From: Andrey Rys <rys@lynxlynx.ru>
Date: Sun, 28 Aug 2022 13:20:36 +0000 (+0200)
Subject: Add Propagating CBC (PCBC) mode
X-Git-Url: https://jxself.org/git/?a=commitdiff_plain;h=f5397c396bfedcd6de90ab648fa600aca3b22bbb;p=tfcrypt.git

Add Propagating CBC (PCBC) mode
---

diff --git a/VERSION b/VERSION
index 69a893a..3fdcd7c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-66
+67
diff --git a/tfc_bench.c b/tfc_bench.c
index 2c05538..e05ac78 100644
--- a/tfc_bench.c
+++ b/tfc_bench.c
@@ -79,6 +79,10 @@ void do_benchmark(tfc_useconds useconds, double dseconds)
 			tf_cbc_encrypt(key, ctr, srcblk, srcblk, lblock);
 		else if (ctr_mode == TFC_MODE_CBC && do_edcrypt == TFC_DO_DECRYPT)
 			tf_cbc_decrypt(key, ctr, srcblk, srcblk, lblock);
+		else if (ctr_mode == TFC_MODE_PCBC && do_edcrypt == TFC_DO_ENCRYPT)
+			tf_pcbc_encrypt(key, ctr, srcblk, srcblk, lblock);
+		else if (ctr_mode == TFC_MODE_PCBC && do_edcrypt == TFC_DO_DECRYPT)
+			tf_pcbc_decrypt(key, ctr, srcblk, srcblk, lblock);
 
 		delta_processed += lblock;
 	}
diff --git a/tfc_conf.c b/tfc_conf.c
index fc9bec7..fe36a13 100644
--- a/tfc_conf.c
+++ b/tfc_conf.c
@@ -76,6 +76,8 @@ _nspc:
 				ctr_mode = TFC_MODE_STREAM;
 			else if (!strcasecmp(d, "cbc"))
 				ctr_mode = TFC_MODE_CBC;
+			else if (!strcasecmp(d, "pcbc"))
+				ctr_mode = TFC_MODE_PCBC;
 			else if (!strcasecmp(d, "ecb"))
 				ctr_mode = TFC_MODE_ECB;
 			else if (!strcasecmp(d, "xts"))
diff --git a/tfc_misc.c b/tfc_misc.c
index 01998f2..5902896 100644
--- a/tfc_misc.c
+++ b/tfc_misc.c
@@ -97,6 +97,7 @@ const char *tfc_modename(int mode)
 		case TFC_MODE_XTS: return "XTS";
 		case TFC_MODE_ECB: return "ECB";
 		case TFC_MODE_CBC: return "CBC";
+		case TFC_MODE_PCBC: return "PCBC";
 	}
 
 	return NULL;
diff --git a/tfcrypt.c b/tfcrypt.c
index cb126ae..45438cb 100644
--- a/tfcrypt.c
+++ b/tfcrypt.c
@@ -209,6 +209,8 @@ _baddfname:
 					ctr_mode = TFC_MODE_STREAM;
 				else if (!strcasecmp(optarg, "cbc"))
 					ctr_mode = TFC_MODE_CBC;
+				else if (!strcasecmp(optarg, "pcbc"))
+					ctr_mode = TFC_MODE_PCBC;
 				else if (!strcasecmp(optarg, "ecb"))
 					ctr_mode = TFC_MODE_ECB;
 				else if (!strcasecmp(optarg, "xts"))
@@ -1246,6 +1248,10 @@ _ragain:	lio = xread(sfd, pblk, lrem);
 			tf_cbc_encrypt(key, ctr, dstblk, srcblk, ldone);
 		else if (ctr_mode == TFC_MODE_CBC && do_edcrypt == TFC_DO_DECRYPT)
 			tf_cbc_decrypt(key, ctr, dstblk, srcblk, ldone);
+		else if (ctr_mode == TFC_MODE_PCBC && do_edcrypt == TFC_DO_ENCRYPT)
+			tf_pcbc_encrypt(key, ctr, dstblk, srcblk, ldone);
+		else if (ctr_mode == TFC_MODE_PCBC && do_edcrypt == TFC_DO_DECRYPT)
+			tf_pcbc_decrypt(key, ctr, dstblk, srcblk, ldone);
 
