diff options
author | Dr. Stephen Henson <steve@openssl.org> | 2012-11-18 15:13:55 +0000 |
---|---|---|
committer | Dr. Stephen Henson <steve@openssl.org> | 2012-11-18 15:13:55 +0000 |
commit | d88926f1815d79c800e4cf11ecee8e43f3a7ad1f (patch) | |
tree | 75522b25e26843fbb6bb002ad684c062821153b1 /crypto | |
parent | 24f77b34d574cb02bdd8e2f37a8c12965ddd2a1f (diff) |
PR: 2909
Contributed by: Florian Weimer <fweimer@redhat.com>
Fixes to X509 hostname and email address checking. Wildcard matching support.
New test program and manual page.
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/x509v3/Makefile | 2 | ||||
-rw-r--r-- | crypto/x509v3/v3_utl.c | 204 | ||||
-rw-r--r-- | crypto/x509v3/v3nametest.c | 346 | ||||
-rw-r--r-- | crypto/x509v3/x509v3.h | 2 |
4 files changed, 539 insertions, 15 deletions
diff --git a/crypto/x509v3/Makefile b/crypto/x509v3/Makefile index 07e2df4368..b54f540a35 100644 --- a/crypto/x509v3/Makefile +++ b/crypto/x509v3/Makefile @@ -13,7 +13,7 @@ AR= ar r CFLAGS= $(INCLUDES) $(CFLAG) GENERAL=Makefile README -TEST= +TEST=v3nametest.c APPS= LIB=$(TOP)/libcrypto.a diff --git a/crypto/x509v3/v3_utl.c b/crypto/x509v3/v3_utl.c index db9f05ebb9..ffd9f0d577 100644 --- a/crypto/x509v3/v3_utl.c +++ b/crypto/x509v3/v3_utl.c @@ -568,12 +568,177 @@ void X509_email_free(STACK_OF(OPENSSL_STRING) *sk) sk_OPENSSL_STRING_pop_free(sk, str_free); } +typedef int (*equal_fn)(const unsigned char *pattern, size_t pattern_len, + const unsigned char *subject, size_t subject_len); + +/* Compare while ASCII ignoring case. */ +static int equal_nocase(const unsigned char *pattern, size_t pattern_len, + const unsigned char *subject, size_t subject_len) + { + if (pattern_len != subject_len) + return 0; + while (pattern_len) + { + unsigned char l = *pattern; + unsigned char r = *subject; + /* The pattern must not contain NUL characters. */ + if (l == 0) + return 0; + if (l != r) + { + if ('A' <= l && l <= 'Z') + l = (l - 'A') + 'a'; + if ('A' <= r && r <= 'Z') + r = (r - 'A') + 'a'; + if (l != r) + return 0; + } + ++pattern; + ++subject; + --pattern_len; + } + return 1; + } + +/* Compare using memcmp. */ +static int equal_case(const unsigned char *pattern, size_t pattern_len, + const unsigned char *subject, size_t subject_len) +{ + /* The pattern must not contain NUL characters. */ + if (memchr(pattern, '\0', pattern_len) != NULL) + return 0; + if (pattern_len != subject_len) + return 0; + return !memcmp(pattern, subject, pattern_len); +} + +/* RFC 5280, section 7.5, requires that only the domain is compared in + a case-insensitive manner. */ +static int equal_email(const unsigned char *a, size_t a_len, + const unsigned char *b, size_t b_len) + { + size_t i = a_len; + if (a_len != b_len) + return 0; + /* We search backwards for the '@' character, so that we do + not have to deal with quoted local-parts. The domain part + is compared in a case-insensitive manner. */ + while (i > 0) + { + --i; + if (a[i] == '@' || b[i] == '@') + { + if (!equal_nocase(a + i, a_len - i, + b + i, a_len - i)) + return 0; + break; + } + } + if (i == 0) + i = a_len; + return equal_case(a, i, b, i); + } + +/* Compare the prefix and suffix with the subject, and check that the + characters in-between are valid. */ +static int wildcard_match(const unsigned char *prefix, size_t prefix_len, + const unsigned char *suffix, size_t suffix_len, + const unsigned char *subject, size_t subject_len) + { + const unsigned char *wildcard_start; + const unsigned char *wildcard_end; + const unsigned char *p; + if (subject_len < prefix_len + suffix_len) + return 0; + if (!equal_nocase(prefix, prefix_len, subject, prefix_len)) + return 0; + wildcard_start = subject + prefix_len; + wildcard_end = subject + (subject_len - suffix_len); + if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len)) + return 0; + /* The wildcard must match at least one character. */ + if (wildcard_start == wildcard_end) + return 0; + /* Check that the part matched by the wildcard contains only + permitted characters and only matches a single label. */ + for (p = wildcard_start; p != wildcard_end; ++p) + if (!