Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Backport 2.x: Fix mbedtls_debug_print_mpi crash on 0 #4623

Merged
merged 5 commits into from
Jun 22, 2021
Merged

Backport 2.x: Fix mbedtls_debug_print_mpi crash on 0 #4623

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
b37abdc
Clarify test case descriptions
gilles-peskine-arm Jun 2, 2021
fba257d
Add mbedtls_debug_print_mpi test case for 0
gilles-peskine-arm Jun 2, 2021
2ee0bb3
Simplify mbedtls_debug_print_mpi and fix the case of empty bignums
gilles-peskine-arm Jun 2, 2021
e247b10
Indicate that the truncation from size_t to int is deliberate
gilles-peskine-arm Jun 3, 2021
4de5a60
Add missing parentheses
gilles-peskine-arm Jun 7, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions ChangeLog.d/mbedtls_debug_print_mpi.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
Bugfix
* Fix a crash in mbedtls_mpi_debug_mpi on a bignum having 0 limbs. This
could notably be triggered by setting the TLS debug level to 3 or above
and using a Montgomery curve for the key exchange. Reported by lhuang04
in #4578. Fixes #4608.
70 changes: 29 additions & 41 deletions library/debug.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -220,8 +220,8 @@ void mbedtls_debug_print_mpi( const mbedtls_ssl_context *ssl, int level,
const char *text, const mbedtls_mpi *X )
{
char str[DEBUG_BUF_SIZE];
int j, k, zeros = 1;
size_t i, n, idx = 0;
size_t bitlen;
size_t idx = 0;

if( NULL == ssl ||
NULL == ssl->conf ||
Expand All @@ -232,55 +232,43 @@ void mbedtls_debug_print_mpi( const mbedtls_ssl_context *ssl, int level,
return;
}

for( n = X->n - 1; n > 0; n-- )
if( X->p[n] != 0 )
break;

for( j = ( sizeof(mbedtls_mpi_uint) << 3 ) - 1; j >= 0; j-- )
if( ( ( X->p[n] >> j ) & 1 ) != 0 )
break;

mbedtls_snprintf( str + idx, sizeof( str ) - idx, "value of '%s' (%d bits) is:\n",
text, (int) ( ( n * ( sizeof(mbedtls_mpi_uint) << 3 ) ) + j + 1 ) );
bitlen = mbedtls_mpi_bitlen( X );

mbedtls_snprintf( str, sizeof( str ), "value of '%s' (%u bits) is:\n",
text, (unsigned) bitlen );
debug_send_line( ssl, level, file, line, str );

idx = 0;
for( i = n + 1, j = 0; i > 0; i-- )
if( bitlen == 0 )
{
if( zeros && X->p[i - 1] == 0 )
continue;

for( k = sizeof( mbedtls_mpi_uint ) - 1; k >= 0; k-- )
str[0] = ' '; str[1] = '0'; str[2] = '0';
idx = 3;
}
else
{
int n;
for( n = (int) ( ( bitlen - 1 ) / 8 ); n >= 0; n-- )
{
if( zeros && ( ( X->p[i - 1] >> ( k << 3 ) ) & 0xFF ) == 0 )
continue;
else
zeros = 0;

if( j % 16 == 0 )
size_t limb_offset = n / sizeof( mbedtls_mpi_uint );
size_t offset_in_limb = n % sizeof( mbedtls_mpi_uint );
unsigned char octet =
( X->p[limb_offset] >> ( offset_in_limb * 8 ) ) & 0xff;
mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", octet );
idx += 3;
/* Wrap lines after 16 octets that each take 3 columns */
if( idx >= 3 * 16 )
{
if( j > 0 )
{
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
idx = 0;
}
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
idx = 0;
}

idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", (unsigned int)
( X->p[i - 1] >> ( k << 3 ) ) & 0xFF );

j++;
}

}

if( zeros == 1 )
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " 00" );

mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
if( idx != 0 )
{
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
}
}
#endif /* MBEDTLS_BIGNUM_C */

