diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ecp.c')
| -rw-r--r-- | thirdparty/mbedtls/library/ecp.c | 1380 |
1 files changed, 718 insertions, 662 deletions
diff --git a/thirdparty/mbedtls/library/ecp.c b/thirdparty/mbedtls/library/ecp.c index 31a6b9e305..427059bb53 100644 --- a/thirdparty/mbedtls/library/ecp.c +++ b/thirdparty/mbedtls/library/ecp.c @@ -60,187 +60,35 @@ #if defined(MBEDTLS_ECP_INTERNAL_ALT) #endif -#if defined(MBEDTLS_ECP_C) +#if defined(MBEDTLS_ECP_LIGHT) #include "mbedtls/ecp.h" #include "mbedtls/threading.h" #include "mbedtls/platform_util.h" #include "mbedtls/error.h" -#include "mbedtls/bn_mul.h" +#include "bn_mul.h" #include "ecp_invasive.h" #include <string.h> #if !defined(MBEDTLS_ECP_ALT) -/* Parameter validation macros based on platform_util.h */ -#define ECP_VALIDATE_RET(cond) \ - MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA) -#define ECP_VALIDATE(cond) \ - MBEDTLS_INTERNAL_VALIDATE(cond) - #include "mbedtls/platform.h" -#include "mbedtls/ecp_internal.h" - -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) -#if defined(MBEDTLS_HMAC_DRBG_C) -#include "mbedtls/hmac_drbg.h" -#elif defined(MBEDTLS_CTR_DRBG_C) -#include "mbedtls/ctr_drbg.h" -#else -#error \ - "Invalid configuration detected. Include check_config.h to ensure that the configuration is valid." -#endif -#endif /* MBEDTLS_ECP_NO_INTERNAL_RNG */ +#include "ecp_internal_alt.h" #if defined(MBEDTLS_SELF_TEST) /* * Counts of point addition and doubling, and field multiplications. * Used to test resistance of point multiplication to simple timing attacks. */ -static unsigned long add_count, dbl_count, mul_count; +#if defined(MBEDTLS_ECP_C) +static unsigned long add_count, dbl_count; +#endif /* MBEDTLS_ECP_C */ +static unsigned long mul_count; #endif -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) -/* - * Currently ecp_mul() takes a RNG function as an argument, used for - * side-channel protection, but it can be NULL. The initial reasoning was - * that people will pass non-NULL RNG when they care about side-channels, but - * unfortunately we have some APIs that call ecp_mul() with a NULL RNG, with - * no opportunity for the user to do anything about it. - * - * The obvious strategies for addressing that include: - * - change those APIs so that they take RNG arguments; - * - require a global RNG to be available to all crypto modules. - * - * Unfortunately those would break compatibility. So what we do instead is - * have our own internal DRBG instance, seeded from the secret scalar. - * - * The following is a light-weight abstraction layer for doing that with - * HMAC_DRBG (first choice) or CTR_DRBG. - */ - -#if defined(MBEDTLS_HMAC_DRBG_C) - -/* DRBG context type */ -typedef mbedtls_hmac_drbg_context ecp_drbg_context; - -/* DRBG context init */ -static inline void ecp_drbg_init(ecp_drbg_context *ctx) -{ - mbedtls_hmac_drbg_init(ctx); -} - -/* DRBG context free */ -static inline void ecp_drbg_free(ecp_drbg_context *ctx) -{ - mbedtls_hmac_drbg_free(ctx); -} - -/* DRBG function */ -static inline int ecp_drbg_random(void *p_rng, - unsigned char *output, size_t output_len) -{ - return mbedtls_hmac_drbg_random(p_rng, output, output_len); -} - -/* DRBG context seeding */ -static int ecp_drbg_seed(ecp_drbg_context *ctx, - const mbedtls_mpi *secret, size_t secret_len) -{ - int ret; - unsigned char secret_bytes[MBEDTLS_ECP_MAX_BYTES]; - /* The list starts with strong hashes */ - const mbedtls_md_type_t md_type = - (mbedtls_md_type_t) (mbedtls_md_list()[0]); - const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(md_type); - - if (secret_len > MBEDTLS_ECP_MAX_BYTES) { - ret = MBEDTLS_ERR_ECP_RANDOM_FAILED; - goto cleanup; - } - - MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(secret, - secret_bytes, secret_len)); - - ret = mbedtls_hmac_drbg_seed_buf(ctx, md_info, secret_bytes, secret_len); - -cleanup: - mbedtls_platform_zeroize(secret_bytes, secret_len); - - return ret; -} - -#elif defined(MBEDTLS_CTR_DRBG_C) - -/* DRBG context type */ -typedef mbedtls_ctr_drbg_context ecp_drbg_context; - -/* DRBG context init */ -static inline void ecp_drbg_init(ecp_drbg_context *ctx) -{ - mbedtls_ctr_drbg_init(ctx); -} - -/* DRBG context free */ -static inline void ecp_drbg_free(ecp_drbg_context *ctx) -{ - mbedtls_ctr_drbg_free(ctx); -} - -/* DRBG function */ -static inline int ecp_drbg_random(void *p_rng, - unsigned char *output, size_t output_len) -{ - return mbedtls_ctr_drbg_random(p_rng, output, output_len); -} - -/* - * Since CTR_DRBG doesn't have a seed_buf() function the way HMAC_DRBG does, - * we need to pass an entropy function when seeding. So we use a dummy - * function for that, and pass the actual entropy as customisation string. - * (During seeding of CTR_DRBG the entropy input and customisation string are - * concatenated before being used to update the secret state.) - */ -static int ecp_ctr_drbg_null_entropy(void *ctx, unsigned char *out, size_t len) -{ - (void) ctx; - memset(out, 0, len); - return 0; -} - -/* DRBG context seeding */ -static int ecp_drbg_seed(ecp_drbg_context *ctx, - const mbedtls_mpi *secret, size_t secret_len) -{ - int ret; - unsigned char secret_bytes[MBEDTLS_ECP_MAX_BYTES]; - - if (secret_len > MBEDTLS_ECP_MAX_BYTES) { - ret = MBEDTLS_ERR_ECP_RANDOM_FAILED; - goto cleanup; - } - - MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(secret, - secret_bytes, secret_len)); - - ret = mbedtls_ctr_drbg_seed(ctx, ecp_ctr_drbg_null_entropy, NULL, - secret_bytes, secret_len); - -cleanup: - mbedtls_platform_zeroize(secret_bytes, secret_len); - - return ret; -} - -#else -#error \ - "Invalid configuration detected. Include check_config.h to ensure that the configuration is valid." -#endif /* DRBG modules */ -#endif /* MBEDTLS_ECP_NO_INTERNAL_RNG */ - #if defined(MBEDTLS_ECP_RESTARTABLE) /* * Maximum number of "basic operations" to be done in a row. @@ -287,10 +135,6 @@ struct mbedtls_ecp_restart_mul { ecp_rsm_comb_core, /* ecp_mul_comb_core() */ ecp_rsm_final_norm, /* do the final normalization */ } state; -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_context drbg_ctx; - unsigned char drbg_seeded; -#endif }; /* @@ -303,10 +147,6 @@ static void ecp_restart_rsm_init(mbedtls_ecp_restart_mul_ctx *ctx) ctx->T = NULL; ctx->T_size = 0; ctx->state = ecp_rsm_init; -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_init(&ctx->drbg_ctx); - ctx->drbg_seeded = 0; -#endif } /* @@ -329,10 +169,6 @@ static void ecp_restart_rsm_free(mbedtls_ecp_restart_mul_ctx *ctx) mbedtls_free(ctx->T); } -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_free(&ctx->drbg_ctx); -#endif - ecp_restart_rsm_init(ctx); } @@ -380,7 +216,6 @@ static void ecp_restart_ma_free(mbedtls_ecp_restart_muladd_ctx *ctx) */ void mbedtls_ecp_restart_init(mbedtls_ecp_restart_ctx *ctx) { - ECP_VALIDATE(ctx != NULL); ctx->ops_done = 0; ctx->depth = 0; ctx->rsm = NULL; @@ -412,8 +247,6 @@ int mbedtls_ecp_check_budget(const mbedtls_ecp_group *grp, mbedtls_ecp_restart_ctx *rs_ctx, unsigned ops) { - ECP_VALIDATE_RET(grp != NULL); - if (rs_ctx != NULL && ecp_max_ops != 0) { /* scale depending on curve size: the chosen reference is 256-bit, * and multiplication is quadratic. Round to the closest integer. */ @@ -480,6 +313,22 @@ int mbedtls_ecp_check_budget(const mbedtls_ecp_group *grp, #endif /* MBEDTLS_ECP_RESTARTABLE */ +#if defined(MBEDTLS_ECP_C) +static void mpi_init_many(mbedtls_mpi *arr, size_t size) +{ + while (size--) { + mbedtls_mpi_init(arr++); + } +} + +static void mpi_free_many(mbedtls_mpi *arr, size_t size) +{ + while (size--) { + mbedtls_mpi_free(arr++); + } +} +#endif /* MBEDTLS_ECP_C */ + /* * List of supported curves: * - internal ID @@ -488,9 +337,9 @@ int mbedtls_ecp_check_budget(const mbedtls_ecp_group *grp, * - readable name * * Curves are listed in order: largest curves first, and for a given size, - * fastest curves first. This provides the default order for the SSL module. + * fastest curves first. * - * Reminder: update profiles in x509_crt.c when adding a new curves! + * Reminder: update profiles in x509_crt.c and ssl_tls.c when adding a new curve! */ static const mbedtls_ecp_curve_info ecp_supported_curves[] = { @@ -652,8 +501,6 @@ mbedtls_ecp_curve_type mbedtls_ecp_get_type(const mbedtls_ecp_group *grp) */ void mbedtls_ecp_point_init(mbedtls_ecp_point *pt) { - ECP_VALIDATE(pt != NULL); - mbedtls_mpi_init(&pt->X); mbedtls_mpi_init(&pt->Y); mbedtls_mpi_init(&pt->Z); @@ -664,8 +511,6 @@ void mbedtls_ecp_point_init(mbedtls_ecp_point *pt) */ void mbedtls_ecp_group_init(mbedtls_ecp_group *grp) { - ECP_VALIDATE(grp != NULL); - grp->id = MBEDTLS_ECP_DP_NONE; mbedtls_mpi_init(&grp->P); mbedtls_mpi_init(&grp->A); @@ -688,8 +533,6 @@ void mbedtls_ecp_group_init(mbedtls_ecp_group *grp) */ void mbedtls_ecp_keypair_init(mbedtls_ecp_keypair *key) { - ECP_VALIDATE(key != NULL); - mbedtls_ecp_group_init(&key->grp); mbedtls_mpi_init(&key->d); mbedtls_ecp_point_init(&key->Q); @@ -710,6 +553,19 @@ void mbedtls_ecp_point_free(mbedtls_ecp_point *pt) } /* + * Check that the comb table (grp->T) is static initialized. + */ +static int ecp_group_is_static_comb_table(const mbedtls_ecp_group *grp) +{ +#if MBEDTLS_ECP_FIXED_POINT_OPTIM == 1 + return grp->T != NULL && grp->T_size == 0; +#else + (void) grp; + return 0; +#endif +} + +/* * Unallocate (the components of) a group */ void mbedtls_ecp_group_free(mbedtls_ecp_group *grp) @@ -721,14 +577,17 @@ void mbedtls_ecp_group_free(mbedtls_ecp_group *grp) } if (grp->h != 1) { - mbedtls_mpi_free(&grp->P); mbedtls_mpi_free(&grp->A); mbedtls_mpi_free(&grp->B); mbedtls_ecp_point_free(&grp->G); + +#if !defined(MBEDTLS_ECP_WITH_MPI_UINT) mbedtls_mpi_free(&grp->N); + mbedtls_mpi_free(&grp->P); +#endif } - if (grp->T != NULL) { + if (!ecp_group_is_static_comb_table(grp) && grp->T != NULL) { for (i = 0; i < grp->T_size; i++) { mbedtls_ecp_point_free(&grp->T[i]); } @@ -758,9 +617,6 @@ void mbedtls_ecp_keypair_free(mbedtls_ecp_keypair *key) int mbedtls_ecp_copy(mbedtls_ecp_point *P, const mbedtls_ecp_point *Q) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(Q != NULL); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&P->X, &Q->X)); MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&P->Y, &Q->Y)); MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&P->Z, &Q->Z)); @@ -774,9 +630,6 @@ cleanup: */ int mbedtls_ecp_group_copy(mbedtls_ecp_group *dst, const mbedtls_ecp_group *src) { - ECP_VALIDATE_RET(dst != NULL); - ECP_VALIDATE_RET(src != NULL); - return mbedtls_ecp_group_load(dst, src->id); } @@ -786,8 +639,6 @@ int mbedtls_ecp_group_copy(mbedtls_ecp_group *dst, const mbedtls_ecp_group *src) int mbedtls_ecp_set_zero(mbedtls_ecp_point *pt) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(pt != NULL); - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&pt->X, 1)); MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&pt->Y, 1)); MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&pt->Z, 0)); @@ -801,8 +652,6 @@ cleanup: */ int mbedtls_ecp_is_zero(mbedtls_ecp_point *pt) { - ECP_VALIDATE_RET(pt != NULL); - return mbedtls_mpi_cmp_int(&pt->Z, 0) == 0; } @@ -812,9 +661,6 @@ int mbedtls_ecp_is_zero(mbedtls_ecp_point *pt) int mbedtls_ecp_point_cmp(const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q) { - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(Q != NULL); - if (mbedtls_mpi_cmp_mpi(&P->X, &Q->X) == 0 && mbedtls_mpi_cmp_mpi(&P->Y, &Q->Y) == 0 && mbedtls_mpi_cmp_mpi(&P->Z, &Q->Z) == 0) { @@ -831,10 +677,6 @@ int mbedtls_ecp_point_read_string(mbedtls_ecp_point *P, int radix, const char *x, const char *y) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(x != NULL); - ECP_VALIDATE_RET(y != NULL); - MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&P->X, radix, x)); MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&P->Y, radix, y)); MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&P->Z, 1)); @@ -853,12 +695,10 @@ int mbedtls_ecp_point_write_binary(const mbedtls_ecp_group *grp, { int ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; size_t plen; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(olen != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(format == MBEDTLS_ECP_PF_UNCOMPRESSED || - format == MBEDTLS_ECP_PF_COMPRESSED); + if (format != MBEDTLS_ECP_PF_UNCOMPRESSED && + format != MBEDTLS_ECP_PF_COMPRESSED) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } plen = mbedtls_mpi_size(&grp->P); @@ -916,6 +756,13 @@ cleanup: return ret; } +#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) +static int mbedtls_ecp_sw_derive_y(const mbedtls_ecp_group *grp, + const mbedtls_mpi *X, + mbedtls_mpi *Y, + int parity_bit); +#endif /* MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */ + /* * Import a point from unsigned binary data (SEC1 2.3.4 and RFC7748) */ @@ -925,10 +772,6 @@ int mbedtls_ecp_point_read_binary(const mbedtls_ecp_group *grp, { int ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; size_t plen; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(pt != NULL); - ECP_VALIDATE_RET(buf != NULL); - if (ilen < 1) { return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } @@ -962,18 +805,29 @@ int mbedtls_ecp_point_read_binary(const mbedtls_ecp_group *grp, } } - if (buf[0] != 0x04) { - return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; - } - - if (ilen != 2 * plen + 1) { + if (ilen < 1 + plen) { return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&pt->X, buf + 1, plen)); - MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&pt->Y, - buf + 1 + plen, plen)); MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&pt->Z, 1)); + + if (buf[0] == 0x04) { + /* format == MBEDTLS_ECP_PF_UNCOMPRESSED */ + if (ilen != 1 + plen * 2) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + return mbedtls_mpi_read_binary(&pt->Y, buf + 1 + plen, plen); + } else if (buf[0] == 0x02 || buf[0] == 0x03) { + /* format == MBEDTLS_ECP_PF_COMPRESSED */ + if (ilen != 1 + plen) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + return mbedtls_ecp_sw_derive_y(grp, &pt->X, &pt->Y, + (buf[0] & 1)); + } else { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } } #endif @@ -993,11 +847,6 @@ int mbedtls_ecp_tls_read_point(const mbedtls_ecp_group *grp, { unsigned char data_len; const unsigned char *buf_start; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(pt != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(*buf != NULL); - /* * We must have at least two bytes (1 for length, at least one for data) */ @@ -1030,12 +879,10 @@ int mbedtls_ecp_tls_write_point(const mbedtls_ecp_group *grp, const mbedtls_ecp_ unsigned char *buf, size_t blen) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(pt != NULL); - ECP_VALIDATE_RET(olen != