ml: Support all ML-DSA private key formats

diff --git a/src/libstrongswan/plugins/ml/ml_dsa_private_key.c b/src/libstrongswan/plugins/ml/ml_dsa_private_key.c
index 359ce4ec32690b0f59ca2d496e2729645500a7cf..ee926a6657e810655e7b753e6f066b96e4709557 100644 (file)
--- a/src/libstrongswan/plugins/ml/ml_dsa_private_key.c
+++ b/src/libstrongswan/plugins/ml/ml_dsa_private_key.c
@@ -976,7 +976,8 @@ private_key_t *ml_dsa_private_key_gen(key_type_t type, va_list args)
 private_key_t *ml_dsa_private_key_load(key_type_t type, va_list args)
 {
        private_private_key_t *this;
-       chunk_t priv = chunk_empty;
+       chunk_t priv = chunk_empty, seed = chunk_empty;
+       int asn1_type;
 
        while (TRUE)
        {
@@ -997,17 +998,7 @@ private_key_t *ml_dsa_private_key_load(key_type_t type, va_list args)
        {
                return NULL;
        }
-       if (priv.len == ML_DSA_SEED_LEN + 2 &&
-               priv.ptr[0] == 0x80 && priv.ptr[1] == ML_DSA_SEED_LEN)
-       {
-               priv = chunk_skip(priv, 2);
-       }
-       if (priv.len != ML_DSA_SEED_LEN)
-       {
-               DBG1(DBG_LIB, "error: the size of the loaded ML-DSA private key seed is "
-                                         "%u bytes instead of %d bytes", priv.len, ML_DSA_SEED_LEN);
-               return NULL;
-       }
+
 
        this = create_instance(type);
        if (!this)
@@ -1015,10 +1006,81 @@ private_key_t *ml_dsa_private_key_load(key_type_t type, va_list args)
                return NULL;
        }
 
-       if (!generate_keypair(this, chunk_clone(priv)))
+       if (priv.len == ML_DSA_SEED_LEN)
        {
-               destroy(this);
-               return NULL;
+               asn1_type = ASN1_CONTEXT_S_0;
+       }
+       else
+       {
+               asn1_type = asn1_unwrap(&priv, &priv);
+       }
+
+       /* three supported ML-DSA private key formats */
+       switch(asn1_type)
+       {
+               /* private key in seed-only format */
+               case ASN1_CONTEXT_S_0:
+                       seed = priv;
+                       if (seed.len != ML_DSA_SEED_LEN ||
+                          !generate_keypair(this, chunk_clone(seed)))
+                       {
+                               DBG1(DBG_LIB, "failed to load ML-DSA private key seed");
+                               destroy(this);
+                               return NULL;
+                       }
+                       break;
+
+               /* private key in epanded format */
+               case ASN1_OCTET_STRING:
+                       if (priv.len != this->params->privkey_len)
+                       {
+                               DBG1(DBG_LIB, "failed to load ML-DSA expanded private key");
+                               destroy(this);
+                               return NULL;
+                       }
+                       memcpy(this->privkey.ptr, priv.ptr, priv.len);
+                       break;
+
+               /* private key in both seed and expanded format */
+               case ASN1_SEQUENCE:
+                       if (priv.len < 2 || priv.ptr[0] != ASN1_OCTET_STRING ||
+                               asn1_length(&priv) != ML_DSA_SEED_LEN)
+                       {
+                               DBG1(DBG_LIB, "failed to identify ML-DSA private key seed");
+                               destroy(this);
+                               return NULL;
+                       }
+                       seed = chunk_create(priv.ptr, ML_DSA_SEED_LEN);
+                       if (!generate_keypair(this, chunk_clone(seed)))
+                       {
+                               DBG1(DBG_LIB, "failed to load ML-DSA private key seed");
+                               destroy(this);
+                               return NULL;
+                       }
+                       priv.ptr += ML_DSA_SEED_LEN;
+                       priv.len -= ML_DSA_SEED_LEN;
+                       if (priv.len < 2 || priv.ptr[0] != ASN1_OCTET_STRING ||
+                               asn1_length(&priv) != this->params->privkey_len)
+                       {
+                               DBG1(DBG_LIB, "failed to identify ML-DSA expanded private key");
+                               destroy(this);
+                               return NULL;
+                       }
+                       if (!chunk_equals(priv, this->privkey))
+                       {
+                               DBG1(DBG_LIB, "loaded expanded private key is not derived "
+                                                         "from loaded seed");
+                               destroy(this);
+                               return NULL;
+                       }
+                       break;
+
+               /* invalid private key format */
+               case ASN1_INVALID:
+               default:
+                       DBG1(DBG_LIB, "unknown ML-DSA private key format");
+                       destroy(this);
+                       return NULL;
        }
 
        return &this->public;