diff --git a/tests/api/test_asn.c b/tests/api/test_asn.c index ecfe4ede50..0a3f6a0a75 100644 --- a/tests/api/test_asn.c +++ b/tests/api/test_asn.c @@ -920,3 +920,111 @@ int test_wc_DecodeRsaPssParams(void) #endif /* WC_RSA_PSS && !NO_RSA && !NO_ASN */ return EXPECT_RESULT(); } + +/* Test that DecodeAltNames rejects a SAN entry whose length exceeds the + * remaining SEQUENCE length (integer underflow on the length tracker). */ +int test_DecodeAltNames_length_underflow(void) +{ + EXPECT_DECLS; + +#if !defined(NO_CERTS) && !defined(NO_RSA) && !defined(NO_ASN) + /* Self-signed DER certificate with a well-formed SAN extension. + * Byte at offset 418 is the SAN SEQUENCE length (0x06). The negative + * test below copies this cert and shrinks that byte to 0x03 so the + * DNS entry length exceeds the SEQUENCE bounds. */ + static const unsigned char good_san_cert[] = { + 0x30, 0x82, 0x02, 0xf9, 0x30, 0x82, 0x01, 0xe1, 0xa0, 0x03, 0x02, 0x01, + 0x02, 0x02, 0x02, 0x10, 0x21, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, + 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x30, 0x0f, 0x31, 0x0d, + 0x30, 0x0b, 0x06, 0x03, 0x55, 0x04, 0x03, 0x13, 0x04, 0x61, 0x61, 0x31, + 0x31, 0x30, 0x1e, 0x17, 0x0d, 0x31, 0x36, 0x30, 0x32, 0x30, 0x37, 0x31, + 0x37, 0x32, 0x34, 0x30, 0x30, 0x5a, 0x17, 0x0d, 0x33, 0x34, 0x30, 0x32, + 0x31, 0x34, 0x30, 0x36, 0x32, 0x36, 0x35, 0x33, 0x5a, 0x30, 0x0f, 0x31, + 0x0d, 0x30, 0x0b, 0x06, 0x03, 0x55, 0x04, 0x03, 0x13, 0x04, 0x61, 0x61, + 0x61, 0x61, 0x30, 0x82, 0x01, 0x20, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, + 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x01, + 0x0d, 0x00, 0x30, 0x82, 0x01, 0x08, 0x02, 0x82, 0x01, 0x01, 0x00, 0xa8, + 0x8a, 0x5e, 0x26, 0x23, 0x1b, 0x31, 0xd3, 0x37, 0x1a, 0x70, 0xb2, 0xec, + 0x3f, 0x74, 0xd4, 0xb4, 0x44, 0xe3, 0x7a, 0xa5, 0xc0, 0xf5, 0xaa, 0x97, + 0x26, 0x9a, 0x04, 0xff, 0xda, 0xbe, 0xe5, 0x09, 0x03, 0x98, 0x3d, 0xb5, + 0xbf, 0x01, 0x2c, 0x9a, 0x0a, 0x3a, 0xfb, 0xbc, 0x3c, 0xe7, 0xbe, 0x83, + 0x5c, 0xb3, 0x70, 0xe8, 0x5c, 0xe3, 0xd1, 0x83, 0xc3, 0x94, 0x08, 0xcd, + 0x1a, 0x87, 0xe5, 0xe0, 0x5b, 0x9c, 0x5c, 0x6e, 0xb0, 0x7d, 0xe2, 0x58, + 0x6c, 0xc3, 0xb5, 0xc8, 0x9d, 0x11, 0xf1, 0x5d, 0x96, 0x0d, 0x66, 0x1e, + 0x56, 0x7f, 0x8f, 0x59, 0xa7, 0xa5, 0xe1, 0xc5, 0xe7, 0x81, 0x4c, 0x09, + 0x9d, 0x5e, 0x96, 0xf0, 0x9a, 0xc2, 0x8b, 0x70, 0xd5, 0xab, 0x79, 0x58, + 0x5d, 0xb7, 0x58, 0xaa, 0xfd, 0x75, 0x52, 0xaa, 0x4b, 0xa7, 0x25, 0x68, + 0x76, 0x59, 0x00, 0xee, 0x78, 0x2b, 0x91, 0xc6, 0x59, 0x91, 0x99, 0x38, + 0x3e, 0xa1, 0x76, 0xc3, 0xf5, 0x23, 0x6b, 0xe6, 0x07, 0xea, 0x63, 0x1c, + 0x97, 0x49, 0xef, 0xa0, 0xfe, 0xfd, 0x13, 0xc9, 0xa9, 0x9f, 0xc2, 0x0b, + 0xe6, 0x87, 0x92, 0x5b, 0xcc, 0xf5, 0x42, 0x95, 0x4a, 0xa4, 0x6d, 0x64, + 0xba, 0x7d, 0xce, 0xcb, 0x04, 0xd0, 0xf8, 0xe7, 0xe3, 0xda, 0x75, 0x60, + 0xd3, 0x8b, 0x6a, 0x64, 0xfc, 0x78, 0x56, 0x21, 0x69, 0x5a, 0xe8, 0xa7, + 0x8f, 0xfb, 0x8f, 0x82, 0xe3, 0xae, 0x36, 0xa2, 0x93, 0x66, 0x92, 0xcb, + 0x82, 0xa3, 0xbe, 0x84, 0x00, 0x86, 0xdc, 0x7e, 0x6d, 0x53, 0x77, 0x84, + 0x17, 0xb9, 0x55, 0x43, 0x0d, 0xf1, 0x16, 0x1f, 0xd5, 0x43, 0x75, 0x99, + 0x66, 0x19, 0x52, 0xd0, 0xac, 