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(format == MBEDTLS_ECP_PF_UNCOMPRESSED || - format == MBEDTLS_ECP_PF_COMPRESSED); + if (format != MBEDTLS_ECP_PF_UNCOMPRESSED && + format != MBEDTLS_ECP_PF_COMPRESSED) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } /* * buffer length must be at least one, for our length byte @@ -1066,10 +913,6 @@ int mbedtls_ecp_tls_read_group(mbedtls_ecp_group *grp, { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_group_id grp_id; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(*buf != NULL); - if ((ret = mbedtls_ecp_tls_read_group_id(&grp_id, buf, len)) != 0) { return ret; } @@ -1086,10 +929,6 @@ int mbedtls_ecp_tls_read_group_id(mbedtls_ecp_group_id *grp, { uint16_t tls_id; const mbedtls_ecp_curve_info *curve_info; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(*buf != NULL); - /* * We expect at least three bytes (see below) */ @@ -1107,9 +946,8 @@ int mbedtls_ecp_tls_read_group_id(mbedtls_ecp_group_id *grp, /* * Next two bytes are the namedcurve value */ - tls_id = *(*buf)++; - tls_id <<= 8; - tls_id |= *(*buf)++; + tls_id = MBEDTLS_GET_UINT16_BE(*buf, 0); + *buf += 2; if ((curve_info = mbedtls_ecp_curve_info_from_tls_id(tls_id)) == NULL) { return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; @@ -1127,10 +965,6 @@ int mbedtls_ecp_tls_write_group(const mbedtls_ecp_group *grp, size_t *olen, unsigned char *buf, size_t blen) { const mbedtls_ecp_curve_info *curve_info; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(buf != NULL); - ECP_VALIDATE_RET(olen != NULL); - if ((curve_info = mbedtls_ecp_curve_info_from_grp_id(grp->id)) == NULL) { return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } @@ -1234,17 +1068,13 @@ cleanup: * Reduce a mbedtls_mpi mod p in-place, to use after mbedtls_mpi_sub_mpi * N->s < 0 is a very fast test, which fails only if N is 0 */ -#define MOD_SUB(N) \ - while ((N).s < 0 && mbedtls_mpi_cmp_int(&(N), 0) != 0) \ - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&(N), &(N), &grp->P)) - -#if (defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) && \ - !(defined(MBEDTLS_ECP_NO_FALLBACK) && \ - defined(MBEDTLS_ECP_DOUBLE_JAC_ALT) && \ - defined(MBEDTLS_ECP_ADD_MIXED_ALT))) || \ - (defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) && \ - !(defined(MBEDTLS_ECP_NO_FALLBACK) && \ - defined(MBEDTLS_ECP_DOUBLE_ADD_MXZ_ALT))) +#define MOD_SUB(N) \ + do { \ + while ((N)->s < 0 && mbedtls_mpi_cmp_int((N), 0) != 0) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi((N), (N), &grp->P)); \ + } while (0) + +MBEDTLS_MAYBE_UNUSED static inline int mbedtls_mpi_sub_mod(const mbedtls_ecp_group *grp, mbedtls_mpi *X, const mbedtls_mpi *A, @@ -1252,20 +1082,19 @@ static inline int mbedtls_mpi_sub_mod(const mbedtls_ecp_group *grp, { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(X, A, B)); - MOD_SUB(*X); + MOD_SUB(X); cleanup: return ret; } -#endif /* All functions referencing mbedtls_mpi_sub_mod() are alt-implemented without fallback */ /* * Reduce a mbedtls_mpi mod p in-place, to use after mbedtls_mpi_add_mpi and mbedtls_mpi_mul_int. * We known P, N and the result are positive, so sub_abs is correct, and * a bit faster. */ -#define MOD_ADD(N) \ - while (mbedtls_mpi_cmp_mpi(&(N), &grp->P) >= 0) \ - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_abs(&(N), &(N), &grp->P)) +#define MOD_ADD(N) \ + while (mbedtls_mpi_cmp_mpi((N), &grp->P) >= 0) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_abs((N), (N), &grp->P)) static inline int mbedtls_mpi_add_mod(const mbedtls_ecp_group *grp, mbedtls_mpi *X, @@ -1274,28 +1103,201 @@ static inline int mbedtls_mpi_add_mod(const mbedtls_ecp_group *grp, { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(X, A, B)); - MOD_ADD(*X); + MOD_ADD(X); cleanup: return ret; } -#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) && \ - !(defined(MBEDTLS_ECP_NO_FALLBACK) && \ - defined(MBEDTLS_ECP_DOUBLE_JAC_ALT) && \ - defined(MBEDTLS_ECP_ADD_MIXED_ALT)) +MBEDTLS_MAYBE_UNUSED +static inline int mbedtls_mpi_mul_int_mod(const mbedtls_ecp_group *grp, + mbedtls_mpi *X, + const mbedtls_mpi *A, + mbedtls_mpi_uint c) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + MBEDTLS_MPI_CHK(mbedtls_mpi_mul_int(X, A, c)); + MOD_ADD(X); +cleanup: + return ret; +} + +MBEDTLS_MAYBE_UNUSED +static inline int mbedtls_mpi_sub_int_mod(const mbedtls_ecp_group *grp, + mbedtls_mpi *X, + const mbedtls_mpi *A, + mbedtls_mpi_uint c) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(X, A, c)); + MOD_SUB(X); +cleanup: + return ret; +} + +#define MPI_ECP_SUB_INT(X, A, c) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int_mod(grp, X, A, c)) + +MBEDTLS_MAYBE_UNUSED static inline int mbedtls_mpi_shift_l_mod(const mbedtls_ecp_group *grp, mbedtls_mpi *X, size_t count) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l(X, count)); - MOD_ADD(*X); + MOD_ADD(X); +cleanup: + return ret; +} + +/* + * Macro wrappers around ECP modular arithmetic + * + * Currently, these wrappers are defined via the bignum module. + */ + +#define MPI_ECP_ADD(X, A, B) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, X, A, B)) + +#define MPI_ECP_SUB(X, A, B) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, X, A, B)) + +#define MPI_ECP_MUL(X, A, B) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, X, A, B)) + +#define MPI_ECP_SQR(X, A) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, X, A, A)) + +#define MPI_ECP_MUL_INT(X, A, c) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_mul_int_mod(grp, X, A, c)) + +#define MPI_ECP_INV(dst, src) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod((dst), (src), &grp->P)) + +#define MPI_ECP_MOV(X, A) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_copy(X, A)) + +#define MPI_ECP_SHIFT_L(X, count) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, X, count)) + +#define MPI_ECP_LSET(X, c) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_lset(X, c)) + +#define MPI_ECP_CMP_INT(X, c) \ + mbedtls_mpi_cmp_int(X, c) + +#define MPI_ECP_CMP(X, Y) \ + mbedtls_mpi_cmp_mpi(X, Y) + +/* Needs f_rng, p_rng to be defined. */ +#define MPI_ECP_RAND(X) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_random((X), 2, &grp->P, f_rng, p_rng)) + +/* Conditional negation + * Needs grp and a temporary MPI tmp to be defined. */ +#define MPI_ECP_COND_NEG(X, cond) \ + do \ + { \ + unsigned char nonzero = mbedtls_mpi_cmp_int((X), 0) != 0; \ + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&tmp, &grp->P, (X))); \ + MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign((X), &tmp, \ + nonzero & cond)); \ + } while (0) + +#define MPI_ECP_NEG(X) MPI_ECP_COND_NEG((X), 1) + +#define MPI_ECP_VALID(X) \ + ((X)->p != NULL) + +#define MPI_ECP_COND_ASSIGN(X, Y, cond) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign((X), (Y), (cond))) + +#define MPI_ECP_COND_SWAP(X, Y, cond) \ + MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_swap((X), (Y), (cond))) + +#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) + +/* + * Computes the right-hand side of the Short Weierstrass equation + * RHS = X^3 + A X + B + */ +static int ecp_sw_rhs(const mbedtls_ecp_group *grp, + mbedtls_mpi *rhs, + const mbedtls_mpi *X) +{ + int ret; + + /* Compute X^3 + A X + B as X (X^2 + A) + B */ + MPI_ECP_SQR(rhs, X); + + /* Special case for A = -3 */ + if (mbedtls_ecp_group_a_is_minus_3(grp)) { + MPI_ECP_SUB_INT(rhs, rhs, 3); + } else { + MPI_ECP_ADD(rhs, rhs, &grp->A); + } + + MPI_ECP_MUL(rhs, rhs, X); + MPI_ECP_ADD(rhs, rhs, &grp->B); + cleanup: return ret; } -#endif \ - /* All functions referencing mbedtls_mpi_shift_l_mod() are alt-implemented without fallback */ +/* + * Derive Y from X and a parity bit + */ +static int mbedtls_ecp_sw_derive_y(const mbedtls_ecp_group *grp, + const mbedtls_mpi *X, + mbedtls_mpi *Y, + int parity_bit) +{ + /* w = y^2 = x^3 + ax + b + * y = sqrt(w) = w^((p+1)/4) mod p (for prime p where