[tor-commits] [vidalia/alpha] Add hmac_sha256 implementation based on tor's implementation

chiiph at torproject.org chiiph at torproject.org
Thu Jul 5 00:13:45 UTC 2012


commit 814eba4586ee932e896c6de230592882c49b0f9c
Author: Tomás Touceda <chiiph at torproject.org>
Date:   Wed Jul 4 21:09:09 2012 -0300

    Add hmac_sha256 implementation based on tor's implementation
---
 src/common/crypto.cpp |   87 +++++++++++++
 src/common/crypto.h   |    7 +
 src/common/sha256.c   |  331 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 425 insertions(+), 0 deletions(-)

diff --git a/src/common/crypto.cpp b/src/common/crypto.cpp
index 223d202..5ae5295 100644
--- a/src/common/crypto.cpp
+++ b/src/common/crypto.cpp
@@ -187,3 +187,90 @@ crypto_secret_to_key(const QString &secret, const QByteArray &salt, quint8 c)
   return hash.result();
 }
 
+/**
+ * Read a 32-bit value beginning at <b>cp</b>.  Equivalent to
+ * *(uint32_t*)(cp), but will not cause segfaults on platforms that forbid
+ * unaligned memory access.
+ */
+uint32_t
+get_uint32(const void *cp)
+{
+  uint32_t v;
+  memcpy(&v,cp,4);
+  return v;
+}
+/**
+ * Set a 32-bit value beginning at <b>cp</b> to <b>v</b>. Equivalent to
+ * *(uint32_t*)(cp) = v, but will not cause segfaults on platforms that forbid
+ * unaligned memory access. */
+void
+set_uint32(void *cp, uint32_t v)
+{
+  memcpy(cp,&v,4);
+}
+
+#define STMT_BEGIN do {
+#define STMT_END } while(0)
+#define SHA256_CTX sha256_state
+#define SHA256_Init sha256_init
+#define SHA256_Update sha256_process
+#define LTC_ARGCHK(x) Q_ASSERT(x)
+#include "sha256.c"
+#define SHA256_Final(a,b) sha256_done(b,a)
+
+static unsigned char *
+SHA256(const unsigned char *m, size_t len, unsigned char *d)
+{
+  SHA256_CTX ctx;
+  SHA256_Init(&ctx);
+  SHA256_Update(&ctx, m, len);
+  SHA256_Final(d, &ctx);
+  return d;
+}
+
+/** Compute the HMAC-SHA-256 of the <b>msg_len</b> bytes in <b>msg</b>, using
+ * the <b>key</b> of length <b>key_len</b>.  Store the DIGEST256_LEN-byte
+ * result in <b>hmac_out</b>.
+ */
+void
+crypto_hmac_sha256(char *hmac_out,
+                   const char *key, size_t key_len,
+                   const char *msg, size_t msg_len)
+{
+#define BLOCKSIZE 64
+#define DIGESTSIZE 32
+  uint8_t k[BLOCKSIZE];
+  uint8_t pad[BLOCKSIZE];
+  uint8_t d[DIGESTSIZE];
+  int i;
+  SHA256_CTX st;
+
+  if (key_len <= BLOCKSIZE) {
+    memset(k, 0, sizeof(k));
+    memcpy(k, key, key_len); /* not time invariant in key_len */
+  } else {
+    SHA256((const uint8_t *)key, key_len, k);
+    memset(k+DIGESTSIZE, 0, sizeof(k)-DIGESTSIZE);
+  }
+  for (i = 0; i < BLOCKSIZE; ++i)
+    pad[i] = k[i] ^ 0x36;
+  SHA256_Init(&st);
+  SHA256_Update(&st, pad, BLOCKSIZE);
+  SHA256_Update(&st, (uint8_t*)msg, msg_len);
+  SHA256_Final(d, &st);
+
+  for (i = 0; i < BLOCKSIZE; ++i)
+    pad[i] = k[i] ^ 0x5c;
+  SHA256_Init(&st);
+  SHA256_Update(&st, pad, BLOCKSIZE);
+  SHA256_Update(&st, d, DIGESTSIZE);
+  SHA256_Final((uint8_t*)hmac_out, &st);
+
+  /* Now clear everything. */
+  memset(k, 0, sizeof(k));
+  memset(pad, 0, sizeof(pad));
+  memset(d, 0, sizeof(d));
+  memset(&st, 0, sizeof(st));
+#undef BLOCKSIZE
+#undef DIGESTSIZE
+}
diff --git a/src/common/crypto.h b/src/common/crypto.h
index 65582ed..cbfde62 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -73,6 +73,13 @@ QString crypto_rand_string(int len);
  * return a default-constructed QByteArray. */
 QByteArray
 crypto_secret_to_key(const QString &secret, const QByteArray &salt, quint8 c);
+/** Compute the HMAC-SHA-256 of the <b>msg_len</b> bytes in <b>msg</b>, using
+ * the <b>key</b> of length <b>key_len</b>.  Store the DIGEST256_LEN-byte
+ * result in <b>hmac_out</b>.
+ */
+void
+crypto_hmac_sha256(char *hmac_out, const char *key, size_t key_len,
+                                   const char *msg, size_t msg_len);
 
