#ifndef SEC_UTIL_H
#define SEC_UTIL_H
+#include <cfg/macros.h>
#include <cfg/compiler.h>
#include <cfg/debug.h>
+#include <string.h>
/**
* Purge local variables, by zeroing them.
- *
+ *
* This can be used to clear stack from intermediate results in crypto
* calculations that might somehow be leaked.
*/
/**
* Convert a generic "password" (low-diffused) to a generic "key"
* (high-diffused).
- *
+ *
* In common terminology, a "password" is a key with weak cryptographic
- * characteristics, such as commonly used password input by an user,
+ * characteristics, such as commonly used password input by an user,
* which are usually short and use only a few different characters from
* the 0-255 byte range.
- *
+ *
* This function derives a strong key from the password using a one-way
* process.
- *
+ *
* \note Uses PBKDF2 as key-derivation function, with a fixed salt that
* changes for each Bertos project.
*/
void password2key(const char *pwd, size_t pwd_len,
uint8_t *key, size_t key_len);
-
-/**
- * Perform a bitwise xor between \a in and \a inout, and store
- * the result into \a inout.
- */
-INLINE void xor_block(uint8_t *out, const uint8_t *in1, const uint8_t* in2, size_t len);
-
-/**
- * Perform a bitwise xor over \a inout with constant \a k.
- */
-INLINE void xor_block_const(uint8_t *out, const uint8_t *in, uint8_t k, size_t len);
-
-// FIXME: provide non-32bit fallback
-// FIXME: proper ifdef conditional
-#if 1 // 32-bit optimized versions
+INLINE void xor_block_8(uint8_t *out,
+ const uint8_t *in1, const uint8_t *in2, size_t len)
+{
+ while (len--)
+ *out++ = *in1++ ^ *in2++;
+}
-// FIXME: this code is currently buggy because it ignores alignment issues.
-INLINE void xor_block(uint8_t *out, const uint8_t *in1, const uint8_t* in2, size_t len)
+INLINE void xor_block_const_8(uint8_t *out,
+ const uint8_t *in, uint8_t k, size_t len)
{
- ASSERT(((size_t)in1 % 4) == 0);
- ASSERT(((size_t)in2 % 4) == 0);
- ASSERT(((size_t)out % 4) == 0);
-
- const uint32_t *ibuf1 = (const uint32_t *)in1;
- const uint32_t *ibuf2 = (const uint32_t *)in2;
- uint32_t *obuf = (uint32_t *)out;
- size_t rem = (len & 3);
-
- len /= 4;
while (len--)
- *obuf++ = *ibuf1++ ^ *ibuf2++;
+ *out++ = *in++ ^ k;
+}
- in1 = (const uint8_t*)ibuf1;
- in2 = (const uint8_t*)ibuf2;
- out = (uint8_t*)obuf;
- while (rem--)
+INLINE void xor_block_32(uint32_t *out, const uint32_t *in1,
+ const uint32_t *in2, size_t len)
+{
+ size_t rem = (len & (sizeof(uint32_t) - 1));
+
+ len /= sizeof(uint32_t);
+ while (len--)
*out++ = *in1++ ^ *in2++;
+ xor_block_8((uint8_t *)out,
+ (const uint8_t *)in1, (const uint8_t *)in2, rem);
}
-INLINE void xor_block_const(uint8_t *out, const uint8_t *in, uint8_t k, size_t len)
+INLINE void xor_block_const_32(uint32_t *out, const uint32_t *in,
+ uint8_t k, size_t len)
{
- ASSERT(((size_t)in % 4) == 0);
- ASSERT(((size_t)out % 4) == 0);
-
- uint32_t k32 = k | ((uint32_t)k<<8) | ((uint32_t)k<<16) | ((uint32_t)k<<24);
- const uint32_t *ibuf = (const uint32_t *)in;
- uint32_t *obuf = (uint32_t *)out;
- size_t rem = (len & 3);
-
- len /= 4;
+ uint32_t k32 = k | ((uint32_t)k << 8) |
+ ((uint32_t)k << 16) | ((uint32_t)k << 24);
+ size_t rem = (len & (sizeof(uint32_t) - 1));
+
+ len /= sizeof(uint32_t);
while (len--)
- *obuf++ = *ibuf++ ^ k32;
+ *out++ = *in++ ^ k32;
+ xor_block_const_8((uint8_t *)out, (const uint8_t *)in, k, rem);
+}
+
+/**
+ * Perform a bitwise xor between \a in and \a inout, and store
+ * the result into \a inout.
+ */
+INLINE void xor_block(void *out, const void *in1, const void *in2, size_t len)
+{
+ if (is_aligned(out, sizeof(uint32_t)) &&
+ is_aligned(in1, sizeof(uint32_t)) &&
+ is_aligned(in2, sizeof(uint32_t)))
+ {
+ uint32_t *obuf = (uint32_t *)((size_t)out);
+ const uint32_t *ibuf1 = (const uint32_t *)((size_t)in1);
+ const uint32_t *ibuf2 = (const uint32_t *)((size_t)in2);
+
+ xor_block_32(obuf, ibuf1, ibuf2, len);
+ }
+ else
+ {
+ uint8_t *obuf = (uint8_t *)((size_t)out);
+ const uint8_t *ibuf1 = (const uint8_t *)((size_t)in1);
+ const uint8_t *ibuf2 = (const uint8_t *)((size_t)in2);
- in = (const uint8_t*)ibuf;
- out = (uint8_t*)obuf;
- while (rem--)
- *out++ = *in++ ^ k;
+ xor_block_8(obuf, ibuf1, ibuf2, len);
+ }
}
-#endif
+/**
+ * Perform a bitwise xor over \a inout with constant \a k.
+ */
+INLINE void xor_block_const(uint8_t *out, const uint8_t *in, uint8_t k, size_t len)
+{
+ if (is_aligned(out, sizeof(uint32_t)) &&
+ is_aligned(in, sizeof(uint32_t)))
+ {
+ uint32_t *obuf = (uint32_t *)((size_t)out);
+ const uint32_t *ibuf = (const uint32_t *)((size_t)in);
+
+ xor_block_const_32(obuf, ibuf, k, len);
+ }
+ else
+ {
+ uint8_t *obuf = (uint8_t *)((size_t)out);
+ const uint8_t *ibuf = (const uint8_t *)((size_t)in);
+
+ xor_block_const_8(obuf, ibuf, k, len);
+ }
+}
#endif /* SEC_UTIL_H */
projects / bertos.git / blobdiff