From 22e81f39ace64964bae3b6c89662d1221a11324c Mon Sep 17 00:00:00 2001 From: Stig Palmquist Date: Wed, 6 Jul 2022 14:06:19 +0200 Subject: [PATCH] gnupg: add patch disallowing compressed signatures and certificates https://seclists.org/oss-sec/2022/q3/9 https://seclists.org/oss-sec/2022/q3/27 --- pkgs/tools/security/gnupg/23.nix | 3 + ...mpressed-signatures-and-certificates.patch | 216 ++++++++++++++++++ 2 files changed, 219 insertions(+) create mode 100644 pkgs/tools/security/gnupg/v3-0001-Disallow-compressed-signatures-and-certificates.patch diff --git a/pkgs/tools/security/gnupg/23.nix b/pkgs/tools/security/gnupg/23.nix index b07a3550c76d..13364f5498a8 100644 --- a/pkgs/tools/security/gnupg/23.nix +++ b/pkgs/tools/security/gnupg/23.nix @@ -37,6 +37,9 @@ stdenv.mkDerivation rec { # Patch from upstream 34c649b36013, https://dev.gnupg.org/T6027 ./CVE-2022-34903-g10-fix-garbled-status-messages-in-NOTATION_DATA.patch + + # Patch for DoS vuln from https://seclists.org/oss-sec/2022/q3/27 + ./v3-0001-Disallow-compressed-signatures-and-certificates.patch ]; postPatch = '' sed -i 's,\(hkps\|https\)://keyserver.ubuntu.com,hkps://keys.openpgp.org,g' configure configure.ac doc/dirmngr.texi doc/gnupg.info-1 diff --git a/pkgs/tools/security/gnupg/v3-0001-Disallow-compressed-signatures-and-certificates.patch b/pkgs/tools/security/gnupg/v3-0001-Disallow-compressed-signatures-and-certificates.patch new file mode 100644 index 000000000000..267085dff4c8 --- /dev/null +++ b/pkgs/tools/security/gnupg/v3-0001-Disallow-compressed-signatures-and-certificates.patch @@ -0,0 +1,216 @@ +From 459b61fa21db755d6c879c3ef9ab85b3d1786c9f Mon Sep 17 00:00:00 2001 +From: Demi Marie Obenour +Date: Fri, 27 May 2022 19:51:19 -0400 +Subject: [PATCH GnuPG v3] Disallow compressed signatures and certificates + +Compressed packets have significant attack surface, due to the potential +for both denial of service (zip bombs and the like) and for code +execution via memory corruption vulnerabilities in the decompressor. +Furthermore, I am not aware of any implementation that uses them in keys +or detached signatures. Therefore, disallow their use in such contexts +entirely. This includes signatures that are part of a cleartext-signed +message. + +When parsing detached signatures, forbid any packet that is not a +signature or marker packet. When parsing keys, return an error when +encountering a compressed packet, instead of decompressing the packet. + +Furthermore, certificates, keys, and signatures are not allowed to +contain partial-length or indeterminate-length packets. Reject those in +parse_packet, rather than activating the partial-length filter code. +This is not (yet) implemented for cleartext-signed messages, as these +messages are internally represented as inline-signed messages. + +GnuPG-bug-id: T5993 +Signed-off-by: Demi Marie Obenour +--- + g10/import.c | 18 ++---------------- + g10/mainproc.c | 24 +++++++++++++++++++++--- + g10/packet.h | 2 ++ + g10/parse-packet.c | 44 +++++++++++++++++++++++++++++++++++++++++++- + 4 files changed, 68 insertions(+), 20 deletions(-) + +diff --git a/g10/import.c b/g10/import.c +index bb0bf67934a8316130cde182cd43d56353e0171d..a8136351f6f7dae8c65634ed8e1c242d323e2009 100644 +--- a/g10/import.c ++++ b/g10/import.c +@@ -1042,22 +1042,8 @@ read_block( IOBUF a, unsigned int options, + switch (pkt->pkttype) + { + case PKT_COMPRESSED: +- if (check_compress_algo (pkt->pkt.compressed->algorithm)) +- { +- rc = GPG_ERR_COMPR_ALGO; +- goto ready; +- } +- else +- { +- compress_filter_context_t *cfx = xmalloc_clear( sizeof *cfx ); +- pkt->pkt.compressed->buf = NULL; +- if (push_compress_filter2 (a, cfx, +- pkt->pkt.compressed->algorithm, 1)) +- xfree (cfx); /* e.g. in case of compression_algo NONE. */ +- } +- free_packet (pkt, &parsectx); +- init_packet(pkt); +- break; ++ rc = GPG_ERR_UNEXPECTED; ++ goto ready; + + case PKT_RING_TRUST: + /* Skip those packets unless we are in restore mode. */ +diff --git a/g10/mainproc.c b/g10/mainproc.c +index af11877aa257e46662c42b6ff573ee01c3ad1547..3629fc921b742afd131e8d8e2664b201095990f0 100644 +--- a/g10/mainproc.c ++++ b/g10/mainproc.c +@@ -152,6 +152,7 @@ add_onepass_sig (CTX c, PACKET *pkt) + { + kbnode_t node; + ++ log_assert(!