p = 3 mod 4) + * + * Note: this method for extracting square root does not validate that w + * was indeed a square so this function will return garbage in Y if X + * does not correspond to a point on the curve. + */ + + /* Check prerequisite p = 3 mod 4 */ + if (mbedtls_mpi_get_bit(&grp->P, 0) != 1 || + mbedtls_mpi_get_bit(&grp->P, 1) != 1) { + return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; + } + + int ret; + mbedtls_mpi exp; + mbedtls_mpi_init(&exp); + + /* use Y to store intermediate result, actually w above */ + MBEDTLS_MPI_CHK(ecp_sw_rhs(grp, Y, X)); + + /* w = y^2 */ /* Y contains y^2 intermediate result */ + /* exp = ((p+1)/4) */ + MBEDTLS_MPI_CHK(mbedtls_mpi_add_int(&exp, &grp->P, 1)); + MBEDTLS_MPI_CHK(mbedtls_mpi_shift_r(&exp, 2)); + /* sqrt(w) = w^((p+1)/4) mod p (for prime p where p = 3 mod 4) */ + MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(Y, Y /*y^2*/, &exp, &grp->P, NULL)); + + /* check parity bit match or else invert Y */ + /* This quick inversion implementation is valid because Y != 0 for all + * Short Weierstrass curves supported by mbedtls, as each supported curve + * has an order that is a large prime, so each supported curve does not + * have any point of order 2, and a point with Y == 0 would be of order 2 */ + if (mbedtls_mpi_get_bit(Y, 0) != parity_bit) { + MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(Y, &grp->P, Y)); + } + +cleanup: + + mbedtls_mpi_free(&exp); + return ret; +} +#endif /* MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */ + +#if defined(MBEDTLS_ECP_C) #if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) /* * For curves in short Weierstrass form, we do all the internal operations in @@ -1311,7 +1313,7 @@ cleanup: */ static int ecp_normalize_jac(const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt) { - if (mbedtls_mpi_cmp_int(&pt->Z, 0) == 0) { + if (MPI_ECP_CMP_INT(&pt->Z, 0) == 0) { return 0; } @@ -1325,30 +1327,20 @@ static int ecp_normalize_jac(const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi Zi, ZZi; - mbedtls_mpi_init(&Zi); mbedtls_mpi_init(&ZZi); + mbedtls_mpi T; + mbedtls_mpi_init(&T); - /* - * X = X / Z^2 mod p - */ - MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&Zi, &pt->Z, &grp->P)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &ZZi, &Zi, &Zi)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->X, &pt->X, &ZZi)); + MPI_ECP_INV(&T, &pt->Z); /* T <- 1 / Z */ + MPI_ECP_MUL(&pt->Y, &pt->Y, &T); /* Y' <- Y*T = Y / Z */ + MPI_ECP_SQR(&T, &T); /* T <- T^2 = 1 / Z^2 */ + MPI_ECP_MUL(&pt->X, &pt->X, &T); /* X <- X * T = X / Z^2 */ + MPI_ECP_MUL(&pt->Y, &pt->Y, &T); /* Y'' <- Y' * T = Y / Z^3 */ - /* - * Y = Y / Z^3 mod p - */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->Y, &pt->Y, &ZZi)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->Y, &pt->Y, &Zi)); - - /* - * Z = 1 - */ - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&pt->Z, 1)); + MPI_ECP_LSET(&pt->Z, 1); cleanup: - mbedtls_mpi_free(&Zi); mbedtls_mpi_free(&ZZi); + mbedtls_mpi_free(&T); return ret; #endif /* !defined(MBEDTLS_ECP_NO_FALLBACK) || !defined(MBEDTLS_ECP_NORMALIZE_JAC_ALT) */ @@ -1383,50 +1375,54 @@ static int ecp_normalize_jac_many(const mbedtls_ecp_group *grp, #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t i; - mbedtls_mpi *c, u, Zi, ZZi; + mbedtls_mpi *c, t; if ((c = mbedtls_calloc(T_size, sizeof(mbedtls_mpi))) == NULL) { return MBEDTLS_ERR_ECP_ALLOC_FAILED; } - for (i = 0; i < T_size; i++) { - mbedtls_mpi_init(&c[i]); - } - - mbedtls_mpi_init(&u); mbedtls_mpi_init(&Zi); mbedtls_mpi_init(&ZZi); + mbedtls_mpi_init(&t); + mpi_init_many(c, T_size); /* - * c[i] = Z_0 * ... * Z_i + * c[i] = Z_0 * ... * Z_i, i = 0,..,n := T_size-1 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&c[0], &T[0]->Z)); + MPI_ECP_MOV(&c[0], &T[0]->Z); for (i = 1; i < T_size; i++) { - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &c[i], &c[i-1], &T[i]->Z)); + MPI_ECP_MUL(&c[i], &c[i-1], &T[i]->Z); } /* - * u = 1 / (Z_0 * ... * Z_n) mod P + * c[n] = 1 / (Z_0 * ... * Z_n) mod P */ - MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&u, &c[T_size-1], &grp->P)); + MPI_ECP_INV(&c[T_size-1], &c[T_size-1]); for (i = T_size - 1;; i--) { - /* - * Zi = 1 / Z_i mod p - * u = 1 / (Z_0 * ... * Z_i) mod P + /* At the start of iteration i (note that i decrements), we have + * - c[j] = Z_0 * .... * Z_j for j < i, + * - c[j] = 1 / (Z_0 * .... * Z_j) for j == i, + * + * This is maintained via + * - c[i-1] <- c[i] * Z_i + * + * We also derive 1/Z_i = c[i] * c[i-1] for i>0 and use that + * to do the actual normalization. For i==0, we already have + * c[0] = 1 / Z_0. */ - if (i == 0) { - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&Zi, &u)); + + if (i > 0) { + /* Compute 1/Z_i and establish invariant for the next iteration. */ + MPI_ECP_MUL(&t, &c[i], &c[i-1]); + MPI_ECP_MUL(&c[i-1], &c[i], &T[i]->Z); } else { - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &Zi, &u, &c[i-1])); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &u, &u, &T[i]->Z)); + MPI_ECP_MOV(&t, &c[0]); } - /* - * proceed as in normalize() - */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &ZZi, &Zi, &Zi)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T[i]->X, &T[i]->X, &ZZi)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T[i]->Y, &T[i]->Y, &ZZi)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T[i]->Y, &T[i]->Y, &Zi)); + /* Now t holds 1 / Z_i; normalize as in ecp_normalize_jac() */ + MPI_ECP_MUL(&T[i]->Y, &T[i]->Y, &t); + MPI_ECP_SQR(&t, &t); + MPI_ECP_MUL(&T[i]->X, &T[i]->X, &t); + MPI_ECP_MUL(&T[i]->Y, &T[i]->Y, &t); /* * Post-precessing: reclaim some memory by shrinking coordinates @@ -1436,7 +1432,8 @@ static int ecp_normalize_jac_many(const mbedtls_ecp_group *grp, */ MBEDTLS_MPI_CHK(mbedtls_mpi_shrink(&T[i]->X, grp->P.n)); MBEDTLS_MPI_CHK(mbedtls_mpi_shrink(&T[i]->Y, grp->P.n)); - mbedtls_mpi_free(&T[i]->Z); + + MPI_ECP_LSET(&T[i]->Z, 1); if (i == 0) { break; @@ -1445,10 +1442,8 @@ static int ecp_normalize_jac_many(const mbedtls_ecp_group *grp, cleanup: - mbedtls_mpi_free(&u); mbedtls_mpi_free(&Zi); mbedtls_mpi_free(&ZZi); - for (i = 0; i < T_size; i++) { - mbedtls_mpi_free(&c[i]); - } + mbedtls_mpi_free(&t); + mpi_free_many(c, T_size); mbedtls_free(c); return ret; @@ -1464,19 +1459,13 @@ static int ecp_safe_invert_jac(const mbedtls_ecp_group *grp, unsigned char inv) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char nonzero; - mbedtls_mpi mQY; - - mbedtls_mpi_init(&mQY); + mbedtls_mpi tmp; + mbedtls_mpi_init(&tmp); - /* Use the fact that -Q.Y mod P = P - Q.Y unless Q.Y == 0 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&mQY, &grp->P, &Q->Y)); - nonzero = mbedtls_mpi_cmp_int(&Q->Y, 0) != 0; - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign(&Q->Y, &mQY, inv & nonzero)); + MPI_ECP_COND_NEG(&Q->Y, inv); cleanup: - mbedtls_mpi_free(&mQY); - + mbedtls_mpi_free(&tmp); return ret; } @@ -1495,7 +1484,8 @@ cleanup: * 3M + 6S + 1a otherwise */ static int ecp_double_jac(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, - const mbedtls_ecp_point *P) + const mbedtls_ecp_point *P, + mbedtls_mpi tmp[4]) { #if defined(MBEDTLS_SELF_TEST) dbl_count++; @@ -1511,63 +1501,60 @@ static int ecp_double_jac(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi M, S, T, U; - - mbedtls_mpi_init(&M); mbedtls_mpi_init(&S); mbedtls_mpi_init(&T); mbedtls_mpi_init(&U); /* Special case for A = -3 */ - if (grp->A.p == NULL) { - /* M = 3(X + Z^2)(X - Z^2) */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &P->Z, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &T, &P->X, &S)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &U, &P->X, &S)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &T, &U)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_int(&M, &S, 3)); MOD_ADD(M); + if (mbedtls_ecp_group_a_is_minus_3(grp)) { + /* tmp[0] <- M = 3(X + Z^2)(X - Z^2) */ + MPI_ECP_SQR(&tmp[1], &P->Z); + MPI_ECP_ADD(&tmp[2], &P->X, &tmp[1]); + MPI_ECP_SUB(&tmp[3], &P->X, &tmp[1]); + MPI_ECP_MUL(&tmp[1], &tmp[2], &tmp[3]); + MPI_ECP_MUL_INT(&tmp[0], &tmp[1], 3); } else { - /* M = 3.X^2 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &P->X, &P->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_int(&M, &S, 3)); MOD_ADD(M); + /* tmp[0] <- M = 3.X^2 + A.Z^4 */ + MPI_ECP_SQR(&tmp[1], &P->X); + MPI_ECP_MUL_INT(&tmp[0], &tmp[1], 3); /* Optimize away for "koblitz" curves with A = 0 */ - if (mbedtls_mpi_cmp_int(&grp->A, 0) != 0) { + if (MPI_ECP_CMP_INT(&grp->A, 0) != 0) { /* M += A.Z^4 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &P->Z, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T, &S, &S)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &T, &grp->A)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &M, &M, &S)); + MPI_ECP_SQR(&tmp[1], &P->Z); + MPI_ECP_SQR(&tmp[2], &tmp[1]); + MPI_ECP_MUL(&tmp[1], &tmp[2], &grp->A); + MPI_ECP_ADD(&tmp[0], &tmp[0], &tmp[1]); } } - /* S = 4.X.Y^2 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T, &P->Y, &P->Y)); - MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, &T, 1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &P->X, &T)); - MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, &S, 1)); + /* tmp[1] <- S = 4.X.Y^2 */ + MPI_ECP_SQR(&tmp[2], &P->Y); + MPI_ECP_SHIFT_L(&tmp[2], 1); + MPI_ECP_MUL(&tmp[1], &P->X, &tmp[2]); + MPI_ECP_SHIFT_L(&tmp[1], 1); - /* U = 8.Y^4 */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &U, &T, &T)); - MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, &U, 1)); + /* tmp[3] <- U = 8.Y^4 */ + MPI_ECP_SQR(&tmp[3], &tmp[2]); + MPI_ECP_SHIFT_L(&tmp[3], 1); - /* T = M^2 - 2.S */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T, &M, &M)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &T, &T, &S)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &T, &T, &S)); + /* tmp[2] <- T = M^2 - 2.S */ + MPI_ECP_SQR(&tmp[2], &tmp[0]); + MPI_ECP_SUB(&tmp[2], &tmp[2], &tmp[1]); + MPI_ECP_SUB(&tmp[2], &tmp[2], &tmp[1]); - /* S = M(S - T) - U */ - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &S, &S, &T)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S, &S, &M)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &S, &S, &U)); + /* tmp[1] <- S = M(S - T) - U */ + MPI_ECP_SUB(&tmp[1], &tmp[1], &tmp[2]); + MPI_ECP_MUL(&tmp[1], &tmp[1], &tmp[0]); + MPI_ECP_SUB(&tmp[1], &tmp[1], &tmp[3]); - /* U = 2.Y.Z */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &U, &P->Y, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, &U, 1)); + /* tmp[3] <- U = 2.Y.Z */ + MPI_ECP_MUL(&tmp[3], &P->Y, &P->Z); + MPI_ECP_SHIFT_L(&tmp[3], 1); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->X, &T)); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->Y, &S)); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->Z, &U)); + /* Store results */ + MPI_ECP_MOV(&R->X, &tmp[2]); + MPI_ECP_MOV(&R->Y, &tmp[1]); + MPI_ECP_MOV(&R->Z, &tmp[3]); cleanup: - mbedtls_mpi_free(&M); mbedtls_mpi_free(&S); mbedtls_mpi_free(&T); mbedtls_mpi_free(&U); return ret; #endif /* !defined(MBEDTLS_ECP_NO_FALLBACK) || !defined(MBEDTLS_ECP_DOUBLE_JAC_ALT) */ @@ -1579,6 +1566,10 @@ cleanup: * The coordinates of Q must be normalized (= affine), * but those of P don't need to. R is not normalized. * + * P,Q,R may alias, but only at the level of EC points: they must be either + * equal as pointers, or disjoint (including the coordinate data buffers). + * Fine-grained aliasing at the level of coordinates is not supported. + * * Special cases: (1) P or Q is zero, (2) R is zero, (3) P == Q. * None of these cases can happen as intermediate step in ecp_mul_comb(): * - at each step, P, Q and R are multiples of the base point, the factor @@ -1587,12 +1578,11 @@ cleanup: * due to the choice of precomputed points in the modified comb method. * So branches for these cases do not leak secret information. * - * We accept Q->Z being unset (saving memory in tables) as meaning 1. - * * Cost: 1A := 8M + 3S */ static int ecp_add_mixed(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, - const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q) + const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q, + mbedtls_mpi tmp[4]) { #if defined(MBEDTLS_SELF_TEST) add_count++; @@ -1608,40 +1598,47 @@ static int ecp_add_mixed(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi T1, T2, T3, T4, X, Y, Z; + + /* NOTE: Aliasing between input and output is allowed, so one has to make + * sure that at the point X,Y,Z are written, {P,Q}->{X,Y,Z} are no + * longer read from. */ + mbedtls_mpi * const X = &R->X; + mbedtls_mpi * const Y = &R->Y; + mbedtls_mpi * const Z = &R->Z; + + if (!MPI_ECP_VALID(&Q->Z)) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } /* * Trivial cases: P == 0 or Q == 0 (case 1) */ - if (mbedtls_mpi_cmp_int(&P->Z, 0) == 0) { + if (MPI_ECP_CMP_INT(&P->Z, 0) == 0) { return mbedtls_ecp_copy(R, Q); } - if (Q->Z.p != NULL && mbedtls_mpi_cmp_int(&Q->Z, 0) == 0) { + if (MPI_ECP_CMP_INT(&Q->Z, 0) == 0) { return mbedtls_ecp_copy(R, P); } /* * Make sure Q coordinates are normalized */ - if (Q->Z.p != NULL && mbedtls_mpi_cmp_int(&Q->Z, 1) != 0) { + if (MPI_ECP_CMP_INT(&Q->Z, 1) != 0) { return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } - mbedtls_mpi_init(&T1); mbedtls_mpi_init(&T2); mbedtls_mpi_init(&T3); mbedtls_mpi_init(&T4); - mbedtls_mpi_init(&X); mbedtls_mpi_init(&Y); mbedtls_mpi_init(&Z); - - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T1, &P->Z, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T2, &T1, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T1, &T1, &Q->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T2, &T2, &Q->Y)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &T1, &T1, &P->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &T2, &T2, &P->Y)); + MPI_ECP_SQR(&tmp[0], &P->Z); + MPI_ECP_MUL(&tmp[1], &tmp[0], &P->Z); + MPI_ECP_MUL(&tmp[0], &tmp[0], &Q->X); + MPI_ECP_MUL(&tmp[1], &tmp[1], &Q->Y); + MPI_ECP_SUB(&tmp[0], &tmp[0], &P->X); + MPI_ECP_SUB(&tmp[1], &tmp[1], &P->Y); /* Special cases (2) and (3) */ - if (mbedtls_mpi_cmp_int(&T1, 0) == 0) { - if (mbedtls_mpi_cmp_int(&T2, 0) == 0) { - ret = ecp_double_jac(grp, R, P); + if (MPI_ECP_CMP_INT(&tmp[0], 0) == 0) { + if (MPI_ECP_CMP_INT(&tmp[1], 0) == 0) { + ret = ecp_double_jac(grp, R, P, tmp); goto cleanup; } else { ret = mbedtls_ecp_set_zero(R); @@ -1649,28 +1646,26 @@ static int ecp_add_mixed(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, } } - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &Z, &P->Z, &T1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T3, &T1, &T1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T4, &T3, &T1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T3, &T3, &P->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&T1, &T3)); - MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l_mod(grp, &T1, 