KUZNYECHIK-CTR_ACPKM-OMAC implementation

1 files changed, 254 insertions, 80 deletions

diff --git a/gost_grasshopper_cipher.c b/gost_grasshopper_cipher.c
index 75a0408..9cef0c5 100644
--- a/gost_grasshopper_cipher.c
+++ b/gost_grasshopper_cipher.c
@@ -24,10 +24,11 @@ enum GRASSHOPPER_CIPHER_TYPE {
     GRASSHOPPER_CIPHER_CFB,
     GRASSHOPPER_CIPHER_CTR,
     GRASSHOPPER_CIPHER_CTRACPKM,
+    GRASSHOPPER_CIPHER_CTRACPKMOMAC,
 };
 
-static EVP_CIPHER *gost_grasshopper_ciphers[6] = {
-    NULL, NULL, NULL, NULL, NULL, NULL,
+static EVP_CIPHER *gost_grasshopper_ciphers[7] = {
+    NULL, NULL, NULL, NULL, NULL, NULL, NULL
 };
 
 static GRASSHOPPER_INLINE void
@@ -42,69 +43,87 @@ struct GRASSHOPPER_CIPHER_PARAMS {
     int ctx_size;
     int iv_size;
     bool padding;
+    int extra_flags;
 };
 
-static struct GRASSHOPPER_CIPHER_PARAMS gost_cipher_params[6] = {
- {
-                                NID_grasshopper_ecb,
-                                gost_grasshopper_cipher_init_ecb,
-                                gost_grasshopper_cipher_do_ecb,
-                                NULL,
-                                16,
-                                sizeof(gost_grasshopper_cipher_ctx),
-                                0,
-                                true}
-    ,
-    {
-                                NID_grasshopper_cbc,
-                                gost_grasshopper_cipher_init_cbc,
-                                gost_grasshopper_cipher_do_cbc,
-                                NULL,
-                                16,
-                                sizeof(gost_grasshopper_cipher_ctx),
-                                16,
-                                true}
-    ,
-    {
-                                NID_grasshopper_ofb,
-                                gost_grasshopper_cipher_init_ofb,
-                                gost_grasshopper_cipher_do_ofb,
-                                NULL,
-                                1,
-                                sizeof(gost_grasshopper_cipher_ctx),
-                                16,
-                                false}
-    ,
-    {
-                                NID_grasshopper_cfb,
-                                gost_grasshopper_cipher_init_cfb,
-                                gost_grasshopper_cipher_do_cfb,
-                                NULL,
-                                1,
-                                sizeof(gost_grasshopper_cipher_ctx),
-                                16,
-                                false}
-    ,
-    {
-                                NID_grasshopper_ctr,
-                                gost_grasshopper_cipher_init_ctr,
-                                gost_grasshopper_cipher_do_ctr,
-                                gost_grasshopper_cipher_destroy_ctr,
-                                1,
-                                sizeof(gost_grasshopper_cipher_ctx_ctr),
-                                8,
-                                false}
-    ,
-    {
-                                NID_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm,
-                                gost_grasshopper_cipher_init_ctracpkm,
-                                gost_grasshopper_cipher_do_ctracpkm,
-                                gost_grasshopper_cipher_destroy_ctr,
-                                1,
-                                sizeof(gost_grasshopper_cipher_ctx_ctr),
-                                8,
-                                false}
-    ,
+static struct GRASSHOPPER_CIPHER_PARAMS gost_cipher_params[7] = {
+	{
+		NID_grasshopper_ecb,
+		gost_grasshopper_cipher_init_ecb,
+		gost_grasshopper_cipher_do_ecb,
+		NULL,
+		16,
+		sizeof(gost_grasshopper_cipher_ctx),
+		0,
+		true,
+		0
+	},
+	{
+		NID_grasshopper_cbc,
+		gost_grasshopper_cipher_init_cbc,
+		gost_grasshopper_cipher_do_cbc,
+		NULL,
+		16,
+		sizeof(gost_grasshopper_cipher_ctx),
+		16,
+		true,
+		0
+	},
+	{
+		NID_grasshopper_ofb,
+		gost_grasshopper_cipher_init_ofb,
+		gost_grasshopper_cipher_do_ofb,
+		NULL,
+		1,
+		sizeof(gost_grasshopper_cipher_ctx),
+		16,
+		false,
+		0
+	},
+	{
+		NID_grasshopper_cfb,
+		gost_grasshopper_cipher_init_cfb,
+		gost_grasshopper_cipher_do_cfb,
+		NULL,
+		1,
+		sizeof(gost_grasshopper_cipher_ctx),
+		16,
+		false,
+		0
+	},
+	{
+		NID_grasshopper_ctr,
+		gost_grasshopper_cipher_init_ctr,
+		gost_grasshopper_cipher_do_ctr,
+		gost_grasshopper_cipher_destroy_ctr,
+		1,
+		sizeof(gost_grasshopper_cipher_ctx_ctr),
+		8,
+		false,
+		0
+	},
+	{
+		NID_kuznyechik_ctr_acpkm,
+		gost_grasshopper_cipher_init_ctracpkm,
+		gost_grasshopper_cipher_do_ctracpkm,
+		gost_grasshopper_cipher_destroy_ctr,
+		1,
+		sizeof(gost_grasshopper_cipher_ctx_ctr),
+		8,
+		false,
+		0
+	},
+	{
+		NID_kuznyechik_ctr_acpkm_omac,
+		gost_grasshopper_cipher_init_ctracpkm_omac,
+		gost_grasshopper_cipher_do_ctracpkm_omac,
+		gost_grasshopper_cipher_destroy_ctr,
+		1,
+		sizeof(gost_grasshopper_cipher_ctx_ctr),
+		8,
+		false,
+		EVP_CIPH_FLAG_CUSTOM_CIPHER|EVP_CIPH_FLAG_CIPHER_WITH_MAC|EVP_CIPH_CUSTOM_COPY
+	},
 };
 