 		else if (ctr_mode == TFC_MODE_PLAIN)
 			memcpy(dstblk, srcblk, ldone);
@@ -1340,6 +1346,7 @@ _macragain:		lio = xread(sfd, pblk, lrem);
 		else if (ctr_mode == TFC_MODE_XTS) tf_xts_decrypt(key, xtskey, ctr, tmpdata, macvrfy, TF_FROM_BITS(macbits), xtsblocks);
 		else if (ctr_mode == TFC_MODE_ECB) tf_ecb_decrypt(key, tmpdata, macvrfy, TF_FROM_BITS(macbits));
 		else if (ctr_mode == TFC_MODE_CBC) tf_cbc_decrypt(key, ctr, tmpdata, macvrfy, TF_FROM_BITS(macbits));
+		else if (ctr_mode == TFC_MODE_PCBC) tf_pcbc_decrypt(key, ctr, tmpdata, macvrfy, TF_FROM_BITS(macbits));
 
 		if (!memcmp(tmpdata, macresult, TF_FROM_BITS(macbits))) {
 			if (quiet == NO) {
@@ -1377,6 +1384,7 @@ _shortmac:	memset(macvrfy, 0, sizeof(macvrfy));
 		else if (ctr_mode == TFC_MODE_XTS) tf_xts_encrypt(key, xtskey, ctr, tmpdata, macresult, TF_FROM_BITS(macbits), xtsblocks);
 		else if (ctr_mode == TFC_MODE_ECB) tf_ecb_encrypt(key, tmpdata, macresult, TF_FROM_BITS(macbits));
 		else if (ctr_mode == TFC_MODE_CBC) tf_cbc_encrypt(key, ctr, tmpdata, macresult, TF_FROM_BITS(macbits));
+		else if (ctr_mode == TFC_MODE_PCBC) tf_pcbc_encrypt(key, ctr, tmpdata, macresult, TF_FROM_BITS(macbits));
 		memset(macresult, 0, sizeof(macresult));
 
 		if (!do_mac_file) {
diff --git a/tfcrypt.h b/tfcrypt.h
index 2806614..ad12ef8 100644
--- a/tfcrypt.h
+++ b/tfcrypt.h
@@ -234,7 +234,7 @@ enum { TFC_RAWKEY_KEYFILE = 1, TFC_RAWKEY_ASKSTR, TFC_RAWKEY_ASKHEX };
 enum { TFC_OUTFMT_HEX = 1, TFC_OUTFMT_B64, TFC_OUTFMT_RAW };
 enum {
 	TFC_MODE_SKSUM = -2, TFC_MODE_PLAIN = -1, TFC_MODE_CTR = 1,
-	TFC_MODE_STREAM, TFC_MODE_XTS, TFC_MODE_ECB, TFC_MODE_CBC
+	TFC_MODE_STREAM, TFC_MODE_XTS, TFC_MODE_ECB, TFC_MODE_CBC, TFC_MODE_PCBC
 };
 enum { TFC_CTR_SHOW = 1, TFC_CTR_HEAD, TFC_CTR_RAND, TFC_CTR_ZERO, TFC_CTR_SSET };
 enum { TFC_NO_FTRUNC, TFC_DO_FTRUNC, TFC_FTRUNC_TAIL };
diff --git a/tfdef.h b/tfdef.h
index 0facb02..539ed42 100644
--- a/tfdef.h
+++ b/tfdef.h
@@ -147,6 +147,8 @@ void tf_ecb_encrypt(const void *key, void *out, const void *in, size_t sz);
 void tf_ecb_decrypt(const void *key, void *out, const void *in, size_t sz);
 void tf_cbc_encrypt(const void *key, void *iv, void *out, const void *in, size_t sz);
 void tf_cbc_decrypt(const void *key, void *iv, void *out, const void *in, size_t sz);
+void tf_pcbc_encrypt(const void *key, void *iv, void *out, const void *in, size_t sz);
+void tf_pcbc_decrypt(const void *key, void *iv, void *out, const void *in, size_t sz);
 void tf_xts_encrypt(const void *keyx, const void *keyz, void *ctr, void *out, const void *in, size_t sz, size_t bpi);
 void tf_xts_decrypt(const void *keyx, const void *keyz, void *ctr, void *out, const void *in, size_t sz, size_t bpi);
 
