Renaming x509_get_subject_alt_name to x509_get_general_names and mbedtls_x509_parse_subject_alt_name to mbedtls_x509_parse_general_name so they can be used not only to collect subject alt name, but the V3 authority cert issuer that is also GeneralName type.

Also updated the x509_get_general_names function to be able to parse rfc822Names

Test are also updated according these changes.

Signed-off-by: toth92g <toth92g@gmail.com>

include/mbedtls/x509.h

@@ -249,7 +249,7 @@ typedef mbedtls_asn1_sequence mbedtls_x509_sequence;
 typedef struct mbedtls_x509_authority
 {
     mbedtls_x509_buf keyIdentifier;
-    mbedtls_x509_name authorityCertIssuer;
+    mbedtls_x509_sequence authorityCertIssuer;
     mbedtls_x509_buf authorityCertSerialNumber;
     mbedtls_x509_buf raw;
 }

include/mbedtls/x509_crt.h

@@ -610,7 +610,7 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
  * \param san      The target structure to populate with the parsed presentation
  *                 of the subject alternative name encoded in \p san_raw.
  *
- * \note           Only "dnsName" and "otherName" of type hardware_module_name
+ * \note           Only "dnsName" and "otherName" and "rfc822Name" of type hardware_module_name
  *                 as defined in RFC 4180 is supported.
  *
  * \note           This function should be called on a single raw data of
@@ -628,7 +628,7 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
  *                 SAN type.
  * \return         Another negative value for any other failure.
  */
-int mbedtls_x509_parse_subject_alt_name( const mbedtls_x509_buf *san_buf,
+int mbedtls_x509_parse_general_name( const mbedtls_x509_buf *san_buf,
                                          mbedtls_x509_subject_alternative_name *san );
 
 #if !defined(MBEDTLS_X509_REMOVE_INFO)

library/x509_crt.c

@@ -645,103 +645,6 @@ static int x509_get_subject_key_id( unsigned char** p,
 }
 
 /*
- * AuthorityKeyIdentifier ::= SEQUENCE {
- *        keyIdentifier [0] KeyIdentifier OPTIONAL,
- *        authorityCertIssuer [1] GeneralNames OPTIONAL,
- *        authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
- *
- *    KeyIdentifier ::= OCTET STRING
- */
-static int x509_get_authority_key_id( unsigned char** p,
-    unsigned char* end,
-    mbedtls_x509_authority* authority_key_id )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t len = 0u;
-
-    if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
-        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
-    {
-        return( ret );
-    }
-
-    if ( (ret = mbedtls_asn1_get_tag( p, end, &len,
-        MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
-    {
-        /* KeyIdentifier is an OPTIONAL field */
-    }
-    else
-    {
-        authority_key_id->keyIdentifier.len = len;
-        authority_key_id->keyIdentifier.p = *p;
-        authority_key_id->keyIdentifier.tag = MBEDTLS_ASN1_OCTET_STRING;
-
-        *p += len;
-    }
-
-    if ( *p < end )
-    {
-        if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
-            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_BOOLEAN ) ) != 0 )
-        {
-            /* authorityCertIssuer is an OPTIONAL field */
-        }
-        else
-        {
-            if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
-                MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
-            {
-                return( ret );
-            }
-            else
-            {
-                authority_key_id->raw.p = *p;
-
-                if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
-                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
-                {
-                    return( ret );
-                }
-
-                if ( ( ret = mbedtls_x509_get_name( p, *p + len, &authority_key_id->authorityCertIssuer ) ) != 0 )
-                {
-                    return( ret );
-                }
-
-                authority_key_id->raw.len = *p - authority_key_id->raw.p;
-            }
-        }
-    }
-
-    if ( *p < end )
-    {
-        if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
-            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_INTEGER ) ) != 0 )
-        {
-            /* authorityCertSerialNumber is an OPTIONAL field, but if there are still data it must be the serial number */
-            return( ret );
-        }
-        else
-        {
-            authority_key_id->authorityCertSerialNumber.len = len;
-            authority_key_id->authorityCertSerialNumber.p = *p;
-            authority_key_id->authorityCertSerialNumber.tag = MBEDTLS_ASN1_OCTET_STRING;
-            *p += len;
-        }
-    }
-
-    if ( *p != end )
-    {
-        return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
-            MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
-    }
-
-    return( 0 );
-}
-
-/*
- * SubjectAltName ::= GeneralNames
- *
  * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
  *
  * GeneralName ::= CHOICE {
@@ -766,7 +669,7 @@ static int x509_get_authority_key_id( unsigned char** p,
  * NOTE: we list all types, but only use dNSName and otherName
  * of type HwModuleName, as defined in RFC 4108, at this point.
  */
-static int x509_get_subject_alt_name( unsigned char **p,
+static int x509_get_general_names( unsigned char **p,
                                       const unsigned char *end,
                                       mbedtls_x509_sequence *subject_alt_name )
 {
@@ -795,17 +698,19 @@ static int x509_get_subject_alt_name( unsigned char **p,
         if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
             return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret ) );
 
