adding PRF TLSv1.2

[arm-crypto-lib.git] / prf_tls12 / prf_tls12.c

diff --git a/prf_tls12/prf_tls12.c b/prf_tls12/prf_tls12.c
new file mode 100644 (file)
index 0000000..8b84d52
--- /dev/null
+++ b/prf_tls12/prf_tls12.c
@@ -0,0 +1,135 @@
+/* prf_tls12.c */
+/*
+    This file is part of the ARM-Crypto-Lib.
+    Copyright (C) 2009  Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * \file    prf_tls12.c
+ * \author  Daniel Otte
+ * \email   daniel.otte@rub.de
+ * \date    2011-10-06
+ * \license GPLv3 or later
+ *
+ */
+/* from rfc5246
+
+
+      P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
+                             HMAC_hash(secret, A(2) + seed) +
+                             HMAC_hash(secret, A(3) + seed) + ...
+
+   where + indicates concatenation.
+
+   A() is defined as:
+
+      A(0) = seed
+      A(i) = HMAC_hash(secret, A(i-1))
+
+   P_hash can be iterated as many times as necessary to produce the
+   required quantity of data.  For example, if P_SHA256 is being used to
+   create 80 bytes of data, it will have to be iterated three times
+   (through A(3)), creating 96 bytes of output data; the last 16 bytes
+   of the final iteration will then be discarded, leaving 80 bytes of
+   output data.
+
+   TLS's PRF is created by applying P_hash to the secret as:
+
+      PRF(secret, label, seed) = P_<hash>(secret, label + seed)
+
+*/
+/* long story short:
+ * P(k,s) = H(k, A(1) | s) | H(k, A(2) | s) | ... | H(k, A(n) | s)
+ * A(0) = s
+ * A(i) = H(k, A(i-1))
+ *
+ * PRF(k,l,s) = P(k, l | s)
+ *
+ */
+
+/* This implementation is limited to hashfunctions which return a hash value
+ * of a length (in bits) which is divideable by 8.
+ *
+ * Also note that our HMAC implementation may fail on hashfunction which
+ * return a larger hash value then their nativ blocksize
+ *
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <crypto/hashfunction_descriptor.h>
+#include <crypto/hfal-basic.h>
+#include <crypto/hfal-hmac.h>
+#include "prf_tls12.h"
+
+uint8_t prf_tls12_init(prf_tls12_ctx_t* ctx, const hfdesc_t* hash,
+       const void* key, uint16_t keylength_b,
+       const void* seed, uint16_t seedlength_b){
+       hfhmacgen_ctx_t tmp_ctx;
+       ctx->blocklength_b = hfal_hash_getHashsize(hash);
+       ctx->seed_buffer = malloc(ctx->blocklength_b/8+(seedlength_b+7)/8);
+       if(!ctx->seed_buffer){
+               return 1;
+       }
+       ctx->bufferlength_b = ctx->blocklength_b + seedlength_b;
+       memcpy(ctx->seed_buffer+ctx->blocklength_b/8, seed, seedlength_b/8);
+       if(hfal_hmac_init(hash, &(ctx->mainctx), key, keylength_b)){
+               return 2;
+       }
+       if(hfal_hmac_ctxcopy(&tmp_ctx, &(ctx->mainctx))){
+               prf_tls12_free(ctx);
+               return 3;
+       }
+       hfal_hmac_lastBlock(&tmp_ctx, seed, seedlength_b);
+       hfal_hmac_ctx2mac(ctx->seed_buffer, &tmp_ctx);
+       hfal_hmac_free(&tmp_ctx);
+       return 0;
+}
+
+uint8_t prf_tls12_init_w_label(prf_tls12_ctx_t* ctx, const hfdesc_t* hash,
+       const void* key, uint16_t keylength_b,
+       const void* label, uint16_t labellength_B,
+       const void* seed, uint16_t seedlength_b){
+
+       uint8_t buffer[labellength_B+(seedlength_b+7)/8];
+       memcpy(buffer, label, labellength_B);
+       memcpy(buffer+labellength_B, seed, (seedlength_b+7)/8);
+       return prf_tls12_init(ctx, hash, key, keylength_b, buffer, labellength_B*8+seedlength_b);
+}
+
+
+void prf_tls12_free(prf_tls12_ctx_t* ctx){
+       free(ctx->seed_buffer);
+       hfal_hmac_free(&(ctx->mainctx));
+}
+
+uint8_t prf_tls12_next(void* dest, prf_tls12_ctx_t* ctx){
+       hfhmacgen_ctx_t tmp_ctx;
+       if(hfal_hmac_ctxcopy(&tmp_ctx, &(ctx->mainctx))){
+               return 1;
+       }
+       hfal_hmac_lastBlock(&tmp_ctx, ctx->seed_buffer, ctx->bufferlength_b);
+       hfal_hmac_ctx2mac(dest, &tmp_ctx);
+       hfal_hmac_free(&tmp_ctx);
+       if(hfal_hmac_ctxcopy(&tmp_ctx, &(ctx->mainctx))){
+               return 2;
+       }
+       hfal_hmac_lastBlock(&tmp_ctx, ctx->seed_buffer, ctx->blocklength_b);
+       hfal_hmac_ctx2mac(ctx->seed_buffer, &tmp_ctx);
+       hfal_hmac_free(&tmp_ctx);
+       return 0;
+}
+