Expand Down
35 changes: 19 additions & 16 deletions tests/suites/test_suite_debug.data
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,28 +37,31 @@ mbedtls_debug_print_buf:"MyFile":999:"Test return value":"000102030405060708090A
Debug print buffer #5
mbedtls_debug_print_buf:"MyFile":999:"Test return value":"000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30":"MyFile(0999)\: dumping 'Test return value' (49 bytes)\nMyFile(0999)\: 0000\: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................\nMyFile(0999)\: 0010\: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................\nMyFile(0999)\: 0020\: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./\nMyFile(0999)\: 0030\: 30 0\n"

Debug print certificate #1 (RSA)
depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_BASE64_C:MBEDTLS_RSA_C:MBEDTLS_SHA1_C
mbedtls_debug_print_crt:"data_files/server1.crt":"MyFile":999:"PREFIX_":"MyFile(0999)\: PREFIX_ #1\:\nMyFile(0999)\: cert. version \: 3\nMyFile(0999)\: serial number \: 01\nMyFile(0999)\: issuer name \: C=NL, O=PolarSSL, CN=PolarSSL Test CA\nMyFile(0999)\: subject name \: C=NL, O=PolarSSL, CN=PolarSSL Server 1\nMyFile(0999)\: issued on \: 2019-02-10 14\:44\:06\nMyFile(0999)\: expires on \: 2029-02-10 14\:44\:06\nMyFile(0999)\: signed using \: RSA with SHA1\nMyFile(0999)\: RSA key size \: 2048 bits\nMyFile(0999)\: basic constraints \: CA=false\nMyFile(0999)\: value of 'crt->rsa.N' (2048 bits) is\:\nMyFile(0999)\: a9 02 1f 3d 40 6a d5 55 53 8b fd 36 ee 82 65 2e\nMyFile(0999)\: 15 61 5e 89 bf b8 e8 45 90 db ee 88 16 52 d3 f1\nMyFile(0999)\: 43 50 47 96 12 59 64 87 6b fd 2b e0 46 f9 73 be\nMyFile(0999)\: dd cf 92 e1 91 5b ed 66 a0 6f 89 29 79 45 80 d0\nMyFile(0999)\: 83 6a d5 41 43 77 5f 39 7c 09 04 47 82 b0 57 39\nMyFile(0999)\: 70 ed a3 ec 15 19 1e a8 33 08 47 c1 05 42 a9 fd\nMyFile(0999)\: 4c c3 b4 df dd 06 1f 4d 10 51 40 67 73 13 0f 40\nMyFile(0999)\: f8 6d 81 25 5f 0a b1 53 c6 30 7e 15 39 ac f9 5a\nMyFile(0999)\: ee 7f 92 9e a6 05 5b e7 13 97 85 b5 23 92 d9 d4\nMyFile(0999)\: 24 06 d5 09 25 89 75 07 dd a6 1a 8f 3f 09 19 be\nMyFile(0999)\: ad 65 2c 64 eb 95 9b dc fe 41 5e 17 a6 da 6c 5b\nMyFile(0999)\: 69 cc 02 ba 14 2c 16 24 9c 4a dc cd d0 f7 52 67\nMyFile(0999)\: 73 f1 2d a0 23 fd 7e f4 31 ca 2d 70 ca 89 0b 04\nMyFile(0999)\: db 2e a6 4f 70 6e 9e ce bd 58 89 e2 53 59 9e 6e\nMyFile(0999)\: 5a 92 65 e2 88 3f 0c 94 19 a3 dd e5 e8 9d 95 13\nMyFile(0999)\: ed 29 db ab 70 12 dc 5a ca 6b 17 ab 52 82 54 b1\nMyFile(0999)\: value of 'crt->rsa.E' (17 bits) is\:\nMyFile(0999)\: 01 00 01\n"
Debug print mbedtls_mpi: 0 (empty representation)
mbedtls_debug_print_mpi:16:"":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (0 bits) is\:\nMyFile(0999)\: 00\n"

