diff options
Diffstat (limited to 'usr.bin/ssh/misc.c')
| -rw-r--r-- | usr.bin/ssh/misc.c | 165 |
1 files changed, 134 insertions, 31 deletions
diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c index e52656cad21..73c86438904 100644 --- a/usr.bin/ssh/misc.c +++ b/usr.bin/ssh/misc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: misc.c,v 1.149 2020/05/29 01:20:46 dtucker Exp $ */ +/* $OpenBSD: misc.c,v 1.150 2020/05/29 04:25:40 dtucker Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2005-2020 Damien Miller. All rights reserved. @@ -1049,45 +1049,90 @@ tilde_expand_filename(const char *filename, uid_t uid) } /* - * Expand a string with a set of %[char] escapes. A number of escapes may be - * specified as (char *escape_chars, char *replacement) pairs. The list must - * be terminated by a NULL escape_char. Returns replaced string in memory - * allocated by xmalloc. + * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} + * substitutions. A number of escapes may be specified as + * (char *escape_chars, char *replacement) pairs. The list must be terminated + * by a NULL escape_char. Returns replaced string in memory allocated by + * xmalloc which the caller must free. */ -char * -percent_expand(const char *string, ...) +static char * +vdollar_percent_expand(int *parseerror, int dollar, int percent, + const char *string, va_list ap) { #define EXPAND_MAX_KEYS 16 - u_int num_keys, i; + u_int num_keys = 0, i; struct { const char *key; const char *repl; } keys[EXPAND_MAX_KEYS]; struct sshbuf *buf; - va_list ap; - int r; - char *ret; + int r, missingvar = 0; + char *ret = NULL, *var, *varend, *val; + size_t len; if ((buf = sshbuf_new()) == NULL) fatal("%s: sshbuf_new failed", __func__); - - /* Gather keys */ - va_start(ap, string); - for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { - keys[num_keys].key = va_arg(ap, char *); - if (keys[num_keys].key == NULL) - break; - keys[num_keys].repl = va_arg(ap, char *); - if (keys[num_keys].repl == NULL) - fatal("%s: NULL replacement", __func__); + if (parseerror == NULL) + fatal("%s: null parseerror arg", __func__); + *parseerror = 1; + + /* Gather keys if we're doing percent expansion. */ + if (percent) { + for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { + keys[num_keys].key = va_arg(ap, char *); + if (keys[num_keys].key == NULL) + break; + keys[num_keys].repl = va_arg(ap, char *); + if (keys[num_keys].repl == NULL) + fatal("%s: NULL replacement for token %s", __func__, keys[num_keys].key); + } + if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) + fatal("%s: too many keys", __func__); + if (num_keys == 0) + fatal("%s: percent expansion without token list", + __func__); } - if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) - fatal("%s: too many keys", __func__); - va_end(ap); /* Expand string */ for (i = 0; *string != '\0'; string++) { - if (*string != '%') { + /* Optionally process ${ENVIRONMENT} expansions. */ + if (dollar && string[0] == '$' && string[1] == '{') { + string += 2; /* skip over '${' */ + if ((varend = strchr(string, '}')) == NULL) { + error("%s: environment variable '%s' missing " + "closing '}'", __func__, string); + goto out; + } + len = varend - string; + if (len == 0) { + error("%s: zero-length environment variable", + __func__); + goto out; + } + var = xmalloc(len + 1); + (void)strlcpy(var, string, len + 1); + if ((val = getenv(var)) == NULL) { + error("%s: env var ${%s} has no value", + __func__, var); + missingvar = 1; + } else { + debug3("%s: expand ${%s} -> '%s'", __func__, + var, val); + if ((r = sshbuf_put(buf, val, strlen(val))) !=0) + fatal("%s: sshbuf_put: %s", __func__, + ssh_err(r)); + } + free(var); + string += len; + continue; + } + + /* + * Process percent expansions if we have a list of TOKENs. + * If we're not doing percent expansion everything just gets + * appended here. + */ + if (*string != '%' || !percent) { append: if ((r = sshbuf_put_u8(buf, *string)) != 0) { fatal("%s: sshbuf_put_u8: %s", @@ -1099,8 +1144,10 @@ percent_expand(const char *string, ...) /* %% case */ if (*string == '%') goto append; - if (*string == '\0') - fatal("%s: invalid format", __func__); + if (*string == '\0') { + error("%s: invalid format", __func__); + goto out; + } for (i = 0; i < num_keys; i++) { if (strchr(keys[i].key, *string) != NULL) { if ((r = sshbuf_put(buf, keys[i].repl, @@ -1111,16 +1158,72 @@ percent_expand(const char *string, ...) break; } } - if (i >= num_keys) - fatal("%s: unknown key %%%c", __func__, *string); + if (i >= num_keys) { + error("%s: unknown key %%%c", __func__, *string); + goto out; + } } - if ((ret = sshbuf_dup_string(buf)) == NULL) + if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) fatal("%s: sshbuf_dup_string failed", __func__); + *parseerror = 0; + out: sshbuf_free(buf); - return ret; + return *parseerror ? NULL : ret; #undef EXPAND_MAX_KEYS } +char * +dollar_expand(int *parseerr, const char *string) +{ + char *ret; + int err; + va_list ap; + + memset(ap, 0, sizeof(ap)); /* unused */ + ret = vdollar_percent_expand(&err, 1, 0, string, ap); + if (parseerr != NULL) + *parseerr = err; + return ret; +} + +/* + * Returns expanded string or NULL if a specified environment variable is + * not defined, or calls fatal if the string is invalid. + */ +char * +percent_expand(const char *string, ...) +{ + char *ret; + int err; + va_list ap; + + va_start(ap, string); + ret = vdollar_percent_expand(&err, 0, 1, string, ap); + va_end(ap); + if (err) + fatal("%s failed", __func__); + return ret; +} + +/* + * Returns expanded string or NULL if a specified environment variable is + * not defined, or calls fatal if the string is invalid. + */ +char * +percent_dollar_expand(const char *string, ...) +{ + char *ret; + int err; + va_list ap; + + va_start(ap, string); + ret = vdollar_percent_expand(&err, 1, 1, string, ap); + va_end(ap); + if (err) + fatal("%s failed", __func__); + return ret; +} + int tun_open(int tun, int mode, char **ifname) { |