(c->sigs_only && c->signed_data.used)); + if (c->list) /* Add another packet. */ + add_kbnode (c->list, new_kbnode (pkt)); + else /* Insert the first one. */ +@@ -1076,8 +1077,16 @@ proc_compressed (CTX c, PACKET *pkt) + int rc; + + /*printf("zip: compressed data packet\n");*/ +- if (c->sigs_only) +- rc = handle_compressed (c->ctrl, c, zd, proc_compressed_cb, c); ++ if ( literals_seen ) ++ { ++ log_error ("Compressed packet follows literal data packet\n"); ++ rc = GPG_ERR_UNEXPECTED; ++ } ++ else if ( c->sigs_only ) ++ { ++ log_assert(!c->signed_data.used); ++ rc = handle_compressed (c->ctrl, c, zd, proc_compressed_cb, c); ++ } + else if( c->encrypt_only ) + rc = handle_compressed (c->ctrl, c, zd, proc_encrypt_cb, c); + else +@@ -1596,6 +1605,7 @@ do_proc_packets (CTX c, iobuf_t a) + c->iobuf = a; + init_packet(pkt); + init_parse_packet (&parsectx, a); ++ parsectx.sigs_only = c->sigs_only && c->signed_data.used; + while ((rc=parse_packet (&parsectx, pkt)) != -1) + { + any_data = 1; +@@ -1607,6 +1617,12 @@ do_proc_packets (CTX c, iobuf_t a) + if (gpg_err_code (rc) == GPG_ERR_INV_PACKET + && opt.list_packets == 0) + break; ++ ++ if (gpg_err_code (rc) == GPG_ERR_UNEXPECTED) ++ { ++ write_status_text( STATUS_UNEXPECTED, "0" ); ++ goto leave; ++ } + continue; + } + newpkt = -1; +@@ -1644,7 +1660,9 @@ do_proc_packets (CTX c, iobuf_t a) + case PKT_COMPRESSED: rc = proc_compressed (c, pkt); break; + case PKT_ONEPASS_SIG: newpkt = add_onepass_sig (c, pkt); break; + case PKT_GPG_CONTROL: newpkt = add_gpg_control (c, pkt); break; +- default: newpkt = 0; break; ++ default: ++ log_assert(!c->signed_data.used); ++ newpkt = 0; break; + } + } + else if (c->encrypt_only) +diff --git a/g10/packet.h b/g10/packet.h +index 5a14015a16c872fe7b0b15468598daf7a05ffc02..82dfe786b46051491e7015e64441678140defa9e 100644 +--- a/g10/packet.h ++++ b/g10/packet.h +@@ -657,6 +657,7 @@ struct parse_packet_ctx_s + int free_last_pkt; /* Indicates that LAST_PKT must be freed. */ + int skip_meta; /* Skip ring trust packets. */ + unsigned int n_parsed_packets; /* Number of parsed packets. */ ++ int sigs_only; /* Only accept detached signature packets */ + }; + typedef struct parse_packet_ctx_s *parse_packet_ctx_t; + +@@ -667,6 +668,7 @@ typedef struct parse_packet_ctx_s *parse_packet_ctx_t; + (a)->free_last_pkt = 0; \ + (a)->skip_meta = 0; \ + (a)->n_parsed_packets = 0; \ ++ (a)->sigs_only = 0; \ + } while (0) + + #define deinit_parse_packet(a) do { \ +diff --git a/g10/parse-packet.c b/g10/parse-packet.c +index cea1f7ebc5daec3863ae963c1ab25500f86796fe..dca66ff427ea6778e536782ec6bda83584877342 100644 +--- a/g10/parse-packet.c ++++ b/g10/parse-packet.c +@@ -738,6 +738,20 @@ parse (parse_packet_ctx_t ctx, PACKET *pkt, int onlykeypkts, off_t * retpos, + case PKT_ENCRYPTED_MDC: + case PKT_ENCRYPTED_AEAD: + case PKT_COMPRESSED: ++ if (ctx->sigs_only) ++ { ++ log_error (_("partial length packet of type %d in detached" ++ " signature\n"), pkttype); ++ rc = gpg_error (GPG_ERR_UNEXPECTED); ++ goto leave; ++ } ++ if (onlykeypkts) ++ { ++ log_error (_("partial length packet of type %d in keyring\n"), ++ pkttype); ++ rc = gpg_error (GPG_ERR_UNEXPECTED); ++ goto leave; ++ } + iobuf_set_partial_body_length_mode (inp, c & 0xff); + pktlen = 0; /* To indicate partial length. */ + partial = 1; +@@ -775,6 +789,20 @@ parse (parse_packet_ctx_t ctx, PACKET *pkt, int onlykeypkts, off_t * retpos, + rc = gpg_error (GPG_ERR_INV_PACKET); + goto leave; + } ++ else if (ctx->sigs_only) ++ { ++ log_error (_("indeterminate length packet of type %d in detached" ++ " signature\n"), pkttype); ++ rc = gpg_error (GPG_ERR_UNEXPECTED); ++ goto leave; ++ } ++ else if (onlykeypkts) ++ { ++ log_error (_("indeterminate length packet of type %d in" ++ " keyring\n"), pkttype); ++ rc = gpg_error (GPG_ERR_UNEXPECTED); ++ goto leave; ++ } + } + else + { +@@ -828,7 +856,21 @@ parse (parse_packet_ctx_t ctx, PACKET *pkt, int onlykeypkts, off_t * retpos, + goto leave; + } + +- if (with_uid && pkttype == PKT_USER_ID) ++ if (ctx->sigs_only) ++ switch (pkttype) ++ { ++ case PKT_SIGNATURE: ++ case PKT_MARKER: ++ break; ++ default: ++ log_error(_("Packet type %d not allowed in detached signature\n"), ++ pkttype); ++ iobuf_skip_rest (inp, pktlen, partial); ++ *skip = 1; ++ rc = GPG_ERR_UNEXPECTED; ++ goto leave; ++ } ++ else if (with_uid && pkttype == PKT_USER_ID) + /* If ONLYKEYPKTS is set to 2, then we never skip user id packets, + even if DO_SKIP is set. */ + ; +-- +2.36.1 +