X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=crypto%2Fhkdf.c;fp=crypto%2Fhkdf.c;h=4c601bc7f443e9af07df087044b5e1bcd14cafca;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/crypto/hkdf.c b/crypto/hkdf.c
new file mode 100644
index 0000000..4c601bc
--- /dev/null
+++ b/crypto/hkdf.c
@@ -0,0 +1,133 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <time.h>
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+
+#include <errno.h>
+
+#include <tomcrypt.h>
+#include "tlse.h"
+
+int tls_hkdf_extract(unsigned int mac_length,
+			      unsigned char *output, unsigned int outlen,
+			      const unsigned char *salt,
+			      unsigned int salt_len,
+			      const unsigned char *ikm,
+			      unsigned char ikm_len) {
+	int hash_idx;
+	unsigned long dlen = outlen;
+	unsigned char dummy_label[1] = { 0 };
+
+	if (!salt || salt_len == 0) {
+		salt_len = 1;
+		salt = dummy_label;
+	}
+
+	if (mac_length == TLS_SHA384_MAC_SIZE) {
+		hash_idx = find_hash("sha384");
+		dlen = mac_length;
+	} else {
+		hash_idx = find_hash("sha256");
+	}
+
+	hmac_memory(hash_idx, salt, salt_len, ikm, ikm_len, output, &dlen);
+	return dlen;
+}
+
+static int make_hkdf_label(const char *label, unsigned char label_len,
+			    const unsigned char *data,
+			    unsigned char data_len,
+			    unsigned char *hkdflabel,
+			    unsigned short length, const char *prefix) {
+	int prefix_len;
+	*(unsigned short *) &hkdflabel[0] = htons(length);
+
+	if (prefix) {
+		prefix_len = strlen(prefix);
+		memcpy(&hkdflabel[3], prefix, prefix_len);
+	} else {
+		memcpy(&hkdflabel[3], "tls13 ", 6);
+		prefix_len = 6;
+	}
+
+	hkdflabel[2] = (unsigned char) prefix_len + label_len;
+
+	memcpy(&hkdflabel[3 + prefix_len], label, label_len);
+
+	hkdflabel[3 + prefix_len + label_len] = data_len;
+
+	if (data_len) {
+		memcpy(&hkdflabel[4 + prefix_len + label_len], data,
+		       data_len);
+	}
+
+	return 4 + prefix_len + label_len + data_len;
+}
+
+void tls_hkdf_expand(unsigned int mac_length,
+			      unsigned char *output, unsigned int outlen,
+			      const unsigned char *secret,
+			      unsigned int secret_len,
+			      const unsigned char *info,
+			      unsigned char info_len) {
+	unsigned char digest_out[TLS_MAX_HASH_LEN];
+	unsigned long dlen = 32;
+	int hash_idx;
+	unsigned int i;
+	unsigned char i2 = 0;
+	unsigned int idx = 0;
+	hmac_state hmac;
+	unsigned int copylen;
+
+	if (mac_length == TLS_SHA384_MAC_SIZE) {
+		hash_idx = find_hash("sha384");
+		dlen = mac_length;
+	} else {
+		hash_idx = find_hash("sha256");
+	}
+
+	while (outlen) {
+		hmac_init(&hmac, hash_idx, secret, secret_len);
+		if (i2) {
+			hmac_process(&hmac, digest_out, dlen);
+		}
+		if (info && info_len) {
+			hmac_process(&hmac, info, info_len);
+		}
+		i2++;
+		hmac_process(&hmac, &i2, 1);
+		hmac_done(&hmac, digest_out, &dlen);
+
+		copylen = outlen;
+		if (copylen > dlen) {
+			copylen = (unsigned int) dlen;
+		}
+
+		for (i = 0; i < copylen; i++) {
+			output[idx++] = digest_out[i];
+			outlen--;
+		}
+	}
+}
+
+void tls_hkdf_expand_label(unsigned int mac_length, unsigned char *output,
+		unsigned int outlen, const unsigned char *secret, unsigned int
+		secret_len, const char *label, unsigned char label_len, const
+		unsigned char *data, unsigned char data_len) {
+	unsigned char hkdf_label[512];
+	int len = make_hkdf_label(label, label_len, data, data_len, hkdf_label,
+			outlen, NULL);
+	tls_hkdf_expand(mac_length, output, outlen, secret, secret_len,
+			hkdf_label, len);
+}