Linus Nordberg
2021-Dec-22 08:23 UTC
[PATCH 0/4] ssh-keygen: add signing option -O hashalg=algorithm
This patch series adds -O hashalg=algorithm to -Y sign, defaulting to "sha512". This is useful for interoperability with tooling that use SHA-256 for hashing the message to be signed. Linus Nordberg (4): move sig_process_opts() up so we can call it from sig_sign() add signing option -O hashalg=algorithm add -O to help printout for -Y verify whitespace changes ssh-keygen.1 | 4 ++ ssh-keygen.c | 110 +++++++++++++++++++++++++++++---------------------- 2 files changed, 66 insertions(+), 48 deletions(-) -- 2.30.2
Linus Nordberg
2021-Dec-22 08:23 UTC
[PATCH 1/4] move sig_process_opts() up so we can call it from sig_sign()
--- ssh-keygen.c | 74 ++++++++++++++++++++++++++-------------------------- 1 file changed, 37 insertions(+), 37 deletions(-) diff --git a/ssh-keygen.c b/ssh-keygen.c index ed8d3b9c..d31dc503 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -2602,6 +2602,43 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, return r; } +static int +sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, + int *print_pubkey) +{ + size_t i; + time_t now; + + if (verify_timep != NULL) + *verify_timep = 0; + if (print_pubkey != NULL) + *print_pubkey = 0; + for (i = 0; i < nopts; i++) { + if (verify_timep && + strncasecmp(opts[i], "verify-time=", 12) == 0) { + if (parse_absolute_time(opts[i] + 12, + verify_timep) != 0 || *verify_timep == 0) { + error("Invalid \"verify-time\" option"); + return SSH_ERR_INVALID_ARGUMENT; + } + } else if (print_pubkey && + strcasecmp(opts[i], "print-pubkey") == 0) { + *print_pubkey = 1; + } else { + error("Invalid option \"%s\"", opts[i]); + return SSH_ERR_INVALID_ARGUMENT; + } + } + if (verify_timep && *verify_timep == 0) { + if ((now = time(NULL)) < 0) { + error("Time is before epoch"); + return SSH_ERR_INVALID_ARGUMENT; + } + *verify_timep = (uint64_t)now; + } + return 0; +} + static int sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) { @@ -2673,43 +2710,6 @@ done: return ret; } -static int -sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, - int *print_pubkey) -{ - size_t i; - time_t now; - - if (verify_timep != NULL) - *verify_timep = 0; - if (print_pubkey != NULL) - *print_pubkey = 0; - for (i = 0; i < nopts; i++) { - if (verify_timep && - strncasecmp(opts[i], "verify-time=", 12) == 0) { - if (parse_absolute_time(opts[i] + 12, - verify_timep) != 0 || *verify_timep == 0) { - error("Invalid \"verify-time\" option"); - return SSH_ERR_INVALID_ARGUMENT; - } - } else if (print_pubkey && - strcasecmp(opts[i], "print-pubkey") == 0) { - *print_pubkey = 1; - } else { - error("Invalid option \"%s\"", opts[i]); - return SSH_ERR_INVALID_ARGUMENT; - } - } - if (verify_timep && *verify_timep == 0) { - if ((now = time(NULL)) < 0) { - error("Time is before epoch"); - return SSH_ERR_INVALID_ARGUMENT; - } - *verify_timep = (uint64_t)now; - } - return 0; -} - static int sig_verify(const char *signature, const char *sig_namespace, const char *principal, const char *allowed_keys, const char *revoked_keys, -- 2.30.2
--- ssh-keygen.1 | 4 ++++ ssh-keygen.c | 36 ++++++++++++++++++++++++------------ 2 files changed, 28 insertions(+), 12 deletions(-) diff --git a/ssh-keygen.1 b/ssh-keygen.1 index 58b1f682..f0f211c4 100644 --- a/ssh-keygen.1 +++ b/ssh-keygen.1 @@ -161,6 +161,7 @@ .Fl s Ar signature_file .Nm ssh-keygen .Fl Y Cm sign +.Op Fl O Ar option .Fl f Ar key_file .Fl n Ar namespace .Ar @@ -541,6 +542,9 @@ When performing signature-related options using the .Fl Y flag, the following options are accepted: .Bl -tag -width Ds +.It Cm hashalg Ns = Ns Ar algorithm +Selects the hash algorithm to use for hashing the message to be signed. +Valid algorithms are sha256 and sha512. The default is sha512. .It Cm print-pubkey Print the full public key to standard output after signature verification. .It Cm verify-time Ns = Ns Ar timestamp diff --git