From 8f1738bfca64236a5973a717f22d4eb6555c448b Mon Sep 17 00:00:00 2001
From: Paul Duncan <pabs@pablotron.org>
Date: Wed, 17 Jul 2019 21:48:22 -0400
Subject: remove buf_len member

---
 sha2.c | 24 ++++++++----------------
 sha2.h |  6 ------
 2 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/sha2.c b/sha2.c
index 1e3ae41..0c76743 100644
--- a/sha2.c
+++ b/sha2.c
@@ -59,7 +59,6 @@ rr64(const uint64_t v, const size_t n) {
 #endif /* 0 */
 
 void sha256_init(sha256_t * const ctx) {
-  ctx->buf_len = 0;
   ctx->num_bytes = 0;
   memcpy(ctx->h, SHA256_INIT, sizeof(SHA256_INIT));
 }
@@ -228,13 +227,13 @@ void sha256_push(
   const uint8_t * const src,
   const size_t src_len
 ) {
-  const size_t buf_left = 64 - ctx->buf_len;
+  const size_t buf_len = ctx->num_bytes % 64;
+  const size_t buf_left = 64 - buf_len;
 
   if (src_len >= buf_left) {
     // fill remaining buffer
-    memcpy(ctx->buf + ctx->buf_len, src, buf_left);
+    memcpy(ctx->buf + buf_len, src, buf_left);
     sha256_block(ctx);
-    ctx->buf_len = 0;
 
     const size_t new_src_len = src_len - buf_left;
     const size_t num_blocks = new_src_len / 64;
@@ -248,10 +247,8 @@ void sha256_push(
     // copy remaining bytes to buffer
     const size_t new_buf_len = (new_src_len - 64 * num_blocks);
     memcpy(ctx->buf, src + buf_left + (64 * num_blocks), new_buf_len);
-    ctx->buf_len = new_buf_len;
   } else {
-    memcpy(ctx->buf + ctx->buf_len, src, src_len);
-    ctx->buf_len += src_len;
+    memcpy(ctx->buf + buf_len, src, src_len);
   }
 
   // update byte count
@@ -336,7 +333,6 @@ static const uint32_t SHA224_INIT[8] = {
 };
 
 void sha224_init(sha224_t * const ctx) {
-  ctx->ctx.buf_len = 0;
   ctx->ctx.num_bytes = 0;
   memcpy(ctx->ctx.h, SHA224_INIT, sizeof(SHA224_INIT));
 }
@@ -434,7 +430,6 @@ static const uint64_t K512[80] = {
 };
 
 void sha512_init(sha512_t * const ctx) {
-  ctx->buf_len = 0;
   ctx->num_bytes = 0;
   memcpy(ctx->h, SHA512_INIT, sizeof(SHA512_INIT));
 }
@@ -534,13 +529,13 @@ void sha512_push(
   const uint8_t * const src,
   const size_t src_len
 ) {
-  const size_t buf_left = 128 - ctx->buf_len;
+  const size_t buf_len = ctx->num_bytes % 128;
+  const size_t buf_left = 128 - buf_len;
 
   if (src_len >= buf_left) {
     // fill remaining buffer
-    memcpy(ctx->buf + ctx->buf_len, src, buf_left);
+    memcpy(ctx->buf + buf_len, src, buf_left);
     sha512_block(ctx);
-    ctx->buf_len = 0;
 
     const size_t new_src_len = src_len - buf_left;
     const size_t num_blocks = new_src_len / 128;
@@ -554,10 +549,8 @@ void sha512_push(
     // copy remaining bytes to buffer
     const size_t new_buf_len = (new_src_len - 128 * num_blocks);
     memcpy(ctx->buf, src + buf_left + (128 * num_blocks), new_buf_len);
-    ctx->buf_len = new_buf_len;
   } else {
-    memcpy(ctx->buf + ctx->buf_len, src, src_len);
-    ctx->buf_len += src_len;
+    memcpy(ctx->buf + buf_len, src, src_len);
   }
 
   // update byte count
@@ -656,7 +649,6 @@ static const uint64_t SHA384_INIT[8] = {
 };
 
 void sha384_init(sha384_t * const ctx) {
-  ctx->ctx.buf_len = 0;
   ctx->ctx.num_bytes = 0;
   memcpy(ctx->ctx.h, SHA384_INIT, sizeof(SHA384_INIT));
 }
diff --git a/sha2.h b/sha2.h
index 367b736..c3ede29 100644
--- a/sha2.h
+++ b/sha2.h
@@ -12,10 +12,7 @@ extern "C" {
 
 typedef struct {
   uint8_t buf[64];
-  size_t buf_len;
-
   uint32_t h[8];
-
   uint64_t num_bytes;
 } sha256_t;
 
@@ -40,10 +37,7 @@ void sha224(const uint8_t * const, const size_t, uint8_t * const);
 
 typedef struct {
   uint8_t buf[128];
-  size_t buf_len;
-
   uint64_t h[8];
-
   uint64_t num_bytes;
 } sha512_t;
 
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