/* * Copyright 2025 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include #include #include #include #include #include "internal/encoder.h" #include "prov/ml_kem.h" #include "ml_kem_codecs.h" /* Tables describing supported ASN.1 input/output formats. */ /*- * ML-KEM-512: * Public key bytes: 800 (0x0320) * Private key bytes: 1632 (0x0660) */ static const ML_COMMON_SPKI_FMT ml_kem_512_spkifmt = { { 0x30, 0x82, 0x03, 0x32, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x04, 0x01, 0x03, 0x82, 0x03, 0x21, 0x00, } }; static const ML_COMMON_PKCS8_FMT ml_kem_512_p8fmt[NUM_PKCS8_FORMATS] = { { "seed-priv", 0x06aa, 0, 0x308206a6, 0x0440, 6, 0x40, 0x04820660, 0x4a, 0x0660, 0, 0 }, { "priv-only", 0x0664, 0, 0x04820660, 0, 0, 0, 0, 0x04, 0x0660, 0, 0 }, { "oqskeypair", 0x0984, 0, 0x04820980, 0, 0, 0, 0, 0x04, 0x0660, 0x0664, 0x0320 }, { "seed-only", 0x0042, 2, 0x8040, 0, 2, 0x40, 0, 0, 0, 0, 0 }, { "bare-priv", 0x0660, 4, 0, 0, 0, 0, 0, 0, 0x0660, 0, 0 }, { "bare-seed", 0x0040, 4, 0, 0, 0, 0x40, 0, 0, 0, 0, 0 }, }; /*- * ML-KEM-768: * Public key bytes: 1184 (0x04a0) * Private key bytes: 2400 (0x0960) */ static const ML_COMMON_SPKI_FMT ml_kem_768_spkifmt = { { 0x30, 0x82, 0x04, 0xb2, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x04, 0x02, 0x03, 0x82, 0x04, 0xa1, 0x00, } }; static const ML_COMMON_PKCS8_FMT ml_kem_768_p8fmt[NUM_PKCS8_FORMATS] = { { "seed-priv", 0x09aa, 0, 0x308209a6, 0x0440, 6, 0x40, 0x04820960, 0x4a, 0x0960, 0, 0, }, { "priv-only", 0x0964, 0, 0x04820960, 0, 0, 0, 0, 0x04, 0x0960, 0, 0, }, { "oqskeypair", 0x0e04, 0, 0x04820e00, 0, 0, 0, 0, 0x04, 0x0960, 0x0964, 0x04a0 }, { "seed-only", 0x0042, 2, 0x8040, 0, 2, 0x40, 0, 0, 0, 0, 0, }, { "bare-priv", 0x0960, 4, 0, 0, 0, 0, 0, 0, 0x0960, 0, 0, }, { "bare-seed", 0x0040, 4, 0, 0, 0, 0x40, 0, 0, 0, 0, 0, }, }; /*- * ML-KEM-1024: * Private key bytes: 3168 (0x0c60) * Public key bytes: 1568 (0x0620) */ static const ML_COMMON_SPKI_FMT ml_kem_1024_spkifmt = { { 0x30, 0x82, 0x06, 0x32, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x04, 0x03, 0x03, 0x82, 0x06, 0x21, 0x00, } }; static const ML_COMMON_PKCS8_FMT ml_kem_1024_p8fmt[NUM_PKCS8_FORMATS] = { { "seed-priv", 0x0caa, 0, 0x30820ca6, 0x0440, 6, 0x40, 0x04820c60, 0x4a, 0x0c60, 0, 0 }, { "priv-only", 0x0c64, 0, 0x04820c60, 0, 0, 0, 0, 0x04, 0x0c60, 0, 0 }, { "oqskeypair", 0x1284, 0, 0x04821280, 0, 0, 0, 0, 0x04, 0x0c60, 0x0c64, 0x0620 }, { "seed-only", 0x0042, 2, 0x8040, 0, 2, 0x40, 0, 0, 0, 0, 0 }, { "bare-priv", 0x0c60, 4, 0, 0, 0, 0, 0, 0, 0x0c60, 0, 0 }, { "bare-seed", 0x0040, 4, 0, 0, 0, 0x40, 0, 0, 0, 0, 0 }, }; /* Indices of slots in the `codecs` table below */ #define ML_KEM_512_CODEC 0 #define ML_KEM_768_CODEC 1 #define ML_KEM_1024_CODEC 2 /* * Per-variant fixed parameters */ static const ML_COMMON_CODEC codecs[3] = { { &ml_kem_512_spkifmt, ml_kem_512_p8fmt }, { &ml_kem_768_spkifmt, ml_kem_768_p8fmt }, { &ml_kem_1024_spkifmt, ml_kem_1024_p8fmt } }; /* Retrieve the parameters of one of the ML-KEM variants */ static const ML_COMMON_CODEC *ml_kem_get_codec(int evp_type) { switch (evp_type) { case EVP_PKEY_ML_KEM_512: return &codecs[ML_KEM_512_CODEC]; case EVP_PKEY_ML_KEM_768: return &codecs[ML_KEM_768_CODEC]; case EVP_PKEY_ML_KEM_1024: return &codecs[ML_KEM_1024_CODEC]; } return NULL; } ML_KEM_KEY * ossl_ml_kem_d2i_PUBKEY(const uint8_t *pubenc, int publen, int evp_type, PROV_CTX *provctx, const char *propq) { OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(provctx); const ML_KEM_VINFO *v; const ML_COMMON_CODEC *codec; const ML_COMMON_SPKI_FMT *vspki; ML_KEM_KEY *ret; if ((v = ossl_ml_kem_get_vinfo(evp_type)) == NULL || (codec = ml_kem_get_codec(evp_type)) == NULL) return NULL; vspki = codec->spkifmt; if (publen != ML_COMMON_SPKI_OVERHEAD + (ossl_ssize_t) v->pubkey_bytes || memcmp(pubenc, vspki->asn1_prefix, ML_COMMON_SPKI_OVERHEAD) != 0) return NULL; publen -= ML_COMMON_SPKI_OVERHEAD; pubenc += ML_COMMON_SPKI_OVERHEAD; if ((ret = ossl_ml_kem_key_new(libctx, propq, evp_type)) == NULL) return NULL; if (!ossl_ml_kem_parse_public_key(pubenc, (size_t) publen, ret)) { ERR_raise_data(ERR_LIB_PROV, PROV_R_BAD_ENCODING, "errror parsing %s public key from input SPKI", v->algorithm_name); ossl_ml_kem_key_free(ret); return NULL; } return ret; } ML_KEM_KEY * ossl_ml_kem_d2i_PKCS8(const uint8_t *prvenc, int prvlen, int evp_type, PROV_CTX *provctx, const char *propq) { const ML_KEM_VINFO *v; const ML_COMMON_CODEC *codec; ML_COMMON_PKCS8_FMT_PREF *fmt_slots = NULL, *slot; const ML_COMMON_PKCS8_FMT *p8fmt; ML_KEM_KEY *key = NULL, *ret = NULL; PKCS8_PRIV_KEY_INFO *p8inf = NULL; const uint8_t *buf, *pos; const X509_ALGOR *alg = NULL; const char *formats; int len, ptype; uint32_t magic; uint16_t seed_magic; /* Which ML-KEM variant? */ if ((v = ossl_ml_kem_get_vinfo(evp_type)) == NULL || (codec = ml_kem_get_codec(evp_type)) == NULL) return 0; /* Extract the key OID and any parameters. */ if ((p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &prvenc, prvlen)) == NULL) return 0; /* Shortest prefix is 4 bytes: seq tag/len + octet string tag/len */ if (!PKCS8_pkey_get0(NULL, &buf, &len, &alg, p8inf)) goto end; /* Bail out early if this is some other key type. */ if (OBJ_obj2nid(alg->algorithm) != evp_type) goto end; /* Get the list of enabled decoders. Their order is not important here. */ formats = ossl_prov_ctx_get_param( provctx, OSSL_PKEY_PARAM_ML_KEM_INPUT_FORMATS, NULL); fmt_slots = ossl_ml_common_pkcs8_fmt_order(v->algorithm_name, codec->p8fmt, "input", formats); if (fmt_slots == NULL) goto end; /* Parameters must be absent. */ X509_ALGOR_get0(NULL, &ptype, NULL, alg); if (ptype != V_ASN1_UNDEF) { ERR_raise_data(ERR_LIB_PROV, PROV_R_UNEXPECTED_KEY_PARAMETERS, "unexpected parameters with a PKCS#8 %s private key", v->algorithm_name); goto end; } if ((ossl_ssize_t)len < (ossl_ssize_t)sizeof(magic)) goto end; /* Find the matching p8 info slot, that also has the expected length. */ pos = OPENSSL_load_u32_be(&magic, buf); for (slot = fmt_slots; (p8fmt = slot->fmt) != NULL; ++slot) { if (len != (ossl_ssize_t)p8fmt->p8_bytes) continue; if (p8fmt->p8_shift == sizeof(magic) || (magic >> (p8fmt->p8_shift * 8)) == p8fmt->p8_magic) { pos -= p8fmt->p8_shift; break; } } if (p8fmt == NULL || (p8fmt->seed_length > 0 && p8fmt->seed_length != ML_KEM_SEED_BYTES) || (p8fmt->priv_length > 0 && p8fmt->priv_length != v->prvkey_bytes) || (p8fmt->pub_length > 0 && p8fmt->pub_length != v->pubkey_bytes)) { ERR_raise_data(ERR_LIB_PROV, PROV_R_ML_KEM_NO_FORMAT, "no matching enabled %s private key input formats", v->algorithm_name); goto end; } if (p8fmt->seed_length > 0) { /* Check |seed| tag/len, if not subsumed by |magic|. */ if (pos + sizeof(uint16_t) == buf + p8fmt->seed_offset) { pos = OPENSSL_load_u16_be(&seed_magic, pos); if (seed_magic != p8fmt->seed_magic) goto end; } else if (pos != buf + p8fmt->seed_offset) { goto end; } pos += ML_KEM_SEED_BYTES; } if (p8fmt->priv_length > 0) { /* Check |priv| tag/len */ if (pos + sizeof(uint32_t) == buf + p8fmt->priv_offset) { pos = OPENSSL_load_u32_be(&magic, pos); if (magic != p8fmt->priv_magic) goto end; } else if (pos != buf + p8fmt->priv_offset) { goto end; } pos += v->prvkey_bytes; } if (p8fmt->pub_length > 0) { if (pos != buf + p8fmt->pub_offset) goto end; pos += v->pubkey_bytes; } if (pos != buf + len) goto end; /* * Collect the seed and/or key into a "decoded" private key object, * to be turned into a real key on provider "load" or "import". */ if ((key = ossl_prov_ml_kem_new(provctx, propq, evp_type)) == NULL) goto end; if (p8fmt->seed_length > 0) { if (!ossl_ml_kem_set_seed(buf + p8fmt->seed_offset, ML_KEM_SEED_BYTES, key)) { ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR, "error storing %s private key seed", v->algorithm_name); goto end; } } if (p8fmt->priv_length > 0) { if ((key->encoded_dk = OPENSSL_malloc(p8fmt->priv_length)) == NULL) { ERR_raise_data(ERR_LIB_PROV, PROV_R_INVALID_KEY, "error parsing %s private key", v->algorithm_name); goto end; } memcpy(key->encoded_dk, buf + p8fmt->priv_offset, p8fmt->priv_length); } /* Any OQS public key content is ignored */ ret = key; end: OPENSSL_free(fmt_slots); PKCS8_PRIV_KEY_INFO_free(p8inf); if (ret == NULL) ossl_ml_kem_key_free(key); return ret; } /* Same as ossl_ml_kem_encode_pubkey, but allocates the output buffer. */ int ossl_ml_kem_i2d_pubkey(const ML_KEM_KEY *key, unsigned char **out) { size_t publen; if (!ossl_ml_kem_have_pubkey(key)) { ERR_raise_data(ERR_LIB_PROV, PROV_R_NOT_A_PUBLIC_KEY, "no %s public key data available", key->vinfo->algorithm_name); return 0; } publen = key->vinfo->pubkey_bytes; if (out != NULL && (*out = OPENSSL_malloc(publen)) == NULL) return 0; if (!ossl_ml_kem_encode_public_key(*out, publen, key)) { ERR_raise_data(ERR_LIB_OSSL_ENCODER, ERR_R_INTERNAL_ERROR, "error encoding %s public key", key->vinfo->algorithm_name); OPENSSL_free(*out); return 0; } return (int)publen; } /* Allocate and encode PKCS#8 private key payload. */ int ossl_ml_kem_i2d_prvkey(const ML_KEM_KEY *key, uint8_t **out, PROV_CTX *provctx) { const ML_KEM_VINFO *v = key->vinfo; const ML_COMMON_CODEC *codec; ML_COMMON_PKCS8_FMT_PREF *fmt_slots, *slot; const ML_COMMON_PKCS8_FMT *p8fmt; uint8_t *buf = NULL, *pos; const char *formats; int len = ML_KEM_SEED_BYTES; int ret = 0; /* Not ours to handle */ if ((codec = ml_kem_get_codec(v->evp_type)) == NULL) return 0; if (!ossl_ml_kem_have_prvkey(key)) { ERR_raise_data(ERR_LIB_PROV, PROV_R_NOT_A_PRIVATE_KEY, "no %s private key data available", key->vinfo->algorithm_name); return 0; } formats = ossl_prov_ctx_get_param( provctx, OSSL_PKEY_PARAM_ML_KEM_OUTPUT_FORMATS, NULL); fmt_slots = ossl_ml_common_pkcs8_fmt_order(v->algorithm_name, codec->p8fmt, "output", formats); if (fmt_slots == NULL) return 0; /* If we don't have a seed, skip seedful entries */ for (slot = fmt_slots; (p8fmt = slot->fmt) != NULL; ++slot) if (ossl_ml_kem_have_seed(key) || p8fmt->seed_length == 0) break; /* No matching table entries, give up */ if (p8fmt == NULL || (p8fmt->seed_length > 0 && p8fmt->seed_length != ML_KEM_SEED_BYTES) || (p8fmt->priv_length > 0 && p8fmt->priv_length != v->prvkey_bytes) || (p8fmt->pub_length > 0 && p8fmt->pub_length != v->pubkey_bytes)) { ERR_raise_data(ERR_LIB_PROV, PROV_R_ML_KEM_NO_FORMAT, "no matching enabled %s private key output formats", v->algorithm_name); goto end; } len = p8fmt->p8_bytes; if (out == NULL) { ret = len; goto end; } if ((pos = buf = OPENSSL_malloc((size_t) len)) == NULL) goto