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Diffstat (limited to 'toys/other/sha1sum.c')
| -rw-r--r-- | toys/other/sha1sum.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/toys/other/sha1sum.c b/toys/other/sha1sum.c new file mode 100644 index 00000000..3229cd12 --- /dev/null +++ b/toys/other/sha1sum.c @@ -0,0 +1,185 @@ +/* vi: set sw=4 ts=4: + * + * sha1sum.c - Calculate sha1 cryptographic hash for input. + * + * Copyright 2007 Rob Landley <rob@landley.net> + * + * 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. + +USE_SHA1SUM(NEWTOY(sha1sum, NULL, TOYFLAG_USR|TOYFLAG_BIN)) + +config SHA1SUM + bool "sha1sum" + default y + help + usage: sha1sum [file...] + + Calculate sha1 hash of files (or stdin). +*/ + +#include <toys.h> + +struct sha1 { + uint32_t state[5]; + uint32_t oldstate[5]; + uint64_t count; + union { + unsigned char c[64]; + uint32_t i[16]; + } buffer; +}; + +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 +#if 1 +#define blk0(i) (block[i] = (rol(block[i],24)&0xFF00FF00) \ + |(rol(block[i],8)&0x00FF00FF)) +#else // big endian? +#define blk0(i) block[i] +#endif +#define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \ + ^block[(i+2)&15]^block[i&15],1)) + +static const uint32_t rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6}; + +// Hash a single 512-bit block. This is the core of the algorithm. + +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 + for (i=0; i<5; i++) { + this->oldstate[i] = this->state[i]; + rot[i] = this->state + i; + } + // 4 rounds of 20 operations each. + for (i=count=0; i<4; i++) { + for (j=0; j<20; j++) { + uint32_t work; + + work = *rot[2] ^ *rot[3]; + if (!i) work = (work & *rot[1]) ^ *rot[3]; + else { + if (i==2) + work = ((*rot[1]|*rot[2])&*rot[3])|(*rot[1]&*rot[2]); + else work ^= *rot[1]; + } + if (!i && j<16) work += blk0(count); + else work += blk(count); + *rot[4] += work + rol(*rot[0],5) + rconsts[i]; + *rot[1] = rol(*rot[1],30); + + // Rotate by one for next time. + temp = rot[4]; + for (k=4; k; k--) rot[k] = rot[k-1]; + *rot = temp; + count++; + } + } + // Add the previous values of state[] + for (i=0; i<5; i++) this->state[i] += this->oldstate[i]; +} + + +// Initialize a struct sha1. + +static void sha1_init(struct sha1 *this) +{ + /* SHA1 initialization constants */ + this->state[0] = 0x67452301; + this->state[1] = 0xEFCDAB89; + this->state[2] = 0x98BADCFE; + this->state[3] = 0x10325476; + this->state[4] = 0xC3D2E1F0; + this->count = 0; +} + +// Fill the 64-byte working buffer and call sha1_transform() when full. + +void sha1_update(struct sha1 *this, char *data, unsigned int len) +{ + unsigned int i, j; + + j = this->count & 63; + this->count += len; + + // Enough data to process a frame? + if ((j + len) > 63) { + i = 64-j; + memcpy(this->buffer.c + j, data, i); + sha1_transform(this); + for ( ; i + 63 < len; i += 64) { + memcpy(this->buffer.c, data + i, 64); + sha1_transform(this); + } + j = 0; + } else i = 0; + // Grab remaining chunk + memcpy(this->buffer.c + j, data + i, len - i); +} + +// Add padding and return the message digest. + +void sha1_final(struct sha1 *this, char digest[20]) +{ + uint64_t count = this->count << 3; + unsigned int i; + char buf; + + // 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. + + buf = 0x80; + do { + sha1_update(this, &buf, 1); + buf = 0; + } while ((this->count & 63) != 56); + for (i = 0; i < 8; i++) + this->buffer.c[56+i] = count >> (8*(7-i)); + sha1_transform(this); + + for (i = 0; i < 20; i++) + digest[i] = this->state[i>>2] >> ((3-(i & 3)) * 8); + // Wipe variables. Cryptogropher paranoia. + memset(this, 0, sizeof(struct sha1)); +} + +// Callback for loopfiles() + +static void do_sha1(int fd, char *name) +{ + struct sha1 this; + int len; + + sha1_init(&this); + for (;;) { + len = read(fd, toybuf, sizeof(toybuf)); + if (len<1) break; + sha1_update(&this, toybuf, len); + } + sha1_final(&this, toybuf); + for (len = 0; len < 20; len++) printf("%02x", toybuf[len]); + printf(" %s\n", name); +} + +void sha1sum_main(void) +{ + loopfiles(toys.optargs, do_sha1); +} |