From 7809f29b68e17a455478990ae9b22728381a126b Mon Sep 17 00:00:00 2001

From: Ondrej Mosnacek <omosnace@redhat.com>

Date: Thu, 3 Feb 2022 17:53:23 +0100

Subject: [PATCH] semodule,libsemanage: move module hashing into libsemanage

The main goal of this move is to have the SHA-256 implementation under

libsemanage, since upcoming patches will make use of SHA-256 for a

different (but similar) purpose in libsemanage. Having the hashing code

in libsemanage will reduce code duplication and allow for easier hash

algorithm upgrade in the future.

Note that libselinux currently also contains a hash function

implementation (for yet another different purpose). This patch doesn't

make any effort to address that duplicity yet.

This patch also changes the format of the hash string printed by

semodule to include the name of the hash. The intent is to avoid

ambiguity and potential collisions when the algorithm is potentially

changed in the future.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

---

 policycoreutils/semodule/Makefile   |   2 +-

 policycoreutils/semodule/semodule.c |  53 ++---

 policycoreutils/semodule/sha256.c   | 294 ----------------------------

 policycoreutils/semodule/sha256.h   |  89 ---------

 4 files changed, 17 insertions(+), 421 deletions(-)

 delete mode 100644 policycoreutils/semodule/sha256.c

 delete mode 100644 policycoreutils/semodule/sha256.h

diff --git a/policycoreutils/semodule/Makefile b/policycoreutils/semodule/Makefile

index 9875ac383280..73801e487a76 100644

--- a/policycoreutils/semodule/Makefile

+++ b/policycoreutils/semodule/Makefile

@@ -6,7 +6,7 @@ MANDIR = $(PREFIX)/share/man

 CFLAGS ?= -Werror -Wall -W

 override LDLIBS += -lsepol -lselinux -lsemanage

-SEMODULE_OBJS = semodule.o sha256.o

+SEMODULE_OBJS = semodule.o

 all: semodule genhomedircon

diff --git a/policycoreutils/semodule/semodule.c b/policycoreutils/semodule/semodule.c

index 94a9d131bb79..f4a76289efa3 100644

--- a/policycoreutils/semodule/semodule.c

+++ b/policycoreutils/semodule/semodule.c

@@ -25,8 +25,6 @@

 #include <sepol/cil/cil.h>

 #include <semanage/modules.h>

-#include "sha256.h"

-

 enum client_modes {

 	NO_MODE, INSTALL_M, REMOVE_M, EXTRACT_M, CIL_M, HLL_M,

 	LIST_M, RELOAD, PRIORITY_M, ENABLE_M, DISABLE_M

@@ -348,60 +346,38 @@ static void parse_command_line(int argc, char **argv)

 /* Get module checksum */

 static char *hash_module_data(const char *module_name, const int prio) {

-	semanage_module_info_t *extract_info = NULL;

 	semanage_module_key_t *modkey = NULL;

-	Sha256Context context;

-	uint8_t sha256_hash[SHA256_HASH_SIZE];

-	char *sha256_buf = NULL;

-	void *data;

-	size_t data_len = 0, i;

+	char *hash_str = NULL;

+	void *hash = NULL;

+	size_t hash_len = 0;

 	int result;

 	result = semanage_module_key_create(sh, &modkey);

 	if (result != 0) {

-		goto cleanup_extract;

+		goto cleanup;

 	}

 	result = semanage_module_key_set_name(sh, modkey, module_name);

 	if (result != 0) {

-		goto cleanup_extract;

+		goto cleanup;

 	}

 	result = semanage_module_key_set_priority(sh, modkey, prio);

 	if (result != 0) {

-		goto cleanup_extract;

+		goto cleanup;

 	}

-	result = semanage_module_extract(sh, modkey, 1, &data, &data_len,

-									 &extract_info);

+	result = semanage_module_compute_checksum(sh, modkey, 1, &hash_str,

+						  &hash_len);

 	if (result != 0) {

-		goto cleanup_extract;

-	}

-

-	Sha256Initialise(&context);

-	Sha256Update(&context, data, data_len);

-

-	Sha256Finalise(&context, (SHA256_HASH *)sha256_hash);

-

-	sha256_buf = calloc(1, SHA256_HASH_SIZE * 2 + 1);

-

-	if (sha256_buf == NULL)

-		goto cleanup_extract;

-

-	for (i = 0; i < SHA256_HASH_SIZE; i++) {

-		sprintf((&sha256_buf[i * 2]), "%02x", sha256_hash[i]);

+		goto cleanup;

 	}

-	sha256_buf[i * 2] = 0;

-cleanup_extract:

-	if (data_len > 0) {

-		munmap(data, data_len);

-	}

-	semanage_module_info_destroy(sh, extract_info);

-	free(extract_info);

+cleanup:

+	free(hash);

 	semanage_module_key_destroy(sh, modkey);

 	free(modkey);

-	return sha256_buf;

+	return hash_str;

 }

 int main(int argc, char *argv[])

@@ -669,7 +645,10 @@ cleanup_extract:

 					/* fixed width columns */

 					column[0] = sizeof("000") - 1;

 					column[3] = sizeof("disabled") - 1;

-					column[4] = 64; /* SHA256_HASH_SIZE * 2 */

+

+					result = semanage_module_compute_checksum(sh, NULL, 0, NULL,

+										  &column[4]);

+					if (result != 0) goto cleanup_list;

 					/* variable width columns */

 					const char *tmp = NULL;

diff --git a/policycoreutils/semodule/sha256.c b/policycoreutils/semodule/sha256.c

deleted file mode 100644

index fe2aeef07f53..000000000000

--- a/policycoreutils/semodule/sha256.c

+++ /dev/null

@@ -1,294 +0,0 @@

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  WjCryptLib_Sha256

-//

-//  Implementation of SHA256 hash function.