 /* first 256 bit of D from draft-irtf-cfrg-re-keying-12 */
@@ -182,6 +201,9 @@ gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx * c)
     gost_grasshopper_cipher_ctx_ctr *ctx =
         (gost_grasshopper_cipher_ctx_ctr *) c;
 
+    if (ctx->omac_ctx)
+        EVP_MD_CTX_free(ctx->omac_ctx);
+
     grasshopper_zero128(&ctx->partial_buffer);
 }
 
@@ -278,6 +300,54 @@ GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm(EVP_CIPHER_CTX
     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 }
 
+GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm_omac(EVP_CIPHER_CTX
+                                                             *ctx, const unsigned
+                                                             char *key, const unsigned
+                                                             char *iv, int enc)
+{
+	gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
+
+	/* NB: setting type makes EVP do_cipher callback useless */
+	c->c.type = GRASSHOPPER_CIPHER_CTRACPKMOMAC;
+	EVP_CIPHER_CTX_set_num(ctx, 0);
+	c->section_size = 4096;
+
+	if (key) {
+		unsigned char keys[64];
+		const EVP_MD *md = EVP_get_digestbynid(NID_kuznyechik_mac);
+		EVP_PKEY *mac_key;
+
+		if (md == NULL)
+			return 0;
+
+		if (enc) {
+			if (RAND_bytes(c->kdf_seed, 8) != 1)
+				return 0;
+		}
+
+		if (gost_kdftree2012_256(keys, 64, key, 32, (const unsigned char *)"kdf tree", 8, c->kdf_seed, 8, 1) <= 0)
+			return 0;
+
+		c->omac_ctx = EVP_MD_CTX_new();
+		mac_key = EVP_PKEY_new_mac_key(NID_kuznyechik_mac, NULL, keys+32, 32);
+
+		if (mac_key == NULL || c->omac_ctx == NULL) {
+			EVP_PKEY_free(mac_key);
+			return 0;
+		}
+
+		if (EVP_DigestInit_ex(c->omac_ctx, md, NULL) <= 0 ||
+				EVP_DigestSignInit(c->omac_ctx, NULL, md, NULL, mac_key) <= 0) {
+			EVP_PKEY_free(mac_key);
+			return 0;
+		}
+		EVP_PKEY_free(mac_key);
+
+		return gost_grasshopper_cipher_init(ctx, keys, iv, enc);
+	}
+	return gost_grasshopper_cipher_init(ctx, key, iv, enc);
+}
+
 GRASSHOPPER_INLINE int gost_grasshopper_cipher_do(EVP_CIPHER_CTX *ctx,
                                                   unsigned char *out,
                                                   const unsigned char *in,
@@ -498,9 +568,31 @@ int gost_grasshopper_cipher_do_ctracpkm(EVP_CIPHER_CTX *ctx,
     }
     EVP_CIPHER_CTX_set_num(ctx, num);
 
