| Message ID | 20240911122911.1381864-5-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KEYS: Add support for PGP keys and signatures | expand |
On Wed Sep 11, 2024 at 3:29 PM EEST, Roberto Sassu wrote: > From: David Howells <dhowells@redhat.com> > > Provide a simple parser that extracts the packets from a PGP packet blob > and passes the desirous ones to the given processor function: > > struct pgp_parse_context { > u64 types_of_interest; > int (*process_packet)(struct pgp_parse_context *context, > enum pgp_packet_tag type, > u8 headerlen, > const u8 *data, > size_t datalen); > }; > > int pgp_parse_packets(const u8 *data, size_t datalen, > struct pgp_parse_context *ctx); > > This is configured on with CONFIG_PGP_LIBRARY. > > Signed-off-by: David Howells <dhowells@redhat.com> > Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > --- > crypto/asymmetric_keys/Kconfig | 6 + > crypto/asymmetric_keys/Makefile | 5 + > crypto/asymmetric_keys/pgp_library.c | 262 +++++++++++++++++++++++++++ > crypto/asymmetric_keys/pgplib.h | 33 ++++ > 4 files changed, 306 insertions(+) > create mode 100644 crypto/asymmetric_keys/pgp_library.c > create mode 100644 crypto/asymmetric_keys/pgplib.h > > diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig > index e1345b8f39f1..8215e3fcd8db 100644 > --- a/crypto/asymmetric_keys/Kconfig > +++ b/crypto/asymmetric_keys/Kconfig > @@ -103,4 +103,10 @@ config FIPS_SIGNATURE_SELFTEST_ECDSA > depends on CRYPTO_SHA256=y || CRYPTO_SHA256=FIPS_SIGNATURE_SELFTEST > depends on CRYPTO_ECDSA=y || CRYPTO_ECDSA=FIPS_SIGNATURE_SELFTEST > > +config PGP_LIBRARY > + tristate "PGP parsing library" > + help > + This option enables a library that provides a number of simple > + utility functions for parsing PGP (RFC 9580) packet-based messages. > + > endif # ASYMMETRIC_KEY_TYPE > diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile > index bc65d3b98dcb..055b28207111 100644 > --- a/crypto/asymmetric_keys/Makefile > +++ b/crypto/asymmetric_keys/Makefile > @@ -79,3 +79,8 @@ verify_signed_pefile-y := \ > > $(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h > $(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h > + > +# > +# PGP handling > +# > +obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o > diff --git a/crypto/asymmetric_keys/pgp_library.c b/crypto/asymmetric_keys/pgp_library.c > new file mode 100644 > index 000000000000..1b87f8af411b > --- /dev/null > +++ b/crypto/asymmetric_keys/pgp_library.c > @@ -0,0 +1,262 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* PGP packet parser (RFC 9580) /* * PGP packet parser (RFC 9580) > + * > + * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. > + * Written by David Howells (dhowells@redhat.com) > + */ > + > +#define pr_fmt(fmt) "PGPL: "fmt > +#include <linux/errno.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > + > +#include "pgplib.h" > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("PGP library"); > + > +const char *const pgp_hash_algorithms[PGP_HASH__LAST] = { > + [PGP_HASH_MD5] = "md5", > + [PGP_HASH_SHA1] = "sha1", > + [PGP_HASH_RIPE_MD_160] = "rmd160", > + [PGP_HASH_SHA256] = "sha256", > + [PGP_HASH_SHA384] = "sha384", > + [PGP_HASH_SHA512] = "sha512", > + [PGP_HASH_SHA224] = "sha224", > + [PGP_HASH_SHA3_256] = "sha3-256", > + [PGP_HASH_SHA3_512] = "sha3-512", > +}; > +EXPORT_SYMBOL_GPL(pgp_hash_algorithms); > + > +/** > + * pgp_parse_packet_header - Parse a PGP packet header > + * @_data: Start of the PGP packet (updated to PGP packet data) > + * @_datalen: Amount of data remaining in buffer (decreased) > + * @_type: Where the packet type will be returned > + * @_headerlen: Where the header length will be returned > + * > + * Parse a set of PGP packet header [RFC 9580: 4.2]. > + * > + * Return: Packet data size on success; non-zero on error. If successful, > + * *_data and *_datalen will have been updated and *_headerlen will be set to > + * hold the length of the packet header. > + */ > +static ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, > + enum pgp_packet_tag *_type, > + u8 *_headerlen) > +{ > + enum pgp_packet_tag type; > + const u8 *data = *_data; > + size_t size, datalen = *_datalen; Move the last declaration as the first declaration, makes more readable (reverse christmas tree order). I don't have time to go this patch fully for this round but I saw some other similar nits below. > + > + pr_devel("-->%s(,%zu,,)\n", __func__, datalen); > + > + if (datalen < 2) > + goto short_packet; > + > + pr_devel("pkthdr %02x, %02x\n", data[0], data[1]); > + > + type = *data++; > + datalen--; > + if (!(type & 0x80)) { > + pr_debug("Packet type does not have MSB set\n"); > + return -EBADMSG; > + } > + type &= ~0x80; > + > + if (type & 0x40) { > + /* New packet length format */ > + type &= ~0x40; > + pr_devel("new format: t=%u\n", type); > + switch (data[0]) { > + case 0x00 ... 0xbf: > + /* One-byte length */ > + size = data[0]; > + data++; > + datalen--; > + *_headerlen = 2; > + break; > + case 0xc0 ... 0xdf: > + /* Two-byte length */ > + if (datalen < 2) > + goto short_packet; > + size = (data[0] - 192) * 256; > + size += data[1] + 192; > + data += 2; > + datalen -= 2; > + *_headerlen = 3; > + break; > + case 0xff: > + /* Five-byte length */ > + if (datalen < 5) > + goto short_packet; > + size = data[1] << 24; > + size |= data[2] << 16; > + size |= data[3] << 8; > + size |= data[4]; > + data += 5; > + datalen -= 5; > + *_headerlen = 6; > + break; > + default: > + pr_debug("Partial body length packet not supported\n"); > + return -EBADMSG; > + } > + } else { > + /* Old packet length format */ > + u8 length_type = type & 0x03; > + > + type >>= 2; > + pr_devel("old format: t=%u lt=%u\n", type, length_type); > + > + switch (length_type) { > + case 0: > + /* One-byte length */ > + size = data[0]; > + data++; > + datalen--; > + *_headerlen = 2; > + break; > + case 1: > + /* Two-byte length */ > + if (datalen < 2) > + goto short_packet; > + size = data[0] << 8; > + size |= data[1]; > + data += 2; > + datalen -= 2; > + *_headerlen = 3; > + break; > + case 2: > + /* Four-byte length */ > + if (datalen < 4) > + goto short_packet; > + size = data[0] << 24; > + size |= data[1] << 16; > + size |= data[2] << 8; > + size |= data[3]; > + data += 4; > + datalen -= 4; > + *_headerlen = 5; > + break; > + default: > + pr_debug("Indefinite length packet not supported\n"); > + return -EBADMSG; > + } > + } > + > + pr_devel("datalen=%zu size=%zu\n", datalen, size); > + if (datalen < size) > + goto short_packet; > + if (size > INT_MAX) > + goto too_big; > + > + *_data = data; > + *_datalen = datalen; > + *_type = type; > + pr_devel("Found packet type=%u size=%zd\n", type, size); > + return size; > + > +short_packet: > + pr_debug("Attempt to parse short packet\n"); > + return -EBADMSG; > +too_big: > + pr_debug("Signature subpacket size >2G\n"); > + return -EMSGSIZE; > +} > + > +/** > + * pgp_parse_packets - Parse a set of PGP packets > + * @data: Data to be parsed (updated) > + * @datalen: Amount of data (updated) > + * @ctx: Parsing context > + * > + * Parse a set of PGP packets [RFC 9580: 4]. > + * > + * Return: 0 on successful parsing, a negative value otherwise. > + */ > +int pgp_parse_packets(const u8 *data, size_t datalen, > + struct pgp_parse_context *ctx) > +{ > + enum pgp_packet_tag type; > + ssize_t pktlen; > + u8 headerlen; > + int ret; > + > + while (datalen > 2) { > + pktlen = pgp_parse_packet_header(&data, &datalen, &type, > + &headerlen); > + if (pktlen < 0) > + return pktlen; > + > + if ((ctx->types_of_interest >> type) & 1) { > + ret = ctx->process_packet(ctx, type, headerlen, > + data, pktlen); > + if (ret < 0) > + return ret; > + } > + data += pktlen; > + datalen -= pktlen; > + } > + > + if (datalen != 0) { > + pr_debug("Excess octets in packet stream\n"); > + return -EBADMSG; > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(pgp_parse_packets); > + > +/** > + * pgp_parse_public_key - Parse the common part of a PGP pubkey packet > + * @_data: Content of packet (updated) > + * @_datalen: Length of packet remaining (updated) > + * @pk: Public key data > + * > + * Parse the common data struct for a PGP pubkey packet [RFC 9580: 5.5.2]. > + * > + * Return: 0 on successful parsing, a negative value otherwise. > + */ > +int pgp_parse_public_key(const u8 **_data, size_t *_datalen, > + struct pgp_parse_pubkey *pk) > +{ > + const u8 *data = *_data; > + size_t datalen = *_datalen; > + unsigned int tmp; > + > + if (datalen < 12) { > + pr_debug("Public key packet too short\n"); > + return -EBADMSG; > + } > + > + pk->version = *data++; > + switch (pk->version) { > + case PGP_KEY_VERSION_4: > + break; > + default: > + pr_debug("Public key packet with unhandled version %d\n", > + pk->version); > + return -EBADMSG; > + } > + > + tmp = *data++ << 24; > + tmp |= *data++ << 16; > + tmp |= *data++ << 8; > + tmp |= *data++; > + pk->creation_time = tmp; > + if (pk->version == PGP_KEY_VERSION_4) > + pk->expires_at = 0; /* Have to get it from the selfsignature */ > + > + pk->pubkey_algo = *data++; > + datalen -= 6; > + > + pr_devel("%x,%x,%lx,%lx\n", > + pk->version, pk->pubkey_algo, pk->creation_time, > + pk->expires_at); > + > + *_data = data; > + *_datalen = datalen; > + return 0; > +} > +EXPORT_SYMBOL_GPL(pgp_parse_public_key); > diff --git a/crypto/asymmetric_keys/pgplib.h b/crypto/asymmetric_keys/pgplib.h > new file mode 100644 > index 000000000000..3ec4b408a11e > --- /dev/null > +++ b/crypto/asymmetric_keys/pgplib.h > @@ -0,0 +1,33 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* PGP library definitions (RFC 9580) > + * > + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. > + * Written by David Howells (dhowells@redhat.com) > + */ > + > +#include "pgp.h" > + > +/* > + * PGP library packet parser > + */ > +struct pgp_parse_context { > + u64 types_of_interest; > + int (*process_packet)(struct pgp_parse_context *context, > + enum pgp_packet_tag type, > + u8 headerlen, > + const u8 *data, > + size_t datalen); > +}; > + > +extern int pgp_parse_packets(const u8 *data, size_t datalen, > + struct pgp_parse_context *ctx); > + > +struct pgp_parse_pubkey { > + enum pgp_key_version version : 8; > + enum pgp_pubkey_algo pubkey_algo : 8; > + __kernel_old_time_t creation_time; > + __kernel_old_time_t expires_at; > +}; > + > +extern int pgp_parse_public_key(const u8 **_data, size_t *_datalen, > + struct pgp_parse_pubkey *pk); BR, Jarkko
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index e1345b8f39f1..8215e3fcd8db 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -103,4 +103,10 @@ config FIPS_SIGNATURE_SELFTEST_ECDSA depends on CRYPTO_SHA256=y || CRYPTO_SHA256=FIPS_SIGNATURE_SELFTEST depends on CRYPTO_ECDSA=y || CRYPTO_ECDSA=FIPS_SIGNATURE_SELFTEST +config PGP_LIBRARY + tristate "PGP parsing library" + help + This option enables a library that provides a number of simple + utility functions for parsing PGP (RFC 9580) packet-based messages. + endif # ASYMMETRIC_KEY_TYPE diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile index bc65d3b98dcb..055b28207111 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -79,3 +79,8 @@ verify_signed_pefile-y := \ $(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h $(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h + +# +# PGP handling +# +obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o diff --git a/crypto/asymmetric_keys/pgp_library.c b/crypto/asymmetric_keys/pgp_library.c new file mode 100644 index 000000000000..1b87f8af411b --- /dev/null +++ b/crypto/asymmetric_keys/pgp_library.