a/ssh-keygen.c b/ssh-keygen.c index d31dc503..ef99b9b6 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -142,6 +142,9 @@ struct cert_ext { static struct cert_ext *cert_ext; static size_t ncert_ext; +/* Default hash algorithm for -Y sign and verify. */ +#define DEFAULT_SIGN_HASHALG_NAME "sha512" + /* Conversion to/from various formats */ enum { FMT_RFC4716, @@ -2512,7 +2515,7 @@ load_sign_key(const char *keypath, const struct sshkey *pubkey) static int sign_one(struct sshkey *signkey, const char *filename, int fd, - const char *sig_namespace, sshsig_signer *signer, void *signer_ctx) + const char *sig_namespace, const char *hashalg, sshsig_signer *signer, void *signer_ctx) { struct sshbuf *sigbuf = NULL, *abuf = NULL; int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno; @@ -2542,7 +2545,7 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, free(fp); } } - if ((r = sshsig_sign_fd(signkey, NULL, sk_provider, pin, + if ((r = sshsig_sign_fd(signkey, hashalg, sk_provider, pin, fd, sig_namespace, &sigbuf, signer, signer_ctx)) != 0) { error_r(r, "Signing %s failed", filename); goto out; @@ -2603,18 +2606,23 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, } static int -sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, +sig_process_opts(char * const *opts, size_t nopts, char *hashalg, size_t hashalg_size, uint64_t *verify_timep, int *print_pubkey) { size_t i; time_t now; + if (hashalg != NULL) + strlcpy(hashalg, DEFAULT_SIGN_HASHALG_NAME, hashalg_size); if (verify_timep != NULL) *verify_timep = 0; if (print_pubkey != NULL) *print_pubkey = 0; for (i = 0; i < nopts; i++) { - if (verify_timep && + if (hashalg && + strncasecmp(opts[i], "hashalg=", 8) == 0) { + strlcpy(hashalg, opts[i] + 8, hashalg_size); + } else if (verify_timep && strncasecmp(opts[i], "verify-time=", 12) == 0) { if (parse_absolute_time(opts[i] + 12, verify_timep) != 0 || *verify_timep == 0) { @@ -2640,12 +2648,13 @@ sig_process_opts(char * const *opts, size_t nopts, uint64_t *verify_timep, } static int -sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) +sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv, char * const *opts, size_t nopts) { int i, fd = -1, r, ret = -1; int agent_fd = -1; struct sshkey *pubkey = NULL, *privkey = NULL, *signkey = NULL; sshsig_signer *signer = NULL; + char hashalg[7]; /* "shaXXX" */ /* Check file arguments. */ for (i = 0; i < argc; i++) { @@ -2655,6 +2664,9 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) fatal("Cannot sign mix of paths and standard input"); } + if (sig_process_opts(opts, nopts, hashalg, sizeof(hashalg), NULL, NULL) != 0) + goto done; /* error already logged */ + if ((r = sshkey_load_public(keypath, &pubkey, NULL)) != 0) { error_r(r, "Couldn't load public key %s", keypath); goto done; @@ -2681,7 +2693,7 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) if (argc == 0) { if ((r = sign_one(signkey, "(stdin)", STDIN_FILENO, - sig_namespace, signer, &agent_fd)) != 0) + sig_namespace, hashalg, signer, &agent_fd)) != 0) goto done; } else { for (i = 0; i < argc; i++) { @@ -2693,7 +2705,7 @@ sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv) goto done; } if ((r = sign_one(signkey, argv[i], fd, sig_namespace, - signer, &agent_fd)) != 0) + hashalg, signer, &agent_fd)) != 0) goto done; if (fd != STDIN_FILENO) close(fd); @@ -2723,7 +2735,7 @@ sig_verify(const char *signature, const char *sig_namespace, struct sshkey_sig_details *sig_details = NULL; uint64_t verify_time = 0; - if (sig_process_opts(opts, nopts, &verify_time, &print_pubkey) != 0) + if (sig_process_opts(opts, nopts, NULL, 0, &verify_time, &print_pubkey) != 0) goto done; /* error already logged */ memset(&sig_details, 0, sizeof(sig_details)); @@ -2811,7 +2823,7 @@ sig_find_principals(const char *signature, const char *allowed_keys, char *principals = NULL, *cp, *tmp; uint64_t verify_time = 0; - if (sig_process_opts(opts, nopts, &verify_time, NULL) != 0) + if (sig_process_opts(opts, nopts, NULL, 0, &verify_time, NULL) != 0) goto done; /* error already logged */ if ((r = sshbuf_load_file(signature, &abuf)) != 0) { @@ -2857,7 +2869,7 @@ sig_match_principals(const char *allowed_keys, char *principal, char **principals = NULL; size_t i, nprincipals = 0; - if ((r = sig_process_opts(opts, nopts, NULL, NULL)) != 0) + if ((r = sig_process_opts(opts, nopts, NULL, 0, NULL, NULL)) != 0) return r; /* error already logged */ if ((r = sshsig_match_principals(allowed_keys, principal, @@ -3215,7 +3227,7 @@ usage(void) " ssh-keygen -Y find-principals -s signature_file -f allowed_signers_file\n" " ssh-keygen -Y match-principals -I signer_identity -f allowed_signers_file\n" " ssh-keygen -Y check-novalidate -n namespace -s signature_file\n" - " ssh-keygen -Y sign -f key_file -n namespace file ...\n" + " ssh-keygen -Y sign -f key_file -n namespace file [-O option] ...\n" " ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n" " -n namespace -s signature_file [-r revocation_file]\n"); exit(1); @@ -3521,7 +3533,7 @@ main(int argc, char **argv) exit(1); } return sig_sign(identity_file, cert_principals, - argc, argv); + argc, argv, opts, nopts); } else if (strncmp(sign_op, "check-novalidate", 16) == 0) { if (ca_key_path == NULL) { error("Too few arguments for check-novalidate: " -- 2.30.2
--- ssh-keygen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ssh-keygen.c b/ssh-keygen.c index ef99b9b6..3a57925e 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -3229,7 +3229,7 @@ usage(void) " ssh-keygen -Y check-novalidate -n namespace -s signature_file\n" " ssh-keygen -Y sign -f key_file -n namespace file [-O option] ...\n" " ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n" - " -n namespace -s signature_file [-r revocation_file]\n"); + " -n namespace -s signature_file [-r revocation_file] [-O option]\n"); exit(1); } -- 2.30.2
Break (most) long lines. --- ssh-keygen.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/ssh-keygen.c b/ssh-keygen.c index 3a57925e..1f79f27c 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -2515,7 +2515,8 @@ load_sign_key(const char *keypath, const struct sshkey *pubkey) static int sign_one(struct sshkey *signkey, const char *filename, int fd, - const char *sig_namespace, const char *hashalg, sshsig_signer *signer, void *signer_ctx) + const char *sig_namespace, const char *hashalg, sshsig_signer *signer, + void *signer_ctx) { struct sshbuf *sigbuf = NULL, *abuf = NULL; int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno; @@ -2606,8 +2607,8 @@ sign_one(struct sshkey *signkey, const char *filename, int fd, } static int -sig_process_opts(char * const *opts, size_t nopts, char *hashalg, size_t hashalg_size, uint64_t *verify_timep, - int *print_pubkey) +sig_process_opts(char * const *opts, size_t nopts, char *hashalg, + size_t hashalg_size, uint64_t *verify_timep, int *print_pubkey) { size_t i; time_t now; @@ -2648,7 +2649,8 @@ sig_process_opts(char * const *opts, size_t nopts, char *hashalg, size_t hashalg } static int -sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv, char * const *opts, size_t nopts) +sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv, + char * const *opts, size_t nopts) { int i, fd = -1, r, ret = -1; int agent_fd = -1; -- 2.30.2
Damien Miller
2022-Jan-05 05:06 UTC
[PATCH 0/4] ssh-keygen: add signing option -O hashalg=algorithm
On Wed, 22 Dec 2021, Linus Nordberg wrote:> This patch series adds -O hashalg=algorithm to -Y sign, defaulting to > "sha512". This is useful for interoperability with tooling that use > SHA-256 for hashing the message to be signed. > > Linus Nordberg (4): > move sig_process_opts() up so we can call it from sig_sign() > add signing option -O hashalg=algorithm > add -O to help printout for -Y verify > whitespace changesHi Linus, These have all been committed (w/ some tweaks) and regress/sshsig.sh adjusted to test both available hash algorithms. Thanks! -d