 #endif
 
diff --git a/src/common/sha256.c b/src/common/sha256.c
new file mode 100644
index 0000000..813c68d
--- /dev/null
+++ b/src/common/sha256.c
@@ -0,0 +1,331 @@
+/* Copyright (c) 2009-2012, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+/* This SHA256 implementation is adapted from the public domain one in
+   LibTomCrypt, version 1.6.  Tor uses it on platforms where OpenSSL doesn't
+   have a SHA256. */
+
+
+typedef struct sha256_state {
+    uint64_t length;
+    uint32_t state[8], curlen;
+    unsigned char buf[64];
+} sha256_state;
+
+#define CRYPT_OK 0
+#define CRYPT_NOP -1
+#define CRYPT_INVALID_ARG -2
+
+#define LOAD32H(x,y) STMT_BEGIN x = ntohl(get_uint32((const char*)y)); STMT_END
+#define STORE32H(x,y) STMT_BEGIN set_uint32((char*)y, htonl(x)); STMT_END
+#define STORE64H(x,y) STMT_BEGIN                                \
+  set_uint32((char*)y, htonl((uint32_t)((x)>>32)));             \
+  set_uint32(((char*)y)+4, htonl((uint32_t)((x)&0xffffffff)));  \
+  STMT_END
+#define RORc(x, y) ( ((((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)((y)&31)) | ((unsigned long)(x)<<(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
+#ifndef MIN
+   #define MIN(x, y) ( ((x)<(y))?(x):(y) )
+#endif
+
+
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis at gmail.com, http://libtomcrypt.com
+ */
+
+/**
+  @file sha256.c
+  SHA256 by Tom St Denis
+*/
+
+
+#ifdef LTC_SMALL_CODE
+/* the K array */
+static const uint32_t K[64] = {
+    0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
+    0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
+    0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
+    0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+    0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
+    0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
+    0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
+    0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+    0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
+    0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
+    0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
+    0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+    0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+#endif
+
+/* Various logical functions */
+#define Ch(x,y,z)       (z ^ (x & (y ^ z)))
+#define Maj(x,y,z)      (((x | y) & z) | (x & y))
+#define S(x, n)         RORc((x),(n))
+#define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
+#define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
+#define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
+#define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
+#define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))
+
+/* compress 512-bits */
+#ifdef LTC_CLEAN_STACK
+static int _sha256_compress(sha256_state * md, unsigned char *buf)
+#else
+static int  sha256_compress(sha256_state * md, unsigned char *buf)
+#endif
+{
+    uint32_t S[8], W[64], t0, t1;
+#ifdef LTC_SMALL_CODE
+    uint32_t t;
+#endif
+    int i;
+
+    /* copy state into S */
+    for (i = 0; i < 8; i++) {
+        S[i] = md->state[i];
+    }
+
+    /* copy the state into 512-bits into W[0..15] */
+    for (i = 0; i < 16; i++) {
+        LOAD32H(W[i], buf + (4*i));
+    }
+
+    /* fill W[16..63] */
+    for (i = 16; i < 64; i++) {
+        W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];
+    }
+
+    /* Compress */
+#ifdef LTC_SMALL_CODE
+#define RND(a,b,c,d,e,f,g,h,i)                         \
+     t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i];   \
+     t1 = Sigma0(a) + Maj(a, b, c);                    \
+     d += t0;                                          \
+     h  = t0 + t1;
+
+     for (i = 0; i < 64; ++i) {
+         RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],i);
+         t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
+         S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
+     }
+#else
+#define RND(a,b,c,d,e,f,g,h,i,ki)                    \
