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-rw-r--r--third_party/bearssl/src/aes_ct_ctrcbc.c422
1 files changed, 422 insertions, 0 deletions
diff --git a/third_party/bearssl/src/aes_ct_ctrcbc.c b/third_party/bearssl/src/aes_ct_ctrcbc.c
new file mode 100644
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+++ b/third_party/bearssl/src/aes_ct_ctrcbc.c
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+/*
+ * Copyright (c) 2017 Thomas Pornin <[email protected]>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see bearssl_block.h */
+void
+br_aes_ct_ctrcbc_init(br_aes_ct_ctrcbc_keys *ctx,
+	const void *key, size_t len)
+{
+	ctx->vtable = &br_aes_ct_ctrcbc_vtable;
+	ctx->num_rounds = br_aes_ct_keysched(ctx->skey, key, len);
+}
+
+static void
+xorbuf(void *dst, const void *src, size_t len)
+{
+	unsigned char *d;
+	const unsigned char *s;
+
+	d = dst;
+	s = src;
+	while (len -- > 0) {
+		*d ++ ^= *s ++;
+	}
+}
+
+/* see bearssl_block.h */
+void
+br_aes_ct_ctrcbc_ctr(const br_aes_ct_ctrcbc_keys *ctx,
+	void *ctr, void *data, size_t len)
+{
+	unsigned char *buf;
+	unsigned char *ivbuf;
+	uint32_t iv0, iv1, iv2, iv3;
+	uint32_t sk_exp[120];
+
+	br_aes_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
+
+	/*
+	 * We keep the counter as four 32-bit values, with big-endian
+	 * convention, because that's what is expected for purposes of
+	 * incrementing the counter value.
+	 */
+	ivbuf = ctr;
+	iv0 = br_dec32be(ivbuf +  0);
+	iv1 = br_dec32be(ivbuf +  4);
+	iv2 = br_dec32be(ivbuf +  8);
+	iv3 = br_dec32be(ivbuf + 12);
+
+	buf = data;
+	while (len > 0) {
+		uint32_t q[8], carry;
+		unsigned char tmp[32];
+
+		/*
+		 * The bitslice implementation expects values in
+		 * little-endian convention, so we have to byteswap them.
+		 */
+		q[0] = br_swap32(iv0);
+		q[2] = br_swap32(iv1);
+		q[4] = br_swap32(iv2);
+		q[6] = br_swap32(iv3);
+		iv3 ++;
+		carry = ~(iv3 | -iv3) >> 31;
+		iv2 += carry;
+		carry &= -(~(iv2 | -iv2) >> 31);
+		iv1 += carry;
+		carry &= -(~(iv1 | -iv1) >> 31);
+		iv0 += carry;
+		q[1] = br_swap32(iv0);
+		q[3] = br_swap32(iv1);
+		q[5] = br_swap32(iv2);
+		q[7] = br_swap32(iv3);
+		if (len > 16) {
+			iv3 ++;
+			carry = ~(iv3 | -iv3) >> 31;
+			iv2 += carry;
+			carry &= -(~(iv2 | -iv2) >> 31);
+			iv1 += carry;
+			carry &= -(~(iv1 | -iv1) >> 31);
+			iv0 += carry;
+		}
+
+		br_aes_ct_ortho(q);
+		br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+		br_aes_ct_ortho(q);
+
+		br_enc32le(tmp, q[0]);
+		br_enc32le(tmp + 4, q[2]);
+		br_enc32le(tmp + 8, q[4]);
+		br_enc32le(tmp + 12, q[6]);
+		br_enc32le(tmp + 16, q[1]);
+		br_enc32le(tmp + 20, q[3]);
+		br_enc32le(tmp + 24, q[5]);
+		br_enc32le(tmp + 28, q[7]);
+
+		if (len <= 32) {
+			xorbuf(buf, tmp, len);
+			break;
+		}
+		xorbuf(buf, tmp, 32);
+		buf += 32;
+		len -= 32;
+	}
+	br_enc32be(ivbuf +  0, iv0);
+	br_enc32be(ivbuf +  4, iv1);
+	br_enc32be(ivbuf +  8, iv2);
+	br_enc32be(ivbuf + 12, iv3);
+}
+
+/* see bearssl_block.h */
+void
+br_aes_ct_ctrcbc_mac(const br_aes_ct_ctrcbc_keys *ctx,
+	void *cbcmac, const void *data, size_t len)
+{
+	const unsigned char *buf;
+	uint32_t cm0, cm1, cm2, cm3;
+	uint32_t q[8];
+	uint32_t sk_exp[120];
+
+	br_aes_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
+
+	buf = data;
+	cm0 = br_dec32le((unsigned char *)cbcmac +  0);
+	cm1 = br_dec32le((unsigned char *)cbcmac +  4);
+	cm2 = br_dec32le((unsigned char *)cbcmac +  8);
+	cm3 = br_dec32le((unsigned char *)cbcmac + 12);
+	q[1] = 0;
+	q[3] = 0;
+	q[5] = 0;
+	q[7] = 0;
+
+	while (len > 0) {
+		q[0] = cm0 ^ br_dec32le(buf +  0);
+		q[2] = cm1 ^ br_dec32le(buf +  4);
+		q[4] = cm2 ^ br_dec32le(buf +  8);
+		q[6] = cm3 ^ br_dec32le(buf + 12);
+
+		br_aes_ct_ortho(q);
+		br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+		br_aes_ct_ortho(q);
+
+		cm0 = q[0];
+		cm1 = q[2];
+		cm2 = q[4];
+		cm3 = q[6];
+		buf += 16;
+		len -= 16;
+	}
+
+	br_enc32le((unsigned char *)cbcmac +  0, cm0);
+	br_enc32le((unsigned char *)cbcmac +  4, cm1);
+	br_enc32le((unsigned char *)cbcmac +  8, cm2);
+	br_enc32le((unsigned char *)cbcmac + 12, cm3);
+}
+
+/* see bearssl_block.h */
+void
+br_aes_ct_ctrcbc_encrypt(const br_aes_ct_ctrcbc_keys *ctx,
+	void *ctr, void *cbcmac, void *data, size_t len)
+{
+	/*
+	 * When encrypting, the CBC-MAC processing must be lagging by
+	 * one block, since it operates on the encrypted values, so
+	 * it must wait for that encryption to complete.
