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-rw-r--r--sshhmac.c257
1 files changed, 0 insertions, 257 deletions
diff --git a/sshhmac.c b/sshhmac.c
deleted file mode 100644
index 8f18eb28..00000000
--- a/sshhmac.c
+++ /dev/null
@@ -1,257 +0,0 @@
-/*
- * Implementation of HMAC (RFC 2104) for PuTTY, in a general form that
- * can wrap any underlying hash function.
- */
-
-#include "ssh.h"
-
-struct hmac {
- const ssh_hashalg *hashalg;
- ssh_hash *h_outer, *h_inner, *h_live;
- uint8_t *digest;
- strbuf *text_name;
- ssh2_mac mac;
-};
-
-struct hmac_extra {
- const ssh_hashalg *hashalg_base;
- const char *suffix, *annotation;
-};
-
-static ssh2_mac *hmac_new(const ssh2_macalg *alg, ssh_cipher *cipher)
-{
- struct hmac *ctx = snew(struct hmac);
- const struct hmac_extra *extra = (const struct hmac_extra *)alg->extra;
-
- ctx->h_outer = ssh_hash_new(extra->hashalg_base);
- /* In case that hashalg was a selector vtable, we'll now switch to
- * using whatever real one it selected, for all future purposes. */
- ctx->hashalg = ssh_hash_alg(ctx->h_outer);
- ctx->h_inner = ssh_hash_new(ctx->hashalg);
- ctx->h_live = ssh_hash_new(ctx->hashalg);
-
- /*
- * HMAC is not well defined as a wrapper on an absolutely general
- * hash function; it expects that the function it's wrapping will
- * consume data in fixed-size blocks, and it's partially defined
- * in terms of that block size. So we insist that the hash we're
- * given must have defined a meaningful block size.
- */
- assert(ctx->hashalg->blocklen);
-
- ctx->digest = snewn(ctx->hashalg->hlen, uint8_t);
-
- ctx->text_name = strbuf_new();
- strbuf_catf(ctx->text_name, "HMAC-%s%s",
- ctx->hashalg->text_basename, extra->suffix);
- if (extra->annotation || ctx->hashalg->annotation) {
- strbuf_catf(ctx->text_name, " (");
- const char *sep = "";
- if (extra->annotation) {
- strbuf_catf(ctx->text_name, "%s%s", sep, extra->annotation);
- sep = ", ";
- }
- if (ctx->hashalg->annotation) {
- strbuf_catf(ctx->text_name, "%s%s", sep, ctx->hashalg->annotation);
- sep = ", ";
- }
- strbuf_catf(ctx->text_name, ")");
- }
-
- ctx->mac.vt = alg;
- BinarySink_DELEGATE_INIT(&ctx->mac, ctx->h_live);
-
- return &ctx->mac;
-}
-
-static void hmac_free(ssh2_mac *mac)
-{
- struct hmac *ctx = container_of(mac, struct hmac, mac);
-
- ssh_hash_free(ctx->h_outer);
- ssh_hash_free(ctx->h_inner);
- ssh_hash_free(ctx->h_live);
- smemclr(ctx->digest, ctx->hashalg->hlen);
- sfree(ctx->digest);
- strbuf_free(ctx->text_name);
-
- smemclr(ctx, sizeof(*ctx));
- sfree(ctx);
-}
-
-#define PAD_OUTER 0x5C
-#define PAD_INNER 0x36
-
-static void hmac_key(ssh2_mac *mac, ptrlen key)
-{
- struct hmac *ctx = container_of(mac, struct hmac, mac);
-
- const uint8_t *kp;
- size_t klen;
- strbuf *sb = NULL;
-
- if (key.len > ctx->hashalg->blocklen) {
- /*
- * RFC 2104 section 2: if the key exceeds the block length of
- * the underlying hash, then we start by hashing the key, and
- * use that hash as the 'true' key for the HMAC construction.
- */
- sb = strbuf_new_nm();
- strbuf_append(sb, ctx->hashalg->hlen);
- hash_simple(ctx->hashalg, key, sb->u);
- kp = sb->u;
- klen = sb->len;
- } else {
- /*
- * A short enough key is used as is.
