diff options
Diffstat (limited to 'thirdparty/mbedtls/library/x509_crt.c')
| -rw-r--r-- | thirdparty/mbedtls/library/x509_crt.c | 728 |
1 files changed, 390 insertions, 338 deletions
diff --git a/thirdparty/mbedtls/library/x509_crt.c b/thirdparty/mbedtls/library/x509_crt.c index 2a5dbb8783..038eae0257 100644 --- a/thirdparty/mbedtls/library/x509_crt.c +++ b/thirdparty/mbedtls/library/x509_crt.c @@ -27,6 +27,8 @@ * * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf + * + * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf */ #if !defined(MBEDTLS_CONFIG_FILE) @@ -39,6 +41,7 @@ #include "mbedtls/x509_crt.h" #include "mbedtls/oid.h" +#include "mbedtls/platform_util.h" #include <stdio.h> #include <string.h> @@ -88,10 +91,18 @@ #endif /* !_WIN32 || EFIX64 || EFI32 */ #endif -/* Implementation that should never be optimized out by the compiler */ -static void mbedtls_zeroize( void *v, size_t n ) { - volatile unsigned char *p = v; while( n-- ) *p++ = 0; -} +/* + * Item in a verification chain: cert and flags for it + */ +typedef struct { + mbedtls_x509_crt *crt; + uint32_t flags; +} x509_crt_verify_chain_item; + +/* + * Max size of verification chain: end-entity + intermediates + trusted root + */ +#define X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 ) /* * Default profile @@ -160,7 +171,7 @@ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb = /* * Check md_alg against profile - * Return 0 if md_alg acceptable for this profile, -1 otherwise + * Return 0 if md_alg is acceptable for this profile, -1 otherwise */ static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile, mbedtls_md_type_t md_alg ) @@ -173,7 +184,7 @@ static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile, /* * Check pk_alg against profile - * Return 0 if pk_alg acceptable for this profile, -1 otherwise + * Return 0 if pk_alg is acceptable for this profile, -1 otherwise */ static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile, mbedtls_pk_type_t pk_alg ) @@ -186,12 +197,13 @@ static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile, /* * Check key against profile - * Return 0 if pk_alg acceptable for this profile, -1 otherwise + * Return 0 if pk is acceptable for this profile, -1 otherwise */ static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile, - mbedtls_pk_type_t pk_alg, const mbedtls_pk_context *pk ) { + const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk ); + #if defined(MBEDTLS_RSA_C) if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS ) { @@ -207,7 +219,7 @@ static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile, pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH ) { - mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id; + const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id; if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 ) return( 0 ); @@ -730,7 +742,7 @@ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char * memcpy( p, buf, crt->raw.len ); - // Direct pointers to the new buffer + // Direct pointers to the new buffer p += crt->raw.len - len; end = crt_end = p + len; @@ -1112,7 +1124,7 @@ int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path ) ret = mbedtls_x509_crt_parse( chain, buf, n ); - mbedtls_zeroize( buf, n ); + mbedtls_platform_zeroize( buf, n ); mbedtls_free( buf ); return( ret ); @@ -1662,7 +1674,7 @@ int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509 /* * Check that the given certificate is not revoked according to the CRL. - * Skip validation is no CRL for the given CA is present. + * Skip validation if no CRL for the given CA is present. */ static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca, mbedtls_x509_crl *crl_list, @@ -1707,18 +1719,14 @@ static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca, flags |= MBEDTLS_X509_BADCRL_BAD_PK; md_info = mbedtls_md_info_from_type( crl_list->sig_md ); - if( md_info == NULL ) + if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 ) { - /* - * Cannot check 'unknown' hash - */ + /* Note: this can't happen except after an internal error */ flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED; break; } - mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ); - - if( x509_profile_check_key( profile, crl_list->sig_pk, &ca->pk ) != 0 ) + if( x509_profile_check_key( profile, &ca->pk ) != 0 ) flags |= MBEDTLS_X509_BADCERT_BAD_KEY; if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk, @@ -1786,13 +1794,14 @@ static int x509_memcasecmp( const void *s1, const void *s2, size_t len ) /* * Return 0 if name matches wildcard, -1 otherwise */ -static int x509_check_wildcard( const char *cn, mbedtls_x509_buf *name ) +static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name ) { size_t i; size_t cn_idx = 0, cn_len = strlen( cn ); + /* We can't have a match if there is no wildcard to match */ if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' ) - return( 0 ); + return( -1 ); for( i = 0; i < cn_len; ++i ) { @@ -1884,15 +1893,40 @@ static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b } /* + * Check the signature of a certificate by its parent + */ +static int x509_crt_check_signature( const mbedtls_x509_crt *child, + mbedtls_x509_crt *parent ) +{ + const mbedtls_md_info_t *md_info; + unsigned char hash[MBEDTLS_MD_MAX_SIZE]; + + md_info = mbedtls_md_info_from_type( child->sig_md ); + if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 ) + { + /* Note: this can't happen except after an internal error */ + return( -1 ); + } + + if( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk, + child->sig_md, hash, mbedtls_md_get_size( md_info ), + child->sig.p, child->sig.len ) != 0 ) + { + return( -1 ); + } + + return( 0 ); +} + +/* * Check if 'parent' is a suitable parent (signing CA) for 'child'. * Return 0 if yes, -1 if not. * * top means parent is a locally-trusted certificate - * bottom means child is the end entity cert */ static int x509_crt_check_parent( const mbedtls_x509_crt *child, const mbedtls_x509_crt *parent, - int top, int bottom ) + int top ) { int need_ca_bit; @@ -1907,14 +1941,6 @@ static int x509_crt_check_parent( const mbedtls_x509_crt *child, if( top && parent->version < 3 ) need_ca_bit = 0; - /* Exception: self-signed end-entity certs that are locally trusted. */ - if( top && bottom && - child->raw.len == parent->raw.len && - memcmp( child->raw.p, parent->raw.p, child->raw.len ) == 0 ) - { - need_ca_bit = 0; - } - if( need_ca_bit && ! parent->ca_istrue ) return( -1 ); @@ -1929,86 +1955,78 @@ static int x509_crt_check_parent( const mbedtls_x509_crt *child, return( 0 ); } -static int x509_crt_verify_top( - mbedtls_x509_crt *child, mbedtls_x509_crt *trust_ca, - mbedtls_x509_crl *ca_crl, - const mbedtls_x509_crt_profile *profile, - int path_cnt, int self_cnt, uint32_t *flags, - int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), - void *p_vrfy ) +/* + * Find a suitable parent for child in candidates, or return NULL. + * + * Here suitable is defined as: + * 1. subject name matches child's issuer + * 2. if necessary, the CA bit is set and key usage allows signing certs + * 3. for trusted roots, the signature is correct + * 4. pathlen constraints are satisfied + * + * If there's a suitable candidate which is also time-valid, return the first + * such. Otherwise, return the first suitable candidate (or NULL if there is + * none). + * + * The rationale for this rule is that someone could have a list of trusted + * roots with two versions on the same root with different validity periods. + * (At least one user reported having such a list and wanted it to just work.) + * The reason we don't just require time-validity is that generally there is + * only one version, and if it's expired we want the flags to state that + * rather than NOT_TRUSTED, as would be the case if we required it here. + * + * The rationale for rule 3 (signature for trusted roots) is that users might + * have two versions of the same CA with different keys in their list, and the + * way we select the correct one is by checking the signature (as we don't + * rely on key identifier extensions). (This is one way users might choose to + * handle key rollover, another relies on self-issued certs, see [SIRO].) + * + * Arguments: + * - [in] child: certificate for which we're looking for a parent + * - [in] candidates: chained list of potential parents + * - [in] top: 1 if candidates consists of trusted roots, ie we're at the top + * of the chain, 0 otherwise + * - [in] path_cnt: number of intermediates seen so far + * - [in] self_cnt: number of self-signed intermediates seen so far + * (will never be greater than path_cnt) + * + * Return value: + * - the first suitable parent found (see above regarding time-validity) + * - NULL if no suitable parent was found + */ +static mbedtls_x509_crt *x509_crt_find_parent_in( mbedtls_x509_crt *child, + mbedtls_x509_crt *candidates, + int top, + size_t path_cnt, + size_t self_cnt ) { - int ret; - uint32_t ca_flags = 0; - int check_path_cnt; - unsigned char hash[MBEDTLS_MD_MAX_SIZE]; - const mbedtls_md_info_t *md_info; - mbedtls_x509_crt *future_past_ca = NULL; + mbedtls_x509_crt *parent, *badtime_parent = NULL; - if( mbedtls_x509_time_is_past( &child->valid_to ) ) - *flags |= MBEDTLS_X509_BADCERT_EXPIRED; - - if( mbedtls_x509_time_is_future( &child->valid_from ) ) - *flags |= MBEDTLS_X509_BADCERT_FUTURE; - - if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_MD; - - if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_PK; - - /* - * Child is the top of the chain. Check against the trust_ca list. - */ - *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; - - md_info = mbedtls_md_info_from_type( child->sig_md ); - if( md_info == NULL ) + for( parent = candidates; parent != NULL; parent = parent->next ) { - /* - * Cannot check 'unknown', no need to try any CA - */ - trust_ca = NULL; - } - else - mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ); - - for( /* trust_ca */ ; trust_ca != NULL; trust_ca = trust_ca->next ) - { - if( x509_crt_check_parent( child, trust_ca, 1, path_cnt == 0 ) != 0 ) + /* basic parenting skills (name, CA bit, key usage) */ + if( x509_crt_check_parent( child, parent, top ) != 0 ) continue; - check_path_cnt = path_cnt + 1; - - /* - * Reduce check_path_cnt to check against if top of the chain is - * the same as the trusted CA - */ - if( child->subject_raw.len == trust_ca->subject_raw.len && - memcmp( child->subject_raw.p, trust_ca->subject_raw.p, - child->issuer_raw.len ) == 0 ) - { - check_path_cnt--; - } - - /* Self signed certificates do not count towards the limit */ - if( trust_ca->max_pathlen > 0 && - trust_ca->max_pathlen < check_path_cnt - self_cnt ) + /* +1 because stored max_pathlen is 1 higher that the actual value */ + if( parent->max_pathlen > 0 && + (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt ) { continue; } - if( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &trust_ca->pk, - child->sig_md, hash, mbedtls_md_get_size( md_info ), - child->sig.p, child->sig.len ) != 0 ) + /* Signature */ + if( top && x509_crt_check_signature( child, parent ) != 0 ) { continue; } - if( mbedtls_x509_time_is_past( &trust_ca->valid_to ) || - mbedtls_x509_time_is_future( &trust_ca->valid_from ) ) + /* optional time check */ + if( mbedtls_x509_time_is_past( &parent->valid_to ) || + mbedtls_x509_time_is_future( &parent->valid_from ) ) { - if ( future_past_ca == NULL ) - future_past_ca = trust_ca; + if( badtime_parent == NULL ) + badtime_parent = parent; continue; } @@ -2016,190 +2034,292 @@ static int x509_crt_verify_top( break; } - if( trust_ca != NULL || ( trust_ca = future_past_ca ) != NULL ) - { - /* - * Top of chain is signed by a trusted CA - */ - *flags &= ~MBEDTLS_X509_BADCERT_NOT_TRUSTED; + if( parent == NULL ) + parent = badtime_parent; - if( x509_profile_check_key( profile, child->sig_pk, &trust_ca->pk ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; - } + return( parent ); +} - /* - * If top of chain is not the same as the trusted CA send a verify request - * to the callback for any issues with validity and CRL presence for the - * trusted CA certificate. - */ - if( trust_ca != NULL && - ( child->subject_raw.len != trust_ca->subject_raw.len || - memcmp( child->subject_raw.p, trust_ca->subject_raw.p, - child->issuer_raw.len ) != 0 ) ) - { -#if defined(MBEDTLS_X509_CRL_PARSE_C) - /* Check trusted CA's CRL for the chain's top crt */ - *flags |= x509_crt_verifycrl( child, trust_ca, ca_crl, profile ); -#else - ((void) ca_crl); -#endif +/* + * Find a parent in trusted CAs or the provided chain, or return NULL. + * + * Searches in trusted CAs first, and return the first suitable parent found + * (see find_parent_in() for definition of