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0 +/* PGP packet parser (RFC 9580) + * + * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) "PGPL: "fmt +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "pgplib.h" + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("PGP library"); + +const char *const pgp_hash_algorithms[PGP_HASH__LAST] = { + [PGP_HASH_MD5] = "md5", + [PGP_HASH_SHA1] = "sha1", + [PGP_HASH_RIPE_MD_160] = "rmd160", + [PGP_HASH_SHA256] = "sha256", + [PGP_HASH_SHA384] = "sha384", + [PGP_HASH_SHA512] = "sha512", + [PGP_HASH_SHA224] = "sha224", + [PGP_HASH_SHA3_256] = "sha3-256", + [PGP_HASH_SHA3_512] = "sha3-512", +}; +EXPORT_SYMBOL_GPL(pgp_hash_algorithms); + +/** + * pgp_parse_packet_header - Parse a PGP packet header + * @_data: Start of the PGP packet (updated to PGP packet data) + * @_datalen: Amount of data remaining in buffer (decreased) + * @_type: Where the packet type will be returned + * @_headerlen: Where the header length will be returned + * + * Parse a set of PGP packet header [RFC 9580: 4.2]. + * + * Return: Packet data size on success; non-zero on error. If successful, + * *_data and *_datalen will have been updated and *_headerlen will be set to + * hold the length of the packet header. + */ +static ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + enum pgp_packet_tag *_type, + u8 *_headerlen) +{ + enum pgp_packet_tag type; + const u8 *data = *_data; + size_t size, datalen = *_datalen; + + pr_devel("-->%s(,%zu,,)\n", __func__, datalen); + + if (datalen < 2) + goto short_packet; + + pr_devel("pkthdr %02x, %02x\n", data[0], data[1]); + + type = *data++; + datalen--; + if (!(type & 0x80)) { + pr_debug("Packet type does not have MSB set\n"); + return -EBADMSG; + } + type &= ~0x80; + + if (type & 0x40) { + /* New packet length format */ + type &= ~0x40; + pr_devel("new format: t=%u\n", type); + switch (data[0]) { + case 0x00 ... 0xbf: + /* One-byte length */ + size = data[0]; + data++; + datalen--; + *_headerlen = 2; + break; + case 0xc0 ... 0xdf: + /* Two-byte length */ + if (datalen < 2) + goto short_packet; + size = (data[0] - 192) * 256; + size += data[1] + 192; + data += 2; + datalen -= 2; + *_headerlen = 3; + break; + case 0xff: + /* Five-byte length */ + if (datalen < 5) + goto short_packet; + size = data[1] << 24; + size |= data[2] << 16; + size |= data[3] << 8; + size |= data[4]; + data += 5; + datalen -= 5; + *_headerlen = 6; + break; + default: + pr_debug("Partial body length packet not supported\n"); + return -EBADMSG; + } + } else { + /* Old packet length format */ + u8 length_type = type & 0x03; + + type >>= 2; + pr_devel("old format: t=%u lt=%u\n", type, length_type); + + switch (length_type) { + case 0: + /* One-byte length */ + size = data[0]; + data++; + datalen--; + *_headerlen = 2; + break; + case 1: + /* Two-byte length */ + if (datalen < 2) + goto short_packet; + size = data[0] << 8; + size |= data[1]; + data += 2; + datalen -= 2; + *_headerlen = 3; + break; + case 2: + /* Four-byte length */ + if (datalen < 4) + goto short_packet; + size = data[0] << 24; + size |= data[1] << 16; + size |= data[2] << 8; + size |= data[3]; + data += 4; + datalen -= 4; + *_headerlen = 5; + break; + default: + pr_debug("Indefinite length packet not supported\n"); + return -EBADMSG; + } + } + + pr_devel("datalen=%zu size=%zu\n", datalen, size); + if (datalen < size) + goto short_packet; + if (size > INT_MAX) + goto too_big; + + *_data = data; + *_datalen = datalen; + *_type = type; + pr_devel("Found packet type=%u size=%zd\n", type, size); + return size; + +short_packet: + pr_debug("Attempt to parse short packet\n"); + return -EBADMSG; +too_big: + pr_debug("Signature subpacket size >2G\n"); + return -EMSGSIZE; +} + +/** + * pgp_parse_packets - Parse a set of PGP packets + * @data: Data to be parsed (updated) + * @datalen: Amount of data (updated) + * @ctx: Parsing context + * + * Parse a set of PGP packets [RFC 9580: 4]. + * + * Return: 0 on successful parsing, a negative value otherwise. + */ +int pgp_parse_packets(const u8 *data, size_t datalen, + struct pgp_parse_context *ctx) +{ + enum pgp_packet_tag type; + ssize_t pktlen; + u8 headerlen; + int ret; + + while (datalen > 2) { + pktlen = pgp_parse_packet_header(&data, &datalen, &type, + &headerlen); + if (pktlen < 0) + return pktlen; + + if ((ctx->types_of_interest >> type) & 1) { + ret = ctx->process_packet(ctx, type, headerlen, + data, pktlen); + if (ret < 0) + return ret; + } + data += pktlen; + datalen -= pktlen; + } + + if (datalen != 0) { + pr_debug("Excess octets in packet stream\n"); + return -EBADMSG; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pgp_parse_packets); + +/** + * pgp_parse_public_key - Parse the common part of a PGP pubkey packet + * @_data: Content of packet (updated) + * @_datalen: Length of packet remaining (updated) + * @pk: Public key data + * + * Parse the common data struct for a PGP pubkey packet [RFC 9580: 5.5.2]. + * + * Return: 0 on successful parsing, a negative value otherwise. + */ +int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + struct pgp_parse_pubkey *pk) +{ + const u8 *data = *_data; + size_t datalen = *_datalen; + unsigned int tmp; + + if (datalen < 12) { + pr_debug("Public key packet too short\n"); + return -EBADMSG; + } + + pk->version = *data++; + switch (pk->version) { + case PGP_KEY_VERSION_4: + break; + default: + pr_debug("Public key packet with unhandled version %d\n", + pk->version); + return -EBADMSG; + } + + tmp = *data++ << 24; + tmp |= *data++ << 16; + tmp |= *data++ << 8; + tmp |= *data++; + pk->creation_time = tmp; + if (pk->version == PGP_KEY_VERSION_4) + pk->expires_at = 0; /* Have to get it from the selfsignature */ + + pk->pubkey_algo = *data++; + datalen -= 6; + + pr_devel("%x,%x,%lx,%lx\n", + pk->version, pk->pubkey_algo, pk->creation_time, + pk->expires_at); + + *_data = data; + *_datalen = datalen; + return 0; +} +EXPORT_SYMBOL_GPL(pgp_parse_public_key); diff --git a/crypto/asymmetric_keys/pgplib.h b/crypto/asymmetric_keys/pgplib.h new file mode 100644 index 000000000000..3ec4b408a11e --- /dev/null +++ b/crypto/asymmetric_keys/pgplib.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* PGP library definitions (RFC 9580) + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include "pgp.h" + +/* + * PGP library packet parser + */ +struct pgp_parse_context { + u64 types_of_interest; + int (*process_packet)(struct pgp_parse_context *context, + enum pgp_packet_tag type, + u8 headerlen, + const u8 *data, + size_t datalen); +}; + +extern int pgp_parse_packets(const u8 *data, size_t datalen, + struct pgp_parse_context *ctx); + +struct pgp_parse_pubkey { + enum pgp_key_version version : 8; + enum pgp_pubkey_algo pubkey_algo : 8; + __kernel_old_time_t creation_time; + __kernel_old_time_t expires_at; +}; + +extern int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + struct pgp_parse_pubkey *pk);