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Diffstat (limited to 'src/libkeccak/mac/hmac.c')
-rw-r--r--src/libkeccak/mac/hmac.c183
1 files changed, 180 insertions, 3 deletions
diff --git a/src/libkeccak/mac/hmac.c b/src/libkeccak/mac/hmac.c
index b679e8e..e5318fd 100644
--- a/src/libkeccak/mac/hmac.c
+++ b/src/libkeccak/mac/hmac.c
@@ -34,6 +34,14 @@
+static void* (*volatile my_explicit_memset)(void*, int, size_t) = memset;
+static __attribute__((optimize("-O0")))
+void my_explicit_bzero(void* ptr, size_t size)
+{
+ (*my_explicit_memset)(ptr, 0, size);
+}
+
+
/**
* Change to HMAC-hashing key on the state
*
@@ -185,7 +193,6 @@ size_t libkeccak_hmac_unmarshal(libkeccak_hmac_state_t* restrict state, const ch
* @param msglen The length of the partial message, in bytes
* @return Zero on success, -1 on error
*/
-__attribute__((nonnull))
int libkeccak_hmac_fast_update(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen)
{
char* old;
@@ -201,6 +208,9 @@ int libkeccak_hmac_fast_update(libkeccak_hmac_state_t* restrict state, const cha
state->key_ipad = NULL;
}
+ if ((msg == NULL) || (msglen == 0))
+ return 0;
+
if (!(state->key_length & 7))
return libkeccak_fast_update(&(state->sponge), msg, msglen);
@@ -231,7 +241,6 @@ int libkeccak_hmac_fast_update(libkeccak_hmac_state_t* restrict state, const cha
* @param msglen The length of the partial message, in bytes
* @return Zero on success, -1 on error
*/
-__attribute__((nonnull))
int libkeccak_hmac_update(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen)
{
size_t i;
@@ -246,6 +255,9 @@ int libkeccak_hmac_update(libkeccak_hmac_state_t* restrict state, const char* re
state->key_ipad = NULL;
}
+ if ((msg == NULL) || (msglen == 0))
+ return 0;
+
if (!(state->key_length & 7))
return libkeccak_update(&(state->sponge), msg, msglen);
@@ -266,8 +278,173 @@ int libkeccak_hmac_update(libkeccak_hmac_state_t* restrict state, const char* re
r = libkeccak_update(&(state->sponge), state->buffer, msglen);
saved_errno = errno;
- __builtin_memset(state->buffer, 0, msglen);
+ my_explicit_bzero(state->buffer, msglen);
errno = saved_errno;
return r;
}
+
+/**
+ * Absorb the last part of the message and fetch the hash
+ * without wiping sensitive data when possible
+ *
+ * You may use `&(state->sponge)` for continued squeezing
+ *
+ * @param state The hashing state
+ * @param msg The rest of the message, may be `NULL`, may be modified
+ * @param msglen The length of the partial message
+ * @param bits The number of bits at the end of the message not covered by `msglen`
+ * @param suffix The suffix concatenate to the message, only '1':s and '0':s, and NUL-termination
+ * @param hashsum Output parameter for the hashsum, may be `NULL`
+ * @return Zero on success, -1 on error
+ */
+int libkeccak_hmac_fast_digest(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen,
+ size_t bits, const char* restrict suffix, char* restrict hashsum)
+{
+ size_t hashsize = state->sponge.n >> 3;
+ char* tmp = malloc(((state->sponge.n + 7) >> 3) * sizeof(char));
+ char leftover[2];
+ size_t newlen;
+ int saved_errno;
+
+ if (tmp == NULL)
+ return -1;
+
+ if (!(state->key_length & 7))
+ {
+ if (libkeccak_fast_digest(&(state->sponge), msg, msglen, bits, suffix, tmp) < 0)
+ goto fail;
+ goto stage_2;
+ }
+
+ if (libkeccak_hmac_fast_update(state, msg, msglen) < 0)
+ goto fail;
+ leftover[0] = state->leftover;
+ if (bits)
+ {
+ leftover[0] |= msg[msglen] >> (state->key_length & 7);
+ leftover[1] = ((unsigned char)(msg[msglen])) << (8 - (state->key_length & 7));
+ }
+ newlen = (state->key_length & 7) + bits;