end; switch (p8fmt->p8_shift) { case 0: pos = OPENSSL_store_u32_be(pos, p8fmt->p8_magic); break; case 2: pos = OPENSSL_store_u16_be(pos, (uint16_t)p8fmt->p8_magic); break; case 4: break; default: ERR_raise_data(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR, "error encoding %s private key", v->algorithm_name); goto end; } if (p8fmt->seed_length != 0) { /* * Either the tag/len were already included in |magic| or they require * us to write two bytes now. */ if (pos + sizeof(uint16_t) == buf + p8fmt->seed_offset) pos = OPENSSL_store_u16_be(pos, p8fmt->seed_magic); if (pos != buf + p8fmt->seed_offset || !ossl_ml_kem_encode_seed(pos, ML_KEM_SEED_BYTES, key)) { ERR_raise_data(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR, "error encoding %s private key", v->algorithm_name); goto end; } pos += ML_KEM_SEED_BYTES; } if (p8fmt->priv_length != 0) { if (pos + sizeof(uint32_t) == buf + p8fmt->priv_offset) pos = OPENSSL_store_u32_be(pos, p8fmt->priv_magic); if (pos != buf + p8fmt->priv_offset || !ossl_ml_kem_encode_private_key(pos, v->prvkey_bytes, key)) { ERR_raise_data(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR, "error encoding %s private key", v->algorithm_name); goto end; } pos += v->prvkey_bytes; } /* OQS form output with tacked-on public key */ if (p8fmt->pub_length != 0) { /* The OQS pubkey is never separately DER-wrapped */ if (pos != buf + p8fmt->pub_offset || !ossl_ml_kem_encode_public_key(pos, v->pubkey_bytes, key)) { ERR_raise_data(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR, "error encoding %s private key", v->algorithm_name); goto end; } pos += v->pubkey_bytes; } if (pos == buf + len) { *out = buf; ret = len; } end: OPENSSL_free(fmt_slots); if (ret == 0) OPENSSL_free(buf); return ret; } int ossl_ml_kem_key_to_text(BIO *out, const ML_KEM_KEY *key, int selection) { uint8_t seed[ML_KEM_SEED_BYTES], *prvenc = NULL, *pubenc = NULL; size_t publen, prvlen; const char *type_label = NULL; int ret = 0; if (out == NULL || key == NULL) { ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER); return 0; } type_label = key->vinfo->algorithm_name; publen = key->vinfo->pubkey_bytes; prvlen = key->vinfo->prvkey_bytes; if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0 && (ossl_ml_kem_have_prvkey(key) || ossl_ml_kem_have_seed(key))) { if (BIO_printf(out, "%s Private-Key:\n", type_label) <= 0) return 0; if (ossl_ml_kem_have_seed(key)) { if (!ossl_ml_kem_encode_seed(seed, sizeof(seed), key)) goto end; if (!ossl_bio_print_labeled_buf(out, "seed:", seed, sizeof(seed))) goto end; } if (ossl_ml_kem_have_prvkey(key)) { if ((prvenc = OPENSSL_malloc(prvlen)) == NULL) return 0; if (!ossl_ml_kem_encode_private_key(prvenc, prvlen, key)) goto end; if (!ossl_bio_print_labeled_buf(out, "dk:", prvenc, prvlen)) goto end; } ret = 1; } /* The public key is output regardless of the selection */ if (ossl_ml_kem_have_pubkey(key)) { /* If we did not output private key bits, this is a public key */ if (ret == 0 && BIO_printf(out, "%s Public-Key:\n", type_label) <= 0) goto end; if ((pubenc = OPENSSL_malloc(key->vinfo->pubkey_bytes)) == NULL || !ossl_ml_kem_encode_public_key(pubenc, publen, key) || !ossl_bio_print_labeled_buf(out, "ek:", pubenc, publen)) goto end; ret = 1; } /* If we got here, and ret == 0, there was no key material */ if (ret == 0) ERR_raise_data(ERR_LIB_PROV, PROV_R_MISSING_KEY, "no %s key material available", type_label); end: OPENSSL_free(pubenc); OPENSSL_free(prvenc); return ret; }