+	 */
+
+	unsigned char *buf;
+	unsigned char *ivbuf;
+	uint32_t iv0, iv1, iv2, iv3;
+	uint32_t cm0, cm1, cm2, cm3;
+	uint32_t sk_exp[120];
+	int first_iter;
+
+	br_aes_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
+
+	/*
+	 * We keep the counter as four 32-bit values, with big-endian
+	 * convention, because that's what is expected for purposes of
+	 * incrementing the counter value.
+	 */
+	ivbuf = ctr;
+	iv0 = br_dec32be(ivbuf +  0);
+	iv1 = br_dec32be(ivbuf +  4);
+	iv2 = br_dec32be(ivbuf +  8);
+	iv3 = br_dec32be(ivbuf + 12);
+
+	/*
+	 * The current CBC-MAC value is kept in little-endian convention.
+	 */
+	cm0 = br_dec32le((unsigned char *)cbcmac +  0);
+	cm1 = br_dec32le((unsigned char *)cbcmac +  4);
+	cm2 = br_dec32le((unsigned char *)cbcmac +  8);
+	cm3 = br_dec32le((unsigned char *)cbcmac + 12);
+
+	buf = data;
+	first_iter = 1;
+	while (len > 0) {
+		uint32_t q[8], carry;
+
+		/*
+		 * The bitslice implementation expects values in
+		 * little-endian convention, so we have to byteswap them.
+		 */
+		q[0] = br_swap32(iv0);
+		q[2] = br_swap32(iv1);
+		q[4] = br_swap32(iv2);
+		q[6] = br_swap32(iv3);
+		iv3 ++;
+		carry = ~(iv3 | -iv3) >> 31;
+		iv2 += carry;
+		carry &= -(~(iv2 | -iv2) >> 31);
+		iv1 += carry;
+		carry &= -(~(iv1 | -iv1) >> 31);
+		iv0 += carry;
+
+		/*
+		 * The odd values are used for CBC-MAC.
+		 */
+		q[1] = cm0;
+		q[3] = cm1;
+		q[5] = cm2;
+		q[7] = cm3;
+
+		br_aes_ct_ortho(q);
+		br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+		br_aes_ct_ortho(q);
+
+		/*
+		 * We do the XOR with the plaintext in 32-bit registers,
+		 * so that the value are available for CBC-MAC processing
+		 * as well.
+		 */
+		q[0] ^= br_dec32le(buf +  0);
+		q[2] ^= br_dec32le(buf +  4);
+		q[4] ^= br_dec32le(buf +  8);
+		q[6] ^= br_dec32le(buf + 12);
+		br_enc32le(buf +  0, q[0]);
+		br_enc32le(buf +  4, q[2]);
+		br_enc32le(buf +  8, q[4]);
+		br_enc32le(buf + 12, q[6]);
+
+		buf += 16;
+		len -= 16;
+
+		/*
+		 * We set the cm* values to the block to encrypt in the
+		 * next iteration.
+		 */
+		if (first_iter) {
+			first_iter = 0;
+			cm0 ^= q[0];
+			cm1 ^= q[2];
+			cm2 ^= q[4];
+			cm3 ^= q[6];
+		} else {
+			cm0 = q[0] ^ q[1];
+			cm1 = q[2] ^ q[3];
+			cm2 = q[4] ^ q[5];
+			cm3 = q[6] ^ q[7];
+		}
+
+		/*
+		 * If this was the last iteration, then compute the
+		 * extra block encryption to complete CBC-MAC.