(('0' <= *p && *p <= '9') || + ('A' <= *p && *p <= 'Z') || + ('a' <= *p && *p <= 'z') || + *p == '-')) + return 0; + return 1; + } + +/* Checks if the memory region consistens of [0-9A-Za-z.-]. */ +static int valid_domain_characters(const unsigned char *p, size_t len) + { + while (len) + { + if (!(('0' <= *p && *p <= '9') || + ('A' <= *p && *p <= 'Z') || + ('a' <= *p && *p <= 'z') || + *p == '-' || *p == '.')) + return 0; + ++p; + --len; + } + return 1; + } + +/* Find the '*' in a wildcard pattern. If no such character is found + or the pattern is otherwise invalid, returns NULL. */ +static const unsigned char *wildcard_find_star(const unsigned char *pattern, + size_t pattern_len) + { + const unsigned char *star = memchr(pattern, '*', pattern_len); + size_t dot_count = 0; + const unsigned char *suffix_start; + size_t suffix_length; + if (star == NULL) + return NULL; + suffix_start = star + 1; + suffix_length = (pattern + pattern_len) - (star + 1); + if (!(valid_domain_characters(pattern, star - pattern) && + valid_domain_characters(suffix_start, suffix_length))) + return NULL; + /* Check that the suffix matches at least two labels. */ + while (suffix_length) + { + if (*suffix_start == '.') + ++dot_count; + ++suffix_start; + --suffix_length; + } + if (dot_count < 2) + return NULL; + return star; + } + +/* Compare using wildcards. */ +static int equal_wildcard(const unsigned char *pattern, size_t pattern_len, + const unsigned char *subject, size_t subject_len) + { + const unsigned char *star; + /* Do not match IDNA names. */ + if (subject_len >=4 && memcmp(subject, "xn--", 4) == 0) + star = NULL; + else + star = wildcard_find_star(pattern, pattern_len); + if (star == NULL) + return equal_nocase(pattern, pattern_len, + subject, subject_len); + return wildcard_match(pattern, star - pattern, + star + 1, (pattern + pattern_len) - star - 1, + subject, subject_len); + } + /* Compare an ASN1_STRING to a supplied string. If they match * return 1. If cmp_type > 0 only compare if string matches the * type, otherwise convert it to UTF8. */ -static int do_check_string(ASN1_STRING *a, int cmp_type, +static int do_check_string(ASN1_STRING *a, int cmp_type, equal_fn equal, const unsigned char *b, size_t blen) { if (!a->data || !a->length) @@ -582,6 +747,8 @@ static int do_check_string(ASN1_STRING *a, int cmp_type, { if (cmp_type != a->type) return 0; + if (cmp_type == V_ASN1_IA5STRING) + return equal(a->data, a->length, b, blen); if (a->length == (int)blen && !memcmp(a->data, b, blen)) return 1; else @@ -593,11 +760,8 @@ static int do_check_string(ASN1_STRING *a, int cmp_type, unsigned char *astr; astrlen = ASN1_STRING_to_UTF8(&astr, a); if (astrlen < 0) - return 0; - if (astrlen == (int)blen && !memcmp(astr, b, blen)) - rv = 1; - else - rv = 0; + return -1; + rv = equal(astr, astrlen, b, blen); OPENSSL_free(astr); return rv; } @@ -610,12 +774,29 @@ static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen, X509_NAME *name = NULL; int i; int cnid; + int alt_type; + equal_fn equal; if (check_type == GEN_EMAIL) + { cnid = NID_pkcs9_emailAddress; + alt_type = V_ASN1_IA5STRING; + equal = equal_email; + } else if (check_type == GEN_DNS) + { cnid = NID_commonName; + alt_type = V_ASN1_IA5STRING; + if (flags & X509_CHECK_FLAG_NO_WILDCARDS) + equal = equal_nocase; + else + equal = equal_wildcard; + } else + { cnid = 0; + alt_type = V_ASN1_OCTET_STRING; + equal = equal_case; + } if (chklen == 0) chklen = strlen((const char *)chk); @@ -624,11 +805,6 @@ static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen, if (gens) { int rv = 0; - int alt_type; - if (cnid) - alt_type = V_ASN1_IA5STRING; - else - alt_type = V_ASN1_OCTET_STRING; for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { GENERAL_NAME *gen; @@ -642,7 +818,7 @@ static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen, cstr = gen->d.dNSName; else cstr = gen->d.iPAddress; - if (do_check_string(cstr, alt_type, chk, chklen)) + if (do_check_string(cstr, alt_type, equal, chk, chklen)) { rv = 1; break; @@ -662,7 +838,7 @@ static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen, ASN1_STRING *str; ne = X509_NAME_get_entry(name, i); str = X509_NAME_ENTRY_get_data(ne); - if (do_check_string(str, -1, chk, chklen)) + if (do_check_string(str, -1, equal, chk, chklen)) return 1; } return 0; @@ -692,7 +868,7 @@ int X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags) int iplen; iplen = a2i_ipadd(ipout, ipasc); if (iplen == 0) - return 0; + return -2; return do_x509_check(x, ipout, (size_t)iplen, flags, GEN_IPADD); } diff --git a/crypto/x509v3/v3nametest.c b/crypto/x509v3/v3nametest.c new file mode 100644 index 0000000000..5bf1201c6e --- /dev/null +++ b/crypto/x509v3/v3nametest.c @@ -0,0 +1,346 @@ +#include <openssl/x509.h> +#include <openssl/x509v3.h> +#include <string.h> + +static const char *const names[] = + { + "a", "b", ".", "*", "@", + ".a", "a.", ".b", "b.", ".*", "*.", "*@", "@*", "a@", "@a", "b@", "..", + "@@", "**", + "*.com", "*com", "*.*.com", "*com", "com*", "*example.com", + "*@example.com", "test@*.example.com", + "example.com", "www.example.com", "test.www.example.com", + "*.example.com", "*.www.example.com", "test.*.example.com", "www.*.com", + "example.net", "xn--rger-koa.example.com", + "a.example.com", "b.example.com", + "postmaster@example.com", "Postmaster@example.com", + "postmaster@EXAMPLE.COM", + NULL + }; + +static const char *const exceptions[] = + { + "set CN: host: [*.example.com] does not match [*.example.com]", + "set CN: host: [*.example.com] matches [a.example.com]", + "set CN: host: [*.example.com] matches [b.example.com]", + "set CN: host: [*.example.com] matches [www.example.com]", + "set CN: host: [test.*.example.com] does not match [test.*.example.com]", + "set CN: host: [test.*.example.com] matches [test.www.example.com]", + "set CN: host: [*.www.example.com] does not match [*.www.example.com]", + "set CN: host: [*.www.example.com] matches [test.www.example.com]", + "set emailAddress: email: [postmaster@example.com] does not match [Postmaster@example.com]", + "set emailAddress: email: [postmaster@EXAMPLE.COM] does not match [Postmaster@example.com]", + "set emailAddress: email: [Postmaster@example.com] does not match [postmaster@example.com]", + "set emailAddress: email: [Postmaster@example.com] does not match [postmaster@EXAMPLE.COM]", + "set dnsName: host: [*.example.com] matches [www.example.com]", + "set dnsName: host: [*.example.com] does not match [*.example.com]", + "set dnsName: host: [*.example.com] matches [a.example.com]", + "set dnsName: host: [*.example.com] matches [b.example.com]", + "set dnsName: host: [*.www.example.com] matches [test.www.example.com]", + "set dnsName: host: [*.www.example.com] does not match [*.www.example.com]", + "set dnsName: host: [test.*.example.com] matches [test.www.example.com]", + "set dnsName: host: [test.