diff options
| -rw-r--r-- | toys/sha1sum.c | 40 |
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)); } |