+        /* Tag shall be CONTEXT_SPECIFIC or SET */
         if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
                 MBEDTLS_ASN1_CONTEXT_SPECIFIC )
         {
-            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
-                    MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
+            if( ( tag & (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
+                return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+                        MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
         }
 
         /*
          * Check that the SAN is structured correctly.
          */
-        ret = mbedtls_x509_parse_subject_alt_name( &(cur->buf), &dummy_san_buf );
+        ret = mbedtls_x509_parse_general_name( &(cur->buf), &dummy_san_buf );
         /*
          * In case the extension is malformed, return an error,
          * and clear the allocated sequences.
@@ -849,6 +754,91 @@ static int x509_get_subject_alt_name( unsigned char **p,
     return( 0 );
 }
 
+/*
+ * AuthorityKeyIdentifier ::= SEQUENCE {
+ *        keyIdentifier [0] KeyIdentifier OPTIONAL,
+ *        authorityCertIssuer [1] GeneralNames OPTIONAL,
+ *        authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
+ *
+ *    KeyIdentifier ::= OCTET STRING
+ */
+static int x509_get_authority_key_id( unsigned char** p,
+    unsigned char* end,
+    mbedtls_x509_authority* authority_key_id )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len = 0u;
+
+    if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE | 0 ) ) != 0 )
+    {
+        return( ret );
+    }
+
+    if ( (ret = mbedtls_asn1_get_tag( p, end, &len,
+        MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
+    {
+        /* KeyIdentifier is an OPTIONAL field */
+    }
+    else
+    {
+        authority_key_id->keyIdentifier.len = len;
+        authority_key_id->keyIdentifier.p = *p;
+        authority_key_id->keyIdentifier.tag = MBEDTLS_ASN1_OCTET_STRING;
+
+        *p += len;
+    }
+
+    if ( *p < end )
+    {
+        if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) != 0)
+        {
+            /* authorityCertIssuer is an OPTIONAL field */
+        }
+        else
+        {
+            if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 4 ) ) != 0)
+            {
+                return(ret);
+            }
+            else
+            {
+                /* "end" also includes the CertSerialNumber field so "len" shall be used */
+                ret = x509_get_general_names( p,
+                    (*p+len),
+                    &authority_key_id->authorityCertIssuer );
+            }
+        }
+    }
+
+    if ( *p < end )
+    {
+        if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_INTEGER ) ) != 0 )
+        {
+            /* authorityCertSerialNumber is an OPTIONAL field, but if there are still data it must be the serial number */
+            return( ret );
+        }
+        else
+        {
+            authority_key_id->authorityCertSerialNumber.len = len;
+            authority_key_id->authorityCertSerialNumber.p = *p;
+            authority_key_id->authorityCertSerialNumber.tag = MBEDTLS_ASN1_OCTET_STRING;
+            *p += len;
+        }
+    }
+
+    if ( *p != end )
+    {
+        return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+            MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+    }
+
+    return( 0 );
+}
+
 /*
  * id-ce-certificatePolicies OBJECT IDENTIFIER ::=  { id-ce 32 }
  *
@@ -1132,6 +1122,7 @@ static int x509_get_crt_ext( unsigned char **p,
                     &crt->ext_key_usage ) ) != 0 )
                 return( ret );
             break;
+
         case MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER:
             /* Parse subject key identifier */
             if ( ( ret = x509_get_subject_key_id( p, end_ext_data,
@@ -1140,17 +1131,20 @@ static int x509_get_crt_ext( unsigned char **p,
                 return ( ret );
             }
             break;
+
         case MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER:
             /* Parse authority key identifier */
-            if ( (ret = x509_get_authority_key_id(p, end_ext_octet,
-                    &crt->authority_key_id)) != 0 )
+            if ( ( ret = x509_get_authority_key_id( p, end_ext_octet,
+                    &crt->authority_key_id ) ) != 0 )
             {
                 return ( ret );
             }
             break;
         case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
-            /* Parse subject alt name */
-            if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
+            /* Parse subject alt name 
+             * SubjectAltName ::= GeneralNames
+             */
+            if( ( ret = x509_get_general_names( p, end_ext_octet,
                     &crt->subject_alt_names ) ) != 0 )
                 return( ret );
             break;
@@ -1989,7 +1983,7 @@ static int x509_info_subject_alt_name( char **buf, size_t *size,
     while( cur != NULL )
     {
         memset( &san, 0, sizeof( san ) );
-        parse_ret = mbedtls_x509_parse_subject_alt_name( &cur->buf, &san );
+        parse_ret = mbedtls_x509_parse_general_name( &cur->buf, &san );
         if( parse_ret != 0 )
         {
             if( parse_ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE )
@@ -2080,6 +2074,80 @@ static int x509_info_subject_alt_name( char **buf, size_t *size,
     return( 0 );
 }
 
