diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:14:06 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:14:06 +0000 |
commit | eee068778cb28ecf3c14e1bf843a95547d72c42d (patch) | |
tree | 0e07b30ddc5ea579d682d5dbe57998200d1c9ab7 /agent/pkdecrypt.c | |
parent | Initial commit. (diff) | |
download | gnupg2-eee068778cb28ecf3c14e1bf843a95547d72c42d.tar.xz gnupg2-eee068778cb28ecf3c14e1bf843a95547d72c42d.zip |
Adding upstream version 2.2.40.upstream/2.2.40
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'agent/pkdecrypt.c')
-rw-r--r-- | agent/pkdecrypt.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/agent/pkdecrypt.c b/agent/pkdecrypt.c new file mode 100644 index 0000000..6aed96b --- /dev/null +++ b/agent/pkdecrypt.c @@ -0,0 +1,147 @@ +/* pkdecrypt.c - public key decryption (well, actually using a secret key) + * Copyright (C) 2001, 2003 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG 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 3 of the License, or + * (at your option) any later version. + * + * GnuPG 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, see <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <assert.h> +#include <unistd.h> +#include <sys/stat.h> + +#include "agent.h" + + +/* DECRYPT the stuff in ciphertext which is expected to be a S-Exp. + Try to get the key from CTRL and write the decoded stuff back to + OUTFP. The padding information is stored at R_PADDING with -1 + for not known. */ +int +agent_pkdecrypt (ctrl_t ctrl, const char *desc_text, + const unsigned char *ciphertext, size_t ciphertextlen, + membuf_t *outbuf, int *r_padding) +{ + gcry_sexp_t s_skey = NULL, s_cipher = NULL, s_plain = NULL; + unsigned char *shadow_info = NULL; + int rc; + char *buf = NULL; + size_t len; + + *r_padding = -1; + + if (!ctrl->have_keygrip) + { + log_error ("speculative decryption not yet supported\n"); + rc = gpg_error (GPG_ERR_NO_SECKEY); + goto leave; + } + + rc = gcry_sexp_sscan (&s_cipher, NULL, (char*)ciphertext, ciphertextlen); + if (rc) + { + log_error ("failed to convert ciphertext: %s\n", gpg_strerror (rc)); + rc = gpg_error (GPG_ERR_INV_DATA); + goto leave; + } + + if (DBG_CRYPTO) + { + log_printhex (ctrl->keygrip, 20, "keygrip:"); + log_printhex (ciphertext, ciphertextlen, "cipher: "); + } + rc = agent_key_from_file (ctrl, NULL, desc_text, + ctrl->keygrip, &shadow_info, + CACHE_MODE_NORMAL, NULL, &s_skey, NULL); + if (rc) + { + if (gpg_err_code (rc) != GPG_ERR_NO_SECKEY) + log_error ("failed to read the secret key\n"); + goto leave; + } + + if (shadow_info) + { /* divert operation to the smartcard */ + + if (!gcry_sexp_canon_len (ciphertext, ciphertextlen, NULL, NULL)) + { + rc = gpg_error (GPG_ERR_INV_SEXP); + goto leave; + } + + rc = divert_pkdecrypt (ctrl, desc_text, ciphertext, + ctrl->keygrip, shadow_info, + &buf, &len, r_padding); + if (rc) + { + log_error ("smartcard decryption failed: %s\n", gpg_strerror (rc)); + goto leave; + } + + put_membuf_printf (outbuf, "(5:value%u:", (unsigned int)len); + put_membuf (outbuf, buf, len); + put_membuf (outbuf, ")", 2); + } + else + { /* No smartcard, but a private key */ +/* if (DBG_CRYPTO ) */ +/* { */ +/* log_debug ("skey: "); */ +/* gcry_sexp_dump (s_skey); */ +/* } */ + + rc = gcry_pk_decrypt (&s_plain, s_cipher, s_skey); + if (rc) + { + log_error ("decryption failed: %s\n", gpg_strerror (rc)); + goto leave; + } + + if (DBG_CRYPTO) + { + log_debug ("plain: "); + gcry_sexp_dump (s_plain); + } + len = gcry_sexp_sprint (s_plain, GCRYSEXP_FMT_CANON, NULL, 0); + assert (len); + buf = xmalloc (len); + len = gcry_sexp_sprint (s_plain, GCRYSEXP_FMT_CANON, buf, len); + assert (len); + if (*buf == '(') + put_membuf (outbuf, buf, len); + else + { + /* Old style libgcrypt: This is only an S-expression + part. Turn it into a complete S-expression. */ + put_membuf (outbuf, "(5:value", 8); + put_membuf (outbuf, buf, len); + put_membuf (outbuf, ")", 2); + } + } + + + leave: + gcry_sexp_release (s_skey); + gcry_sexp_release (s_plain); + gcry_sexp_release (s_cipher); + xfree (buf); + xfree (shadow_info); + return rc; +} |