+		 */
+		if (len == 0) {
+			q[0] = cm0;
+			q[2] = cm1;
+			q[4] = cm2;
+			q[6] = cm3;
+			br_aes_ct_ortho(q);
+			br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+			br_aes_ct_ortho(q);
+			cm0 = q[0];
+			cm1 = q[2];
+			cm2 = q[4];
+			cm3 = q[6];
+			break;
+		}
+	}
+
+	br_enc32be(ivbuf +  0, iv0);
+	br_enc32be(ivbuf +  4, iv1);
+	br_enc32be(ivbuf +  8, iv2);
+	br_enc32be(ivbuf + 12, iv3);
+	br_enc32le((unsigned char *)cbcmac +  0, cm0);
+	br_enc32le((unsigned char *)cbcmac +  4, cm1);
+	br_enc32le((unsigned char *)cbcmac +  8, cm2);
+	br_enc32le((unsigned char *)cbcmac + 12, cm3);
+}
+
+/* see bearssl_block.h */
+void
+br_aes_ct_ctrcbc_decrypt(const br_aes_ct_ctrcbc_keys *ctx,
+	void *ctr, void *cbcmac, void *data, size_t len)
+{
+	unsigned char *buf;
+	unsigned char *ivbuf;
+	uint32_t iv0, iv1, iv2, iv3;
+	uint32_t cm0, cm1, cm2, cm3;
+	uint32_t sk_exp[120];
+
+	br_aes_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
+
+	/*
+	 * We keep the counter as four 32-bit values, with big-endian
+	 * convention, because that's what is expected for purposes of
+	 * incrementing the counter value.
+	 */
+	ivbuf = ctr;
+	iv0 = br_dec32be(ivbuf +  0);
+	iv1 = br_dec32be(ivbuf +  4);
+	iv2 = br_dec32be(ivbuf +  8);
+	iv3 = br_dec32be(ivbuf + 12);
+
+	/*
+	 * The current CBC-MAC value is kept in little-endian convention.
+	 */
+	cm0 = br_dec32le((unsigned char *)cbcmac +  0);
+	cm1 = br_dec32le((unsigned char *)cbcmac +  4);
+	cm2 = br_dec32le((unsigned char *)cbcmac +  8);
+	cm3 = br_dec32le((unsigned char *)cbcmac + 12);
+
+	buf = data;
+	while (len > 0) {
+		uint32_t q[8], carry;
+		unsigned char tmp[16];
+
+		/*
+		 * The bitslice implementation expects values in
+		 * little-endian convention, so we have to byteswap them.
+		 */
+		q[0] = br_swap32(iv0);
+		q[2] = br_swap32(iv1);
+		q[4] = br_swap32(iv2);
+		q[6] = br_swap32(iv3);
+		iv3 ++;
+		carry = ~(iv3 | -iv3) >> 31;
+		iv2 += carry;
+		carry &= -(~(iv2 | -iv2) >> 31);
+		iv1 += carry;
+		carry &= -(~(iv1 | -iv1) >> 31);
+		iv0 += carry;
+
+		/*
+		 * The odd values are used for CBC-MAC.
+		 */
+		q[1] = cm0 ^ br_dec32le(buf +  0);
+		q[3] = cm1 ^ br_dec32le(buf +  4);
+		q[5] = cm2 ^ br_dec32le(buf +  8);
+		q[7] = cm3 ^ br_dec32le(buf + 12);
+
+		br_aes_ct_ortho(q);
+		br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+		br_aes_ct_ortho(q);
+
+		br_enc32le(tmp +  0, q[0]);
+		br_enc32le(tmp +  4, q[2]);
+		br_enc32le(tmp +  8, q[4]);
+		br_enc32le(tmp + 12, q[6]);
+		xorbuf(buf, tmp, 16);
+		cm0 = q[1];
+		cm1 = q[3];
+		cm2 = q[5];
+		cm3 = q[7];
+		buf += 16;
+		len -= 16;
+	}
+
+	br_enc32be(ivbuf +  0, iv0);
+	br_enc32be(ivbuf +  4, iv1);
+	br_enc32be(ivbuf +  8, iv2);
+	br_enc32be(ivbuf + 12, iv3);
+	br_enc32le((unsigned char *)cbcmac +  0, cm0);
+	br_enc32le((unsigned char *)cbcmac +  4, cm1);
+	br_enc32le((unsigned char *)cbcmac +  8, cm2);
+	br_enc32le((unsigned char *)cbcmac + 12, cm3);
+}
+
+/* see bearssl_block.h */
+const br_block_ctrcbc_class br_aes_ct_ctrcbc_vtable = {
+	sizeof(br_aes_ct_ctrcbc_keys),
+	16,
+	4,
+	(void (*)(const br_block_ctrcbc_class **, const void *, size_t))
+		&br_aes_ct_ctrcbc_init,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, void *, size_t))
+		&br_aes_ct_ctrcbc_encrypt,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, void *, size_t))
+		&br_aes_ct_ctrcbc_decrypt,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, size_t))
+		&br_aes_ct_ctrcbc_ctr,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, const void *, size_t))
+		&br_aes_ct_ctrcbc_mac
+};
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