From 84add97ce9e094e9299db181d53ba8859f4a3e67 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Thu, 28 Jul 2016 22:51:50 +0100 Subject: [PATCH] [crypto] Add PEM image format Add PEM-encoded ASN.1 as an image format. We accept as PEM any image containing a line starting with a "-----BEGIN" boundary marker. We allow for PEM files containing multiple ASN.1 objects, such as a certificate chain produced by concatenating individual certificate files. Signed-off-by: Michael Brown --- src/config/config.c | 3 + src/config/general.h | 1 + src/image/pem.c | 208 +++++++++++++++++++++++++++++++++++++ src/include/ipxe/errfile.h | 1 + src/include/ipxe/pem.h | 22 ++++ src/tests/pem_test.c | 107 +++++++++++++++++++ src/tests/tests.c | 1 + 7 files changed, 343 insertions(+) create mode 100644 src/image/pem.c create mode 100644 src/include/ipxe/pem.h create mode 100644 src/tests/pem_test.c diff --git a/src/config/config.c b/src/config/config.c index acdbebaa..c24b58d5 100644 --- a/src/config/config.c +++ b/src/config/config.c @@ -191,6 +191,9 @@ REQUIRE_OBJECT ( png ); #ifdef IMAGE_DER REQUIRE_OBJECT ( der ); #endif +#ifdef IMAGE_PEM +REQUIRE_OBJECT ( pem ); +#endif /* * Drag in all requested commands diff --git a/src/config/general.h b/src/config/general.h index 6ff4b74a..efded483 100644 --- a/src/config/general.h +++ b/src/config/general.h @@ -113,6 +113,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); //#define IMAGE_PNM /* PNM image support */ //#define IMAGE_PNG /* PNG image support */ //#define IMAGE_DER /* DER image support */ +//#define IMAGE_PEM /* PEM image support */ /* * Command-line commands to include diff --git a/src/image/pem.c b/src/image/pem.c new file mode 100644 index 00000000..721b11ec --- /dev/null +++ b/src/image/pem.c @@ -0,0 +1,208 @@ +/* + * Copyright (C) 2016 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +#include +#include +#include +#include +#include +#include +#include +#include + +/** @file + * + * PEM-encoded ASN.1 data + * + */ + +/** + * Locate next line + * + * @v image PEM image + * @v offset Starting offset + * @ret next Offset to next line + */ +static size_t pem_next ( struct image *image, size_t offset ) { + off_t eol; + + /* Find and skip next newline character, if any */ + eol = memchr_user ( image->data, offset, '\n', ( image->len - offset )); + if ( eol < 0 ) + return image->len; + return ( eol + 1 ); +} + +/** + * Locate boundary marker line + * + * @v image PEM image + * @v offset Starting offset + * @v marker Boundary marker + * @ret offset Offset to boundary marker line, or negative error + */ +static int pem_marker ( struct image *image, size_t offset, + const char *marker ) { + char buf[ strlen ( marker ) ]; + + /* Sanity check */ + assert ( offset <= image->len ); + + /* Scan for marker at start of line */ + while ( offset < image->len ) { + + /* Check for marker */ + if ( ( image->len - offset ) < sizeof ( buf ) ) + break; + copy_from_user ( buf, image->data, offset, sizeof ( buf ) ); + if ( memcmp ( buf, marker, sizeof ( buf ) ) == 0 ) + return offset; + + /* Move to next line */ + offset = pem_next ( image, offset ); + assert ( offset <= image->len ); + } + + return -ENOENT; +} + +/** + * Extract ASN.1 object from image + * + * @v image PEM image + * @v offset Offset within image + * @v cursor ASN.1 cursor to fill in + * @ret next Offset to next image, or negative error + * + * The caller is responsible for eventually calling free() on the + * allocated ASN.1 cursor. + */ +static int pem_asn1 ( struct