-//  Original author: Tom St Denis, tomstdenis@gmail.com, http://libtom.org

-//  Modified by WaterJuice retaining Public Domain license.

-//

-//  This is free and unencumbered software released into the public domain - June 2013 waterjuice.org

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  IMPORTS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-#include "sha256.h"

-#include <memory.h>

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  MACROS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-#define ror(value, bits) (((value) >> (bits)) | ((value) << (32 - (bits))))

-

-#define MIN(x, y) ( ((x)<(y))?(x):(y) )

-

-#define STORE32H(x, y)                                                                     \

-     { (y)[0] = (uint8_t)(((x)>>24)&255); (y)[1] = (uint8_t)(((x)>>16)&255);   \

-       (y)[2] = (uint8_t)(((x)>>8)&255); (y)[3] = (uint8_t)((x)&255); }

-

-#define LOAD32H(x, y)                            \

-     { x = ((uint32_t)((y)[0] & 255)<<24) | \

-           ((uint32_t)((y)[1] & 255)<<16) | \

-           ((uint32_t)((y)[2] & 255)<<8)  | \

-           ((uint32_t)((y)[3] & 255)); }

-

-#define STORE64H(x, y)                                                                     \

-   { (y)[0] = (uint8_t)(((x)>>56)&255); (y)[1] = (uint8_t)(((x)>>48)&255);     \

-     (y)[2] = (uint8_t)(((x)>>40)&255); (y)[3] = (uint8_t)(((x)>>32)&255);     \

-     (y)[4] = (uint8_t)(((x)>>24)&255); (y)[5] = (uint8_t)(((x)>>16)&255);     \

-     (y)[6] = (uint8_t)(((x)>>8)&255); (y)[7] = (uint8_t)((x)&255); }

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  CONSTANTS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-// 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

-};

-

-#define BLOCK_SIZE          64

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  INTERNAL FUNCTIONS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-// 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 )         ror((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))

-

-#define Sha256Round( 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;

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  TransformFunction

-//

-//  Compress 512-bits

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-static

-void

-    TransformFunction

-    (

-        Sha256Context*      Context,

-        uint8_t const*      Buffer

-    )

-{

-    uint32_t    S[8];

-    uint32_t    W[64];

-    uint32_t    t0;

-    uint32_t    t1;

-    uint32_t    t;

-    int         i;

-

-    // Copy state into S

-    for( i=0; i<8; i++ )

-    {

-        S[i] = Context->state[i];

-    }

-

-    // Copy the state into 512-bits into W[0..15]

-    for( i=0; i<16; i++ )

-    {

-        LOAD32H( W[i], Buffer + (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

-    for( i=0; i<64; i++ )

-    {

-        Sha256Round( 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;

-    }

-

-    // Feedback

-    for( i=0; i<8; i++ )

-    {

-        Context->state[i] = Context->state[i] + S[i];

-    }

-}

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  PUBLIC FUNCTIONS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Initialise

-//

-//  Initialises a SHA256 Context. Use this to initialise/reset a context.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Initialise

-    (

-        Sha256Context*      Context         // [out]

-    )

-{

-    Context->curlen = 0;

-    Context->length = 0;

-    Context->state[0] = 0x6A09E667UL;

-    Context->state[1] = 0xBB67AE85UL;

-    Context->state[2] = 0x3C6EF372UL;

-    Context->state[3] = 0xA54FF53AUL;

-    Context->state[4] = 0x510E527FUL;

-    Context->state[5] = 0x9B05688CUL;

-    Context->state[6] = 0x1F83D9ABUL;

-    Context->state[7] = 0x5BE0CD19UL;

-}

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Update

-//

-//  Adds data to the SHA256 context. This will process the data and update the internal state of the context. Keep on

-//  calling this function until all the data has been added. Then call Sha256Finalise to calculate the hash.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Update

-    (

-        Sha256Context*      Context,        // [in out]

-        void const*         Buffer,         // [in]

-        uint32_t            BufferSize      // [in]

-    )

-{

-    uint32_t n;

-

-    if( Context->curlen > sizeof(Context->buf) )

-    {

-       return;

-    }

-

-    while( BufferSize > 0 )

-    {

-        if( Context->curlen == 0 && BufferSize >= BLOCK_SIZE )

-        {

-           TransformFunction( Context, (uint8_t*)Buffer );