Debug print certificate #2 (EC)
depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_BASE64_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SHA256_C
mbedtls_debug_print_crt:"data_files/test-ca2.crt":"MyFile":999:"PREFIX_":"MyFile(0999)\: PREFIX_ #1\:\nMyFile(0999)\: cert. version \: 3\nMyFile(0999)\: serial number \: C1\:43\:E2\:7E\:62\:43\:CC\:E8\nMyFile(0999)\: issuer name \: C=NL, O=PolarSSL, CN=Polarssl Test EC CA\nMyFile(0999)\: subject name \: C=NL, O=PolarSSL, CN=Polarssl Test EC CA\nMyFile(0999)\: issued on \: 2019-02-10 14\:44\:00\nMyFile(0999)\: expires on \: 2029-02-10 14\:44\:00\nMyFile(0999)\: signed using \: ECDSA with SHA256\nMyFile(0999)\: EC key size \: 384 bits\nMyFile(0999)\: basic constraints \: CA=true\nMyFile(0999)\: value of 'crt->eckey.Q(X)' (384 bits) is\:\nMyFile(0999)\: c3 da 2b 34 41 37 58 2f 87 56 fe fc 89 ba 29 43\nMyFile(0999)\: 4b 4e e0 6e c3 0e 57 53 33 39 58 d4 52 b4 91 95\nMyFile(0999)\: 39 0b 23 df 5f 17 24 62 48 fc 1a 95 29 ce 2c 2d\nMyFile(0999)\: value of 'crt->eckey.Q(Y)' (384 bits) is\:\nMyFile(0999)\: 87 c2 88 52 80 af d6 6a ab 21 dd b8 d3 1c 6e 58\nMyFile(0999)\: b8 ca e8 b2 69 8e f3 41 ad 29 c3 b4 5f 75 a7 47\nMyFile(0999)\: 6f d5 19 29 55 69 9a 53 3b 20 b4 66 16 60 33 1e\n"

Debug print mbedtls_mpi #1
mbedtls_debug_print_mpi:16:"01020304050607":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (49 bits) is\:\nMyFile(0999)\: 01 02 03 04 05 06 07\n"
Debug print mbedtls_mpi: 0 (non-empty representation)
mbedtls_debug_print_mpi:16:"00000000000000":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (0 bits) is\:\nMyFile(0999)\: 00\n"

Debug print mbedtls_mpi #2
Debug print mbedtls_mpi #2: 3 bits
mbedtls_debug_print_mpi:16:"00000000000007":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (3 bits) is\:\nMyFile(0999)\: 07\n"

Debug print mbedtls_mpi #3
mbedtls_debug_print_mpi:16:"00000000000000":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (0 bits) is\:\nMyFile(0999)\: 00\n"
Debug print mbedtls_mpi: 49 bits
mbedtls_debug_print_mpi:16:"01020304050607":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (49 bits) is\:\nMyFile(0999)\: 01 02 03 04 05 06 07\n"

Debug print mbedtls_mpi #4
Debug print mbedtls_mpi: 759 bits
mbedtls_debug_print_mpi:16:"0000000000000000000000000000000000000000000000000000000041379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (759 bits) is\:\nMyFile(0999)\: 41 37 9d 00 fe d1 49 1f e1 5d f2 84 df de 4a 14\nMyFile(0999)\: 2f 68 aa 8d 41 20 23 19 5c ee 66 88 3e 62 90 ff\nMyFile(0999)\: e7 03 f4 ea 59 63 bf 21 27 13 ce e4 6b 10 7c 09\nMyFile(0999)\: 18 2b 5e dc d9 55 ad ac 41 8b f4 91 8e 28 89 af\nMyFile(0999)\: 48 e1 09 9d 51 38 30 ce c8 5c 26 ac 1e 15 8b 52\nMyFile(0999)\: 62 0e 33 ba 86 92 f8 93 ef bb 2f 95 8b 44 24\n"

