hare

commit 8da991279b174154c51394fe1edb80fb53c75124
parent 5f81cf1878feab2e2566c7865ef243838317c2ce
Author: Armin Preiml <apreiml@strohwolke.at>
Date:   Wed, 19 Jan 2022 11:41:50 +0100

crypto::hmac: provide sha256 variant of hmac

Signed-off-by: Armin Preiml <apreiml@strohwolke.at>

Diffstat:
M
crypto/hmac/+test.ha
 | 
19
+++++++++++++++++++
A
crypto/hmac/sha256.ha
 | 
49
+++++++++++++++++++++++++++++++++++++++++++++++++
M
scripts/gen-stdlib
 | 
8
+++++---
M
stdlib.mk
 | 
8
+++++---

4 files changed, 78 insertions(+), 6 deletions(-)
diff --git a/crypto/hmac/+test.ha b/crypto/hmac/+test.ha
@@ -1,6 +1,7 @@
 use bytes;
 use crypto::mac;
 use crypto::sha1;
+use crypto::sha256;
 use encoding::hex;
 use hash;
 use io;
@@ -126,3 +127,21 @@ fn assert_hmac_sha1(keystr: str, vectors: [](str, [20]u8)) void = {
 		"jklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu";
 	assert_hmac_sha1(key, vectors);
 };
+
+@test fn sha256() void = {
+	const expected: [_]u8 = [
+		0xb6, 0x13, 0x67, 0x9a, 0x08, 0x14, 0xd9, 0xec, 0x77, 0x2f,
+		0x95, 0xd7, 0x78, 0xc3, 0x5f, 0xc5, 0xff, 0x16, 0x97, 0xc4,
+		0x93, 0x71, 0x56, 0x53, 0xc6, 0xc7, 0x12, 0x14, 0x42, 0x92,
+		0xc5, 0xad,
+	];
+
+	let hmac = sha256([]);
+	defer mac::finish(&hmac);
+
+	let sum: [sha256::SIZE]u8 = [0...];
+	mac::sum(&hmac, sum);
+
+	assert(bytes::equal(expected, sum));
+};
+
diff --git a/crypto/hmac/sha256.ha b/crypto/hmac/sha256.ha
@@ -0,0 +1,49 @@
+use bytes;
+use crypto::mac;
+use crypto::sha256;
+use hash;
+use io;
+
+export type sha256state = struct {
+	mac::mac,
+	h: sha256::state,
+	keypad: [sha256::BLOCKSIZE]u8,
+};
+
+// Creates a [[crypto::mac::mac]] that computes an HMAC with given 'key' using
+// SHA256 as underlying hash function. 
+//
+// The caller must take extra care to call [[mac::finish]] when they are
+// finished using the MAC function, which, in addition to freeing state
+// associated with the MAC, will securely erase state which contains secret
+// information.
+export fn sha256(key: []u8) sha256state = {
+	let s = sha256state {
+		h = sha256::sha256(),
+		sz = sha256::SIZE,
+		bsz = sha256::BLOCKSIZE,
+		writer = &sha256write,
+		sum = &sha256sum,
+		finish = &sha256finish,
+		...
+	};
+
+	init(&s.h, key, s.keypad);
+	return s;
+};
+
+fn sha256write(st: *io::stream, buf: const []u8) (size | io::error) = {
+	let hm = st: *sha256state;
+	return hash::write(&hm.h, buf);
+};
+
+fn sha256sum(mac: *mac::mac, dest: []u8) void = {
+	let hm = mac: *sha256state;
+	sum(&hm.h, hm.keypad, dest);
+};
+
+fn sha256finish(mac: *mac::mac) void = {
+	let hm = mac: *sha256state;
+	bytes::zero(hm.keypad);
+	io::close(&hm.h);
+};
diff --git a/scripts/gen-stdlib b/scripts/gen-stdlib
@@ -278,14 +278,16 @@ crypto_hmac() {
 	if [ $testing -eq 0 ]
 	then
 		gen_srcs crypto::hmac \
-			hmac.ha
-		gen_ssa crypto::hmac crypto::mac hash io bytes
+			hmac.ha \
+			sha256.ha
+		gen_ssa crypto::hmac crypto::mac crypto::sha256 hash io bytes
 	else
 		gen_srcs crypto::hmac \
 			hmac.ha \
+			sha256.ha \
 			+test.ha
 		gen_ssa crypto::hmac bytes crypto::mac hash crypto::sha1 \
-			encoding::hex io strings
+			crypto::sha256 encoding::hex io strings
 	fi
 }
 