suitable). + * + * Arguments: + * - [in] child: certificate for which we're looking for a parent, followed + * by a chain of possible intermediates + * - [in] trust_ca: locally trusted CAs + * - [out] 1 if parent was found in trust_ca, 0 if found in provided chain + * - [in] path_cnt: number of intermediates seen so far + * - [in] self_cnt: number of self-signed intermediates seen so far + * (will always be no greater than path_cnt) + * + * Return value: + * - the first suitable parent found (see find_parent_in() for "suitable") + * - NULL if no suitable parent was found + */ +static mbedtls_x509_crt *x509_crt_find_parent( mbedtls_x509_crt *child, + mbedtls_x509_crt *trust_ca, + int *parent_is_trusted, + size_t path_cnt, + size_t self_cnt ) +{ + mbedtls_x509_crt *parent; - if( mbedtls_x509_time_is_past( &trust_ca->valid_to ) ) - ca_flags |= MBEDTLS_X509_BADCERT_EXPIRED; + /* Look for a parent in trusted CAs */ + *parent_is_trusted = 1; + parent = x509_crt_find_parent_in( child, trust_ca, 1, path_cnt, self_cnt ); - if( mbedtls_x509_time_is_future( &trust_ca->valid_from ) ) - ca_flags |= MBEDTLS_X509_BADCERT_FUTURE; + if( parent != NULL ) + return( parent ); - if( NULL != f_vrfy ) - { - if( ( ret = f_vrfy( p_vrfy, trust_ca, path_cnt + 1, - &ca_flags ) ) != 0 ) - { - return( ret ); - } - } - } + /* Look for a parent upwards the chain */ + *parent_is_trusted = 0; + return( x509_crt_find_parent_in( child, child->next, 0, path_cnt, self_cnt ) ); +} - /* Call callback on top cert */ - if( NULL != f_vrfy ) +/* + * Check if an end-entity certificate is locally trusted + * + * Currently we require such certificates to be self-signed (actually only + * check for self-issued as self-signatures are not checked) + */ +static int x509_crt_check_ee_locally_trusted( + mbedtls_x509_crt *crt, + mbedtls_x509_crt *trust_ca ) +{ + mbedtls_x509_crt *cur; + + /* must be self-issued */ + if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 ) + return( -1 ); + + /* look for an exact match with trusted cert */ + for( cur = trust_ca; cur != NULL; cur = cur->next ) { - if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 ) - return( ret ); + if( crt->raw.len == cur->raw.len && + memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 ) + { + return( 0 ); + } } - *flags |= ca_flags; - - return( 0 ); + /* too bad */ + return( -1 ); } -static int x509_crt_verify_child( - mbedtls_x509_crt *child, mbedtls_x509_crt *parent, - mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, +/* + * Build and verify a certificate chain + * + * Given a peer-provided list of certificates EE, C1, ..., Cn and + * a list of trusted certs R1, ... Rp, try to build and verify a chain + * EE, Ci1, ... Ciq [, Rj] + * such that every cert in the chain is a child of the next one, + * jumping to a trusted root as early as possible. + * + * Verify that chain and return it with flags for all issues found. + * + * Special cases: + * - EE == Rj -> return a one-element list containing it + * - EE, Ci1, ..., Ciq cannot be continued with a trusted root + * -> return that chain with NOT_TRUSTED set on Ciq + * + * Arguments: + * - [in] crt: the cert list EE, C1, ..., Cn + * - [in] trust_ca: the trusted list R1, ..., Rp + * - [in] ca_crl, profile: as in verify_with_profile() + * - [out] ver_chain, chain_len: the built and verified chain + * + * Return value: + * - non-zero if the chain could not be fully built and examined + * - 0 is the chain was successfully built and examined, + * even if it was found to be invalid + */ +static int x509_crt_verify_chain( + mbedtls_x509_crt *crt, + mbedtls_x509_crt *trust_ca, + mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, - int path_cnt, int self_cnt, uint32_t *flags, - int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), - void *p_vrfy ) + x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE], + size_t *chain_len ) { - int ret; - uint32_t parent_flags = 0; - unsigned char hash[MBEDTLS_MD_MAX_SIZE]; - mbedtls_x509_crt *grandparent; - const mbedtls_md_info_t *md_info; + uint32_t *flags; + mbedtls_x509_crt *child; + mbedtls_x509_crt *parent; + int parent_is_trusted = 0; + int child_is_trusted = 0; + size_t self_cnt = 0; - /* Counting intermediate self signed certificates */ - if( ( path_cnt != 0 ) && x509_name_cmp( &child->issuer, &child->subject ) == 0 ) - self_cnt++; + child = crt; + *chain_len = 0; - /* path_cnt is 0 for the first intermediate CA */ - if( 1 + path_cnt > MBEDTLS_X509_MAX_INTERMEDIATE_CA ) - { - /* return immediately as the goal is to avoid unbounded recursion */ - return( MBEDTLS_ERR_X509_FATAL_ERROR ); - } + while( 1 ) { + /* Add certificate to the verification chain */ + ver_chain[*chain_len].crt = child; + flags = &ver_chain[*chain_len].flags; + ++*chain_len; - if( mbedtls_x509_time_is_past( &child->valid_to ) ) - *flags |= MBEDTLS_X509_BADCERT_EXPIRED; + /* Check time-validity (all certificates) */ + if( mbedtls_x509_time_is_past( &child->valid_to ) ) + *flags |= MBEDTLS_X509_BADCERT_EXPIRED; - if( mbedtls_x509_time_is_future( &child->valid_from ) ) - *flags |= MBEDTLS_X509_BADCERT_FUTURE; + if( mbedtls_x509_time_is_future( &child->valid_from ) ) + *flags |= MBEDTLS_X509_BADCERT_FUTURE; - if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_MD; + /* Stop here for trusted roots (but not for trusted EE certs) */ + if( child_is_trusted ) + return( 0 ); - if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_PK; + /* Check signature algorithm: MD & PK algs */ + if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 ) + *flags |= MBEDTLS_X509_BADCERT_BAD_MD; - md_info = mbedtls_md_info_from_type( child->sig_md ); - if( md_info == NULL ) - { - /* - * Cannot check 'unknown' hash - */ - *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; - } - else - { - mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ); + if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 ) + *flags |= MBEDTLS_X509_BADCERT_BAD_PK; - if( x509_profile_check_key( profile, child->sig_pk, &parent->pk ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; + /* Special case: EE certs that are locally trusted */ + if( *chain_len == 1 && + x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 ) + { + return( 0 ); + } - if( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk, - child->sig_md, hash, mbedtls_md_get_size( md_info ), - child->sig.p, child->sig.len ) != 0 ) + /* Look for a parent in trusted CAs or up the chain */ + parent = x509_crt_find_parent( child, trust_ca, &parent_is_trusted, + *chain_len - 1, self_cnt ); + + /* No parent? We're done here */ + if( parent == NULL ) { *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; + return( 0 ); + } + + /* Count intermediate self-issued (not necessarily self-signed) certs. + * These can occur with some strategies for key rollover, see [SIRO], + * and should be excluded from max_pathlen checks. */ + if( *chain_len != 1 && + x509_name_cmp( &child->issuer, &child->subject ) == 0 ) + { + self_cnt++; } - } + + /* path_cnt is 0 for the first intermediate CA, + * and if parent is trusted it's not an intermediate CA */ + if( ! parent_is_trusted && + *chain_len > MBEDTLS_X509_MAX_INTERMEDIATE_CA ) + { + /* return immediately to avoid overflow the chain array */ + return( MBEDTLS_ERR_X509_FATAL_ERROR ); + } + + /* if parent is trusted, the signature was checked by find_parent() */ + if( ! parent_is_trusted && x509_crt_check_signature( child, parent ) != 0 ) + *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; + + /* check size of signing key */ + if( x509_profile_check_key( profile, &parent->pk ) != 0 ) + *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; #if defined(MBEDTLS_X509_CRL_PARSE_C) - /* Check trusted CA's CRL for the given crt */ - *flags |= x509_crt_verifycrl(child, parent, ca_crl, profile ); + /* Check trusted CA's CRL for the given crt */ + *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile ); +#else + (void) ca_crl; #endif - /* Look for a grandparent in trusted CAs */ - for( grandparent = trust_ca; - grandparent != NULL; - grandparent = grandparent->next ) + /* prepare for next iteration */ + child = parent; + parent = NULL; + child_is_trusted = parent_is_trusted; + } +} + +/* + * Check for CN match + */ +static int x509_crt_check_cn( const mbedtls_x509_buf *name, + const char *cn, size_t cn_len ) +{ + /* try exact match */ + if( name->len == cn_len && + x509_memcasecmp( cn, name->p, cn_len ) == 0 ) { - if( x509_crt_check_parent( parent, grandparent, - 0, path_cnt == 0 ) == 0 ) - break; + return( 0 ); } - if( grandparent != NULL ) + /* try wildcard match */ + if( x509_check_wildcard( cn, name ) == 0 ) { - ret = x509_crt_verify_top( parent, grandparent, ca_crl, profile, - path_cnt + 1, self_cnt, &parent_flags, f_vrfy, p_vrfy ); - if( ret != 0 ) - return( ret ); + return( 0 ); } - else + + return( -1 ); +} + +/* + * Verify the requested CN - only call this if cn is not NULL! + */ +static void x509_crt_verify_name( const mbedtls_x509_crt *crt, + const char *cn, + uint32_t *flags ) +{ + const mbedtls_x509_name *name; + const mbedtls_x509_sequence *cur; + size_t cn_len = strlen( cn ); + + if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) { - /* Look for a grandparent upwards the chain */ - for( grandparent = parent->next; - grandparent != NULL; - grandparent = grandparent->next ) + for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next ) { - /* +2 because the current step is not yet accounted for - * and because max_pathlen is one higher than it should be. - * Also self signed certificates do not count to the limit. */ - if( grandparent->max_pathlen > 0 && - grandparent->max_pathlen < 2 + path_cnt - self_cnt ) - { - continue; - } - - if( x509_crt_check_parent( parent, grandparent, - 0, path_cnt == 0 ) == 0 ) + if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 ) break; } - /* Is our parent part of the chain or at the top? */ - if( grandparent != NULL ) - { - ret = x509_crt_verify_child( parent, grandparent, trust_ca, ca_crl, - profile, path_cnt + 1, self_cnt, &parent_flags, - f_vrfy, p_vrfy ); - if( ret != 0 ) - return( ret ); - } - else + if( cur == NULL ) + *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; + } + else + { + for( name = &crt->subject; name != NULL; name = name->next ) { - ret = x509_crt_verify_top( parent, trust_ca, ca_crl, profile, - path_cnt + 1, self_cnt, &parent_flags, - f_vrfy, p_vrfy ); - if( ret != 0 ) - return( ret ); + if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 && + x509_crt_check_cn( &name->val, cn, cn_len ) == 0 ) + { + break; + } } + + if( name == NULL ) + *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; } +} - /* child is verified to be a child of the parent, call verify callback */ - if( NULL != f_vrfy ) - if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 ) - return( ret ); +/* + * Merge the flags for all certs in the chain, after calling callback + */ +static int x509_crt_merge_flags_with_cb( + uint32_t *flags, + x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE], + size_t chain_len, + int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), + void *p_vrfy ) +{ + int ret; + size_t i; + uint32_t cur_flags; + + for( i = chain_len; i != 0; --i ) + { + cur_flags = ver_chain[i-1].flags; + + if( NULL != f_vrfy ) + if( ( ret = f_vrfy( p_vrfy, ver_chain[i-1].crt, (int) i-1, &cur_flags ) ) != 0 ) + return( ret ); - *flags |= parent_flags; + *flags |= cur_flags; + } return( 0 ); } @@ -2218,9 +2338,15 @@ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt, &mbedtls_x509_crt_profile_default, cn, flags, f_vrfy, p_vrfy ) ); } - /* * Verify the certificate validity, with profile + * + * This function: + * - checks the requested CN (if any) + * - checks the type and size of the EE cert's key, + * as that isn't done as part of chain building/verification currently + * - builds and verifies the chain + * - then calls the callback and merges the flags */ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, @@ -2230,15 +2356,15 @@ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { - size_t cn_len; int ret; - int pathlen = 0, selfsigned = 0; - mbedtls_x509_crt *parent; - mbedtls_x509_name *name; - mbedtls_x509_sequence *cur = NULL; mbedtls_pk_type_t pk_type; + x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE]; + size_t chain_len; + uint32_t *ee_flags = &ver_chain[0].flags; *flags = 0; + memset( ver_chain, 0, sizeof( ver_chain ) ); + chain_len = 0; if( profile == NULL ) { @@ -2246,104 +2372,28 @@ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt, goto exit; } + /* check name if requested */ if( cn != NULL ) - { - name = &crt->subject; - cn_len = strlen( cn ); - - if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) - { - cur = &crt->subject_alt_names; - - while( cur != NULL ) - { - if( cur->buf.len == cn_len && - x509_memcasecmp( cn, cur->buf.p, cn_len ) == 0 ) - break; - - if( cur->buf.len > 2 && - memcmp( cur->buf.p, "*.", 2 ) == 0 && - x509_check_wildcard( cn, &cur->buf ) == 0 ) - { - break; - } - - cur = cur->next; - } - - if( cur == NULL ) - *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; - } - else - { - while( name != NULL ) - { - if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 ) - { - if( name->val.len == cn_len && - x509_memcasecmp( name->val.p, cn, cn_len ) == 0 ) - break; - - if( name->val.len > 2 && - memcmp( name->val.p, "*.", 2 ) == 0 && - x509_check_wildcard( cn, &name->val ) == 0 ) - break; - } - - name = name->next; - } - - if( name == NULL ) - *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; - } - } + x509_crt_verify_name( crt, cn, ee_flags ); /* Check the type and size of the key */ pk_type = mbedtls_pk_get_type( &crt->pk ); if( x509_profile_check_pk_alg( profile, pk_type ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_PK; + *ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK; - if( x509_profile_check_key( profile, pk_type, &crt->pk ) != 0 ) - *flags |= MBEDTLS_X509_BADCERT_BAD_KEY; + if( x509_profile_check_key( profile, &crt->pk ) != 0 ) + *ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY; - /* Look for a parent in trusted CAs */ - for( parent = trust_ca; parent != NULL; parent = parent->next ) - { - if( x509_crt_check_parent( crt, parent, 0, pathlen == 0 ) == 0 ) - break; - } - - if( parent != NULL ) - { - ret = x509_crt_verify_top( crt, parent, ca_crl, profile, - pathlen, selfsigned, flags, f_vrfy, p_vrfy ); - if( ret != 0 ) - goto exit; - } - else - { - /* Look for a parent upwards the chain */ - for( parent = crt->next; parent != NULL; parent = parent->next ) - if( x509_crt_check_parent( crt, parent, 0, pathlen == 0 ) == 0 ) - break; + /* Check the chain */ + ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile, + ver_chain, &chain_len ); + if( ret != 0 ) + goto exit; - /* Are we part of the chain or at the top? */ - if( parent != NULL ) - { - ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl, profile, - pathlen, selfsigned, flags, f_vrfy, p_vrfy ); - if( ret != 0 ) - goto exit; - } - else - { - ret = x509_crt_verify_top( crt, trust_ca, ca_crl, profile, - pathlen, selfsigned, flags, f_vrfy, p_vrfy ); - if( ret != 0 ) - goto exit; - } - } + /* Build final flags, calling callback on the way if any */ + ret = x509_crt_merge_flags_with_cb( flags, + ver_chain, chain_len, f_vrfy, p_vrfy ); exit: /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by @@ -2400,7 +2450,7 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) { name_prv = name_cur; name_cur = name_cur->next; - mbedtls_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); + mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); mbedtls_free( name_prv ); } @@ -2409,7 +2459,7 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) { name_prv = name_cur; name_cur = name_cur->next; - mbedtls_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); + mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); mbedtls_free( name_prv ); } @@ -2418,7 +2468,8 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) { seq_prv = seq_cur; seq_cur = seq_cur->next; - mbedtls_zeroize( seq_prv, sizeof( mbedtls_x509_sequence ) ); + mbedtls_platform_zeroize( seq_prv, + sizeof( mbedtls_x509_sequence ) ); mbedtls_free( seq_prv ); } @@ -2427,13 +2478,14 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) { seq_prv = seq_cur; seq_cur = seq_cur->next; - mbedtls_zeroize( seq_prv, sizeof( mbedtls_x509_sequence ) ); + mbedtls_platform_zeroize( seq_prv, + sizeof( mbedtls_x509_sequence ) ); mbedtls_free( seq_prv ); } if( cert_cur->raw.p != NULL ) { - mbedtls_zeroize( cert_cur->raw.p, cert_cur->raw.len ); + mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len ); mbedtls_free( cert_cur->raw.p ); } @@ -2447,7 +2499,7 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ) cert_prv = cert_cur; cert_cur = cert_cur->next; - mbedtls_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) ); + mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) ); if( cert_prv != crt ) mbedtls_free( cert_prv ); } |