Debug print mbedtls_mpi: 764 bits #1
mbedtls_debug_print_mpi:16:"0941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (764 bits) is\:\nMyFile(0999)\: 09 41 37 9d 00 fe d1 49 1f e1 5d f2 84 df de 4a\nMyFile(0999)\: 14 2f 68 aa 8d 41 20 23 19 5c ee 66 88 3e 62 90\nMyFile(0999)\: ff e7 03 f4 ea 59 63 bf 21 27 13 ce e4 6b 10 7c\nMyFile(0999)\: 09 18 2b 5e dc d9 55 ad ac 41 8b f4 91 8e 28 89\nMyFile(0999)\: af 48 e1 09 9d 51 38 30 ce c8 5c 26 ac 1e 15 8b\nMyFile(0999)\: 52 62 0e 33 ba 86 92 f8 93 ef bb 2f 95 8b 44 24\n"

Debug print mbedtls_mpi #5
Debug print mbedtls_mpi: 764 bits #2
mbedtls_debug_print_mpi:16:"0000000000000000000000000000000000000000000000000000000941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (764 bits) is\:\nMyFile(0999)\: 09 41 37 9d 00 fe d1 49 1f e1 5d f2 84 df de 4a\nMyFile(0999)\: 14 2f 68 aa 8d 41 20 23 19 5c ee 66 88 3e 62 90\nMyFile(0999)\: ff e7 03 f4 ea 59 63 bf 21 27 13 ce e4 6b 10 7c\nMyFile(0999)\: 09 18 2b 5e dc d9 55 ad ac 41 8b f4 91 8e 28 89\nMyFile(0999)\: af 48 e1 09 9d 51 38 30 ce c8 5c 26 ac 1e 15 8b\nMyFile(0999)\: 52 62 0e 33 ba 86 92 f8 93 ef bb 2f 95 8b 44 24\n"

Debug print mbedtls_mpi #6
mbedtls_debug_print_mpi:16:"0000000000000000000000000000000000000000000000000000000041379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"MyFile":999:"VALUE":"MyFile(0999)\: value of 'VALUE' (759 bits) is\:\nMyFile(0999)\: 41 37 9d 00 fe d1 49 1f e1 5d f2 84 df de 4a 14\nMyFile(0999)\: 2f 68 aa 8d 41 20 23 19 5c ee 66 88 3e 62 90 ff\nMyFile(0999)\: e7 03 f4 ea 59 63 bf 21 27 13 ce e4 6b 10 7c 09\nMyFile(0999)\: 18 2b 5e dc d9 55 ad ac 41 8b f4 91 8e 28 89 af\nMyFile(0999)\: 48 e1 09 9d 51 38 30 ce c8 5c 26 ac 1e 15 8b 52\nMyFile(0999)\: 62 0e 33 ba 86 92 f8 93 ef bb 2f 95 8b 44 24\n"
Debug print certificate #1 (RSA)
depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_BASE64_C:MBEDTLS_RSA_C:MBEDTLS_SHA1_C
mbedtls_debug_print_crt:"data_files/server1.crt":"MyFile":999:"PREFIX_":"MyFile(0999)\: PREFIX_ #1\:\nMyFile(0999)\: cert. version \: 3\nMyFile(0999)\: serial number \: 01\nMyFile(0999)\: issuer name \: C=NL, O=PolarSSL, CN=PolarSSL Test CA\nMyFile(0999)\: subject name \: C=NL, O=PolarSSL, CN=PolarSSL Server 1\nMyFile(0999)\: issued on \: 2019-02-10 14\:44\:06\nMyFile(0999)\: expires on \: 2029-02-10 14\:44\:06\nMyFile(0999)\: signed using \: RSA with SHA1\nMyFile(0999)\: RSA key size \: 2048 bits\nMyFile(0999)\: basic constraints \: CA=false\nMyFile(0999)\: value of 'crt->rsa.N' (2048 bits) is\:\nMyFile(0999)\: a9 02 1f 3d 40 6a d5 55 53 8b fd 36 ee 82 65 2e\nMyFile(0999)\: 15 61 5e 89 bf b8 e8 45 90 db ee 88 16 52 d3 f1\nMyFile(0999)\: 43 50 47 96 12 59 64 87 6b fd 2b e0 46 f9 73 be\nMyFile(0999)\: dd cf 92 e1 91 5b ed 66 a0 6f 89 29 79 45 80 d0\nMyFile(0999)\: 83 6a d5 41 43 77 5f 39 7c 09 04 47 82 b0 57 39\nMyFile(0999)\: 70 ed a3 ec 15 19 1e a8 33 08 47 c1 05 42 a9 fd\nMyFile(0999)\: 4c c3 b4 df dd 06 1f 4d 10 51 40 67 73 13 0f 40\nMyFile(0999)\: f8 6d 81 25 5f 0a b1 53 c6 30 7e 15 39 ac f9 5a\nMyFile(0999)\: ee 7f 92 9e a6 05 5b e7 13 97 85 b5 23 92 d9 d4\nMyFile(0999)\: 24 06 d5 09 25 89 75 07 dd a6 1a 8f 3f 09 19 be\nMyFile(0999)\: ad 65 2c 64 eb 95 9b dc fe 41 5e 17 a6 da 6c 5b\nMyFile(0999)\: 69 cc 02 ba 14 2c 16 24 9c 4a dc cd d0 f7 52 67\nMyFile(0999)\: 73 f1 2d a0 23 fd 7e f4 31 ca 2d 70 ca 89 0b 04\nMyFile(0999)\: db 2e a6 4f 70 6e 9e ce bd 58 89 e2 53 59 9e 6e\nMyFile(0999)\: 5a 92 65 e2 88 3f 0c 94 19 a3 dd e5 e8 9d 95 13\nMyFile(0999)\: ed 29 db ab 70 12 dc 5a ca 6b 17 ab 52 82 54 b1\nMyFile(0999)\: value of 'crt->rsa.E' (17 bits) is\:\nMyFile(0999)\: 01 00 01\n"