1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &X, &T2, &T2)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &X, &X, &T1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &X, &X, &T4)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &T3, &T3, &X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T3, &T3, &T2)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &T4, &T4, &P->Y)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &Y, &T3, &T4)); - - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->X, &X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->Y, &Y)); - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&R->Z, &Z)); + /* {P,Q}->Z no longer used, so OK to write to Z even if there's aliasing. */ + MPI_ECP_MUL(Z, &P->Z, &tmp[0]); + MPI_ECP_SQR(&tmp[2], &tmp[0]); + MPI_ECP_MUL(&tmp[3], &tmp[2], &tmp[0]); + MPI_ECP_MUL(&tmp[2], &tmp[2], &P->X); -cleanup: + MPI_ECP_MOV(&tmp[0], &tmp[2]); + MPI_ECP_SHIFT_L(&tmp[0], 1); + + /* {P,Q}->X no longer used, so OK to write to X even if there's aliasing. */ + MPI_ECP_SQR(X, &tmp[1]); + MPI_ECP_SUB(X, X, &tmp[0]); + MPI_ECP_SUB(X, X, &tmp[3]); + MPI_ECP_SUB(&tmp[2], &tmp[2], X); + MPI_ECP_MUL(&tmp[2], &tmp[2], &tmp[1]); + MPI_ECP_MUL(&tmp[3], &tmp[3], &P->Y); + /* {P,Q}->Y no longer used, so OK to write to Y even if there's aliasing. */ + MPI_ECP_SUB(Y, &tmp[2], &tmp[3]); - mbedtls_mpi_free(&T1); mbedtls_mpi_free(&T2); mbedtls_mpi_free(&T3); mbedtls_mpi_free(&T4); - mbedtls_mpi_free(&X); mbedtls_mpi_free(&Y); mbedtls_mpi_free(&Z); +cleanup: return ret; #endif /* !defined(MBEDTLS_ECP_NO_FALLBACK) || !defined(MBEDTLS_ECP_ADD_MIXED_ALT) */ @@ -1696,26 +1691,28 @@ static int ecp_randomize_jac(const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi l, ll; + mbedtls_mpi l; - mbedtls_mpi_init(&l); mbedtls_mpi_init(&ll); + mbedtls_mpi_init(&l); /* Generate l such that 1 < l < p */ - MBEDTLS_MPI_CHK(mbedtls_mpi_random(&l, 2, &grp->P, f_rng, p_rng)); + MPI_ECP_RAND(&l); - /* Z = l * Z */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->Z, &pt->Z, &l)); + /* Z' = l * Z */ + MPI_ECP_MUL(&pt->Z, &pt->Z, &l); - /* X = l^2 * X */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &ll, &l, &l)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->X, &pt->X, &ll)); + /* Y' = l * Y */ + MPI_ECP_MUL(&pt->Y, &pt->Y, &l); - /* Y = l^3 * Y */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &ll, &ll, &l)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &pt->Y, &pt->Y, &ll)); + /* X' = l^2 * X */ + MPI_ECP_SQR(&l, &l); + MPI_ECP_MUL(&pt->X, &pt->X, &l); + + /* Y'' = l^2 * Y' = l^3 * Y */ + MPI_ECP_MUL(&pt->Y, &pt->Y, &l); cleanup: - mbedtls_mpi_free(&l); mbedtls_mpi_free(&ll); + mbedtls_mpi_free(&l); if (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) { ret = MBEDTLS_ERR_ECP_RANDOM_FAILED; @@ -1858,7 +1855,11 @@ static int ecp_precompute_comb(const mbedtls_ecp_group *grp, unsigned char i; size_t j = 0; const unsigned char T_size = 1U << (w - 1); - mbedtls_ecp_point *cur, *TT[COMB_MAX_PRE - 1]; + mbedtls_ecp_point *cur, *TT[COMB_MAX_PRE - 1] = { NULL }; + + mbedtls_mpi tmp[4]; + + mpi_init_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); #if defined(MBEDTLS_ECP_RESTARTABLE) if (rs_ctx != NULL && rs_ctx->rsm != NULL) { @@ -1912,7 +1913,7 @@ dbl: MBEDTLS_MPI_CHK(mbedtls_ecp_copy(cur, T + (i >> 1))); } - MBEDTLS_MPI_CHK(ecp_double_jac(grp, cur, cur)); + MBEDTLS_MPI_CHK(ecp_double_jac(grp, cur, cur, tmp)); } #if defined(MBEDTLS_ECP_RESTARTABLE) @@ -1923,8 +1924,11 @@ dbl: norm_dbl: #endif /* - * Normalize current elements in T. As T has holes, - * use an auxiliary array of pointers to elements in T. + * Normalize current elements in T to allow them to be used in + * ecp_add_mixed() below, which requires one normalized input. + * + * As T has holes, use an auxiliary array of pointers to elements in T. + * */ j = 0; for (i = 1; i < T_size; i <<= 1) { @@ -1951,7 +1955,7 @@ add: for (i = 1; i < T_size; i <<= 1) { j = i; while (j--) { - MBEDTLS_MPI_CHK(ecp_add_mixed(grp, &T[i + j], &T[j], &T[i])); + MBEDTLS_MPI_CHK(ecp_add_mixed(grp, &T[i + j], &T[j], &T[i], tmp)); } } @@ -1975,7 +1979,19 @@ norm_add: MBEDTLS_MPI_CHK(ecp_normalize_jac_many(grp, TT, j)); + /* Free Z coordinate (=1 after normalization) to save RAM. + * This makes T[i] invalid as mbedtls_ecp_points, but this is OK + * since from this point onwards, they are only accessed indirectly + * via the getter function ecp_select_comb() which does set the + * target's Z coordinate to 1. */ + for (i = 0; i < T_size; i++) { + mbedtls_mpi_free(&T[i].Z); + } + cleanup: + + mpi_free_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); + #if defined(MBEDTLS_ECP_RESTARTABLE) if (rs_ctx != NULL && rs_ctx->rsm != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { @@ -2005,13 +2021,15 @@ static int ecp_select_comb(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, /* Read the whole table to thwart cache-based timing attacks */ for (j = 0; j < T_size; j++) { - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign(&R->X, &T[j].X, j == ii)); - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign(&R->Y, &T[j].Y, j == ii)); + MPI_ECP_COND_ASSIGN(&R->X, &T[j].X, j == ii); + MPI_ECP_COND_ASSIGN(&R->Y, &T[j].Y, j == ii); } /* Safely invert result if i is "negative" */ MBEDTLS_MPI_CHK(ecp_safe_invert_jac(grp, R, i >> 7)); + MPI_ECP_LSET(&R->Z, 1); + cleanup: return ret; } @@ -2031,9 +2049,11 @@ static int ecp_mul_comb_core(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_point Txi; + mbedtls_mpi tmp[4]; size_t i; mbedtls_ecp_point_init(&Txi); + mpi_init_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); #if !defined(MBEDTLS_ECP_RESTARTABLE) (void) rs_ctx; @@ -2053,19 +2073,10 @@ static int ecp_mul_comb_core(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, } else #endif { - int have_rng = 1; - /* Start with a non-zero point and randomize its coordinates */ i = d; MBEDTLS_MPI_CHK(ecp_select_comb(grp, R, T, T_size, x[i])); - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&R->Z, 1)); - -#if defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - if (f_rng == NULL) { - have_rng = 0; - } -#endif - if (have_rng) { + if (f_rng != 0) { MBEDTLS_MPI_CHK(ecp_randomize_jac(grp, R, f_rng, p_rng)); } } @@ -2074,14 +2085,15 @@ static int ecp_mul_comb_core(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, MBEDTLS_ECP_BUDGET(MBEDTLS_ECP_OPS_DBL + MBEDTLS_ECP_OPS_ADD); --i; - MBEDTLS_MPI_CHK(ecp_double_jac(grp, R, R)); + MBEDTLS_MPI_CHK(ecp_double_jac(grp, R, R, tmp)); MBEDTLS_MPI_CHK(ecp_select_comb(grp, &Txi, T, T_size, x[i])); - MBEDTLS_MPI_CHK(ecp_add_mixed(grp, R, R, &Txi)); + MBEDTLS_MPI_CHK(ecp_add_mixed(grp, R, R, &Txi, tmp)); } cleanup: mbedtls_ecp_point_free(&Txi); + mpi_free_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); #if defined(MBEDTLS_ECP_RESTARTABLE) if (rs_ctx != NULL && rs_ctx->rsm != NULL && @@ -2164,7 +2176,6 @@ static int ecp_mul_comb_after_precomp(const mbedtls_ecp_group *grp, unsigned char parity_trick; unsigned char k[COMB_MAX_D + 1]; mbedtls_ecp_point *RR = R; - int have_rng = 1; #if defined(MBEDTLS_ECP_RESTARTABLE) if (rs_ctx != NULL && rs_ctx->rsm != NULL) { @@ -2201,12 +2212,7 @@ final_norm: * * Avoid the leak by randomizing coordinates before we normalize them. */ -#if defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - if (f_rng == NULL) { - have_rng = 0; - } -#endif - if (have_rng) { + if (f_rng != 0) { MBEDTLS_MPI_CHK(ecp_randomize_jac(grp, RR, f_rng, p_rng)); } @@ -2247,11 +2253,16 @@ static unsigned char ecp_pick_window_size(const mbedtls_ecp_group *grp, } /* - * Make sure w is within bounds. + * If static comb table may not be used (!p_eq_g) or static comb table does + * not exists, make sure w is within