diff --git a/tfpcbc.c b/tfpcbc.c
new file mode 100644
index 0000000..72ac9a3
--- /dev/null
+++ b/tfpcbc.c
@@ -0,0 +1,86 @@
+#include <string.h>
+#include "tfdef.h"
+
+void tf_pcbc_encrypt(const void *key, void *iv, void *out, const void *in, size_t sz)
+{
+	const TF_BYTE_TYPE *uin = (const TF_BYTE_TYPE *)in;
+	TF_BYTE_TYPE *uout = (TF_BYTE_TYPE *)out;
+	TF_UNIT_TYPE x[TF_NR_BLOCK_UNITS], y[TF_NR_BLOCK_UNITS];
+	TF_UNIT_TYPE *uiv = (TF_UNIT_TYPE *)iv;
+	const TF_UNIT_TYPE *ukey = (const TF_UNIT_TYPE *)key;
+	size_t sl = sz, i;
+
+	if (sl >= TF_BLOCK_SIZE) {
+		do {
+			memcpy(x, uin, TF_BLOCK_SIZE);
+			uin += TF_BLOCK_SIZE;
+			data_to_words(x, TF_BLOCK_SIZE);
+
+			for (i = 0; i < TF_NR_BLOCK_UNITS; i++) y[i] = x[i] ^ uiv[i];
+			tf_encrypt_rawblk(y, y, ukey);
+			for (i = 0; i < TF_NR_BLOCK_UNITS; i++) uiv[i] = y[i] ^ x[i];
+
+			data_to_words(y, TF_BLOCK_SIZE);
+			memcpy(uout, y, TF_BLOCK_SIZE);
+			uout += TF_BLOCK_SIZE;
+		} while ((sl -= TF_BLOCK_SIZE) >= TF_BLOCK_SIZE);
+	}
+
+	if (sl) {
+		memset(x, 0, TF_BLOCK_SIZE);
+		memcpy(x, uin, sl);
+		data_to_words(x, TF_BLOCK_SIZE);
+
+		ctr_inc(uiv, TF_NR_BLOCK_UNITS);
+		tf_encrypt_rawblk(y, uiv, ukey);
+		for (i = 0; i < TF_NR_BLOCK_UNITS; i++) y[i] ^= x[i];
+
+		data_to_words(y, TF_BLOCK_SIZE);
+		memcpy(uout, y, sl);
+	}
+
+	memset(x, 0, TF_BLOCK_SIZE);
+	memset(y, 0, TF_BLOCK_SIZE);
+}
+
+void tf_pcbc_decrypt(const void *key, void *iv, void *out, const void *in, size_t sz)
+{
+	const TF_BYTE_TYPE *uin = (const TF_BYTE_TYPE *)in;
+	TF_BYTE_TYPE *uout = (TF_BYTE_TYPE *)out;
+	TF_UNIT_TYPE x[TF_NR_BLOCK_UNITS], y[TF_NR_BLOCK_UNITS];
+	TF_UNIT_TYPE *uiv = (TF_UNIT_TYPE *)iv;
+	const TF_UNIT_TYPE *ukey = (const TF_UNIT_TYPE *)key;
+	size_t sl = sz, i;
+
+	if (sl >= TF_BLOCK_SIZE) {
+		do {
+			memcpy(x, uin, TF_BLOCK_SIZE);
+			uin += TF_BLOCK_SIZE;
+			data_to_words(x, TF_BLOCK_SIZE);
+
+			tf_decrypt_rawblk(y, x, ukey);
+			for (i = 0; i < TF_NR_BLOCK_UNITS; i++) y[i] ^= uiv[i];
+			for (i = 0; i < TF_NR_BLOCK_UNITS; i++) uiv[i] = y[i] ^ x[i];
+
+			data_to_words(y, TF_BLOCK_SIZE);
+			memcpy(uout, y, TF_BLOCK_SIZE);
+			uout += TF_BLOCK_SIZE;
+		} while ((sl -= TF_BLOCK_SIZE) >= TF_BLOCK_SIZE);
+	}
+
+	if (sl) {
+		memset(x, 0, TF_BLOCK_SIZE);
+		memcpy(x, uin, sl);
+		data_to_words(x, TF_BLOCK_SIZE);
+
+		ctr_inc(uiv, TF_NR_BLOCK_UNITS);
+		tf_encrypt_rawblk(y, uiv, ukey);
+		for (i = 0; i < TF_NR_BLOCK_UNITS; i++) y[i] ^= x[i];
+
+		data_to_words(y, TF_BLOCK_SIZE);
+		memcpy(uout, y, sl);
+	}
+
+	memset(x, 0, TF_BLOCK_SIZE);
+	memset(y, 0, TF_BLOCK_SIZE);
+}