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-rw-r--r--toys/sha1sum.c40
1 files changed, 22 insertions, 18 deletions
diff --git a/toys/sha1sum.c b/toys/sha1sum.c
index 6db3b552..1d405f33 100644
--- a/toys/sha1sum.c
+++ b/toys/sha1sum.c
@@ -3,6 +3,8 @@
*
* Based on the public domain SHA-1 in C by Steve Reid <steve@edmweb.com>
* from http://www.mirrors.wiretapped.net/security/cryptography/hashes/sha1/
+ *
+ * Not in SUSv3.
*/
#include <toys.h>
@@ -17,15 +19,15 @@ struct sha1 {
} buffer;
};
-void sha1_init(struct sha1 *this);
-void sha1_transform(struct sha1 *this);
-void sha1_update(struct sha1 *this, char *data, unsigned int len);
-void sha1_final(struct sha1 *this, char digest[20]);
+static void sha1_init(struct sha1 *this);
+static void sha1_transform(struct sha1 *this);
+static void sha1_update(struct sha1 *this, char *data, unsigned int len);
+static void sha1_final(struct sha1 *this, char digest[20]);
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
-/* blk0() and blk() perform the initial expand. */
-/* The idea of expanding during the round function comes from SSLeay */
+// blk0() and blk() perform the initial expand.
+// The idea of expanding during the round function comes from SSLeay
#if 1
#define blk0(i) (block[i] = (rol(block[i],24)&0xFF00FF00) \
|(rol(block[i],8)&0x00FF00FF))
@@ -37,20 +39,20 @@ void sha1_final(struct sha1 *this, char digest[20]);
static const uint32_t rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6};
-/* Hash a single 512-bit block. This is the core of the algorithm. */
+// Hash a single 512-bit block. This is the core of the algorithm.
-void sha1_transform(struct sha1 *this)
+static void sha1_transform(struct sha1 *this)
{
int i, j, k, count;
uint32_t *block = this->buffer.i;
uint32_t *rot[5], *temp;
- /* Copy context->state[] to working vars */
+ // Copy context->state[] to working vars
for (i=0; i<5; i++) {
this->oldstate[i] = this->state[i];
rot[i] = this->state + i;
}
- /* 4 rounds of 20 operations each. */
+ // 4 rounds of 20 operations each.
for (i=count=0; i<4; i++) {
for (j=0; j<20; j++) {
uint32_t work;
@@ -74,14 +76,14 @@ void sha1_transform(struct sha1 *this)
count++;
}
}
- /* Add the previous values of state[] */
+ // Add the previous values of state[]
for (i=0; i<5; i++) this->state[i] += this->oldstate[i];
}
-/* SHA1Init - Initialize new context */
+// Initialize a struct sha1.
-void sha1_init(struct sha1 *this)
+static void sha1_init(struct sha1 *this)
{
/* SHA1 initialization constants */
this->state[0] = 0x67452301;
@@ -92,7 +94,7 @@ void sha1_init(struct sha1 *this)
this->count = 0;
}
-/* Run your data through this function. */
+// Fill the 64-byte working buffer and call sha1_transform() when full.
void sha1_update(struct sha1 *this, char *data, unsigned int len)
{
@@ -116,7 +118,7 @@ void sha1_update(struct sha1 *this, char *data, unsigned int len)
memcpy(this->buffer.c + j, data + i, len - i);
}
-/* Add padding and return the message digest. */
+// Add padding and return the message digest.
void sha1_final(struct sha1 *this, char digest[20])
{
@@ -126,8 +128,10 @@ void sha1_final(struct sha1 *this, char digest[20])
// End the message by appending a "1" bit to the data, ending with the
// message size (in bits, big endian), and adding enough zero bits in
- // between to pad to the end of the next 64-byte frame. Since our input
- // up to now has been in whole bytes, we can deal with bytes here too.
+ // between to pad to the end of the next 64-byte frame.
+ //
+ // Since our input up to now has been in whole bytes, we can deal with
+ // bytes here too.
buf = 0x80;
do {
@@ -140,7 +144,7 @@ void sha1_final(struct sha1 *this, char digest[20])
for (i = 0; i < 20; i++)
digest[i] = this->state[i>>2] >> ((3-(i & 3)) * 8);
- /* Wipe variables */
+ // Wipe variables. Cryptogropher paranoia.
memset(this, 0, sizeof(struct sha1));
}