Fixed bad bit shift and sign extension errors

src/libstrongswan/crypto/mgf1/mgf1_bitspender.c

@@ -80,12 +80,18 @@ METHOD(mgf1_bitspender_t, get_bits, bool,
 {
 	int bits_now;
 
+	*bits = 0x00000000;
+
+	if (bits_needed == 0)
+	{
+		/* trivial */
+		return TRUE;
+	}
 	if (bits_needed > 32)
 	{
 		/* too many bits requested */
 		return FALSE;
 	}
-	*bits = 0x00000000;
 
 	while (bits_needed)
 	{
@@ -113,17 +119,25 @@ METHOD(mgf1_bitspender_t, get_bits, bool,
 			bits_now = this->bits_left;
 			this->bits_left = 0;
 			bits_needed -= bits_now;
-			*bits <<= bits_now;
-			*bits |= this->bits;
 		}
 		else
 		{
 			bits_now = bits_needed;
 			this->bits_left -= bits_needed;
 			bits_needed = 0;
+		}
+		if (bits_now == 32)
+		{
+			*bits = this->bits;
+		}
+		else
+		{
 			*bits <<= bits_now;
 			*bits |= this->bits >> this->bits_left;
-			this->bits &= 0xffffffff >> (32 - this->bits_left);
+			if (this->bits_left)
+			{
+				this->bits &= 0xffffffff >> (32 - this->bits_left);
+			}
 		}
 	}
 	return TRUE;

src/libstrongswan/plugins/bliss/bliss_bitpacker.c

@@ -62,12 +62,19 @@ METHOD(bliss_bitpacker_t, get_bits, size_t,
 METHOD(bliss_bitpacker_t, write_bits, bool,
 	private_bliss_bitpacker_t *this, uint32_t value, size_t bits)
 {
+	if (bits == 0)
+	{
+		return TRUE;
+	}
 	if (bits > 32)
 	{
 		return FALSE;
 	}
+	if (bits < 32)
+	{
+		value &= (1 << bits) - 1;
+	}
 	this->bits += bits;
-	value &= (1 << bits) - 1;
 
 	while (TRUE)
 	{
@@ -152,7 +159,7 @@ METHOD(bliss_bitpacker_t, destroy, void,
 /**
  * See header.
  */
-bliss_bitpacker_t *bliss_bitpacker_create(size_t max_bits)
+bliss_bitpacker_t *bliss_bitpacker_create(uint16_t max_bits)
 {
 	private_bliss_bitpacker_t *this;
 

src/libstrongswan/plugins/bliss/bliss_bitpacker.h

@@ -73,7 +73,7 @@ struct bliss_bitpacker_t {
  *
  * @param max_bits		Total number of bits to be stored
  */
-bliss_bitpacker_t* bliss_bitpacker_create(size_t max_bits);
+bliss_bitpacker_t* bliss_bitpacker_create(uint16_t max_bits);
 
 /**
  * Create a bliss_bitpacker_t object for reading

src/libstrongswan/plugins/bliss/bliss_public_key.c

@@ -391,12 +391,15 @@ bool bliss_public_key_from_asn1(chunk_t object, bliss_param_set_t *set,
 {
 	bliss_bitpacker_t *packer;
 	uint32_t coefficient;
+	uint16_t needed_bits;
 	int i;
 
 	/* skip initial bit string octet defining unused bits */
 	object = chunk_skip(object, 1);
 
-	if (8 * object.len < set->n * set->q_bits)
+	needed_bits = set->n * set->q_bits;
+
+	if (8 * object.len < needed_bits)
 	{
 		return FALSE;
 	}