Explicitely setting cofactor

[openssl-gost/engine.git] / gost_grasshopper_cipher.c

diff --git a/gost_grasshopper_cipher.c b/gost_grasshopper_cipher.c
index 23ba575a66d424bcd56420992f285deda77a7b40..e7c8dd6299de4e93001e53b08370dda259ee1c3d 100644 (file)
--- a/gost_grasshopper_cipher.c
+++ b/gost_grasshopper_cipher.c
@@ -17,6 +17,7 @@ extern "C" {
 #include <openssl/err.h>
 #include <string.h>
 
+#include "gost_lcl.h"
 #include "e_gost_err.h"
 
 enum GRASSHOPPER_CIPHER_TYPE {
@@ -138,8 +139,6 @@ static GRASSHOPPER_INLINE void gost_grasshopper_cipher_destroy_ctr(gost_grasshop
 
     grasshopper_zero128(&ctx->iv_buffer);
     grasshopper_zero128(&ctx->partial_buffer);
-
-    ctx->counter = 0;
 }
 
 int gost_grasshopper_cipher_init(EVP_CIPHER_CTX* ctx, const unsigned char* key,
@@ -214,8 +213,6 @@ GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctr(EVP_CIPHER_CTX* ctx, con
     grasshopper_zero128(&c->iv_buffer);
     grasshopper_zero128(&c->partial_buffer);
 
-    c->counter = 0;
-
     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 }
 
@@ -283,6 +280,26 @@ int gost_grasshopper_cipher_do_cbc(EVP_CIPHER_CTX* ctx, unsigned char* out,
     return 1;
 }
 
+void inc_counter(unsigned char* counter, size_t counter_bytes)
+{
+    unsigned char c;
+    unsigned int n = counter_bytes;
+
+    do {
+        --n;
+        c = counter[n];
+        ++c;
+        counter[n] = c;
+        if (c) return;
+    } while (n);
+}
+
+/* increment counter (128-bit int) by 1 */
+static void ctr128_inc(unsigned char *counter)
+{
+       inc_counter(counter, 16);
+}
+
 int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX* ctx, unsigned char* out,
                                           const unsigned char* in, size_t inl) {
     gost_grasshopper_cipher_ctx_ctr* c = (gost_grasshopper_cipher_ctx_ctr*) EVP_CIPHER_CTX_get_cipher_data(ctx);
@@ -301,10 +318,9 @@ int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX* ctx, unsigned char* out,
     for (i = 0; i < blocks; i++) {
         currentInputBlock = (grasshopper_w128_t*) current_in;
         currentOutputBlock = (grasshopper_w128_t*) current_out;
-        memcpy(c->iv_buffer.b + 8, &c->counter, 8);
         grasshopper_encrypt_block(&c->c.encrypt_round_keys, &c->iv_buffer, currentOutputBlock, &c->c.buffer);
         grasshopper_append128(currentOutputBlock, currentInputBlock);
-        c->counter += 1;
+        ctr128_inc(c->iv_buffer.b);
         current_in += GRASSHOPPER_BLOCK_SIZE;
         current_out += GRASSHOPPER_BLOCK_SIZE;
     }
@@ -314,12 +330,11 @@ int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX* ctx, unsigned char* out,
     if (lasted > 0) {
         currentInputBlock = (grasshopper_w128_t*) current_in;
         currentOutputBlock = (grasshopper_w128_t*) current_out;
-        memcpy(c->iv_buffer.b + 8, &c->counter, 8);
         grasshopper_encrypt_block(&c->c.encrypt_round_keys, &c->iv_buffer, &c->partial_buffer, &c->c.buffer);
         for (i = 0; i < lasted; i++) {
             currentOutputBlock->b[i] = c->partial_buffer.b[i] ^ currentInputBlock->b[i];
         }
-        c->counter += 1;
+        ctr128_inc(c->iv_buffer.b);
     }
 
     return 1;
@@ -532,7 +547,7 @@ int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX* ctx, ASN1_TYPE* params)
 
     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
         OPENSSL_free(buf);
-        GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, ERR_R_MALLOC_FAILURE);
+        GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS, ERR_R_MALLOC_FAILURE);
         return 0;
     }
     OPENSSL_free(buf);
@@ -555,13 +570,13 @@ int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX* ctx, int type, int arg, void* pt
     switch (type) {
         case EVP_CTRL_RAND_KEY: {
             if (RAND_bytes((unsigned char*) ptr, EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
-                GOSTerr(GOST_F_GOST_CIPHER_CTL, GOST_R_RNG_ERROR);
+                GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_RNG_ERROR);
                 return -1;
             }
             break;
         }
         default:
-            GOSTerr(GOST_F_GOST_CIPHER_CTL, GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
+            GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
             return -1;
     }
     return 1;