-           Context->length += BLOCK_SIZE * 8;

-           Buffer = (uint8_t*)Buffer + BLOCK_SIZE;

-           BufferSize -= BLOCK_SIZE;

-        }

-        else

-        {

-           n = MIN( BufferSize, (BLOCK_SIZE - Context->curlen) );

-           memcpy( Context->buf + Context->curlen, Buffer, (size_t)n );

-           Context->curlen += n;

-           Buffer = (uint8_t*)Buffer + n;

-           BufferSize -= n;

-           if( Context->curlen == BLOCK_SIZE )

-           {

-              TransformFunction( Context, Context->buf );

-              Context->length += 8*BLOCK_SIZE;

-              Context->curlen = 0;

-           }

-       }

-    }

-}

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Finalise

-//

-//  Performs the final calculation of the hash and returns the digest (32 byte buffer containing 256bit hash). After

-//  calling this, Sha256Initialised must be used to reuse the context.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Finalise

-    (

-        Sha256Context*      Context,        // [in out]

-        SHA256_HASH*        Digest          // [out]

-    )

-{

-    int i;

-

-    if( Context->curlen >= sizeof(Context->buf) )

-    {

-       return;

-    }

-

-    // Increase the length of the message

-    Context->length += Context->curlen * 8;

-

-    // Append the '1' bit

-    Context->buf[Context->curlen++] = (uint8_t)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( Context->curlen > 56 )

-    {

-        while( Context->curlen < 64 )

-        {

-            Context->buf[Context->curlen++] = (uint8_t)0;

-        }

-        TransformFunction(Context, Context->buf);

-        Context->curlen = 0;

-    }

-

-    // Pad up to 56 bytes of zeroes

-    while( Context->curlen < 56 )

-    {

-        Context->buf[Context->curlen++] = (uint8_t)0;

-    }

-

-    // Store length

-    STORE64H( Context->length, Context->buf+56 );

-    TransformFunction( Context, Context->buf );

-

-    // Copy output

-    for( i=0; i<8; i++ )

-    {

-        STORE32H( Context->state[i], Digest->bytes+(4*i) );

-    }

-}

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Calculate

-//

-//  Combines Sha256Initialise, Sha256Update, and Sha256Finalise into one function. Calculates the SHA256 hash of the

-//  buffer.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Calculate

-    (

-        void  const*        Buffer,         // [in]

-        uint32_t            BufferSize,     // [in]

-        SHA256_HASH*        Digest          // [in]

-    )

-{

-    Sha256Context context;

-

-    Sha256Initialise( &context );

-    Sha256Update( &context, Buffer, BufferSize );

-    Sha256Finalise( &context, Digest );

-}

diff --git a/policycoreutils/semodule/sha256.h b/policycoreutils/semodule/sha256.h

deleted file mode 100644

index 406ed869cd82..000000000000

--- a/policycoreutils/semodule/sha256.h

+++ /dev/null

@@ -1,89 +0,0 @@

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  WjCryptLib_Sha256

-//

-//  Implementation of SHA256 hash function.

-//  Original author: Tom St Denis, tomstdenis@gmail.com, http://libtom.org

-//  Modified by WaterJuice retaining Public Domain license.

-//

-//  This is free and unencumbered software released into the public domain - June 2013 waterjuice.org

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-#pragma once

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  IMPORTS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-#include <stdint.h>

-#include <stdio.h>

-

-typedef struct

-{

-    uint64_t    length;

-    uint32_t    state[8];

-    uint32_t    curlen;

-    uint8_t     buf[64];

-} Sha256Context;

-

-#define SHA256_HASH_SIZE           ( 256 / 8 )

-

-typedef struct

-{

-    uint8_t      bytes [SHA256_HASH_SIZE];

-} SHA256_HASH;

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  PUBLIC FUNCTIONS

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Initialise

-//

-//  Initialises a SHA256 Context. Use this to initialise/reset a context.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Initialise

-    (

-        Sha256Context*      Context         // [out]

-    );

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Update

-//

-//  Adds data to the SHA256 context. This will process the data and update the internal state of the context. Keep on

-//  calling this function until all the data has been added. Then call Sha256Finalise to calculate the hash.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Update

-    (

-        Sha256Context*      Context,        // [in out]

-        void const*         Buffer,         // [in]

-        uint32_t            BufferSize      // [in]

-    );

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Finalise

-//

-//  Performs the final calculation of the hash and returns the digest (32 byte buffer containing 256bit hash). After

-//  calling this, Sha256Initialised must be used to reuse the context.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Finalise

-    (

-        Sha256Context*      Context,        // [in out]

-        SHA256_HASH*        Digest          // [out]

-    );

-

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-//  Sha256Calculate

-//

-//  Combines Sha256Initialise, Sha256Update, and Sha256Finalise into one function. Calculates the SHA256 hash of the

-//  buffer.

-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

-void

-    Sha256Calculate

-    (

-        void  const*        Buffer,         // [in]

-        uint32_t            BufferSize,     // [in]

-        SHA256_HASH*        Digest          // [in]

-    );

-- 

2.34.1