Andrew's git - gitweb.git/blob

e71b59daf67b28f0699035e7834bb6c0b56c5425
   1#include "cache.h"
   2#include "run-command.h"
   3#include "strbuf.h"
   4#include "gpg-interface.h"
   5#include "sigchain.h"
   6
   7static char *configured_signing_key;
   8static const char *gpg_program = "gpg";
   9
  10void signature_check_clear(struct signature_check *sigc)
  11{
  12        free(sigc->gpg_output);
  13        free(sigc->gpg_status);
  14        free(sigc->signer);
  15        free(sigc->key);
  16        sigc->gpg_output = NULL;
  17        sigc->gpg_status = NULL;
  18        sigc->signer = NULL;
  19        sigc->key = NULL;
  20}
  21
  22void set_signing_key(const char *key)
  23{
  24        free(configured_signing_key);
  25        configured_signing_key = xstrdup(key);
  26}
  27
  28int git_gpg_config(const char *var, const char *value, void *cb)
  29{
  30        if (!strcmp(var, "user.signingkey")) {
  31                set_signing_key(value);
  32        }
  33        if (!strcmp(var, "gpg.program")) {
  34                if (!value)
  35                        return config_error_nonbool(var);
  36                gpg_program = xstrdup(value);
  37        }
  38        return 0;
  39}
  40
  41const char *get_signing_key(void)
  42{
  43        if (configured_signing_key)
  44                return configured_signing_key;
  45        return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
  46}
  47
  48/*
  49 * Create a detached signature for the contents of "buffer" and append
  50 * it after "signature"; "buffer" and "signature" can be the same
  51 * strbuf instance, which would cause the detached signature appended
  52 * at the end.
  53 */
  54int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
  55{
  56        struct child_process gpg;
  57        const char *args[4];
  58        ssize_t len;
  59        size_t i, j, bottom;
  60
  61        memset(&gpg, 0, sizeof(gpg));
  62        gpg.argv = args;
  63        gpg.in = -1;
  64        gpg.out = -1;
  65        args[0] = gpg_program;
  66        args[1] = "-bsau";
  67        args[2] = signing_key;
  68        args[3] = NULL;
  69
  70        if (start_command(&gpg))
  71                return error(_("could not run gpg."));
  72
  73        /*
  74         * When the username signingkey is bad, program could be terminated
  75         * because gpg exits without reading and then write gets SIGPIPE.
  76         */
  77        sigchain_push(SIGPIPE, SIG_IGN);
  78
  79        if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
  80                close(gpg.in);
  81                close(gpg.out);
  82                finish_command(&gpg);
  83                return error(_("gpg did not accept the data"));
  84        }
  85        close(gpg.in);
  86
  87        bottom = signature->len;
  88        len = strbuf_read(signature, gpg.out, 1024);
  89        close(gpg.out);
  90
  91        sigchain_pop(SIGPIPE);
  92
  93        if (finish_command(&gpg) || !len || len < 0)
  94                return error(_("gpg failed to sign the data"));
  95
  96        /* Strip CR from the line endings, in case we are on Windows. */
  97        for (i = j = bottom; i < signature->len; i++)
  98                if (signature->buf[i] != '\r') {
  99                        if (i != j)
 100                                signature->buf[j] = signature->buf[i];
 101                        j++;
 102                }
 103        strbuf_setlen(signature, j);
 104
 105        return 0;
 106}
 107
 108/*
 109 * Run "gpg" to see if the payload matches the detached signature.
 110 * gpg_output, when set, receives the diagnostic output from GPG.
 111 * gpg_status, when set, receives the status output from GPG.
 112 */
 113int verify_signed_buffer(const char *payload, size_t payload_size,
 114                         const char *signature, size_t signature_size,
 115                         struct strbuf *gpg_output, struct strbuf *gpg_status)
 116{
 117        struct child_process gpg;
 118        const char *args_gpg[] = {NULL, "--status-fd=1", "--verify", "FILE", "-", NULL};
 119        char path[PATH_MAX];
 120        int fd, ret;
 121        struct strbuf buf = STRBUF_INIT;
 122        struct strbuf *pbuf = &buf;
 123
 124        args_gpg[0] = gpg_program;
 125        fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
 126        if (fd < 0)
 127                return error(_("could not create temporary file '%s': %s"),
 128                             path, strerror(errno));
 129        if (write_in_full(fd, signature, signature_size) < 0)
 130                return error(_("failed writing detached signature to '%s': %s"),
 131                             path, strerror(errno));
 132        close(fd);
 133
 134        memset(&gpg, 0, sizeof(gpg));
 135        gpg.argv = args_gpg;
 136        gpg.in = -1;
 137        gpg.out = -1;
 138        if (gpg_output)
 139                gpg.err = -1;
 140        args_gpg[3] = path;
 141        if (start_command(&gpg)) {
 142                unlink(path);
 143                return error(_("could not run gpg."));
 144        }
 145
 146        write_in_full(gpg.in, payload, payload_size);
 147        close(gpg.in);
 148
 149        if (gpg_output) {
 150                strbuf_read(gpg_output, gpg.err, 0);
 151                close(gpg.err);
 152        }
 153        if (gpg_status)
 154                pbuf = gpg_status;
 155        strbuf_read(pbuf, gpg.out, 0);
 156        close(gpg.out);
 157
 158        ret = finish_command(&gpg);
 159
 160        unlink_or_warn(path);
 161
 162        ret |= !strstr(pbuf->buf, "\n[GNUPG:] GOODSIG ");
 163        strbuf_release(&buf); /* no matter it was used or not */
 164
 165        return ret;
 166}