diff --git a/ChangeLog.d/X509Parse_SignatureKeyId_AuthorityKeyId.txt b/ChangeLog.d/X509Parse_SignatureKeyId_AuthorityKeyId.txt
index cf4c9e9531..9aa3ff91d1 100644
--- a/ChangeLog.d/X509Parse_SignatureKeyId_AuthorityKeyId.txt
+++ b/ChangeLog.d/X509Parse_SignatureKeyId_AuthorityKeyId.txt
@@ -1,2 +1,3 @@
-API changes
-   * x509 certificate parse functionality is extended with the possibility of extracting SignatureKeyId and AuthorityKeyId fields
+Features
+   * When parsing X.509 certificates, support the extensions
+     SignatureKeyIdentifier and AuthorityKeyIdentifier.
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 5395f455df..5a356af9b8 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -624,8 +624,8 @@ static int x509_get_subject_key_id( unsigned char** p,
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0u;
 
-    if ( (ret = mbedtls_asn1_get_tag(p, end, &len,
-        MBEDTLS_ASN1_OCTET_STRING)) != 0 )
+    if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+        MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
     {
         return( ret );
     }
@@ -636,6 +636,10 @@ static int x509_get_subject_key_id( unsigned char** p,
         subject_key_id->p = *p;
         *p += len;
     }
+	
+	if( *p != end )
+		return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+			MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
 
     return( 0 );
 }
@@ -655,14 +659,14 @@ static int x509_get_authority_key_id( unsigned char** p,
     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 )
+    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 )
+    if ( (ret = mbedtls_asn1_get_tag( p, end, &len,
+        MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
     {
         /* KeyIdentifier is an OPTIONAL field */
     }
@@ -677,15 +681,15 @@ static int x509_get_authority_key_id( unsigned char** p,
 
     if ( *p < end )
     {
-        if ( (ret = mbedtls_asn1_get_tag(p, end, &len,
-            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_BOOLEAN)) != 0 )
+        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 )
+            if ( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+                MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
             {
                 return( ret );
             }
@@ -693,13 +697,13 @@ static int x509_get_authority_key_id( unsigned char** p,
             {
                 authority_key_id->raw.p = *p;
 
-                if ( (ret = mbedtls_asn1_get_tag(p, end, &len,
-                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0 )
+                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 )
+                if ( ( ret = mbedtls_x509_get_name( p, *p + len, &authority_key_id->authorityCertIssuer ) ) != 0 )
                 {
                     return( ret );
                 }
@@ -711,8 +715,8 @@ static int x509_get_authority_key_id( unsigned char** p,
 
     if ( *p < end )
     {
-        if ( (ret = mbedtls_asn1_get_tag(p, end, &len,
-            MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_INTEGER)) != 0 )
+        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 );
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 8408d88bfd..3a56adf0fa 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -1414,16 +1414,16 @@ void mbedtls_x509_crt_parse_subjectkeyid( char * crt_path, char *subjectKeyId, i
 
     TEST_ASSERT( mbedtls_x509_crt_parse_file( &crt, crt_path ) == retVal );
 
-    if(retVal != 0)
+    if( retVal != 0 )
     {
-        while(i < subjectKeyIdLength)
+        while( i < subjectKeyIdLength )
         {
             result |= crt.subject_key_id.p[i] != subjectKeyId[i*2];
             result |= crt.subject_key_id.p[i+1] != subjectKeyId[i*2+1];
             i++;
         }
 
-        TEST_ASSERT(result == 0);
+        TEST_ASSERT( result == 0 );
     }
 
 exit:
@@ -1444,10 +1444,10 @@ void mbedtls_x509_crt_parse_authoritykeyid( char * crt_path, char *authorityKeyI
 
     TEST_ASSERT( mbedtls_x509_crt_parse_file( &crt, crt_path ) == retVal );
 
-    if (retVal != 0)
+    if ( retVal != 0 )
     {
         /* KeyId test */
-        while(i < keyIdLength)
+        while( i < keyIdLength )
         {
             result |= crt.authority_key_id.keyIdentifier.p[i] != authorityKeyId_keyId[i*2];
             result |= crt.authority_key_id.keyIdentifier.p[i+1] != authorityKeyId_keyId[i*2+1];
@@ -1456,11 +1456,11 @@ void mbedtls_x509_crt_parse_authoritykeyid( char * crt_path, char *authorityKeyI
 
         /* Issuer test */
         mbedtls_x509_name* issuerPtr = &crt.authority_key_id.authorityCertIssuer;
-        while (issuerPtr != NULL)
+        while ( issuerPtr != NULL )
         {
-            for (issuerCounter = 0u; issuerCounter < issuerPtr->val.len; issuerCounter++)
+            for ( issuerCounter = 0u; issuerCounter < issuerPtr->val.len; issuerCounter++ )
             {
-                result |= (authorityKeyId_issuer[bufferCounter++] != issuerPtr->val.p[issuerCounter]);
+                result |= ( authorityKeyId_issuer[bufferCounter++] != issuerPtr->val.p[issuerCounter] );
             }
             bufferCounter++; /* Skipping the slash */
             issuerPtr = issuerPtr->next;
@@ -1468,14 +1468,14 @@ void mbedtls_x509_crt_parse_authoritykeyid( char * crt_path, char *authorityKeyI
 
         /* Serial test */
         i = 0;
-        while(i < serialLength)
+        while( i < serialLength )
         {
             result |= crt.authority_key_id.authorityCertSerialNumber.p[i] != authorityKeyId_serial[i*2];
             result |= crt.authority_key_id.authorityCertSerialNumber.p[i+1] != authorityKeyId_serial[i*2+1];
             i++;
         }
 
-        TEST_ASSERT(result == 0);
+        TEST_ASSERT( result == 0 );
     }
 
 exit: