crypto: Move + rework prf_sha1 into crypto.c

Makefile.am

@@ -135,8 +135,8 @@ unit_test_hmac_sha1_SOURCES = unit/test-hmac-sha1.c \
 unit_test_hmac_sha1_LDADD = ell/libell-internal.la
 
 unit_test_hmac_sha256_SOURCES = unit/test-hmac-sha256.c \
-					src/sha1.h src/sha1.c \
+					src/crypto.h src/crypto.c \
-					src/crypto.h src/crypto.c
+					src/sha1.h src/sha1.c
 unit_test_hmac_sha256_LDADD = ell/libell-internal.la
 
 unit_test_pbkdf2_sha1_SOURCES = unit/test-pbkdf2-sha1.c \
@@ -144,6 +144,7 @@ unit_test_pbkdf2_sha1_SOURCES = unit/test-pbkdf2-sha1.c \
 unit_test_pbkdf2_sha1_LDADD = ell/libell-internal.la
 
 unit_test_prf_sha1_SOURCES = unit/test-prf-sha1.c \
+					src/crypto.h src/crypto.c \
 					src/sha1.h src/sha1.c
 unit_test_prf_sha1_LDADD = ell/libell-internal.la
 

src/crypto.c

@@ -241,6 +241,45 @@ int crypto_psk_from_passphrase(const char *passphrase,
 	return 0;
 }
 
+bool prf_sha1(const void *key, size_t key_len,
+		const void *prefix, size_t prefix_len,
+		const void *data, size_t data_len, void *output, size_t size)
+{
+	struct l_checksum *hmac;
+	unsigned int i, offset = 0;
+	unsigned char empty = '\0';
+	unsigned char counter;
+	struct iovec iov[4] = {
+		[0] = { .iov_base = (void *) prefix, .iov_len = prefix_len },
+		[1] = { .iov_base = &empty, .iov_len = 1 },
+		[2] = { .iov_base = (void *) data, .iov_len = data_len },
+		[3] = { .iov_base = &counter, .iov_len = 1 },
+	};
+
+	hmac = l_checksum_new_hmac(L_CHECKSUM_SHA1, key, key_len);
+	if (!hmac)
+		return false;
+
+	/* PRF processes in 160-bit chunks (20 bytes) */
+	for (i = 0, counter = 0; i < (size + 19) / 20; i++, counter++) {
+		size_t len;
+
+		if (size - offset > 20)
+			len = 20;
+		else
+			len = size - offset;
+
+		l_checksum_updatev(hmac, iov, 4);
+		l_checksum_get_digest(hmac, output + offset, len);
+
+		offset += len;
+	}
+
+	l_checksum_free(hmac);
+
+	return true;
+}
+
 /*
  * 802.11, Section 11.6.6.7:
  * PTK = PRF-X(PMK, "Pairwise key expansion", Min(AA, SA) || Max(AA, SA) ||

src/crypto.h

@@ -58,6 +58,10 @@ int crypto_psk_from_passphrase(const char *passphrase,
 				const unsigned char *ssid, size_t ssid_len,
 				unsigned char *out_psk);
 
+bool prf_sha1(const void *key, size_t key_len,
+		const void *prefix, size_t prefix_len,
+		const void *data, size_t data_len, void *output, size_t size);
+
 bool crypto_derive_ptk(const uint8_t *pmk, size_t pmk_len, const char *label,
 			const uint8_t *addr1, const uint8_t *addr2,
 			const uint8_t *nonce1, const uint8_t *nonce2,

src/sha1.c

@@ -136,43 +136,3 @@ bool pbkdf2_sha1(const void *password, size_t password_len,
 	return true;
 }
 
-bool prf_sha1(const void *key, size_t key_len,
-		const void *prefix, size_t prefix_len,
-		const void *data, size_t data_len, void *output, size_t size)
-{
-	struct l_checksum *checksum;
-	unsigned char input[1024];
-	size_t input_len;
-	unsigned int i, offset = 0;
-
-	checksum = l_checksum_new(L_CHECKSUM_SHA1);
-	if (!checksum)
-		return false;
-
-	memcpy(input, prefix, prefix_len);
-	input[prefix_len] = 0;
-
-	memcpy(input + prefix_len + 1, data, data_len);
-	input[prefix_len + 1 + data_len] = 0;
-
-	input_len = prefix_len + 1 + data_len + 1;
-
-	for (i = 0; i < (size + 19) / 20; i++) {
-		size_t len;
-
-		if (size - offset > SHA1_MAC_LEN)
-			len = SHA1_MAC_LEN;
-		else
-			len = size - offset;
-
-		__hmac_sha1(checksum, key, key_len, input, input_len,
-							output + offset, len);
-
-		offset += len;
-		input[input_len - 1]++;
-	}
-
-	l_checksum_free(checksum);
-
-	return true;
-}

src/sha1.h

@@ -25,7 +25,3 @@
 bool pbkdf2_sha1(const void *password, size_t password_len,
 			const void *salt, size_t salt_len,
 			unsigned int iterations, void *output, size_t size);
-
-bool prf_sha1(const void *key, size_t key_len,
-		const void *prefix, size_t prefix_len,
-		const void *data, size_t data_len, void *output, size_t size);