*.example.com] does not match [test.*.example.com]", + "set rfc822Name: email: [postmaster@example.com] does not match [Postmaster@example.com]", + "set rfc822Name: email: [Postmaster@example.com] does not match [postmaster@example.com]", + "set rfc822Name: email: [Postmaster@example.com] does not match [postmaster@EXAMPLE.COM]", + "set rfc822Name: email: [postmaster@EXAMPLE.COM] does not match [Postmaster@example.com]", + NULL + }; + +static int is_exception(const char *msg) + { + const char *const *p; + for (p = exceptions; *p; ++p) + if (strcmp(msg, *p) == 0) + return 1; + return 0; + } + +static int set_cn(X509 *crt, ...) + { + int ret = 0; + X509_NAME *n = NULL; + va_list ap; + va_start(ap, crt); + n = X509_NAME_new(); + if (n == NULL) + goto out; + while (1) { + int nid; + const char *name; + nid = va_arg(ap, int); + if (nid == 0) + break; + name = va_arg(ap, const char *); + if (!X509_NAME_add_entry_by_NID(n, nid, MBSTRING_ASC, + (unsigned char *)name, + -1, -1, 1)) + goto out; + } + if (!X509_set_subject_name(crt, n)) + goto out; + ret = 1; + out: + X509_NAME_free(n); + va_end(ap); + return ret; + } + +/* +int X509_add_ext(X509 *x, X509_EXTENSION *ex, int loc); +X509_EXTENSION *X509_EXTENSION_create_by_NID(X509_EXTENSION **ex, + int nid, int crit, ASN1_OCTET_STRING *data); +int X509_add_ext(X509 *x, X509_EXTENSION *ex, int loc); +*/ + +static int set_altname(X509 *crt, ...) + { + int ret = 0; + GENERAL_NAMES *gens = NULL; + GENERAL_NAME *gen = NULL; + ASN1_IA5STRING *ia5 = NULL; + va_list ap; + va_start(ap, crt); + gens = sk_GENERAL_NAME_new_null(); + if (gens == NULL) + goto out; + while (1) { + int type; + const char *name; + type = va_arg(ap, int); + if (type == 0) + break; + name = va_arg(ap, const char *); + + gen = GENERAL_NAME_new(); + if (gen == NULL) + goto out; + ia5 = ASN1_IA5STRING_new(); + if (ia5 == NULL) + goto out; + if (!ASN1_STRING_set(ia5, name, -1)) + goto out; + switch (type) + { + case GEN_EMAIL: + case GEN_DNS: + GENERAL_NAME_set0_value(gen, type, ia5); + ia5 = NULL; + break; + default: + abort(); + } + sk_GENERAL_NAME_push(gens, gen); + gen = NULL; + } + if (!X509_add1_ext_i2d(crt, NID_subject_alt_name, gens, 0, 0)) + goto out; + ret = 1; + out: + ASN1_IA5STRING_free(ia5); + GENERAL_NAME_free(gen); + GENERAL_NAMES_free(gens); + va_end(ap); + return ret; + } + +static int set_cn1(X509 *crt, const char *name) + { + return set_cn(crt, NID_commonName, name, 0); + } + + +static int set_cn_and_email(X509 *crt, const char *name) + { + return set_cn(crt, NID_commonName, name, + NID_pkcs9_emailAddress, "dummy@example.com", 0); + } + +static int set_cn2(X509 *crt, const char *name) + { + return set_cn(crt, NID_commonName, "dummy value", + NID_commonName, name, 0); + } + +static int set_cn3(X509 *crt, const char *name) + { + return set_cn(crt, NID_commonName, name, + NID_commonName, "dummy value", 0); + } + +static int set_email1(X509 *crt, const char *name) + { + return set_cn(crt, NID_pkcs9_emailAddress, name, 0); + } + +static int set_email2(X509 *crt, const char *name) + { + return set_cn(crt, NID_pkcs9_emailAddress, "dummy@example.com", + NID_pkcs9_emailAddress, name, 0); + } + +static int set_email3(X509 *crt, const char *name) + { + return set_cn(crt, NID_pkcs9_emailAddress, name, + NID_pkcs9_emailAddress, "dummy@example.com", 0); + } + +static int set_email_and_cn(X509 *crt, const char *name) + { + return set_cn(crt, NID_pkcs9_emailAddress, name, + NID_commonName, "www.example.org", 0); + } + +static int set_altname_dns(X509 *crt, const char *name) + { + return set_altname(crt, GEN_DNS, name, 0); + } + +static int