hdr) < 0) return -1; if (hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER) { wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for " "version field - found class %d tag 0x%x", hdr.class, hdr.tag); return -1; } if (hdr.length != 1) { wpa_printf(MSG_DEBUG, "X509: Unexpected version field " "length %u (expected 1)", hdr.length); return -1; } pos = hdr.payload; left = hdr.length; value = 0; while (left) { value <<= 8; value |= *pos++; left--; } cert->version = value; if (cert->version != X509_CERT_V1 && cert->version != X509_CERT_V2 && cert->version != X509_CERT_V3) { wpa_printf(MSG_DEBUG, "X509: Unsupported version %d", cert->version + 1); return -1; } if (asn1_get_next(pos, end - pos, &hdr) < 0) return -1; } else cert->version = X509_CERT_V1; wpa_printf(MSG_MSGDUMP, "X509: Version X.509v%d", cert->version + 1); /* serialNumber CertificateSerialNumber ::= INTEGER */ if (hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER || hdr.length < 1 || hdr.length > X509_MAX_SERIAL_NUM_LEN) { wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for " "serialNumber; class=%d tag=0x%x length=%u", hdr.class, hdr.tag, hdr.length); return -1; } pos = hdr.payload + hdr.length; while (hdr.length > 0 && hdr.payload[0] == 0) { hdr.payload++; hdr.length--; } os_memcpy(cert->serial_number, hdr.payload, hdr.length); cert->serial_number_len = hdr.length; wpa_hexdump(MSG_MSGDUMP, "X509: serialNumber", cert->serial_number, cert->serial_number_len); /* signature AlgorithmIdentifier */ if (x509_parse_algorithm_identifier(pos, end - pos, &cert->signature, &pos)) return -1; /* issuer Name */ if (x509_parse_name(pos, end - pos, &cert->issuer, &pos)) return -1; x509_name_string(&cert->issuer, sbuf, sizeof(sbuf)); wpa_printf(MSG_MSGDUMP, "X509: issuer %s", sbuf); /* validity Validity */ if (x509_parse_validity(pos, end - pos, cert, &pos)) return -1; /* subject Name */ subject_dn = pos; if (x509_parse_name(pos, end - pos, &cert->subject, &pos)) return -1; cert->subject_dn = os_malloc(pos - subject_dn); if (!cert->subject_dn) return -1; cert->subject_dn_len = pos - subject_dn; os_memcpy(cert->subject_dn, subject_dn, cert->subject_dn_len); x509_name_string(&cert->subject, sbuf, sizeof(sbuf)); wpa_printf(MSG_MSGDUMP, "X509: subject %s", sbuf); /* subjectPublicKeyInfo SubjectPublicKeyInfo */ if (x509_parse_public_key(pos, end - pos, cert, &pos)) return -1; if (pos == end) return 0; if (cert->version == X509_CERT_V1) return 0; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) { wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific" " tag to parse optional tbsCertificate " "field(s); parsed class %d tag 0x%x", hdr.class, hdr.tag); return -1; } if (hdr.tag == 1) { /* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL */ wpa_printf(MSG_DEBUG, "X509: issuerUniqueID"); /* TODO: parse UniqueIdentifier ::= BIT STRING */ pos = hdr.payload + hdr.length; if (pos == end) return 0; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) { wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific" " tag to parse optional tbsCertificate " "field(s); parsed class %d tag 0x%x", hdr.class, hdr.tag); return -1; } } if (hdr.tag == 2) { /* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL */ wpa_printf(MSG_DEBUG, "X509: subjectUniqueID"); /* TODO: parse UniqueIdentifier ::= BIT STRING */ pos = hdr.payload + hdr.length; if (pos == end) return 0; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) { wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific" " tag to parse optional tbsCertificate " "field(s); parsed class %d tag 0x%x", hdr.class, hdr.tag); return -1; } } if (hdr.tag != 3) { wpa_printf(MSG_DEBUG, "X509: Ignored unexpected " "Context-Specific tag %d in optional " "tbsCertificate fields", hdr.tag); return 0; } /* extensions [3] EXPLICIT Extensions OPTIONAL */ if (cert->version != X509_CERT_V3) { wpa_printf(MSG_DEBUG, "X509: X.509%d certificate and " "Extensions data which are only allowed for " "version 3", cert->version + 1); return -1; } if (x509_parse_extensions(cert, hdr.payload, hdr.length) < 0) return -1; pos = hdr.payload + hdr.length; if (pos < end) { wpa_hexdump(MSG_DEBUG, "X509: Ignored extra tbsCertificate data", pos, end - pos); } return 0; } static int x509_rsadsi_oid(struct asn1_oid *oid) { return oid->len >= 4 && oid->oid[0] == 1 /* iso */ && oid->oid[1] == 2 /* member-body */ && oid->oid[2] == 840 /* us */ && oid->oid[3] == 113549 /* rsadsi */; } static int x509_pkcs_oid(struct asn1_oid *oid) { return oid->len >= 5 && x509_rsadsi_oid(oid) && oid->oid[4] == 1 /* pkcs */; } static int x509_digest_oid(struct asn1_oid *oid) { return oid->len >= 5 && x509_rsadsi_oid(oid) && oid->oid[4] == 2 /* digestAlgorithm */; } int x509_sha1_oid(struct asn1_oid *oid) { return oid->len == 6 && oid->oid[0] == 1 /* iso */ && oid->oid[1] == 3 /* identified-organization */ && oid->oid[2] == 14 /* oiw */ && oid->oid[3] == 3 /* secsig */ && oid->oid[4] == 2 /* algorithms */ && oid->oid[5] == 26 /* id-sha1 */; } static int x509_sha2_oid(struct asn1_oid *oid) { return oid->len == 9 && oid->oid[0] == 2 /* joint-iso-itu-t */ && oid->oid[1] == 16 /* country */ && oid->oid[2] == 840 /* us */ && oid->oid[3] == 1 /* organization */ && oid->oid[4] == 101 /* gov */ && oid->oid[5] == 3 /* csor */ && oid->oid[6] == 4 /* nistAlgorithm */ && oid->oid[7] == 2 /* hashAlgs */; } int x509_sha256_oid(struct asn1_oid *oid) { return x509_sha2_oid(oid) && oid->oid[8] == 1 /* sha256 */; } int x509_sha384_oid(struct asn1_oid *oid) { return x509_sha2_oid(oid) && oid->oid[8] == 2 /* sha384 */; } int x509_sha512_oid(struct asn1_oid *oid) { return x509_sha2_oid(oid) && oid->oid[8] == 3 /* sha512 */; } /** * x509_certificate_parse - Parse a X.509 certificate in DER format * @buf: Pointer to the X.509 certificate in DER format * @len: Buffer length * Returns: Pointer to the parsed certificate or %NULL on failure * * Caller is responsible for freeing the returned certificate by calling * x509_certificate_free(). */ struct x509_certificate * x509_certificate_parse(const u8 *buf, size_t len) { struct asn1_hdr hdr; const u8 *pos, *end, *hash_start; struct x509_certificate *cert; cert = os_zalloc(sizeof(*cert) + len); if (cert == NULL) return NULL; os_memcpy(cert + 1, buf, len); cert->cert_start = (u8 *) (cert + 1); cert->cert_len = len; pos = buf; end = buf + len; /* RFC 3280 - X.509 v3 certificate / ASN.1 DER */ /* Certificate ::= SEQUENCE */ if (asn1_get_next(pos, len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Certificate did not start with " "a valid SEQUENCE - found class %d tag 0x%x", hdr.class, hdr.tag); x509_certificate_free(cert); return NULL; } pos = hdr.payload; if (hdr.length > end - pos) { x509_certificate_free(cert); return NULL; } if (hdr.length < end - pos) { wpa_hexdump(MSG_MSGDUMP, "X509: Ignoring extra data after DER " "encoded certificate", pos + hdr.length, end - (pos + hdr.length)); end = pos + hdr.length; } hash_start = pos; cert->tbs_cert_start = cert->cert_start + (hash_start - buf); if (x509_parse_tbs_certificate(pos, end - pos, cert, &pos)) { x509_certificate_free(cert); return NULL; } cert->tbs_cert_len = pos - hash_start; /* signatureAlgorithm AlgorithmIdentifier */ if (x509_parse_algorithm_identifier(pos, end - pos, &cert->signature_alg, &pos)) { x509_certificate_free(cert); return NULL; } /* signatureValue BIT STRING */ if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_BITSTRING) { wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING " "(signatureValue) - found class %d tag 0x%x", hdr.class, hdr.tag); x509_certificate_free(cert); return NULL; } if (hdr.length < 1) { x509_certificate_free(cert); return NULL; } pos = hdr.payload; if (*pos) { wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits", *pos); /* PKCS #1 v1.5 10.2.1: * It is an error if the length in bits of the signature S is * not a multiple of eight. */ x509_certificate_free(cert); return NULL; } os_free(cert->sign_value); cert->sign_value = os_memdup(pos + 1, hdr.length - 1); if (cert->sign_value == NULL) { wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for " "signatureValue"); x509_certificate_free(cert); return NULL; } cert->sign_value_len = hdr.length - 1; wpa_hexdump(MSG_MSGDUMP, "X509: signature", cert->sign_value, cert->sign_value_len); return cert; } /** * x509_certificate_check_signature - Verify certificate signature * @issuer: Issuer certificate * @cert: Certificate to be verified * Returns: 0 if cert has a valid signature that was signed by the issuer, * -1 if not */ int x509_certificate_check_signature(struct x509_certificate *issuer, struct x509_certificate *cert) { return x509_check_signature(issuer, &cert->signature, cert->sign_value, cert->sign_value_len, cert->tbs_cert_start, cert->tbs_cert_len); } int x509_check_signature(struct x509_certificate *issuer, struct x509_algorithm_identifier *signature, const u8 *sign_value, size_t sign_value_len, const u8 *signed_data, size_t signed_data_len) { struct crypto_public_key *pk; u8 *data; const u8 *pos, *end, *next, *da_end; size_t data_len; struct asn1_hdr hdr; struct asn1_oid oid; u8 hash[64]; size_t hash_len; const u8 *addr[1] = { signed_data }; size_t len[1] = { signed_data_len }; if (!x509_pkcs_oid(&signature->oid) || signature->oid.len != 7 || signature->oid.oid[5] != 1 /* pkcs-1 */) { wpa_printf(MSG_DEBUG, "X509: Unrecognized signature " "algorithm"); return -1; } pk = crypto_public_key_import(issuer->public_key, issuer->public_key_len); if (pk == NULL) return -1; data_len = sign_value_len; data = os_malloc(data_len); if (data == NULL) { crypto_public_key_free(pk); return -1; } if (crypto_public_key_decrypt_pkcs1(pk, sign_value, sign_value_len, data, &data_len) < 0) { wpa_printf(MSG_DEBUG, "X509: Failed to decrypt signature"); crypto_public_key_free(pk); os_free(data); return -1; } crypto_public_key_free(pk); wpa_hexdump(MSG_MSGDUMP, "X509: Signature data D", data, data_len); /* * PKCS #1 v1.5, 10.1.2: * * DigestInfo ::= SEQUENCE { * digestAlgorithm DigestAlgorithmIdentifier, * digest Digest * } * * DigestAlgorithmIdentifier ::= AlgorithmIdentifier * * Digest ::= OCTET STRING * */ if (asn1_get_next(data, data_len, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(DigestInfo) - found class %d tag 0x%x", hdr.class, hdr.tag); os_free(data); return -1; } pos = hdr.payload; end = pos + hdr.length; /* * X.509: * AlgorithmIdentifier ::= SEQUENCE { * algorithm OBJECT IDENTIFIER, * parameters ANY DEFINED BY algorithm OPTIONAL * } */ if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE) { wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE " "(AlgorithmIdentifier) - found class %d tag 0x%x", hdr.class, hdr.tag); os_free(data); return -1; } da_end = hdr.payload + hdr.length; if (asn1_get_oid(hdr.payload, hdr.length, &oid, &next)) { wpa_printf(MSG_DEBUG, "X509: Failed to parse digestAlgorithm"); os_free(data); return -1; } if (x509_sha1_oid(&oid)) { if (signature->oid.oid[6] != 5 /* sha-1WithRSAEncryption */) { wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA1 " "does not match with certificate " "signatureAlgorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } goto skip_digest_oid; } if (x509_sha256_oid(&oid)) { if (signature->oid.oid[6] != 11 /* sha2561WithRSAEncryption */) { wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA256 " "does not match with certificate " "signatureAlgorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } goto skip_digest_oid; } if (x509_sha384_oid(&oid)) { if (signature->oid.oid[6] != 12 /* sha384WithRSAEncryption */) { wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA384 " "does not match with certificate " "signatureAlgorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } goto skip_digest_oid; } if (x509_sha512_oid(&oid)) { if (signature->oid.oid[6] != 13 /* sha512WithRSAEncryption */) { wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA512 " "does not match with certificate " "signatureAlgorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } goto skip_digest_oid; } if (!x509_digest_oid(&oid)) { wpa_printf(MSG_DEBUG, "X509: Unrecognized digestAlgorithm"); os_free(data); return -1; } switch (oid.oid[5]) { case 5: /* md5 */ if (signature->oid.oid[6] != 4 /* md5WithRSAEncryption */) { wpa_printf(MSG_DEBUG, "X509: digestAlgorithm MD5 does " "not match with certificate " "signatureAlgorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } break; case 2: /* md2 */ case 4: /* md4 */ default: wpa_printf(MSG_DEBUG, "X509: Unsupported digestAlgorithm " "(%lu)", oid.oid[5]); os_free(data); return -1; } skip_digest_oid: /* Digest ::= OCTET STRING */ pos = da_end; end = data + data_len; if (asn1_get_next(pos, end - pos, &hdr) < 0 || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_OCTETSTRING) { wpa_printf(MSG_DEBUG, "X509: Expected OCTETSTRING " "(Digest) - found class %d tag 0x%x", hdr.class, hdr.tag); os_free(data); return -1; } wpa_hexdump(MSG_MSGDUMP, "X509: Decrypted Digest", hdr.payload, hdr.length); switch (signature->oid.oid[6]) { case 4: /* md5WithRSAEncryption */ md5_vector(1, addr, len, hash); hash_len = 16; wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (MD5)", hash, hash_len); break; case 5: /* sha-1WithRSAEncryption */ sha1_vector(1, addr, len, hash); hash_len = 20; wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA1)", hash, hash_len); break; case 11: /* sha256WithRSAEncryption */ sha256_vector(1, addr, len, hash); hash_len = 32; wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA256)", hash, hash_len); break; case 12: /* sha384WithRSAEncryption */ sha384_vector(1, addr, len, hash); hash_len = 48; wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA384)", hash, hash_len); break; case 13: /* sha512WithRSAEncryption */ sha512_vector(1, addr, len, hash); hash_len = 64; wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA512)", hash, hash_len); break; case 2: /* md2WithRSAEncryption */ default: wpa_printf(MSG_INFO, "X509: Unsupported certificate signature " "algorithm (%lu)", signature->oid.oid[6]); os_free(data); return -1; } if (hdr.length != hash_len || os_memcmp_const(hdr.payload, hash, hdr.length) != 0) { wpa_printf(MSG_INFO, "X509: Certificate Digest does not match " "with calculated tbsCertificate hash"); os_free(data); return -1; } if (hdr.payload + hdr.length < data + data_len) { wpa_hexdump(MSG_INFO, "X509: Extra data after certificate signature hash", hdr.payload + hdr.length, data + data_len - hdr.payload - hdr.length); os_free(data); return -1; } os_free(data); wpa_printf(MSG_DEBUG, "X509: Certificate Digest matches with " "calculated tbsCertificate hash"); return 0; } static int x509_valid_issuer(const struct x509_certificate *cert) { if ((cert->extensions_present & X509_EXT_BASIC_CONSTRAINTS) && !cert->ca) { wpa_printf(MSG_DEBUG, "X509: Non-CA certificate used as an " "issuer"); return -1; } if (cert->version == X509_CERT_V3 && !(cert->extensions_present & X509_EXT_BASIC_CONSTRAINTS)) { wpa_printf(MSG_DEBUG, "X509: v3 CA certificate did not " "include BasicConstraints extension"); return -1; } if ((cert->extensions_present & X509_EXT_KEY_USAGE) && !