+int mbedtls_x509_parse_general_name( const mbedtls_x509_buf *san_buf,
+                                         mbedtls_x509_subject_alternative_name *san )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    switch( san_buf->tag &
+            ( MBEDTLS_ASN1_TAG_CLASS_MASK |
+              MBEDTLS_ASN1_TAG_VALUE_MASK ) )
+    {
+        /*
+         * otherName
+         */
+        case( MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_OTHER_NAME ):
+        {
+            mbedtls_x509_san_other_name other_name;
+
+            ret = x509_get_other_name( san_buf, &other_name );
+            if( ret != 0 )
+                return( ret );
+
+            memset( san, 0, sizeof( mbedtls_x509_subject_alternative_name ) );
+            san->type = MBEDTLS_X509_SAN_OTHER_NAME;
+            memcpy( &san->san.other_name,
+                    &other_name, sizeof( other_name ) );
+
+        }
+        break;
+
+        /*
+         * dNSName
+         */
+        case( MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_DNS_NAME ):
+        {
+            memset( san, 0, sizeof( mbedtls_x509_subject_alternative_name ) );
+            san->type = MBEDTLS_X509_SAN_DNS_NAME;
+
+            memcpy( &san->san.unstructured_name,
+                    san_buf, sizeof( *san_buf ) );
+
+        }
+        break;
+
+        /*
+         * RFC822 Name
+         */
+        case( MBEDTLS_ASN1_SEQUENCE | MBEDTLS_X509_SAN_RFC822_NAME ):
+        {
+            mbedtls_x509_name rfc822Name;
+            unsigned char* bufferPointer = san_buf->p;
+            unsigned char** p = &bufferPointer;
+            const unsigned char* end = san_buf->p + san_buf->len;
+            
+            /* The leading ASN1 tag and length has been processed. Stepping back with 2 bytes, because mbedtls_x509_get_name expects the beginning of the SET tag */
+            *p = *p - 2;
+
+            ret = mbedtls_x509_get_name( p, end, &rfc822Name );
+            if ( ret != 0 )
+                return( ret );
+
+            memset( san, 0, sizeof( mbedtls_x509_subject_alternative_name ) );
+            san->type = MBEDTLS_X509_SAN_OTHER_NAME;
+            memcpy( &san->san.unstructured_name,
+                &rfc822Name, sizeof( rfc822Name ) );
+        }
+        break;
+
+        /*
+         * Type not supported
+         */
+        default:
+            return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
+    }
+    return( 0 );
+}
+
 #define PRINT_ITEM(i)                           \
     {                                           \
         ret = mbedtls_snprintf( p, n, "%s" i, sep );    \
@@ -3442,13 +3510,14 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
         mbedtls_asn1_sequence_free( cert_cur->subject_alt_names.next );
         mbedtls_asn1_sequence_free( cert_cur->certificate_policies.next );
 
