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| 1 | +#include "cache.h" |
| 2 | +#include "run-command.h" |
| 3 | +#include "strbuf.h" |
| 4 | +#include "gpg-interface.h" |
| 5 | +#include "sigchain.h" |
| 6 | + |
| 7 | +static char *configured_signing_key; |
| 8 | + |
| 9 | +void set_signing_key(const char *key) |
| 10 | +{ |
| 11 | + free(configured_signing_key); |
| 12 | + configured_signing_key = xstrdup(key); |
| 13 | +} |
| 14 | + |
| 15 | +int git_gpg_config(const char *var, const char *value, void *cb) |
| 16 | +{ |
| 17 | + if (!strcmp(var, "user.signingkey")) { |
| 18 | + if (!value) |
| 19 | + return config_error_nonbool(var); |
| 20 | + set_signing_key(value); |
| 21 | + } |
| 22 | + return 0; |
| 23 | +} |
| 24 | + |
| 25 | +const char *get_signing_key(void) |
| 26 | +{ |
| 27 | + if (configured_signing_key) |
| 28 | + return configured_signing_key; |
| 29 | + return git_committer_info(IDENT_ERROR_ON_NO_NAME|IDENT_NO_DATE); |
| 30 | +} |
| 31 | + |
| 32 | +/* |
| 33 | + * Create a detached signature for the contents of "buffer" and append |
| 34 | + * it after "signature"; "buffer" and "signature" can be the same |
| 35 | + * strbuf instance, which would cause the detached signature appended |
| 36 | + * at the end. |
| 37 | + */ |
| 38 | +int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key) |
| 39 | +{ |
| 40 | + struct child_process gpg; |
| 41 | + const char *args[4]; |
| 42 | + ssize_t len; |
| 43 | + size_t i, j, bottom; |
| 44 | + |
| 45 | + memset(&gpg, 0, sizeof(gpg)); |
| 46 | + gpg.argv = args; |
| 47 | + gpg.in = -1; |
| 48 | + gpg.out = -1; |
| 49 | + args[0] = "gpg"; |
| 50 | + args[1] = "-bsau"; |
| 51 | + args[2] = signing_key; |
| 52 | + args[3] = NULL; |
| 53 | + |
| 54 | + if (start_command(&gpg)) |
| 55 | + return error(_("could not run gpg.")); |
| 56 | + |
| 57 | + /* |
| 58 | + * When the username signingkey is bad, program could be terminated |
| 59 | + * because gpg exits without reading and then write gets SIGPIPE. |
| 60 | + */ |
| 61 | + sigchain_push(SIGPIPE, SIG_IGN); |
| 62 | + |
| 63 | + if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) { |
| 64 | + close(gpg.in); |
| 65 | + close(gpg.out); |
| 66 | + finish_command(&gpg); |
| 67 | + return error(_("gpg did not accept the data")); |
| 68 | + } |
| 69 | + close(gpg.in); |
| 70 | + |
| 71 | + bottom = signature->len; |
| 72 | + len = strbuf_read(signature, gpg.out, 1024); |
| 73 | + close(gpg.out); |
| 74 | + |
| 75 | + sigchain_pop(SIGPIPE); |
| 76 | + |
| 77 | + if (finish_command(&gpg) || !len || len < 0) |
| 78 | + return error(_("gpg failed to sign the data")); |
| 79 | + |
| 80 | + /* Strip CR from the line endings, in case we are on Windows. */ |
| 81 | + for (i = j = bottom; i < signature->len; i++) |
| 82 | + if (signature->buf[i] != '\r') { |
| 83 | + if (i != j) |
| 84 | + signature->buf[j] = signature->buf[i]; |
| 85 | + j++; |
| 86 | + } |
| 87 | + strbuf_setlen(signature, j); |
| 88 | + |
| 89 | + return 0; |
| 90 | +} |
| 91 | + |
| 92 | +/* |
| 93 | + * Run "gpg" to see if the payload matches the detached signature. |
| 94 | + * gpg_output_to tells where the output from "gpg" should go: |
| 95 | + * < 0: /dev/null |
| 96 | + * = 0: standard error of the calling process |
| 97 | + * > 0: the specified file descriptor |
| 98 | + */ |
| 99 | +int verify_signed_buffer(const char *payload, size_t payload_size, |
| 100 | + const char *signature, size_t signature_size, |
| 101 | + struct strbuf *gpg_output) |
| 102 | +{ |
| 103 | + struct child_process gpg; |
| 104 | + const char *args_gpg[] = {"gpg", "--verify", "FILE", "-", NULL}; |
| 105 | + char path[PATH_MAX]; |
| 106 | + int fd, ret; |
| 107 | + |
| 108 | + fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX"); |
| 109 | + if (fd < 0) |
| 110 | + return error("could not create temporary file '%s': %s", |
| 111 | + path, strerror(errno)); |
| 112 | + if (write_in_full(fd, signature, signature_size) < 0) |
| 113 | + return error("failed writing detached signature to '%s': %s", |
| 114 | + path, strerror(errno)); |
| 115 | + close(fd); |
| 116 | + |
| 117 | + memset(&gpg, 0, sizeof(gpg)); |
| 118 | + gpg.argv = args_gpg; |
| 119 | + gpg.in = -1; |
| 120 | + if (gpg_output) |
| 121 | + gpg.err = -1; |
| 122 | + args_gpg[2] = path; |
| 123 | + if (start_command(&gpg)) { |
| 124 | + unlink(path); |
| 125 | + return error("could not run gpg."); |
| 126 | + } |
| 127 | + |
| 128 | + write_in_full(gpg.in, payload, payload_size); |
| 129 | + close(gpg.in); |
| 130 | + |
| 131 | + if (gpg_output) |
| 132 | + strbuf_read(gpg_output, gpg.err, 0); |
| 133 | + ret = finish_command(&gpg); |
| 134 | + |
| 135 | + unlink_or_warn(path); |
| 136 | + |
| 137 | + return ret; |
| 138 | +} |
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