(cert->key_usage & X509_KEY_USAGE_KEY_CERT_SIGN)) { wpa_printf(MSG_DEBUG, "X509: Issuer certificate did not have " "keyCertSign bit in Key Usage"); return -1; } return 0; } /** * x509_certificate_chain_validate - Validate X.509 certificate chain * @trusted: List of trusted certificates * @chain: Certificate chain to be validated (first chain must be issued by * signed by the second certificate in the chain and so on) * @reason: Buffer for returning failure reason (X509_VALIDATE_*) * Returns: 0 if chain is valid, -1 if not */ int x509_certificate_chain_validate(struct x509_certificate *trusted, struct x509_certificate *chain, int *reason, int disable_time_checks) { long unsigned idx; int chain_trusted = 0; struct x509_certificate *cert, *trust; char buf[128]; struct os_time now; *reason = X509_VALIDATE_OK; wpa_printf(MSG_DEBUG, "X509: Validate certificate chain"); os_get_time(&now); for (cert = chain, idx = 0; cert; cert = cert->next, idx++) { cert->issuer_trusted = 0; x509_name_string(&cert->subject, buf, sizeof(buf)); wpa_printf(MSG_DEBUG, "X509: %lu: %s", idx, buf); if (chain_trusted) continue; if (!disable_time_checks && ((unsigned long) now.sec < (unsigned long) cert->not_before || (unsigned long) now.sec > (unsigned long) cert->not_after)) { wpa_printf(MSG_INFO, "X509: Certificate not valid " "(now=%lu not_before=%lu not_after=%lu)", now.sec, cert->not_before, cert->not_after); *reason = X509_VALIDATE_CERTIFICATE_EXPIRED; return -1; } if (cert->next) { if (x509_name_compare(&cert->issuer, &cert->next->subject) != 0) { wpa_printf(MSG_DEBUG, "X509: Certificate " "chain issuer name mismatch"); x509_name_string(&cert->issuer, buf, sizeof(buf)); wpa_printf(MSG_DEBUG, "X509: cert issuer: %s", buf); x509_name_string(&cert->next->subject, buf, sizeof(buf)); wpa_printf(MSG_DEBUG, "X509: next cert " "subject: %s", buf); *reason = X509_VALIDATE_CERTIFICATE_UNKNOWN; return -1; } if (x509_valid_issuer(cert->next) < 0) { *reason = X509_VALIDATE_BAD_CERTIFICATE; return -1; } if ((cert->next->extensions_present & X509_EXT_PATH_LEN_CONSTRAINT) && idx > cert->next->path_len_constraint) { wpa_printf(MSG_DEBUG, "X509: pathLenConstraint" " not met (idx=%lu issuer " "pathLenConstraint=%lu)", idx, cert->next->path_len_constraint); *reason = X509_VALIDATE_BAD_CERTIFICATE; return -1; } if (x509_certificate_check_signature(cert->next, cert) < 0) { wpa_printf(MSG_DEBUG, "X509: Invalid " "certificate signature within " "chain"); *reason = X509_VALIDATE_BAD_CERTIFICATE; return -1; } } for (trust = trusted; trust; trust = trust->next) { if (x509_name_compare(&cert->issuer, &trust->subject) == 0) break; } if (trust) { wpa_printf(MSG_DEBUG, "X509: Found issuer from the " "list of trusted certificates"); if (x509_valid_issuer(trust) < 0) { *reason = X509_VALIDATE_BAD_CERTIFICATE; return -1; } if (x509_certificate_check_signature(trust, cert) < 0) { wpa_printf(MSG_DEBUG, "X509: Invalid " "certificate signature"); *reason = X509_VALIDATE_BAD_CERTIFICATE; return -1; } wpa_printf(MSG_DEBUG, "X509: Trusted certificate " "found to complete the chain"); cert->issuer_trusted = 1; chain_trusted = 1; } } if (!chain_trusted) { wpa_printf(MSG_DEBUG, "X509: Did not find any of the issuers " "from the list of trusted certificates"); if (trusted) { *reason = X509_VALIDATE_UNKNOWN_CA; return -1; } wpa_printf(MSG_DEBUG, "X509: Certificate chain validation " "disabled - ignore unknown CA issue"); } wpa_printf(MSG_DEBUG, "X509: Certificate chain valid"); return 0; } /** * x509_certificate_get_subject - Get a certificate based on Subject name * @chain: Certificate chain to search through * @name: Subject name to search for * Returns: Pointer to the certificate with the given Subject name or * %NULL on failure */ struct x509_certificate * x509_certificate_get_subject(struct x509_certificate *chain, struct x509_name *name) { struct x509_certificate *cert; for (cert = chain; cert; cert = cert->next) { if (x509_name_compare(&cert->subject, name) == 0) return cert; } return NULL; } /** * x509_certificate_self_signed - Is the certificate self-signed? * @cert: Certificate * Returns: 1 if certificate is self-signed, 0 if not */ int x509_certificate_self_signed(struct x509_certificate *cert) { return x509_name_compare(&cert->issuer, &cert->subject) == 0; }