Move bignum helpers to their own module
Move bignum-related helper functions to their own files under tests/include
and tests/src. The primary motivation is that a subsequent commit will make
bignum_helpers.h include library/bignum*.h, but we want to be able to
include <test/helpers.h> without having the library directory on the include
path (we do this in some programs under programs/ intended for testing).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/include/test/bignum_helpers.h b/tests/include/test/bignum_helpers.h
new file mode 100644
index 0000000..22ce7f7
--- /dev/null
+++ b/tests/include/test/bignum_helpers.h
@@ -0,0 +1,90 @@
+/**
+ * \file bignum_helpers.h
+ *
+ * \brief This file contains the prototypes of helper functions for
+ * bignum-related testing.
+ */
+
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TEST_BIGNUM_HELPERS_H
+#define TEST_BIGNUM_HELPERS_H
+
+#include <mbedtls/build_info.h>
+
+#if defined(MBEDTLS_BIGNUM_C)
+
+#include <mbedtls/bignum.h>
+
+/** Allocate and populate a core MPI from a test case argument.
+ *
+ * This function allocates exactly as many limbs as necessary to fit
+ * the length of the input. In other words, it preserves leading zeros.
+ *
+ * The limb array is allocated with mbedtls_calloc() and must later be
+ * freed with mbedtls_free().
+ *
+ * \param[in,out] pX The address where a pointer to the allocated limb
+ * array will be stored.
+ * \c *pX must be null on entry.
+ * On exit, \c *pX is null on error or if the number
+ * of limbs is 0.
+ * \param[out] plimbs The address where the number of limbs will be stored.
+ * \param[in] input The test argument to read.
+ * It is interpreted as a hexadecimal representation
+ * of a non-negative integer.
+ *
+ * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
+ */
+int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
+ const char *input );
+
+/** Read an MPI from a hexadecimal string.
+ *
+ * Like mbedtls_mpi_read_string(), but with tighter guarantees around
+ * edge cases.
+ *
+ * - This function guarantees that if \p s begins with '-' then the sign
+ * bit of the result will be negative, even if the value is 0.
+ * When this function encounters such a "negative 0", it
+ * increments #mbedtls_test_case_uses_negative_0.
+ * - The size of the result is exactly the minimum number of limbs needed
+ * to fit the digits in the input. In particular, this function constructs
+ * a bignum with 0 limbs for an empty string, and a bignum with leading 0
+ * limbs if the string has sufficiently many leading 0 digits.
+ * This is important so that the "0 (null)" and "0 (1 limb)" and
+ * "leading zeros" test cases do what they claim.
+ *
+ * \param[out] X The MPI object to populate. It must be initialized.
+ * \param[in] s The null-terminated hexadecimal string to read from.
+ *
+ * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
+ */
+int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s );
+
+/** Nonzero if the current test case had an input parsed with
+ * mbedtls_test_read_mpi() that is a negative 0 (`"-"`, `"-0"`, `"-00"`, etc.,
+ * constructing a result with the sign bit set to -1 and the value being
+ * all-limbs-0, which is not a valid representation in #mbedtls_mpi but is
+ * tested for robustness).
+ */
+extern unsigned mbedtls_test_case_uses_negative_0;
+
+#endif /* MBEDTLS_BIGNUM_C */
+
+#endif /* TEST_BIGNUM_HELPERS_H */
diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index 5f9bde6..b64bfcb 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -216,6 +216,17 @@
int len );
/**
+ * \brief Convert hexadecimal digit to an integer.
+ *
+ * \param c The digit to convert (`'0'` to `'9'`, `'A'` to `'F'` or
+ * `'a'` to `'f'`).
+ * \param[out] uc On success, the value of the digit (0 to 15).
+ *
+ * \return 0 on success, -1 if \p c is not a hexadecimal digit.
+ */
+int mbedtls_test_ascii2uc(const char c, unsigned char *uc);
+
+/**
* Allocate and zeroize a buffer.
*
* If the size if zero, a pointer to a zeroized 1-byte buffer is returned.
@@ -269,60 +280,4 @@
const char *file, int line);
#endif
-#if defined(MBEDTLS_BIGNUM_C)
-/** Allocate and populate a core MPI from a test case argument.
- *
- * This function allocates exactly as many limbs as necessary to fit
- * the length of the input. In other words, it preserves leading zeros.
- *
- * The limb array is allocated with mbedtls_calloc() and must later be
- * freed with mbedtls_free().
- *
- * \param[in,out] pX The address where a pointer to the allocated limb
- * array will be stored.