- */
- kp = (const uint8_t *)key.ptr;
- klen = key.len;
- }
-
- ssh_hash_reset(ctx->h_outer);
- for (size_t i = 0; i < klen; i++)
- put_byte(ctx->h_outer, PAD_OUTER ^ kp[i]);
- for (size_t i = klen; i < ctx->hashalg->blocklen; i++)
- put_byte(ctx->h_outer, PAD_OUTER);
-
- ssh_hash_reset(ctx->h_inner);
- for (size_t i = 0; i < klen; i++)
- put_byte(ctx->h_inner, PAD_INNER ^ kp[i]);
- for (size_t i = klen; i < ctx->hashalg->blocklen; i++)
- put_byte(ctx->h_inner, PAD_INNER);
-
- if (sb)
- strbuf_free(sb);
-}
-
-static void hmac_start(ssh2_mac *mac)
-{
- struct hmac *ctx = container_of(mac, struct hmac, mac);
- ssh_hash_copyfrom(ctx->h_live, ctx->h_inner);
-}
-
-static void hmac_genresult(ssh2_mac *mac, unsigned char *output)
-{
- struct hmac *ctx = container_of(mac, struct hmac, mac);
- ssh_hash *htmp;
-
- /* Leave h_live and h_outer in place, so that the SSH-2 BPP can
- * continue regenerating test results from different-length
- * prefixes of the packet */
- ssh_hash_digest_nondestructive(ctx->h_live, ctx->digest);
-
- htmp = ssh_hash_copy(ctx->h_outer);
- put_data(htmp, ctx->digest, ctx->hashalg->hlen);
- ssh_hash_final(htmp, ctx->digest);
-
- /*
- * Some instances of HMAC truncate the output hash, so instead of
- * writing it directly to 'output' we wrote it to our own
- * full-length buffer, and now we copy the required amount.
- */
- memcpy(output, ctx->digest, mac->vt->len);
- smemclr(ctx->digest, ctx->hashalg->hlen);
-}
-
-static const char *hmac_text_name(ssh2_mac *mac)
-{
- struct hmac *ctx = container_of(mac, struct hmac, mac);
- return ctx->text_name->s;
-}
-
-static const struct hmac_extra ssh_hmac_sha256_extra = { &ssh_sha256, "" };
-const ssh2_macalg ssh_hmac_sha256 = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-sha2-256",
- .etm_name = "hmac-sha2-256-etm@openssh.com",
- .len = 32,
- .keylen = 32,
- .extra = &ssh_hmac_sha256_extra,
-};
-
-static const struct hmac_extra ssh_hmac_md5_extra = { &ssh_md5, "" };
-const ssh2_macalg ssh_hmac_md5 = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-md5",
- .etm_name = "hmac-md5-etm@openssh.com",
- .len = 16,
- .keylen = 16,
- .extra = &ssh_hmac_md5_extra,
-};
-
-static const struct hmac_extra ssh_hmac_sha1_extra = { &ssh_sha1, "" };
-
-const ssh2_macalg ssh_hmac_sha1 = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-sha1",
- .etm_name = "hmac-sha1-etm@openssh.com",
- .len = 20,
- .keylen = 20,
- .extra = &ssh_hmac_sha1_extra,
-};
-
-static const struct hmac_extra ssh_hmac_sha1_96_extra = { &ssh_sha1, "-96" };
-
-const ssh2_macalg ssh_hmac_sha1_96 = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-sha1-96",
- .etm_name = "hmac-sha1-96-etm@openssh.com",
- .len = 12,
- .keylen = 20,
- .extra = &ssh_hmac_sha1_96_extra,
-};
-
-static const struct hmac_extra ssh_hmac_sha1_buggy_extra = {
- &ssh_sha1, "", "bug-compatible"
-};
-
-const ssh2_macalg ssh_hmac_sha1_buggy = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-sha1",
- .len = 20,
- .keylen = 16,
- .extra = &ssh_hmac_sha1_buggy_extra,
-};
-
-static const struct hmac_extra ssh_hmac_sha1_96_buggy_extra = {
- &ssh_sha1, "-96", "bug-compatible"
-};
-
-const ssh2_macalg ssh_hmac_sha1_96_buggy = {
- .new = hmac_new,
- .free = hmac_free,
- .setkey = hmac_key,
- .start = hmac_start,
- .genresult = hmac_genresult,
- .text_name = hmac_text_name,
- .name = "hmac-sha1-96",
- .len = 12,
- .keylen = 16,
- .extra = &ssh_hmac_sha1_96_buggy_extra,
-};
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 20:31:43 +0300