+ if (libkeccak_fast_digest(&(state->sponge), leftover, newlen >> 3, newlen & 7, suffix, tmp) < 0)
+ goto fail;
+
+ stage_2:
+
+ bits = state->sponge.n & 7;
+ state->key_ipad = state->key_opad;
+ if (libkeccak_hmac_fast_update(state, NULL, 0) < 0)
+ goto fail;
+
+ if (!(state->key_length & 7))
+ {
+ if (libkeccak_fast_digest(&(state->sponge), tmp, hashsize, bits, suffix, hashsum) < 0)
+ goto fail;
+ goto stage_3;
+ }
+
+ if (libkeccak_hmac_fast_update(state, tmp, hashsize) < 0)
+ goto fail;
+ leftover[0] = state->leftover;
+ if (bits)
+ {
+ leftover[0] |= tmp[hashsize] >> (state->key_length & 7);
+ leftover[1] = ((unsigned char)(tmp[hashsize])) << (8 - (state->key_length & 7));
+ }
+ newlen = (state->key_length & 7) + bits;
+ if (libkeccak_fast_digest(&(state->sponge), leftover, newlen >> 3, newlen & 7, suffix, tmp) < 0)
+ goto fail;
+
+ stage_3:
+
+ free(tmp);
+ return 0;
+ fail:
+ saved_errno = errno;
+ free(tmp);
+ return errno = saved_errno, -1;
+}
+
+
+/**
+ * Absorb the last part of the message and fetch the hash
+ * and wipe sensitive data when possible
+ *
+ * You may use `&(state->sponge)` for continued squeezing
+ *
+ * @param state The hashing state
+ * @param msg The rest of the message, may be `NULL`, may be modified
+ * @param msglen The length of the partial message
+ * @param bits The number of bits at the end of the message not covered by `msglen`
+ * @param suffix The suffix concatenate to the message, only '1':s and '0':s, and NUL-termination
+ * @param hashsum Output parameter for the hashsum, may be `NULL`
+ * @return Zero on success, -1 on error
+ */
+int libkeccak_hmac_digest(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen,
+ size_t bits, const char* restrict suffix, char* restrict hashsum)
+{
+ size_t hashsize = state->sponge.n >> 3;
+ char* tmp = malloc(((state->sponge.n + 7) >> 3) * sizeof(char));
+ char leftover[2];
+ size_t newlen;
+ int saved_errno;
+
+ if (tmp == NULL)
+ return -1;
+
+ if (!(state->key_length & 7))
+ {
+ if (libkeccak_digest(&(state->sponge), msg, msglen, bits, suffix, tmp) < 0)
+ goto fail;
+ goto stage_2;
+ }
+
+ if (libkeccak_hmac_update(state, msg, msglen) < 0)
+ goto fail;
+ leftover[0] = state->leftover;
+ if (bits)
+ {
+ leftover[0] |= msg[msglen] >> (state->key_length & 7);
+ leftover[1] = ((unsigned char)(msg[msglen])) << (8 - (state->key_length & 7));
+ }
+ newlen = (state->key_length & 7) + bits;
+ if (libkeccak_digest(&(state->sponge), leftover, newlen >> 3, newlen & 7, suffix, tmp) < 0)
+ goto fail;
+
+ stage_2:
+
+ bits = state->sponge.n & 7;
+ state->key_ipad = state->key_opad;
+ if (libkeccak_hmac_update(state, NULL, 0) < 0)
+ goto fail;
+
+ if (!(state->key_length & 7))
+ {
+ if (libkeccak_digest(&(state->sponge), tmp, hashsize, bits, suffix, hashsum) < 0)
+ goto fail;
+ goto stage_3;
+ }
+
+ if (libkeccak_hmac_update(state, tmp, hashsize) < 0)
+ goto fail;
+ leftover[0] = state->leftover;
+ if (bits)
+ {
+ leftover[0] |= tmp[hashsize] >> (state->key_length & 7);
+ leftover[1] = ((unsigned char)(tmp[hashsize])) << (8 - (state->key_length & 7));
+ }
+ newlen = (state->key_length & 7) + bits;
+ if (libkeccak_digest(&(state->sponge), leftover, newlen >> 3, newlen & 7, suffix, tmp) < 0)
+ goto fail;
+
+ stage_3:
+ my_explicit_bzero(tmp, ((state->sponge.n + 7) >> 3) * sizeof(char));
+ free(tmp);
+ return 0;
+ fail:
+ saved_errno = errno;
+ my_explicit_bzero(tmp, ((state->sponge.n + 7) >> 3) * sizeof(char));
+ free(tmp);
+ return errno = saved_errno, -1;
+}
+
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-09-20 05:39:15 +0000