--- /dev/null
+/*
+Copyright (c) 2011, Network RADIUS SARL
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * Neither the name of the <organization> nor the
+ names of its contributors may be used to endorse or promote products
+ derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file crypto.c
+ * \brief Data obfuscation and signing, using MD5.
+ *
+ * The "encryption" methods defined here are export-safe. The
+ * technical cryptography name for these functions is "obfuscation".
+ * They cannot properly be called "encryption", in the same way that
+ * DES or AES performs encryption.
+ */
+
+/** \cond PRIVATE */
+
+#include "client.h"
+
+
+ssize_t nr_password_encrypt(uint8_t *output, size_t outlen,
+ const uint8_t *input, size_t inlen,
+ const char *secret, const uint8_t *vector)
+{
+ size_t i, j, len;
+ uint8_t digest[16];
+ RS_MD5_CTX ctx, secret_ctx;
+
+ if (!output || (outlen < 16) || !input || (inlen == 0) ||
+ !secret || !vector) {
+ return -RSE_INVAL;
+ }
+
+ len = inlen;
+ if (len > 128) return -RSE_ATTR_OVERFLOW;
+
+ len = (len + 0x0f) & ~0x0f; /* round up to 16 byte boundary */
+
+ if (outlen < len) return -RSE_ATTR_OVERFLOW;
+
+ memcpy(output, input, len);
+ memset(output + len, 0, 128 - len);
+
+ RS_MD5Init(&secret_ctx);
+ RS_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret));
+
+ for (j = 0; j < len; j += 16) {
+ ctx = secret_ctx;
+
+ if (j == 0) {
+ RS_MD5Update(&ctx, vector, 16);
+ RS_MD5Final(digest, &ctx);
+ } else {
+ RS_MD5Update(&ctx, &output[j - 16], 16);
+ RS_MD5Final(digest, &ctx);
+ }
+
+ for (i = 0; i < 16; i++) {
+ output[i + j] ^= digest[i];
+ }
+ }
+
+ return len;
+}
+
+#ifdef FLAG_ENCRYPT_TUNNEL_PASSWORD
+ssize_t nr_tunnelpw_encrypt(uint8_t *output, size_t outlen,
+ const uint8_t *input, size_t inlen,
+ const char *secret, const uint8_t *vector)
+{
+ size_t i, j, len;
+ RS_MD5_CTX ctx, secret_ctx;
+ uint8_t digest[16];
+
+ if (!output || (outlen < 18) || !input || (inlen == 0) ||
+ !secret || !vector) {
+ return -RSE_INVAL;
+ }
+
+ len = ((inlen + 1) + 0x0f) & ~0x0f;
+ if (len > 251) return -RSE_ATTR_OVERFLOW;
+
+ output[0] = (nr_rand() & 0xff) | 0x80;
+ output[1] = nr_rand() & 0xff;
+ output[2] = inlen;
+
+ memcpy(output + 3, input, inlen);
+ memset(output + 3 + inlen, 0, len - inlen - 1);
+
+ RS_MD5Init(&secret_ctx);
+ RS_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret));
+
+ for (j = 0; j < len; j += 16) {
+ ctx = secret_ctx;
+
+ if (j == 0) {
+ RS_MD5Update(&ctx, vector, 16);
+ RS_MD5Update(&ctx, output, 2);
+ RS_MD5Final(digest, &ctx);
+ } else {
+ RS_MD5Update(&ctx, &output[j + 2 - 16], 16);
+ RS_MD5Final(digest, &ctx);
+ }
+
+ for (i = 0; i < 16; i++) {
+ output[i + j + 2] ^= digest[i];
+ }
+ }
+
+ return len + 2;
+}
+
+ssize_t nr_tunnelpw_decrypt(uint8_t *output, size_t outlen,
+ const uint8_t *input, size_t inlen,
+ const char *secret, const uint8_t *vector)
+{
+ size_t i, j, len, encoded_len;
+ RS_MD5_CTX ctx, secret_ctx;
+ uint8_t digest[16];
+
+ if (!output || (outlen < 1) || !input || (inlen < 2) ||
+ !secret || !vector) {
+ return -RSE_INVAL;
+ }
+
+ if (inlen <= 3) {
+ output[0] = 0;
+ return 0;
+ }
+
+ len = inlen - 2;
+
+ if (outlen < (len - 1)) return -RSE_ATTR_OVERFLOW;
+
+ RS_MD5Init(&secret_ctx);
+ RS_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret));
+
+ ctx = secret_ctx;
+
+ RS_MD5Update(&ctx, vector, 16); /* MD5(secret + vector + salt) */
+ RS_MD5Update(&ctx, input, 2);
+ RS_MD5Final(digest, &ctx);
+
+ encoded_len = input[2] ^ digest[0];
+ if (encoded_len >= len) {
+ return -RSE_ATTR_TOO_LARGE;
+ }
+
+ for (i = 0; i < 15; i++) {
+ output[i] = input[i + 3] ^ digest[i + 1];
+ }
+
+ for (j = 16; j < len; j += 16) {
+ ctx = secret_ctx;
+
+ RS_MD5Update(&ctx, input + j - 16 + 2, 16);
+ RS_MD5Final(digest, &ctx);
+
+ for (i = 0; i < 16; i++) {
+ output[i + j - 1] = input[i + j + 2] ^ digest[i];
+ }
+
+
+ }
+
+ output[encoded_len] = '\0';
+ return encoded_len;
+}
+#endif
+
+void
+nr_hmac_md5(const uint8_t *data, size_t data_len,
+ const uint8_t *key, size_t key_len,
+ uint8_t digest[16])
+{
+ size_t i;
+ uint8_t k_ipad[64];
+ uint8_t k_opad[64];
+ uint8_t tk[16];
+ RS_MD5_CTX ctx;
+
+ if (key_len > 64) {
+ RS_MD5Init(&ctx);
+ RS_MD5Update(&ctx, key, key_len);
+ RS_MD5Final(tk, &ctx);
+
+ key = tk;
+ key_len = 16;
+ }
+
+ memset(k_ipad, 0, sizeof(k_ipad));
+ memset(k_opad, 0, sizeof(k_opad));
+ memcpy(k_ipad, key, key_len);
+ memcpy(k_opad, key, key_len);
+
+ for (i = 0; i < sizeof(k_ipad); i++) {
+ k_ipad[i] ^= 0x36;
+ k_opad[i] ^= 0x5c;
+ }
+
+ RS_MD5Init(&ctx);
+ RS_MD5Update(&ctx, k_ipad, sizeof(k_ipad));
+ RS_MD5Update(&ctx, data, data_len);
+ RS_MD5Final(digest, &ctx);
+
+ RS_MD5Init(&ctx);
+ RS_MD5Update(&ctx, k_opad, sizeof(k_opad));
+ RS_MD5Update(&ctx, digest, 16);
+ RS_MD5Final(digest, &ctx);
+}
+
+/** \endcond */
projects / libradsec.git / blobdiff