+     t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i];   \
+     t1 = Sigma0(a) + Maj(a, b, c);                  \
+     d += t0;                                        \
+     h  = t0 + t1;
+
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2);
+
+#undef RND
+
+#endif
+
+    /* feedback */
+    for (i = 0; i < 8; i++) {
+        md->state[i] = md->state[i] + S[i];
+    }
+    return CRYPT_OK;
+}
+
+#ifdef LTC_CLEAN_STACK
+static int sha256_compress(sha256_state * md, unsigned char *buf)
+{
+    int err;
+    err = _sha256_compress(md, buf);
+    burn_stack(sizeof(uint32_t) * 74);
+    return err;
+}
+#endif
+
+/**
+   Initialize the hash state
+   @param md   The hash state you wish to initialize
+   @return CRYPT_OK if successful
+*/
+static int sha256_init(sha256_state * md)
+{
+    LTC_ARGCHK(md != NULL);
+
+    md->curlen = 0;
+    md->length = 0;
+    md->state[0] = 0x6A09E667UL;
+    md->state[1] = 0xBB67AE85UL;
+    md->state[2] = 0x3C6EF372UL;
+    md->state[3] = 0xA54FF53AUL;
+    md->state[4] = 0x510E527FUL;
+    md->state[5] = 0x9B05688CUL;
+    md->state[6] = 0x1F83D9ABUL;
+    md->state[7] = 0x5BE0CD19UL;
+    return CRYPT_OK;
+}
+
+/**
+   Process a block of memory though the hash
+   @param md     The hash state
+   @param in     The data to hash
+   @param inlen  The length of the data (octets)
+   @return CRYPT_OK if successful
+*/
+static int sha256_process (sha256_state * md, const unsigned char *in, unsigned long inlen)
+{
+    unsigned long n;
+    int           err;
+    LTC_ARGCHK(md != NULL);
+    LTC_ARGCHK(in != NULL);
+    if (md->curlen > sizeof(md->buf)) {
+       return CRYPT_INVALID_ARG;
+    }
+    while (inlen > 0) {
+        if (md->curlen == 0 && inlen >= 64) {
+           if ((err = sha256_compress (md, (unsigned char *)in)) != CRYPT_OK) {
+              return err;
+           }
+           md->length += 64 * 8;
+           in             += 64;
+           inlen          -= 64;
+        } else {
+           n = MIN(inlen, (64 - md->curlen));
+           memcpy(md->buf + md->curlen, in, (size_t)n);
+           md->curlen += n;
+           in             += n;
+           inlen          -= n;
+           if (md->curlen == 64) {
+              if ((err = sha256_compress (md, md->buf)) != CRYPT_OK) {
+                 return err;
+              }
+              md->length += 8*64;
+              md->curlen = 0;
+           }
+       }
+    }
+    return CRYPT_OK;
+}
+
+/**
+   Terminate the hash to get the digest
+   @param md  The hash state
+   @param out [out] The destination of the hash (32 bytes)
+   @return CRYPT_OK if successful
+*/
+static int sha256_done(sha256_state * md, unsigned char *out)
+{
+    int i;
+
+    LTC_ARGCHK(md  != NULL);
+    LTC_ARGCHK(out != NULL);
+
+    if (md->curlen >= sizeof(md->buf)) {
+       return CRYPT_INVALID_ARG;
+    }
+
+
+    /* increase the length of the message */
+    md->length += md->curlen * 8;
+
+    /* append the '1' bit */
+    md->buf[md->curlen++] = (unsigned char)0x80;
+
+    /* if the length is currently above 56 bytes we append zeros
+     * then compress.  Then we can fall back to padding zeros and length
+     * encoding like normal.
+     */
+    if (md->curlen > 56) {
+        while (md->curlen < 64) {
+            md->buf[md->curlen++] = (unsigned char)0;
+        }
+        sha256_compress(md, md->buf);
+        md->curlen = 0;
+    }
+
+    /* pad upto 56 bytes of zeroes */
+    while (md->curlen < 56) {
+        md->buf[md->curlen++] = (unsigned char)0;
+    }
+
+    /* store length */
+    STORE64H(md->length, md->buf+56);
+    sha256_compress(md, md->buf);
+
+    /* copy output */
+    for (i = 0; i < 8; i++) {
+        STORE32H(md->state[i], out+(4*i));
+    }
+#ifdef LTC_CLEAN_STACK
+    zeromem(md, sizeof(sha256_state));
+#endif
+    return CRYPT_OK;
+}
+
+/* $Source: /cvs/libtom/libtomcrypt/src/hashes/sha2/sha256.c,v $ */
+/* $Revision: 1.9 $ */
+/* $Date: 2006/11/01 09:28:17 $ */





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