bounds. * (The last test is useful only for very small curves in the test suite.) + * + * The user reduces MBEDTLS_ECP_WINDOW_SIZE does not changes the size of + * static comb table, because the size of static comb table is fixed when + * it is generated. */ #if (MBEDTLS_ECP_WINDOW_SIZE < 6) - if (w > MBEDTLS_ECP_WINDOW_SIZE) { + if ((!p_eq_g || !ecp_group_is_static_comb_table(grp)) && w > MBEDTLS_ECP_WINDOW_SIZE) { w = MBEDTLS_ECP_WINDOW_SIZE; } #endif @@ -2286,46 +2297,13 @@ static int ecp_mul_comb(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, size_t d; unsigned char T_size = 0, T_ok = 0; mbedtls_ecp_point *T = NULL; -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_context drbg_ctx; - - ecp_drbg_init(&drbg_ctx); -#endif ECP_RS_ENTER(rsm); -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - if (f_rng == NULL) { - /* Adjust pointers */ - f_rng = &ecp_drbg_random; -#if defined(MBEDTLS_ECP_RESTARTABLE) - if (rs_ctx != NULL && rs_ctx->rsm != NULL) { - p_rng = &rs_ctx->rsm->drbg_ctx; - } else -#endif - p_rng = &drbg_ctx; - - /* Initialize internal DRBG if necessary */ -#if defined(MBEDTLS_ECP_RESTARTABLE) - if (rs_ctx == NULL || rs_ctx->rsm == NULL || - rs_ctx->rsm->drbg_seeded == 0) -#endif - { - const size_t m_len = (grp->nbits + 7) / 8; - MBEDTLS_MPI_CHK(ecp_drbg_seed(p_rng, m, m_len)); - } -#if defined(MBEDTLS_ECP_RESTARTABLE) - if (rs_ctx != NULL && rs_ctx->rsm != NULL) { - rs_ctx->rsm->drbg_seeded = 1; - } -#endif - } -#endif /* !MBEDTLS_ECP_NO_INTERNAL_RNG */ - /* Is P the base point ? */ #if MBEDTLS_ECP_FIXED_POINT_OPTIM == 1 - p_eq_g = (mbedtls_mpi_cmp_mpi(&P->Y, &grp->G.Y) == 0 && - mbedtls_mpi_cmp_mpi(&P->X, &grp->G.X) == 0); + p_eq_g = (MPI_ECP_CMP(&P->Y, &grp->G.Y) == 0 && + MPI_ECP_CMP(&P->X, &grp->G.X) == 0); #else p_eq_g = 0; #endif @@ -2387,10 +2365,6 @@ static int ecp_mul_comb(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, cleanup: -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_free(&drbg_ctx); -#endif - /* does T belong to the group? */ if (T == grp->T) { T = NULL; @@ -2458,9 +2432,9 @@ static int ecp_normalize_mxz(const mbedtls_ecp_group *grp, mbedtls_ecp_point *P) return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&P->Z, &P->Z, &grp->P)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &P->X, &P->X, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&P->Z, 1)); + MPI_ECP_INV(&P->Z, &P->Z); + MPI_ECP_MUL(&P->X, &P->X, &P->Z); + MPI_ECP_LSET(&P->Z, 1); cleanup: return ret; @@ -2492,10 +2466,10 @@ static int ecp_randomize_mxz(const mbedtls_ecp_group *grp, mbedtls_ecp_point *P, mbedtls_mpi_init(&l); /* Generate l such that 1 < l < p */ - MBEDTLS_MPI_CHK(mbedtls_mpi_random(&l, 2, &grp->P, f_rng, p_rng)); + MPI_ECP_RAND(&l); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &P->X, &P->X, &l)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &P->Z, &P->Z, &l)); + MPI_ECP_MUL(&P->X, &P->X, &l); + MPI_ECP_MUL(&P->Z, &P->Z, &l); cleanup: mbedtls_mpi_free(&l); @@ -2525,7 +2499,8 @@ cleanup: static int ecp_double_add_mxz(const mbedtls_ecp_group *grp, mbedtls_ecp_point *R, mbedtls_ecp_point *S, const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q, - const mbedtls_mpi *d) + const mbedtls_mpi *d, + mbedtls_mpi T[4]) { #if defined(MBEDTLS_ECP_DOUBLE_ADD_MXZ_ALT) if (mbedtls_internal_ecp_grp_capable(grp)) { @@ -2537,35 +2512,27 @@ static int ecp_double_add_mxz(const mbedtls_ecp_group *grp, return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; #else int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi A, AA, B, BB, E, C, D, DA, CB; - - mbedtls_mpi_init(&A); mbedtls_mpi_init(&AA); mbedtls_mpi_init(&B); - mbedtls_mpi_init(&BB); mbedtls_mpi_init(&E); mbedtls_mpi_init(&C); - mbedtls_mpi_init(&D); mbedtls_mpi_init(&DA); mbedtls_mpi_init(&CB); - - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &A, &P->X, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &AA, &A, &A)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &B, &P->X, &P->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &BB, &B, &B)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &E, &AA, &BB)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &C, &Q->X, &Q->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &D, &Q->X, &Q->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &DA, &D, &A)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &CB, &C, &B)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &S->X, &DA, &CB)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S->X, &S->X, &S->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mod(grp, &S->Z, &DA, &CB)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S->Z, &S->Z, &S->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &S->Z, d, &S->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &R->X, &AA, &BB)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &R->Z, &grp->A, &E)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &R->Z, &BB, &R->Z)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &R->Z, &E, &R->Z)); + + MPI_ECP_ADD(&T[0], &P->X, &P->Z); /* Pp := PX + PZ */ + MPI_ECP_SUB(&T[1], &P->X, &P->Z); /* Pm := PX - PZ */ + MPI_ECP_ADD(&T[2], &Q->X, &Q->Z); /* Qp := QX + XZ */ + MPI_ECP_SUB(&T[3], &Q->X, &Q->Z); /* Qm := QX - QZ */ + MPI_ECP_MUL(&T[3], &T[3], &T[0]); /* Qm * Pp */ + MPI_ECP_MUL(&T[2], &T[2], &T[1]); /* Qp * Pm */ + MPI_ECP_SQR(&T[0], &T[0]); /* Pp^2 */ + MPI_ECP_SQR(&T[1], &T[1]); /* Pm^2 */ + MPI_ECP_MUL(&R->X, &T[0], &T[1]); /* Pp^2 * Pm^2 */ + MPI_ECP_SUB(&T[0], &T[0], &T[1]); /* Pp^2 - Pm^2 */ + MPI_ECP_MUL(&R->Z, &grp->A, &T[0]); /* A * (Pp^2 - Pm^2) */ + MPI_ECP_ADD(&R->Z, &T[1], &R->Z); /* [ A * (Pp^2-Pm^2) ] + Pm^2 */ + MPI_ECP_ADD(&S->X, &T[3], &T[2]); /* Qm*Pp + Qp*Pm */ + MPI_ECP_SQR(&S->X, &S->X); /* (Qm*Pp + Qp*Pm)^2 */ + MPI_ECP_SUB(&S->Z, &T[3], &T[2]); /* Qm*Pp - Qp*Pm */ + MPI_ECP_SQR(&S->Z, &S->Z); /* (Qm*Pp - Qp*Pm)^2 */ + MPI_ECP_MUL(&S->Z, d, &S->Z); /* d * ( Qm*Pp - Qp*Pm )^2 */ + MPI_ECP_MUL(&R->Z, &T[0], &R->Z); /* [A*(Pp^2-Pm^2)+Pm^2]*(Pp^2-Pm^2) */ cleanup: - mbedtls_mpi_free(&A); mbedtls_mpi_free(&AA); mbedtls_mpi_free(&B); - mbedtls_mpi_free(&BB); mbedtls_mpi_free(&E); mbedtls_mpi_free(&C); - mbedtls_mpi_free(&D); mbedtls_mpi_free(&DA); mbedtls_mpi_free(&CB); return ret; #endif /* !defined(MBEDTLS_ECP_NO_FALLBACK) || !defined(MBEDTLS_ECP_DOUBLE_ADD_MXZ_ALT) */ @@ -2581,48 +2548,33 @@ static int ecp_mul_mxz(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, void *p_rng) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - int have_rng = 1; size_t i; unsigned char b; mbedtls_ecp_point RP; mbedtls_mpi PX; -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_context drbg_ctx; - - ecp_drbg_init(&drbg_ctx); -#endif + mbedtls_mpi tmp[4]; mbedtls_ecp_point_init(&RP); mbedtls_mpi_init(&PX); -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) + mpi_init_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); + if (f_rng == NULL) { - const size_t m_len = (grp->nbits + 7) / 8; - MBEDTLS_MPI_CHK(ecp_drbg_seed(&drbg_ctx, m, m_len)); - f_rng = &ecp_drbg_random; - p_rng = &drbg_ctx; + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } -#endif /* !MBEDTLS_ECP_NO_INTERNAL_RNG */ /* Save PX and read from P before writing to R, in case P == R */ - MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&PX, &P->X)); + MPI_ECP_MOV(&PX, &P->X); MBEDTLS_MPI_CHK(mbedtls_ecp_copy(&RP, P)); /* Set R to zero in modified x/z coordinates */ - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&R->X, 1)); - MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&R->Z, 