set_altname_email(X509 *crt, const char *name) + { + return set_altname(crt, GEN_EMAIL, name, 0); + } + +struct set_name_fn + { + int (*fn)(X509 *, const char *); + const char *name; + int host; + int email; + }; + +static const struct set_name_fn name_fns[] = + { + {set_cn1, "set CN", 1, 0}, + {set_cn2, "set CN", 1, 0}, + {set_cn3, "set CN", 1, 0}, + {set_cn_and_email, "set CN", 1, 0}, + {set_email1, "set emailAddress", 0, 1}, + {set_email2, "set emailAddress", 0, 1}, + {set_email3, "set emailAddress", 0, 1}, + {set_email_and_cn, "set emailAddress", 0, 1}, + {set_altname_dns, "set dnsName", 1, 0}, + {set_altname_email, "set rfc822Name", 0, 1}, + {NULL, NULL, 0} + }; + +static X509 *make_cert() + { + X509 *ret = NULL; + X509 *crt = NULL; + X509_NAME *issuer = NULL; + crt = X509_new(); + if (crt == NULL) + goto out; + if (!X509_set_version(crt, 3)) + goto out; + ret = crt; + crt = NULL; + out: + X509_NAME_free(issuer); + return ret; + } + +static int errors; + +static void check_message(const struct set_name_fn *fn, const char *op, + const char *nameincert, int match, const char *name) + { + char msg[1024]; + if (match < 0) + return; + snprintf(msg, sizeof(msg), "%s: %s: [%s] %s [%s]", + fn->name, op, nameincert, + match ? "matches" : "does not match", name); + if (is_exception(msg)) + return; + puts(msg); + ++errors; + } + +static void run_cert(X509 *crt, const char *nameincert, + const struct set_name_fn *fn) + { + const char *const *pname = names; + while (*pname) + { + int samename = strcasecmp(nameincert, *pname) == 0; + size_t namelen = strlen(*pname); + char *name = malloc(namelen); + int match, ret; + memcpy(name, *pname, namelen); + + ret = X509_check_host(crt, (const unsigned char *)name, + namelen, 0); + match = -1; + if (fn->host) + { + if (ret && !samename) + match = 1; + if (!ret && samename) + match = 0; + } + else if (ret) + match = 1; + check_message(fn, "host", nameincert, match, *pname); + + ret = X509_check_host(crt, (const unsigned char *)name, + namelen, X509_CHECK_FLAG_NO_WILDCARDS); + match = -1; + if (fn->host) + { + if (ret && !samename) + match = 1; + if (!ret && samename) + match = 0; + } + else if (ret) + match = 1; + check_message(fn, "host-no-wildcards", + nameincert, match, *pname); + + ret = X509_check_email(crt, (const unsigned char *)name, + namelen, 0); + match = -1; + if (fn->email) + { + if (ret && !samename) + match = 1; + if (!ret && samename && strchr(nameincert, '@') != NULL) + match = 0; + } + else if (ret) + match = 1; + check_message(fn, "email", nameincert, match, *pname); + ++pname; + free(name); + } + } + +int +main(void) + { + const struct set_name_fn *pfn = name_fns; + while (pfn->name) { + const char *const *pname = names; + while (*pname) + { + X509 *crt = make_cert(); + if (crt == NULL) + { + fprintf(stderr, "make_cert failed\n"); + return 1; + } + if (!pfn->fn(crt, *pname)) + { + fprintf(stderr, "X509 name setting failed\n"); + return 1; + } + run_cert(crt, *pname, pfn); + X509_free(crt); + ++pname; + } + ++pfn; + } + return errors > 0 ? 1 : 0; + } diff --git a/crypto/x509v3/x509v3.h b/crypto/x509v3/x509v3.h index 23f7091db0..272374e5a2 100644 --- a/crypto/x509v3/x509v3.h +++ b/crypto/x509v3/x509v3.h @@ -704,6 +704,8 @@ STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x); /* Always check subject name for host match even if subject alt names present */ #define X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT 0x1 +/* Disable wild-card matching for dnsName fields and common name. */ +#define X509_CHECK_FLAG_NO_WILDCARDS 0x2 int X509_check_host(X509 *x, const unsigned char *chk, size_t chklen, unsigned int flags); |