-    return 1;
+    return inl;
 }
 
+int gost_grasshopper_cipher_do_ctracpkm_omac(EVP_CIPHER_CTX *ctx,
+                                        unsigned char *out,
+                                        const unsigned char *in, size_t inl)
+{
+	int result;
+  gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
+	/* As in and out can be the same pointer, process unencrypted here */
+	if (EVP_CIPHER_CTX_encrypting(ctx))
+		EVP_DigestSignUpdate(c->omac_ctx, in, inl);
+
+	if (in == NULL && inl == 0) { /* Final call */
+		return gost2015_final_call(ctx, c->omac_ctx, KUZNYECHIK_MAC_MAX_SIZE, c->tag, gost_grasshopper_cipher_do_ctracpkm);
+	}
+
+	result = gost_grasshopper_cipher_do_ctracpkm(ctx, out, in, inl);
+
+	/* As in and out can be the same pointer, process decrypted here */
+	if (!EVP_CIPHER_CTX_encrypting(ctx))
+		EVP_DigestSignUpdate(c->omac_ctx, out, inl);
+
+	return result;
+}
 /*
  * Fixed 128-bit IV implementation make shift regiser redundant.
  */
@@ -691,6 +783,9 @@ int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX *ctx, ASN1_TYPE *params)
 	if (EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_CTR_MODE) {
 		gost_grasshopper_cipher_ctx_ctr *ctr = EVP_CIPHER_CTX_get_cipher_data(ctx);
 
+		/* CMS implies 256kb section_size */
+		ctr->section_size = 256*1024;
+
 		return gost2015_set_asn1_params(params, EVP_CIPHER_CTX_original_iv(ctx), 8,
 				ctr->kdf_seed);
 	}
@@ -714,7 +809,7 @@ GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX
 		memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), iv, iv_len);
 		memcpy((unsigned char *)EVP_CIPHER_CTX_original_iv(ctx), iv, iv_len);
 
-		/* CMS implies 256kb mesh_section_size */
+		/* CMS implies 256kb section_size */
 		ctr->section_size = 256*1024;
 		return 1;
 	}
@@ -736,7 +831,9 @@ int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
     case EVP_CTRL_KEY_MESH:{
             gost_grasshopper_cipher_ctx_ctr *c =
                 EVP_CIPHER_CTX_get_cipher_data(ctx);
-            if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM || !arg
+            if ((c->c.type != GRASSHOPPER_CIPHER_CTRACPKM &&
+						    c->c.type != GRASSHOPPER_CIPHER_CTRACPKMOMAC)
+						    || (arg == 0)
                 || (arg % GRASSHOPPER_BLOCK_SIZE))
                 return -1;
             c->section_size = arg;
@@ -796,6 +893,78 @@ int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
         }
         return -1;
 #endif
+#if 0
+    case EVP_CTRL_AEAD_GET_TAG:
+    case EVP_CTRL_AEAD_SET_TAG:
+        {
+            int taglen = arg;
+            unsigned char *tag = ptr;
+
+            gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
+            if (c->c.type != GRASSHOPPER_CIPHER_MGM)
+                return -1;
+
+            if (taglen > KUZNYECHIK_MAC_MAX_SIZE) {
+                CRYPTOCOMerr(CRYPTOCOM_F_GOST_GRASSHOPPER_CIPHER_CTL,
+                        CRYPTOCOM_R_INVALID_TAG_LENGTH);
+                return -1;
+            }
+
+            if (type == EVP_CTRL_AEAD_GET_TAG)
+                memcpy(tag, c->final_tag, taglen);
+            else
+                memcpy(c->final_tag, tag, taglen);
+
+            return 1;
+        }
+#endif
+		case EVP_CTRL_PROCESS_UNPROTECTED:
+				{
+					gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
+					ASN1_OBJECT *cmsmacobj = NULL;
+					if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKMOMAC)
+						return -1;
+          cmsmacobj = OBJ_txt2obj(OID_GOST_CMS_MAC, 1);
+					if (cmsmacobj == NULL) {
+						GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, ERR_R_MALLOC_FAILURE);
+						return -1;
+					}
+					if (arg == 0) /*Decrypting*/ {
+						STACK_OF(X509_ATTRIBUTE) *x = ptr;
+						ASN1_OCTET_STRING *osExpectedMac = X509at_get0_data_by_OBJ(x,
+								cmsmacobj, -3, V_ASN1_OCTET_STRING);
+						ASN1_OBJECT_free(cmsmacobj);
+
+						if (ptr == NULL || osExpectedMac ==NULL || osExpectedMac->length != KUZNYECHIK_MAC_MAX_SIZE)
+							return -1;
+
+						memcpy(c->tag, osExpectedMac->data, osExpectedMac->length);
+						return 1;
+					} else {
+						STACK_OF(X509_ATTRIBUTE) *x = ptr;
+						return (X509at_add1_attr_by_OBJ(&x, cmsmacobj,
+									V_ASN1_OCTET_STRING, c->tag, KUZNYECHIK_MAC_MAX_SIZE) == NULL) ? -1 : 1;
+					}
+				}
+			return 1;
+    case EVP_CTRL_COPY: {
+			EVP_CIPHER_CTX *out = ptr;
+
+      gost_grasshopper_cipher_ctx_ctr *out_cctx = EVP_CIPHER_CTX_get_cipher_data(out);
+      gost_grasshopper_cipher_ctx_ctr *in_cctx  = EVP_CIPHER_CTX_get_cipher_data(ctx);
+
+      if (in_cctx->c.type != GRASSHOPPER_CIPHER_CTRACPKMOMAC)
+          return -1;
+
+			if (in_cctx->omac_ctx == out_cctx->omac_ctx) {
+				out_cctx->omac_ctx = EVP_MD_CTX_new();
+				if (out_cctx->omac_ctx == NULL) {
+					GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, ERR_R_MALLOC_FAILURE);
+					return -1;
+				}
+			}
+			return EVP_MD_CTX_copy(out_cctx->omac_ctx, in_cctx->omac_ctx);
+		}
     default:
         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
                 GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
@@ -813,20 +982,16 @@ GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_create(int
 }
 