Debug print certificate #2 (EC)
depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_BASE64_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SHA256_C
mbedtls_debug_print_crt:"data_files/test-ca2.crt":"MyFile":999:"PREFIX_":"MyFile(0999)\: PREFIX_ #1\:\nMyFile(0999)\: cert. version \: 3\nMyFile(0999)\: serial number \: C1\:43\:E2\:7E\:62\:43\:CC\:E8\nMyFile(0999)\: issuer name \: C=NL, O=PolarSSL, CN=Polarssl Test EC CA\nMyFile(0999)\: subject name \: C=NL, O=PolarSSL, CN=Polarssl Test EC CA\nMyFile(0999)\: issued on \: 2019-02-10 14\:44\:00\nMyFile(0999)\: expires on \: 2029-02-10 14\:44\:00\nMyFile(0999)\: signed using \: ECDSA with SHA256\nMyFile(0999)\: EC key size \: 384 bits\nMyFile(0999)\: basic constraints \: CA=true\nMyFile(0999)\: value of 'crt->eckey.Q(X)' (384 bits) is\:\nMyFile(0999)\: c3 da 2b 34 41 37 58 2f 87 56 fe fc 89 ba 29 43\nMyFile(0999)\: 4b 4e e0 6e c3 0e 57 53 33 39 58 d4 52 b4 91 95\nMyFile(0999)\: 39 0b 23 df 5f 17 24 62 48 fc 1a 95 29 ce 2c 2d\nMyFile(0999)\: value of 'crt->eckey.Q(Y)' (384 bits) is\:\nMyFile(0999)\: 87 c2 88 52 80 af d6 6a ab 21 dd b8 d3 1c 6e 58\nMyFile(0999)\: b8 ca e8 b2 69 8e f3 41 ad 29 c3 b4 5f 75 a7 47\nMyFile(0999)\: 6f d5 19 29 55 69 9a 53 3b 20 b4 66 16 60 33 1e\n"
4 changes: 3 additions & 1 deletion tests/suites/test_suite_debug.function
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -179,7 +179,9 @@ void mbedtls_debug_print_mpi( int radix, char * value, char * file, int line,

TEST_ASSERT( mbedtls_ssl_setup( &ssl, &conf ) == 0 );

TEST_ASSERT( mbedtls_mpi_read_string( &val, radix, value ) == 0 );
/* If value is empty, keep val->n == 0. */
if( value[0] != 0 )
TEST_ASSERT( mbedtls_mpi_read_string( &val, radix, value ) == 0 );

mbedtls_ssl_conf_dbg( &conf, string_debug, &buffer);

Expand Down