-        name_cur = cert_cur->authority_key_id.authorityCertIssuer.next;
-        while ( name_cur != NULL )
+        seq_cur = cert_cur->authority_key_id.authorityCertIssuer.next;
+        while ( seq_cur != NULL )
         {
-            name_prv = name_cur;
-            name_cur = name_cur->next;
-            mbedtls_platform_zeroize( name_prv, sizeof(mbedtls_x509_name) );
-            mbedtls_free( name_prv );
+            seq_prv = seq_cur;
+            seq_cur = seq_cur->next;
+            mbedtls_platform_zeroize( seq_prv,
+                sizeof( mbedtls_x509_sequence ) );
+            mbedtls_free( seq_prv );
         }
 
         if( cert_cur->raw.p != NULL && cert_cur->own_buffer )

tests/suites/test_suite_x509parse.data

@@ -2926,4 +2926,4 @@ x509_crt_parse_authoritykeyid:"308203873082026fa003020102020100300d06092a864886f
 
 X509 CRT parse Authority Key Id - Wrong Issuer Tag 4
 depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
-x509_crt_parse_authoritykeyid:"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":0:"":0:MBEDTLS_ERR_ASN1_UNEXPECTED_TAG + MBEDTLS_ERR_X509_INVALID_NAME
+x509_crt_parse_authoritykeyid:"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":0:"":0:MBEDTLS_ERR_ASN1_UNEXPECTED_TAG

tests/suites/test_suite_x509parse.function

@@ -434,7 +434,7 @@ void x509_parse_san( char * crt_file, char * result_str )
         cur = &crt.subject_alt_names;
         while( cur != NULL )
         {
-            ret = mbedtls_x509_parse_subject_alt_name( &cur->buf, &san );
+            ret = mbedtls_x509_parse_general_name( &cur->buf, &san );
             TEST_ASSERT( ret == 0 || ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
             /*
              * If san type not supported, ignore.
@@ -1447,18 +1447,19 @@ void x509_crt_parse_authoritykeyid( data_t * buf, unsigned int keyIdLength, char
         TEST_ASSERT( crt.authority_key_id.keyIdentifier.len == keyIdLength );
 
         /* Issuer test */
-        mbedtls_x509_name* issuerPtr = &crt.authority_key_id.authorityCertIssuer;
+        mbedtls_x509_sequence* issuerPtr = &crt.authority_key_id.authorityCertIssuer;
         while ( issuerPtr != NULL )
         {
-            for ( issuerCounter = 0u; issuerCounter < issuerPtr->val.len; issuerCounter++ )
+            /* First 9 bytes are always ASN1 coding related information that does not matter right now. Only the values are asserted */
+            for ( issuerCounter = 9u; issuerCounter < issuerPtr->buf.len; issuerCounter++ )
             {
-                result |= ( authorityKeyId_issuer[bufferCounter++] != issuerPtr->val.p[issuerCounter] );
+                result |= ( authorityKeyId_issuer[bufferCounter++] != issuerPtr->buf.p[issuerCounter] );
             }
             bufferCounter++; /* Skipping the slash */
             issuerPtr = issuerPtr->next;
         }
         TEST_ASSERT( result == 0 );
-        
+
         /* Serial test */
         TEST_ASSERT( crt.authority_key_id.authorityCertSerialNumber.tag == MBEDTLS_ASN1_OCTET_STRING );
         TEST_ASSERT( crt.authority_key_id.authorityCertSerialNumber.len == serialLength );