0x5f, 0x74, 0xad, 0xb2, 0x90, 0x15, 0x50, + 0x04, 0x74, 0x43, 0xdf, 0x6c, 0x35, 0xd0, 0xfd, 0x32, 0x37, 0xb3, 0x8d, + 0xf5, 0xe5, 0x09, 0x02, 0x01, 0x03, 0xa3, 0x61, 0x30, 0x5f, 0x30, 0x0c, + 0x06, 0x03, 0x55, 0x1d, 0x13, 0x01, 0x01, 0xff, 0x04, 0x02, 0x30, 0x00, + /* SAN extension: correct SEQUENCE length 0x06 */ + 0x30, 0x0f, 0x06, 0x03, 0x55, 0x1d, 0x11, 0x04, 0x08, 0x30, 0x06, 0x82, + 0x04, 0x61, 0x2a, 0x00, 0x2a, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d, 0x0e, + 0x04, 0x16, 0x04, 0x14, 0x92, 0x6a, 0x1e, 0x52, 0x3a, 0x1a, 0x57, 0x9f, + 0xc9, 0x82, 0x9a, 0xce, 0xc8, 0xc0, 0xa9, 0x51, 0x9d, 0x2f, 0xc7, 0x72, + 0x30, 0x1f, 0x06, 0x03, 0x55, 0x1d, 0x23, 0x04, 0x18, 0x30, 0x16, 0x80, + 0x14, 0x6b, 0xf9, 0xa4, 0x2d, 0xa5, 0xe9, 0x39, 0x89, 0xa8, 0x24, 0x58, + 0x79, 0x87, 0x11, 0xfc, 0x6f, 0x07, 0x91, 0xef, 0xa6, 0x30, 0x0d, 0x06, + 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, + 0x03, 0x82, 0x01, 0x01, 0x00, 0x3f, 0xd5, 0x37, 0x2f, 0xc7, 0xf8, 0x8b, + 0x39, 0x1c, 0xe3, 0xdf, 0x77, 0xee, 0xc6, 0x4b, 0x5f, 0x84, 0xcf, 0xfa, + 0x33, 0x2c, 0xb2, 0xb5, 0x4b, 0x09, 0xee, 0x56, 0xc0, 0xf2, 0xf0, 0xeb, + 0xad, 0x1c, 0x02, 0xef, 0xae, 0x09, 0x53, 0xc0, 0x06, 0xad, 0x4e, 0xfd, + 0x3e, 0x8c, 0x13, 0xb3, 0xbf, 0x80, 0x05, 0x36, 0xb5, 0x3f, 0x2b, 0xc7, + 0x60, 0x53, 0x14, 0xbf, 0x33, 0x63, 0x47, 0xc3, 0xc6, 0x28, 0xda, 0x10, + 0x12, 0xe2, 0xc4, 0xeb, 0xc5, 0x64, 0x66, 0xc0, 0xcc, 0x6b, 0x84, 0xda, + 0x0c, 0xe9, 0xf6, 0xe3, 0xf8, 0x8e, 0x3d, 0x95, 0x5f, 0xba, 0x9f, 0xe1, + 0xc7, 0xed, 0x6e, 0x97, 0xcc, 0xbd, 0x7d, 0xe5, 0x4e, 0xab, 0xbc, 0x1b, + 0xf1, 0x3a, 0x09, 0x33, 0x09, 0xe1, 0xcc, 0xec, 0x21, 0x16, 0x8e, 0xb1, + 0x74, 0x9e, 0xc8, 0x13, 0x7c, 0xdf, 0x07, 0xaa, 0xeb, 0x70, 0xd7, 0x91, + 0x5c, 0xc4, 0xef, 0x83, 0x88, 0xc3, 0xe4, 0x97, 0xfa, 0xe4, 0xdf, 0xd7, + 0x0d, 0xff, 0xba, 0x78, 0x22, 0xfc, 0x3f, 0xdc, 0xd8, 0x02, 0x8d, 0x93, + 0x57, 0xf9, 0x9e, 0x39, 0x3a, 0x77, 0x00, 0xd9, 0x19, 0xaa, 0x68, 0xa1, + 0xe6, 0x9e, 0x13, 0xeb, 0x37, 0x16, 0xf5, 0x77, 0xa4, 0x0b, 0x40, 0x04, + 0xd3, 0xa5, 0x49, 0x78, 0x35, 0xfa, 0x3b, 0xf6, 0x02, 0xab, 0x85, 0xee, + 0xcb, 0x9b, 0x62, 0xda, 0x05, 0x00, 0x22, 0x2f, 0xf8, 0xbd, 0x0b, 0xe5, + 0x2c, 0xb2, 0x53, 0x78, 0x0a, 0xcb, 0x69, 0xc0, 0xb6, 0x9f, 0x96, 0xff, + 0x58, 0x22, 0x70, 0x9c, 0x01, 0x2e, 0x56, 0x60, 0x5d, 0x37, 0xe3, 0x40, + 0x25, 0xc9, 0x90, 0xc8, 0x0f, 0x41, 0x68, 0xb4, 0xfd, 0x10, 0xe2, 0x09, + 0x99, 0x08, 0x5d, 0x7b, 0xc9, 0xe3, 0x29, 0xd4, 0x5a, 0xcf, 0xc9, 0x34, + 0x55, 0xa1, 0x40, 0x44, 0xd6, 0x88, 0x16, 0xbb, 0xdd + }; + + /* Offset of the SAN SEQUENCE length byte inside good_san_cert. */ + #define SAN_SEQ_LEN_OFFSET 418 + + DecodedCert cert; + unsigned char bad_san_cert[sizeof(good_san_cert)]; + + /* Control: the original cert with correct SAN SEQUENCE length should + * parse successfully (signature won't verify, but NO_VERIFY skips that). */ + wc_InitDecodedCert(&cert, good_san_cert, (word32)sizeof(good_san_cert), + NULL); + ExpectIntEQ(wc_ParseCert(&cert, CERT_TYPE, NO_VERIFY, NULL), 0); + wc_FreeDecodedCert(&cert); + + /* Build a malformed variant: shrink the SAN SEQUENCE length from 6 to 3 + * so the DNS entry length (4) exceeds the SEQUENCE bounds. Without a + * bounds check DecodeAltNames would underflow the length tracker. */ + XMEMCPY(bad_san_cert, good_san_cert, sizeof(good_san_cert)); + bad_san_cert[SAN_SEQ_LEN_OFFSET] = 0x03; + + wc_InitDecodedCert(&cert, bad_san_cert, (word32)sizeof(bad_san_cert), + NULL); + ExpectIntEQ(wc_ParseCert(&cert, CERT_TYPE, NO_VERIFY, NULL), + WC_NO_ERR_TRACE(ASN_PARSE_E)); + wc_FreeDecodedCert(&cert); + +#endif /* !NO_CERTS && !NO_RSA && !NO_ASN */ + return EXPECT_RESULT(); +} diff --git a/tests/api/test_asn.h b/tests/api/test_asn.h index 2403bc81d1..012f2bd23a 100644 --- a/tests/api/test_asn.h +++ b/tests/api/test_asn.h @@ -29,12 +29,14 @@ int test_GetSetShortInt(void); int test_wc_IndexSequenceOf(void); int test_wolfssl_local_MatchBaseName(void); int test_wc_DecodeRsaPssParams(void); +int test_DecodeAltNames_length_underflow(void); #define TEST_ASN_DECLS \ TEST_DECL_GROUP("asn", test_SetAsymKeyDer), \ TEST_DECL_GROUP("asn", test_GetSetShortInt), \ TEST_DECL_GROUP("asn", test_wc_IndexSequenceOf), \ TEST_DECL_GROUP("asn", test_wolfssl_local_MatchBaseName), \ - TEST_DECL_GROUP("asn", test_wc_DecodeRsaPssParams) + TEST_DECL_GROUP("asn", test_wc_DecodeRsaPssParams), \ + TEST_DECL_GROUP("asn", test_DecodeAltNames_length_underflow) #endif /* WOLFCRYPT_TEST_ASN_H */ diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c index 9b2faf19c5..8d8de5a2cd 100644 --- a/wolfcrypt/src/asn.c +++ b/wolfcrypt/src/asn.c @@ -20826,6 +20826,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) AddAltName(cert, dnsEntry); + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -20867,6 +20870,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) dirEntry->next = cert->altDirNames; cert->altDirNames = dirEntry; + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -20902,6 +20908,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) emailEntry->next = cert->altEmailNames; cert->altEmailNames = emailEntry; + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -20981,6 +20990,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) AddAltName(cert, uriEntry); + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -21027,6 +21039,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) } AddAltName(cert, ipAddr); + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -21075,6 +21090,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) AddAltName(cert, rid); + if (strLen > length) { + return ASN_PARSE_E; + } length -= strLen; idx += (word32)strLen; } @@ -21092,6 +21110,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) return ASN_PARSE_E; } /* Consume the rest of this sequence. */ + if ((int)((word32)strLen + idx - lenStartIdx) > length) { + return ASN_PARSE_E; + } length -= (int)(((word32)strLen + idx - lenStartIdx)); if (GetObjectId(input, &idx, &oid, oidCertAltNameType, sz) < 0) { @@ -21144,6 +21165,9 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert) WOLFSSL_MSG("\tfail: unsupported name length"); return ASN_PARSE_E; } + if ((int)((word32)strLen + idx - lenStartIdx) > length) { + return ASN_PARSE_E; + } length -= (int)((word32)strLen + idx - lenStartIdx); idx += (word32)strLen; }