Create cert profile API (unimplemented yet)

include/mbedtls/x509.h

@@ -97,6 +97,13 @@
 #define MBEDTLS_X509_BADCERT_KEY_USAGE         0x0800  /**< Usage does not match the keyUsage extension. */
 #define MBEDTLS_X509_BADCERT_EXT_KEY_USAGE     0x1000  /**< Usage does not match the extendedKeyUsage extension. */
 #define MBEDTLS_X509_BADCERT_NS_CERT_TYPE      0x2000  /**< Usage does not match the nsCertType extension. */
+#define MBEDTLS_X509_BADCERT_BAD_MD            0x4000  /**< The certificate is signed with an unacceptable hash. */
+#define MBEDTLS_X509_BADCERT_BAD_PK            0x8000  /**< The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
+#define MBEDTLS_X509_BADCERT_BAD_KEY         0x010000  /**< The certificate is signed with an unacceptable key (eg bad curve, RSA too short). */
+#define MBEDTLS_X509_BADCRL_BAD_MD           0x020000  /**< The CRL is signed with an unacceptable hash. */
+#define MBEDTLS_X509_BADCRL_BAD_PK           0x040000  /**< The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
+#define MBEDTLS_X509_BADCRL_BAD_KEY          0x080000  /**< The CRL is signed with an unacceptable key (eg bad curve, RSA too short). */
+
 /* \} name */
 /* \} addtogroup x509_module */
 

include/mbedtls/x509_crt.h

@@ -94,6 +94,20 @@ typedef struct mbedtls_x509_crt
 }
 mbedtls_x509_crt;
 
+/*
+ * Security profile for certificate verification
+ *
+ * All lists are terminated by the respective _NONE value.
+ */
+typedef struct
+{
+    const mbedtls_md_type_t *allowed_mds;   /**< MDs for signatures         */
+    const mbedtls_pk_type_t *allowed_pks;   /**< PK algs for signatures     */
+    size_t rsa_min_bitlen;                  /**< Minimum size for RSA keys  */
+    const mbedtls_ecp_group *allowed_curves;/**< Elliptic curves for ECDSA  */
+}
+mbedtls_x509_crt_profile;
+
 #define MBEDTLS_X509_CRT_VERSION_1              0
 #define MBEDTLS_X509_CRT_VERSION_2              1
 #define MBEDTLS_X509_CRT_VERSION_3              2
@@ -232,6 +246,9 @@ int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
  * \note           In case verification failed, the results can be displayed
  *                 using \c mbedtls_x509_crt_verify_info()
  *
+ * \note           Same as \c mbedtls_x509_crt_verify_with_profile() with the
+ *                 default security profile.
+ *
  * \param crt      a certificate to be verified
  * \param trust_ca the trusted CA chain
  * \param ca_crl   the CRL chain for trusted CA's
@@ -255,6 +272,37 @@ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
                      void *p_vrfy );
 
+/**
+ * \brief          Verify the certificate signature according to profile
+ *
+ * \note           Same as \c mbedtls_x509_crt_verify(), but with explicit
+ *                 security profile.
+ *
+ * \param crt      a certificate to be verified
+ * \param trust_ca the trusted CA chain
+ * \param ca_crl   the CRL chain for trusted CA's
+ * \param profile  security profile for verification
+ * \param cn       expected Common Name (can be set to
+ *                 NULL if the CN must not be verified)
+ * \param flags    result of the verification
+ * \param f_vrfy   verification function
+ * \param p_vrfy   verification parameter
+ *
+ * \return         0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED
+ *                 in which case *flags will have one or more
+ *                 MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags
+ *                 set,
+ *                 or another error in case of a fatal error encountered
+ *                 during the verification process.
+ */
+int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
+                     mbedtls_x509_crt *trust_ca,
+                     mbedtls_x509_crl *ca_crl,
+                     const mbedtls_x509_crt_profile *profile,
+                     const char *cn, uint32_t *flags,
+                     int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+                     void *p_vrfy );
+
 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
 /**
  * \brief          Check usage of certificate against keyUsage extension.

library/x509_crt.c

@@ -1401,6 +1401,12 @@ static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
     { MBEDTLS_X509_BADCERT_KEY_USAGE,     "Usage does not match the keyUsage extension" },
     { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
     { MBEDTLS_X509_BADCERT_NS_CERT_TYPE,  "Usage does not match the nsCertType extension" },
+    { MBEDTLS_X509_BADCERT_BAD_MD,        "The certificate is signed with an unacceptable hash." },
+    { MBEDTLS_X509_BADCERT_BAD_PK,        "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
+    { MBEDTLS_X509_BADCERT_BAD_KEY,       "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
+    { MBEDTLS_X509_BADCRL_BAD_MD,         "The CRL is signed with an unacceptable hash." },
+    { MBEDTLS_X509_BADCRL_BAD_PK,         "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
+    { MBEDTLS_X509_BADCRL_BAD_KEY,        "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
     { 0, NULL }
 };
 
@@ -1502,7 +1508,8 @@ int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509
  * Check that the given certificate is valid according to the CRL.
  */
 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
-                               mbedtls_x509_crl *crl_list)
+                               mbedtls_x509_crl *crl_list,
+                               const mbedtls_x509_crt_profile *profile )
 {
     int flags = 0;
     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
@@ -1554,6 +1561,8 @@ static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
 
         mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash );
 
