GOST CMS encryption implementation.

1 files changed, 37 insertions, 28 deletions

diff --git a/gost_ec_keyx.c b/gost_ec_keyx.c
index 2b4a96e..1d13917 100644
--- a/gost_ec_keyx.c
+++ b/gost_ec_keyx.c
@@ -179,7 +179,7 @@ int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
     struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
     int dgst_nid = NID_undef;
 
-    if (!data || !data->shared_ukm) {
+    if (!data || data->shared_ukm_size == 0) {
         GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET);
         return 0;
     }
@@ -259,7 +259,7 @@ static int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
     int key_is_ephemeral = 1;
     gost_ctx cctx;
     EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
-    if (data->shared_ukm) {
+    if (data->shared_ukm_size) {
         memcpy(ukm, data->shared_ukm, 8);
     } else {
         if (RAND_bytes(ukm, 8) <= 0) {
@@ -416,6 +416,14 @@ static int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
       key_is_ephemeral = 1;
     }
 
+    if (data->shared_ukm_size == 0) {
+      if (RAND_bytes(data->shared_ukm, 32) <= 0) {
+        GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_INTERNAL_ERROR);
+        goto err;
+			}
+      data->shared_ukm_size = 32;
+    }
+
     if (gost_keg(data->shared_ukm, pkey_nid,
                  EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
                  EVP_PKEY_get0(sec_key), expkeys) <= 0) {
@@ -437,6 +445,17 @@ static int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
         goto err;
     }
 
+    pst->ukm = ASN1_OCTET_STRING_new();
+    if (pst->ukm == NULL) {
+        GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    if (!ASN1_OCTET_STRING_set(pst->ukm, data->shared_ukm, data->shared_ukm_size)) {
+        GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
     if (!ASN1_OCTET_STRING_set(pst->psexp, exp_buf, exp_len)) {
         GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
         goto err;
@@ -462,15 +481,21 @@ static int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
 int pkey_gost_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
                       size_t *out_len, const unsigned char *key, size_t key_len)
 {
-    struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
-    if (data->shared_ukm == NULL || data->shared_ukm_size == 8)
-        return pkey_GOST_ECcp_encrypt(pctx, out, out_len, key, key_len);
-    else if (data->shared_ukm_size == 32)
-        return pkey_gost2018_encrypt(pctx, out, out_len, key, key_len);
-    else {
-        GOSTerr(GOST_F_PKEY_GOST_ENCRYPT, ERR_R_INTERNAL_ERROR);
-        return -1;
-    }
+  struct gost_pmeth_data *gctx = EVP_PKEY_CTX_get_data(pctx);
+  switch (gctx->cipher_nid)
+  {
+    case NID_id_Gost28147_89:
+    case NID_undef: /* FIXME */
+      return pkey_GOST_ECcp_encrypt(pctx, out, out_len, key, key_len);
+      break;
+    case NID_kuznyechik_ctr:
+    case NID_magma_ctr:
+      return pkey_gost2018_encrypt(pctx, out, out_len, key, key_len);
+      break;
+    default:
+      GOSTerr(GOST_F_PKEY_GOST_ENCRYPT, ERR_R_INTERNAL_ERROR);
+      return -1;
+  }
 }
 
 /*
@@ -620,7 +645,7 @@ static int pkey_gost2018_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
 
    o  q * Q_eph is not equal to zero point.
 */
-    if (data->shared_ukm == NULL && pst->ukm != NULL) {
+    if (data->shared_ukm_size == 0 && pst->ukm != NULL) {
         if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_SET_IV,
         ASN1_STRING_length(pst->ukm), (void *)ASN1_STRING_get0_data(pst->ukm)) < 0) {
             GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_UKM_NOT_SET);
@@ -628,11 +653,6 @@ static int pkey_gost2018_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
         }
     }
 
-    if (data->shared_ukm == NULL) {
-        GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_UKM_NOT_SET);
-        goto err;
-    }
-
     if (gost_keg(data->shared_ukm, pkey_nid,
                  EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)),
                  EVP_PKEY_get0(priv), expkeys) <= 0) {
@@ -661,16 +681,6 @@ int pkey_gost_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
                       size_t *key_len, const unsigned char *in, size_t in_len)
 {
     struct gost_pmeth_data *gctx = EVP_PKEY_CTX_get_data(pctx);
-#if 0
-    if (data->shared_ukm == NULL || data->shared_ukm_size == 8)
-        return pkey_GOST_ECcp_decrypt(pctx, key, key_len, in, in_len);
-    else if (data->shared_ukm_size == 32)
-        return pkey_gost2018_decrypt(pctx, key, key_len, in, in_len);
-    else {
-        GOSTerr(GOST_F_PKEY_GOST_DECRYPT, ERR_R_INTERNAL_ERROR);
-        return -1;
-    }
-#else
 	switch (gctx->cipher_nid)
 	{
 		case NID_id_Gost28147_89:
@@ -683,5 +693,4 @@ int pkey_gost_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
       GOSTerr(GOST_F_PKEY_GOST_DECRYPT, ERR_R_INTERNAL_ERROR);
       return -1;
 	}
-#endif
 }