 const int cipher_gost_grasshopper_setup(EVP_CIPHER *cipher, uint8_t mode,
-                                        int iv_size, bool padding)
+                                        int iv_size, bool padding, int extra_flags)
 {
+	unsigned long flags = (unsigned long)(mode
+	         | ((!padding) ?  EVP_CIPH_NO_PADDING : 0)
+					 | ((iv_size >  0) ?  EVP_CIPH_CUSTOM_IV : 0)
+					 | EVP_CIPH_RAND_KEY | 	EVP_CIPH_ALWAYS_CALL_INIT
+					 | extra_flags);
+
     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size)
-        && EVP_CIPHER_meth_set_flags(cipher,
-                                     (unsigned long)(mode |
-                                                     ((!padding) ?
-                                                      EVP_CIPH_NO_PADDING :
-                                                      0) | ((iv_size >
-                                                             0) ?
-                                                            EVP_CIPH_CUSTOM_IV
-                                                            : 0) |
-                                                     EVP_CIPH_RAND_KEY |
-                                                     EVP_CIPH_ALWAYS_CALL_INIT)
-        )
+        && EVP_CIPHER_meth_set_flags(cipher, flags)
         && EVP_CIPHER_meth_set_cleanup(cipher, gost_grasshopper_cipher_cleanup)
         && EVP_CIPHER_meth_set_set_asn1_params(cipher,
                                                gost_grasshopper_set_asn1_parameters)
@@ -846,7 +1011,7 @@ const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
 
     if (*cipher == NULL) {
         grasshopper_init_cipher_func init_cipher;
-        int nid, block_size, ctx_size, iv_size;
+        int nid, block_size, ctx_size, iv_size, extra_flags;
         bool padding;
 
         params = &gost_cipher_params[num];
@@ -857,13 +1022,14 @@ const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
         ctx_size = params->ctx_size;
         iv_size = params->iv_size;
         padding = params->padding;
+				extra_flags = params->extra_flags;
 
         *cipher = cipher_gost_grasshopper_create(nid, block_size);
         if (*cipher == NULL) {
             return NULL;
         }
 
-        if (!cipher_gost_grasshopper_setup(*cipher, mode, iv_size, padding)
+        if (!cipher_gost_grasshopper_setup(*cipher, mode, iv_size, padding, extra_flags)
             || !EVP_CIPHER_meth_set_init(*cipher, init_cipher)
             || !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
             EVP_CIPHER_meth_free(*cipher);
@@ -905,6 +1071,12 @@ const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm()
                                    GRASSHOPPER_CIPHER_CTRACPKM);
 }
 
+const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm_omac()
+{
+    return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
+                                   GRASSHOPPER_CIPHER_CTRACPKMOMAC);
+}
+
 void cipher_gost_grasshopper_destroy(void)
 {
     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
@@ -919,4 +1091,6 @@ void cipher_gost_grasshopper_destroy(void)
     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM]);
     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
+    EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKMOMAC]);
+    gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKMOMAC] = NULL;
 }