Treat RSASSA-PSS keys like rsaEncryption RSA keys

In theory we should treat any parameters and the identifier itself as
restriction to only use the key to create signatures accordingly (e.g.
only use RSA with PSS padding or even use specific hash algorithms).
But that's currently tricky as we'd have to store and pass this information
along with our private keys (i.e. use PKCS#8 to store them and change the
builder calls to pass along the identifier and parameters). That would
require quite some work.

diff --git a/src/libstrongswan/plugins/openssl/openssl_x509.c b/src/libstrongswan/plugins/openssl/openssl_x509.c
index e4932c2a16d4fabe50ae5a1f8a427eee4d261146..60c08770b2d2355b0e32a8a95d5447c4917cf2da 100644 (file)
--- a/src/libstrongswan/plugins/openssl/openssl_x509.c
+++ b/src/libstrongswan/plugins/openssl/openssl_x509.c
@@ -1090,6 +1090,10 @@ static bool parse_certificate(private_openssl_x509_t *this)
        }
        switch (openssl_asn1_known_oid(oid))
        {
+               case OID_RSASSA_PSS:
+                       /* TODO: we should treat such keys special and use the params as
+                        * restrictions regarding the use of this key (or rather the
+                        * associated private key) */
                case OID_RSA_ENCRYPTION:
                        this->pubkey = lib->creds->create(lib->creds,
                                        CRED_PUBLIC_KEY, KEY_RSA, BUILD_BLOB_ASN1_DER,

diff --git a/src/libstrongswan/plugins/pkcs1/pkcs1_builder.c b/src/libstrongswan/plugins/pkcs1/pkcs1_builder.c
index f642947838fc3fd467b7e887cb7a3e47f09a385a..967e501d1960e33cd21ddbe95fd6ede61e4e0c05 100644 (file)
--- a/src/libstrongswan/plugins/pkcs1/pkcs1_builder.c
+++ b/src/libstrongswan/plugins/pkcs1/pkcs1_builder.c
@@ -57,8 +57,13 @@ static public_key_t *parse_public_key(chunk_t blob)
                                int oid = asn1_parse_algorithmIdentifier(object,
                                                                                parser->get_level(parser)+1, NULL);
 
-                               if (oid == OID_RSA_ENCRYPTION || oid == OID_RSAES_OAEP)
+                               if (oid == OID_RSA_ENCRYPTION || oid == OID_RSAES_OAEP ||
+                                       oid == OID_RSASSA_PSS)
                                {
+                                       /* TODO: we should parse parameters for PSS and pass them
+                                        * (and the type), or the complete subjectPublicKeyInfo,
+                                        * along so we can treat these as restrictions when
+                                        * generating signatures with the associated private key */
                                        type = KEY_RSA;
                                }
                                else if (oid == OID_EC_PUBLICKEY)

diff --git a/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
index beb8866f885836cec887ed90a38e1504ff81e78b..9c1c03dfeb2fc886e6d027e12d9b50395049b947 100644 (file)
--- a/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
+++ b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
@@ -63,6 +63,16 @@ static private_key_t *parse_private_key(chunk_t blob)
 
                                switch (oid)
                                {
+                                       case OID_RSASSA_PSS:
+                                               /* TODO: parameters associated with such keys should be
+                                                * treated as restrictions later when signing (the type
+                                                * itself is already a restriction). However, the
+                                                * builders currently don't expect any parameters for
+                                                * RSA keys (we also only pass along the params, not the
+                                                * exact type, so we'd have to guess that params
+                                                * indicate RSA/PSS, but they are optional so that won't
+                                                * work for keys without specific restrictions) */
+                                               params = chunk_empty;
                                        case OID_RSA_ENCRYPTION:
                                                type = KEY_RSA;
                                                break;