+        (void) profile; /* WIP:TODO: check profile */
+
         if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
                            crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
                            crl_list->sig.p, crl_list->sig.len ) != 0 )
@@ -1764,7 +1773,9 @@ static int x509_crt_check_parent( const mbedtls_x509_crt *child,
 
 static int x509_crt_verify_top(
                 mbedtls_x509_crt *child, mbedtls_x509_crt *trust_ca,
-                mbedtls_x509_crl *ca_crl, int path_cnt, uint32_t *flags,
+                mbedtls_x509_crl *ca_crl,
+                const mbedtls_x509_crt_profile *profile,
+                int path_cnt, uint32_t *flags,
                 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
                 void *p_vrfy )
 {
@@ -1796,6 +1807,8 @@ static int x509_crt_verify_top(
     else
         mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash );
 
+    (void) profile; /* WIP:TODO: check profile */
+
     for( /* trust_ca */ ; trust_ca != NULL; trust_ca = trust_ca->next )
     {
         if( x509_crt_check_parent( child, trust_ca, 1, path_cnt == 0 ) != 0 )
@@ -1846,7 +1859,7 @@ static int x509_crt_verify_top(
     {
 #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 );
+        *flags |= x509_crt_verifycrl( child, trust_ca, ca_crl, profile );
 #else
         ((void) ca_crl);
 #endif
@@ -1880,8 +1893,10 @@ static int x509_crt_verify_top(
 }
 
 static int x509_crt_verify_child(
-                mbedtls_x509_crt *child, mbedtls_x509_crt *parent, mbedtls_x509_crt *trust_ca,
+                mbedtls_x509_crt *child, mbedtls_x509_crt *parent,
-                mbedtls_x509_crl *ca_crl, int path_cnt, uint32_t *flags,
+                mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl,
+                const mbedtls_x509_crt_profile *profile,
+                int path_cnt, uint32_t *flags,
                 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
                 void *p_vrfy )
 {
@@ -1891,6 +1906,8 @@ static int x509_crt_verify_child(
     mbedtls_x509_crt *grandparent;
     const mbedtls_md_info_t *md_info;
 
+    (void) profile; /* WIP */
+
     /* path_cnt is 0 for the first intermediate CA */
     if( 1 + path_cnt > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
     {
@@ -1914,6 +1931,8 @@ static int x509_crt_verify_child(
     }
     else
     {
+        (void) profile; /* WIP:TODO: check profile */
+
         mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash );
 
         if( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
@@ -1926,7 +1945,7 @@ static int x509_crt_verify_child(
 
 #if defined(MBEDTLS_X509_CRL_PARSE_C)
     /* Check trusted CA's CRL for the given crt */
-    *flags |= x509_crt_verifycrl(child, parent, ca_crl);
+    *flags |= x509_crt_verifycrl(child, parent, ca_crl, profile );
 #endif
 
     /* Look for a grandparent upwards the chain */
@@ -1942,14 +1961,14 @@ static int x509_crt_verify_child(
     /* 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,
+        ret = x509_crt_verify_child( parent, grandparent, trust_ca, ca_crl, profile,
                                 path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
         if( ret != 0 )
             return( ret );
     }
     else
     {
-        ret = x509_crt_verify_top( parent, trust_ca, ca_crl,
+        ret = x509_crt_verify_top( parent, trust_ca, ca_crl, profile,
                                 path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
         if( ret != 0 )
             return( ret );
@@ -1974,6 +1993,22 @@ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
                      const char *cn, uint32_t *flags,
                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
                      void *p_vrfy )
+{
+    return( mbedtls_x509_crt_verify_with_profile( crt, trust_ca, ca_crl,
+                NULL /* WIP */, cn, flags, f_vrfy, p_vrfy ) );
+}
+
+
+/*
+ * Verify the certificate validity, with profile
+ */
+int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
+                     mbedtls_x509_crt *trust_ca,
+                     mbedtls_x509_crl *ca_crl,
+                     const mbedtls_x509_crt_profile *profile,
+                     const char *cn, uint32_t *flags,
+                     int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+                     void *p_vrfy )
 {
     size_t cn_len;
     int ret;
@@ -2044,14 +2079,14 @@ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
     /* Are we part of the chain or at the top? */
     if( parent != NULL )
     {
-        ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl,
+        ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl, profile,
                                      pathlen, flags, f_vrfy, p_vrfy );
         if( ret != 0 )
             return( ret );
     }
     else
     {
-        ret = x509_crt_verify_top( crt, trust_ca, ca_crl,
+        ret = x509_crt_verify_top( crt, trust_ca, ca_crl, profile,
                                    pathlen, flags, f_vrfy, p_vrfy );
         if( ret != 0 )
             return( ret );

tests/suites/test_suite_x509parse.data

@@ -272,7 +272,7 @@ X509 Verify Information: two issues
 x509_verify_info:MBEDTLS_X509_BADCERT_EXPIRED | MBEDTLS_X509_BADCRL_EXPIRED:"":"The certificate validity has expired\nThe CRL is expired\n"
 
 X509 Verify Information: two issues, one unknown
-x509_verify_info:MBEDTLS_X509_BADCERT_OTHER | 0x8000:"":"Other reason (can be used by verify callback)\nUnknown reason (this should not happen)\n"
+x509_verify_info:MBEDTLS_X509_BADCERT_OTHER | 0x80000000:"":"Other reason (can be used by verify callback)\nUnknown reason (this should not happen)\n"
 
 X509 Verify Information: empty, with prefix
 x509_verify_info:0:"  ! ":""