diff --git a/stdlib.mk b/stdlib.mk
@@ -750,9 +750,10 @@ $(HARECACHE)/crypto/cipher/crypto_cipher-any.ssa: $(stdlib_crypto_cipher_any_src
 
 # crypto::hmac (+any)
 stdlib_crypto_hmac_any_srcs= \
-	$(STDLIB)/crypto/hmac/hmac.ha
+	$(STDLIB)/crypto/hmac/hmac.ha \
+	$(STDLIB)/crypto/hmac/sha256.ha
 
-$(HARECACHE)/crypto/hmac/crypto_hmac-any.ssa: $(stdlib_crypto_hmac_any_srcs) $(stdlib_rt) $(stdlib_crypto_mac_$(PLATFORM)) $(stdlib_hash_$(PLATFORM)) $(stdlib_io_$(PLATFORM)) $(stdlib_bytes_$(PLATFORM))
+$(HARECACHE)/crypto/hmac/crypto_hmac-any.ssa: $(stdlib_crypto_hmac_any_srcs) $(stdlib_rt) $(stdlib_crypto_mac_$(PLATFORM)) $(stdlib_crypto_sha256_$(PLATFORM)) $(stdlib_hash_$(PLATFORM)) $(stdlib_io_$(PLATFORM)) $(stdlib_bytes_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(HARECACHE)/crypto/hmac
 	@HARECACHE=$(HARECACHE) $(HAREC) $(HAREFLAGS) -o $@ -Ncrypto::hmac \
@@ -2559,9 +2560,10 @@ $(TESTCACHE)/crypto/cipher/crypto_cipher-any.ssa: $(testlib_crypto_cipher_any_sr
 # crypto::hmac (+any)
 testlib_crypto_hmac_any_srcs= \
 	$(STDLIB)/crypto/hmac/hmac.ha \
+	$(STDLIB)/crypto/hmac/sha256.ha \
 	$(STDLIB)/crypto/hmac/+test.ha
 
-$(TESTCACHE)/crypto/hmac/crypto_hmac-any.ssa: $(testlib_crypto_hmac_any_srcs) $(testlib_rt) $(testlib_bytes_$(PLATFORM)) $(testlib_crypto_mac_$(PLATFORM)) $(testlib_hash_$(PLATFORM)) $(testlib_crypto_sha1_$(PLATFORM)) $(testlib_encoding_hex_$(PLATFORM)) $(testlib_io_$(PLATFORM)) $(testlib_strings_$(PLATFORM))
+$(TESTCACHE)/crypto/hmac/crypto_hmac-any.ssa: $(testlib_crypto_hmac_any_srcs) $(testlib_rt) $(testlib_bytes_$(PLATFORM)) $(testlib_crypto_mac_$(PLATFORM)) $(testlib_hash_$(PLATFORM)) $(testlib_crypto_sha1_$(PLATFORM)) $(testlib_crypto_sha256_$(PLATFORM)) $(testlib_encoding_hex_$(PLATFORM)) $(testlib_io_$(PLATFORM)) $(testlib_strings_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(TESTCACHE)/crypto/hmac
 	@HARECACHE=$(TESTCACHE) $(HAREC) $(TESTHAREFLAGS) -o $@ -Ncrypto::hmac \