image *image, size_t offset, + struct asn1_cursor **cursor ) { + size_t encoded_len; + size_t decoded_max_len; + char *encoded; + void *decoded; + int begin; + int end; + int len; + int rc; + + /* Locate and skip BEGIN marker */ + begin = pem_marker ( image, offset, PEM_BEGIN ); + if ( begin < 0 ) { + rc = begin; + DBGC ( image, "PEM %s [%#zx,%#zx) missing BEGIN marker: %s\n", + image->name, offset, image->len, strerror ( rc ) ); + goto err_begin; + } + begin = pem_next ( image, begin ); + + /* Locate and skip END marker */ + end = pem_marker ( image, begin, PEM_END ); + if ( end < 0 ) { + rc = end; + DBGC ( image, "PEM %s [%#zx,%#zx) missing END marker: %s\n", + image->name, offset, image->len, strerror ( rc ) ); + goto err_end; + } + encoded_len = ( end - begin ); + end = pem_next ( image, end ); + + /* Extract Base64-encoded data */ + encoded = malloc ( encoded_len + 1 /* NUL */ ); + if ( ! encoded ) { + rc = -ENOMEM; + goto err_alloc_encoded; + } + copy_from_user ( encoded, image->data, begin, encoded_len ); + encoded[encoded_len] = '\0'; + + /* Allocate cursor and data buffer */ + decoded_max_len = base64_decoded_max_len ( encoded ); + *cursor = malloc ( sizeof ( **cursor ) + decoded_max_len ); + if ( ! *cursor ) { + rc = -ENOMEM; + goto err_alloc_decoded; + } + decoded = ( ( ( void * ) *cursor ) + sizeof ( **cursor ) ); + + /* Decode Base64-encoded data */ + len = base64_decode ( encoded, decoded, decoded_max_len ); + if ( len < 0 ) { + rc = len; + DBGC ( image, "PEM %s could not decode: %s\n", + image->name, strerror ( rc ) ); + goto err_decode; + } + (*cursor)->data = decoded; + (*cursor)->len = len; + assert ( (*cursor)->len <= decoded_max_len ); + + /* Free Base64-encoded data */ + free ( encoded ); + + /* Update offset and skip any unencapsulated trailer */ + offset = end; + if ( pem_marker ( image, offset, PEM_BEGIN ) < 0 ) + offset = image->len; + + return offset; + + err_decode: + free ( decoded ); + err_alloc_decoded: + free ( encoded ); + err_alloc_encoded: + err_end: + err_begin: + return rc; +} + +/** + * Probe PEM image + * + * @v image PEM image + * @ret rc Return status code + */ +static int pem_probe ( struct image *image ) { + int rc; + + /* Check that image contains a BEGIN marker */ + if ( ( rc = pem_marker ( image, 0, PEM_BEGIN ) ) < 0 ) { + DBGC ( image, "PEM %s has no BEGIN marker: %s\n", + image->name, strerror ( rc ) ); + return rc; + } + + return 0; +} + +/** PEM image type */ +struct image_type pem_image_type __image_type ( PROBE_NORMAL ) = { + .name = "PEM", + .probe = pem_probe, + .asn1 = pem_asn1, +}; diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index 61e208a5..f28e5894 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -277,6 +277,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #define ERRFILE_pnm ( ERRFILE_IMAGE | 0x00060000 ) #define ERRFILE_png ( ERRFILE_IMAGE | 0x00070000 ) #define ERRFILE_der ( ERRFILE_IMAGE | 0x00080000 ) +#define ERRFILE_pem ( ERRFILE_IMAGE | 0x00090000 ) #define ERRFILE_asn1 ( ERRFILE_OTHER | 0x00000000 ) #define ERRFILE_chap ( ERRFILE_OTHER | 0x00010000 ) diff --git a/src/include/ipxe/pem.h b/src/include/ipxe/pem.h new file mode 100644 index 00000000..1276f94a --- /dev/null +++ b/src/include/ipxe/pem.h @@ -0,0 +1,22 @@ +#ifndef _IPXE_PEM_H +#define _IPXE_PEM_H + +/** @file + * + * PEM image format + * + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +#include + +/** Pre-encapsulation boundary marker */ +#define PEM_BEGIN "-----BEGIN" + +/** Post-encapsulation boundary marker */ +#define PEM_END "-----END" + +extern struct image_type pem_image_type __image_type ( PROBE_NORMAL ); + +#endif /* _IPXE_PEM_H */ diff --git a/src/tests/pem_test.c b/src/tests/pem_test.c new file mode 100644 index 00000000..df47ad50 --- /dev/null +++ b/src/tests/pem_test.c @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2016 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +/** @file + * + * PEM self-tests + * + */ + +/* Forcibly enable assertions */ +#undef NDEBUG + +#include +#include +#include +#include +#include "asn1_test.h" + +/** Define inline expected digest */ +#define DIGEST(...) { { __VA_ARGS__ } } + +/** Single RSA private key */ +ASN1 ( single, &pem_image_type, + "-----BEGIN RSA PRIVATE KEY-----\n" + "MCwCAQACBQC6loItAgMBAAECBCqhYIkCAwDyVwIDAMUbAgMAr9kCAmr9AgIaWQ==\n" + "-----END RSA PRIVATE KEY-----\n", + DIGEST ( 0xb9, 0x38, 0x83, 0xcd, 0xf4, 0x58, 0xa9, 0xa2, 0x84, 0x11, + 0xfa, 0x0b, 0x6f, 0xdc, 0x3e, 0xa3, 0x7c, 0x90, 0x7c, 0x2d ) ); + +/** Three concatenated RSA private keys */ +ASN1 ( multiple, &pem_image_type, + "-----BEGIN RSA PRIVATE KEY-----\n" + "MCwCAQACBQDtbjyVAgMBAAECBQCEOtJxAgMA+xsCAwDyDwICLGsCAgqTAgIxVQ==\n" + "-----END RSA PRIVATE KEY-----\n" + "-----BEGIN RSA PRIVATE KEY-----\n" + "MCwCAQACBQC3VlyxAgMBAAECBGakxDUCAwDanwIDANavAgIBWQICTuECAwCmWg==\n" + "-----END RSA PRIVATE KEY-----\n" + "-----BEGIN RSA PRIVATE KEY-----\n" + "MCwCAQACBQC89dS1AgMBAAECBQCxjnLBAgMA3qcCAwDZQwICP3cCAgpRAgI57A==\n" + "-----END RSA PRIVATE KEY-----\n", + DIGEST ( 0x9c, 0xb2, 0xc1, 0xa0, 0x9c, 0xcb, 0x11, 0xbf, 0x80, 0xd0, + 0x8c, 0xe5, 0xda, 0xf2, 0x3b, 0x2c, 0xca, 0x64, 0x25, 0x8a ), + DIGEST ( 0x82, 0x66, 0x24, 0xd9, 0xc3, 0x98, 0x1e, 0x5e, 0x56, 0xed, + 0xd0, 0xd0, 0x2a, 0x5e, 0x9c, 0x3a, 0x58, 0xdf, 0x76, 0x0d ), + DIGEST ( 0x01, 0xd2, 0x8a, 0x74, 0x42, 0x08, 0x0f, 0xb0, 0x03, 0x82, + 0xcd, 0xa3, 0xdc, 0x78, 0xfe, 0xd7, 0xa3, 0x28, 0xfc, 0x29 ) ); + +/** Two RSA private keys with various bits of noise added */ +ASN1 ( noisy, &pem_image_type, + "Hello world! This is uninteresting stuff before the actual data.\n" + "-----BEGIN RSA PRIVATE KEY-----\n" + "MCwCAQACBQC3VlyxAgMBAAECBGakxDUCAwDanwIDANavAgIBWQICTuECAwCmWg==\n" + "-----END RSA PRIVATE KEY-----\n" + "Here is some more uninteresting stuff.\n" + "Followed by what is actually another RSA private key, but with " + "extra whitespace added, and the description change to pretend " + "it's a certificate\n" + "-----BEGIN CERTIFICATE-----\n" + " MCwCAQACBQC6loItAgMBAAECBCqhYIkCAwD\r\n" + " yVwIDAMUbAgMAr9kCAmr9AgIaWQ== \r\n" + "-----END CERTIFICATE-----\n" + "and some trailing garbage as well\n" + "and more garbage with no final newline", + DIGEST ( 0x82, 0x66, 0x24, 0xd9, 0xc3, 0x98, 0x1e, 0x5e, 0x56, 0xed, + 0xd0, 0xd0, 0x2a, 0x5e, 0x9c, 0x3a, 0x58, 0xdf, 0x76, 0x0d ), + DIGEST ( 0xb9, 0x38, 0x83, 0xcd, 0xf4, 0x58, 0xa9, 0xa2, 0x84, 0x11, + 0xfa, 0x0b, 0x6f, 0xdc, 0x3e, 0xa3, 0x7c, 0x90, 0x7c, 0x2d ) ); + +/** + * Perform PEM self-test + * + */ +static void pem_test_exec ( void ) { + + /* Perform tests */ + asn1_ok ( &single ); + asn1_ok ( &multiple ); + asn1_ok ( &noisy ); +} + +/** PEM self-test */ +struct self_test pem_test __self_test = { + .name = "pem", + .exec = pem_test_exec, +}; diff --git a/src/tests/tests.c b/src/tests/tests.c index b9679b49..39c5136e 100644 --- a/src/tests/tests.c +++ b/src/tests/tests.c @@ -70,3 +70,4 @@ REQUIRE_OBJECT ( linebuf_test ); REQUIRE_OBJECT ( iobuf_test ); REQUIRE_OBJECT ( bitops_test ); REQUIRE_OBJECT ( der_test ); +REQUIRE_OBJECT ( pem_test );