- * \c *pX must be null on entry.
- * On exit, \c *pX is null on error or if the number
- * of limbs is 0.
- * \param[out] plimbs The address where the number of limbs will be stored.
- * \param[in] input The test argument to read.
- * It is interpreted as a hexadecimal representation
- * of a non-negative integer.
- *
- * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
- */
-int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
- const char *input );
-
-/** Read an MPI from a hexadecimal string.
- *
- * Like mbedtls_mpi_read_string(), but with tighter guarantees around
- * edge cases.
- *
- * - This function guarantees that if \p s begins with '-' then the sign
- * bit of the result will be negative, even if the value is 0.
- * When this function encounters such a "negative 0", it
- * increments #mbedtls_test_case_uses_negative_0.
- * - The size of the result is exactly the minimum number of limbs needed
- * to fit the digits in the input. In particular, this function constructs
- * a bignum with 0 limbs for an empty string, and a bignum with leading 0
- * limbs if the string has sufficiently many leading 0 digits.
- * This is important so that the "0 (null)" and "0 (1 limb)" and
- * "leading zeros" test cases do what they claim.
- *
- * \param[out] X The MPI object to populate. It must be initialized.
- * \param[in] s The null-terminated hexadecimal string to read from.
- *
- * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
- */
-int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s );
-
-/** Nonzero if the current test case had an input parsed with
- * mbedtls_test_read_mpi() that is a negative 0 (`"-"`, `"-0"`, `"-00"`, etc.,
- * constructing a result with the sign bit set to -1 and the value being
- * all-limbs-0, which is not a valid representation in #mbedtls_mpi but is
- * tested for robustness).
- */
-extern unsigned mbedtls_test_case_uses_negative_0;
-#endif /* MBEDTLS_BIGNUM_C */
-
#endif /* TEST_HELPERS_H */
diff --git a/tests/src/bignum_helpers.c b/tests/src/bignum_helpers.c
new file mode 100644
index 0000000..575bd03
--- /dev/null
+++ b/tests/src/bignum_helpers.c
@@ -0,0 +1,119 @@
+/**
+ * \file bignum_helpers.c
+ *
+ * \brief This file contains the prototypes of helper functions for
+ * bignum-related testing.
+ */
+
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+#include <test/bignum_helpers.h>
+
+#if defined(MBEDTLS_BIGNUM_C)
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <mbedtls/bignum.h>
+#include <bignum_core.h>
+#include <bignum_mod.h>
+#include <bignum_mod_raw.h>
+
+#include <test/helpers.h>
+#include <test/macros.h>
+
+int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
+ const char *input )
+{
+ /* Sanity check */
+ if( *pX != NULL )
+ return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+
+ size_t hex_len = strlen( input );
+ size_t byte_len = ( hex_len + 1 ) / 2;
+ *plimbs = CHARS_TO_LIMBS( byte_len );
+
+ /* A core bignum is not allowed to be empty. Forbid it as test data,
+ * this way static analyzers have a chance of knowing we don't expect
+ * the bignum functions to support empty inputs. */
+ if( *plimbs == 0 )
+ return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+
+ *pX = mbedtls_calloc( *plimbs, sizeof( **pX ) );
+ if( *pX == NULL )
+ return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+
+ unsigned char *byte_start = ( unsigned char * ) *pX;
+ if( byte_len % sizeof( mbedtls_mpi_uint ) != 0 )
+ {
+ byte_start += sizeof( mbedtls_mpi_uint ) - byte_len % sizeof( mbedtls_mpi_uint );
+ }
+ if( ( hex_len & 1 ) != 0 )
+ {
+ /* mbedtls_test_unhexify wants an even number of hex digits */
+ TEST_ASSERT( mbedtls_test_ascii2uc( *input, byte_start ) == 0 );
+ ++byte_start;
+ ++input;
+ --byte_len;
+ }
+ TEST_ASSERT( mbedtls_test_unhexify( byte_start,
+ byte_len,
+ input,
+ &byte_len ) == 0 );
+
+ mbedtls_mpi_core_bigendian_to_host( *pX, *plimbs );
+ return( 0 );
+
+exit:
+ mbedtls_free( *pX );
+ return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+}
+
+int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s )
+{
+ int negative = 0;
+ /* Always set the sign bit to -1 if the input has a minus sign, even for 0.
+ * This creates an invalid representation, which mbedtls_mpi_read_string()
+ * avoids but we want to be able to create that in test data. */
+ if( s[0] == '-' )
+ {
+ ++s;
+ negative = 1;
+ }
+ /* mbedtls_mpi_read_string() currently retains leading zeros.
