Comment on origin of sha1 and sha224 initial values.

94d79445 · Niels Möller · 4b98efe1 · 94d79445 · 94d79445
Commit 94d79445 authored Jan 03, 2014 by Niels Möller
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Showing with 2 additions and 2 deletions

sha1.c sha1.c +1 -1

sha256.c sha256.c +1 -1

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--- a/sha1.c
+++ b/sha1.c
@@ -57,7 +57,7 @@ sha1_init(struct sha1_ctx *ctx)
     can initialize with a single memcpy. */
  static const uint32_t iv[_SHA1_DIGEST_LENGTH] = 
    {
-      /* SHA initial values */
+      /* SHA initial values, first 4 identical to md5's. */
      0x67452301L,
      0xEFCDAB89L,
      0x98BADCFEL,

--- a/sha256.c
+++ b/sha256.c
@@ -129,7 +129,7 @@ sha256_digest(struct sha256_ctx *ctx,
 void
 sha224_init(struct sha256_ctx *ctx)
 {
-  /* Initial values. I's unclear how they are chosen. */
+  /* Initial values. Low 32 bits of the initial values for sha384. */
  static const uint32_t H0[_SHA256_DIGEST_LENGTH] =
  {
    0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,