+ * It always allocates at least one limb for the value 0. */
+ if( s[0] == 0 )
+ {
+ mbedtls_mpi_free( X );
+ return( 0 );
+ }
+ int ret = mbedtls_mpi_read_string( X, 16, s );
+ if( ret != 0 )
+ return( ret );
+ if( negative )
+ {
+ if( mbedtls_mpi_cmp_int( X, 0 ) == 0 )
+ ++mbedtls_test_case_uses_negative_0;
+ X->s = -1;
+ }
+ return( 0 );
+}
+
+#endif /* MBEDTLS_BIGNUM_C */
+
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index 7c83714..be5c465 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -48,7 +48,7 @@
#endif /* MBEDTLS_PLATFORM_C */
}
-static int ascii2uc(const char c, unsigned char *uc)
+int mbedtls_test_ascii2uc(const char c, unsigned char *uc)
{
if( ( c >= '0' ) && ( c <= '9' ) )
*uc = c - '0';
@@ -207,10 +207,10 @@
while( *ibuf != 0 )
{
- if ( ascii2uc( *(ibuf++), &uc ) != 0 )
+ if ( mbedtls_test_ascii2uc( *(ibuf++), &uc ) != 0 )
return( -1 );
- if ( ascii2uc( *(ibuf++), &uc2 ) != 0 )
+ if ( mbedtls_test_ascii2uc( *(ibuf++), &uc2 ) != 0 )
return( -1 );
*(obuf++) = ( uc << 4 ) | uc2;
@@ -350,84 +350,3 @@
}
}
#endif /* MBEDTLS_TEST_HOOKS */
-
-#if defined(MBEDTLS_BIGNUM_C)
-#include "bignum_core.h"
-
-int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
- const char *input )
-{
- /* Sanity check */
- if( *pX != NULL )
- return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
-
- size_t hex_len = strlen( input );
- size_t byte_len = ( hex_len + 1 ) / 2;
- *plimbs = CHARS_TO_LIMBS( byte_len );
-
- /* A core bignum is not allowed to be empty. Forbid it as test data,
- * this way static analyzers have a chance of knowing we don't expect
- * the bignum functions to support empty inputs. */
- if( *plimbs == 0 )
- return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
-
- *pX = mbedtls_calloc( *plimbs, sizeof( **pX ) );
- if( *pX == NULL )
- return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
-
- unsigned char *byte_start = ( unsigned char * ) *pX;
- if( byte_len % sizeof( mbedtls_mpi_uint ) != 0 )
- {
- byte_start += sizeof( mbedtls_mpi_uint ) - byte_len % sizeof( mbedtls_mpi_uint );
- }
- if( ( hex_len & 1 ) != 0 )
- {
- /* mbedtls_test_unhexify wants an even number of hex digits */
- TEST_ASSERT( ascii2uc( *input, byte_start ) == 0 );
- ++byte_start;
- ++input;
- --byte_len;
- }
- TEST_ASSERT( mbedtls_test_unhexify( byte_start,
- byte_len,
- input,
- &byte_len ) == 0 );
-
- mbedtls_mpi_core_bigendian_to_host( *pX, *plimbs );
- return( 0 );
-
-exit:
- mbedtls_free( *pX );
- return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
-}
-
-int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s )
-{
- int negative = 0;
- /* Always set the sign bit to -1 if the input has a minus sign, even for 0.
- * This creates an invalid representation, which mbedtls_mpi_read_string()
- * avoids but we want to be able to create that in test data. */
- if( s[0] == '-' )
- {
- ++s;
- negative = 1;
- }
- /* mbedtls_mpi_read_string() currently retains leading zeros.
- * It always allocates at least one limb for the value 0. */
- if( s[0] == 0 )
- {
- mbedtls_mpi_free( X );
- return( 0 );
- }
- int ret = mbedtls_mpi_read_string( X, 16, s );
- if( ret != 0 )
- return( ret );
- if( negative )
- {
- if( mbedtls_mpi_cmp_int( X, 0 ) == 0 )
- ++mbedtls_test_case_uses_negative_0;
- X->s = -1;
- }
- return( 0 );
-}
-#endif
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index fe33f9b..8249564 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -5,6 +5,7 @@
#include <test/helpers.h>
#include <test/macros.h>
#include <test/random.h>
+#include <test/bignum_helpers.h>
#include <test/psa_crypto_helpers.h>
#include <stdlib.h>