0)); + MPI_ECP_LSET(&R->X, 1); + MPI_ECP_LSET(&R->Z, 0); mbedtls_mpi_free(&R->Y); /* RP.X might be slightly larger than P, so reduce it */ - MOD_ADD(RP.X); + MOD_ADD(&RP.X); -#if defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - /* Derandomize coordinates of the starting point */ - if (f_rng == NULL) { - have_rng = 0; - } -#endif - if (have_rng) { - MBEDTLS_MPI_CHK(ecp_randomize_mxz(grp, &RP, f_rng, p_rng)); - } + /* Randomize coordinates of the starting point */ + MBEDTLS_MPI_CHK(ecp_randomize_mxz(grp, &RP, f_rng, p_rng)); /* Loop invariant: R = result so far, RP = R + P */ i = grp->nbits + 1; /* one past the (zero-based) required msb for private keys */ @@ -2635,11 +2587,11 @@ static int ecp_mul_mxz(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, * else double_add( R, RP, R, RP ) * but using safe conditional swaps to avoid leaks */ - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_swap(&R->X, &RP.X, b)); - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_swap(&R->Z, &RP.Z, b)); - MBEDTLS_MPI_CHK(ecp_double_add_mxz(grp, R, &RP, R, &RP, &PX)); - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_swap(&R->X, &RP.X, b)); - MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_swap(&R->Z, &RP.Z, b)); + MPI_ECP_COND_SWAP(&R->X, &RP.X, b); + MPI_ECP_COND_SWAP(&R->Z, &RP.Z, b); + MBEDTLS_MPI_CHK(ecp_double_add_mxz(grp, R, &RP, R, &RP, &PX, tmp)); + MPI_ECP_COND_SWAP(&R->X, &RP.X, b); + MPI_ECP_COND_SWAP(&R->Z, &RP.Z, b); } /* @@ -2653,25 +2605,13 @@ static int ecp_mul_mxz(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, * * Avoid the leak by randomizing coordinates before we normalize them. */ - have_rng = 1; -#if defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - if (f_rng == NULL) { - have_rng = 0; - } -#endif - if (have_rng) { - MBEDTLS_MPI_CHK(ecp_randomize_mxz(grp, R, f_rng, p_rng)); - } - + MBEDTLS_MPI_CHK(ecp_randomize_mxz(grp, R, f_rng, p_rng)); MBEDTLS_MPI_CHK(ecp_normalize_mxz(grp, R)); cleanup: -#if !defined(MBEDTLS_ECP_NO_INTERNAL_RNG) - ecp_drbg_free(&drbg_ctx); -#endif - mbedtls_ecp_point_free(&RP); mbedtls_mpi_free(&PX); + mpi_free_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); return ret; } @@ -2679,20 +2619,19 @@ cleanup: /* * Restartable multiplication R = m * P + * + * This internal function can be called without an RNG in case where we know + * the inputs are not sensitive. */ -int mbedtls_ecp_mul_restartable(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, - const mbedtls_mpi *m, const mbedtls_ecp_point *P, - int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, - mbedtls_ecp_restart_ctx *rs_ctx) +static int ecp_mul_restartable_internal(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, + const mbedtls_mpi *m, const mbedtls_ecp_point *P, + int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, + mbedtls_ecp_restart_ctx *rs_ctx) { int ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA; #if defined(MBEDTLS_ECP_INTERNAL_ALT) char is_grp_capable = 0; #endif - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(R != NULL); - ECP_VALIDATE_RET(m != NULL); - ECP_VALIDATE_RET(P != NULL); #if defined(MBEDTLS_ECP_RESTARTABLE) /* reset ops count for this call if top-level */ @@ -2753,18 +2692,30 @@ cleanup: } /* + * Restartable multiplication R = m * P + */ +int mbedtls_ecp_mul_restartable(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, + const mbedtls_mpi *m, const mbedtls_ecp_point *P, + int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, + mbedtls_ecp_restart_ctx *rs_ctx) +{ + if (f_rng == NULL) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + + return ecp_mul_restartable_internal(grp, R, m, P, f_rng, p_rng, rs_ctx); +} + +/* * Multiplication R = m * P */ int mbedtls_ecp_mul(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(R != NULL); - ECP_VALIDATE_RET(m != NULL); - ECP_VALIDATE_RET(P != NULL); return mbedtls_ecp_mul_restartable(grp, R, m, P, f_rng, p_rng, NULL); } +#endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) /* @@ -2788,22 +2739,12 @@ static int ecp_check_pubkey_sw(const mbedtls_ecp_group *grp, const mbedtls_ecp_p /* * YY = Y^2 - * RHS = X (X^2 + A) + B = X^3 + A X + B + * RHS = X^3 + A X + B */ - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &YY, &pt->Y, &pt->Y)); - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &RHS, &pt->X, &pt->X)); + MPI_ECP_SQR(&YY, &pt->Y); + MBEDTLS_MPI_CHK(ecp_sw_rhs(grp, &RHS, &pt->X)); - /* Special case for A = -3 */ - if (grp->A.p == NULL) { - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&RHS, &RHS, 3)); MOD_SUB(RHS); - } else { - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &RHS, &RHS, &grp->A)); - } - - MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mod(grp, &RHS, &RHS, &pt->X)); - MBEDTLS_MPI_CHK(mbedtls_mpi_add_mod(grp, &RHS, &RHS, &grp->B)); - - if (mbedtls_mpi_cmp_mpi(&YY, &RHS) != 0) { + if (MPI_ECP_CMP(&YY, &RHS) != 0) { ret = MBEDTLS_ERR_ECP_INVALID_KEY; } @@ -2815,6 +2756,7 @@ cleanup: } #endif /* MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */ +#if defined(MBEDTLS_ECP_C) #if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) /* * R = m * P with shortcuts for m == 0, m == 1 and m == -1 @@ -2827,6 +2769,8 @@ static int mbedtls_ecp_mul_shortcuts(mbedtls_ecp_group *grp, mbedtls_ecp_restart_ctx *rs_ctx) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_mpi tmp; + mbedtls_mpi_init(&tmp); if (mbedtls_mpi_cmp_int(m, 0) == 0) { MBEDTLS_MPI_CHK(mbedtls_ecp_check_pubkey(grp, P)); @@ -2837,15 +2781,15 @@ static int mbedtls_ecp_mul_shortcuts(mbedtls_ecp_group *grp, } else if (mbedtls_mpi_cmp_int(m, -1) == 0) { MBEDTLS_MPI_CHK(mbedtls_ecp_check_pubkey(grp, P)); MBEDTLS_MPI_CHK(mbedtls_ecp_copy(R, P)); - if (mbedtls_mpi_cmp_int(&R->Y, 0) != 0) { - MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&R->Y, &grp->P, &R->Y)); - } + MPI_ECP_NEG(&R->Y); } else { - MBEDTLS_MPI_CHK(mbedtls_ecp_mul_restartable(grp, R, m, P, - NULL, NULL, rs_ctx)); + MBEDTLS_MPI_CHK(ecp_mul_restartable_internal(grp, R, m, P, + NULL, NULL, rs_ctx)); } cleanup: + mbedtls_mpi_free(&tmp); + return ret; } @@ -2863,21 +2807,16 @@ int mbedtls_ecp_muladd_restartable( mbedtls_ecp_point mP; mbedtls_ecp_point *pmP = &mP; mbedtls_ecp_point *pR = R; + mbedtls_mpi tmp[4]; #if defined(MBEDTLS_ECP_INTERNAL_ALT) char is_grp_capable = 0; #endif - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(R != NULL); - ECP_VALIDATE_RET(m != NULL); - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(n != NULL); - ECP_VALIDATE_RET(Q != NULL); - if (mbedtls_ecp_get_type(grp) != MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS) { return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; } mbedtls_ecp_point_init(&mP); + mpi_init_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); ECP_RS_ENTER(ma); @@ -2924,7 +2863,7 @@ mul2: add: #endif MBEDTLS_ECP_BUDGET(MBEDTLS_ECP_OPS_ADD); - MBEDTLS_MPI_CHK(ecp_add_mixed(grp, pR, pmP, pR)); + MBEDTLS_MPI_CHK(ecp_add_mixed(grp, pR, pmP, pR, tmp)); #if defined(MBEDTLS_ECP_RESTARTABLE) if (rs_ctx != NULL && rs_ctx->ma != NULL) { rs_ctx->ma->state = ecp_rsma_norm; @@ -2942,6 +2881,9 @@ norm: #endif cleanup: + + mpi_free_many(tmp, sizeof(tmp) / sizeof(mbedtls_mpi)); + #if defined(MBEDTLS_ECP_INTERNAL_ALT) if (is_grp_capable) { mbedtls_internal_ecp_free(grp); @@ -2963,21 +2905,16 @@ int mbedtls_ecp_muladd(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, const mbedtls_mpi *n, const mbedtls_ecp_point *Q) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(R != NULL); - ECP_VALIDATE_RET(m != NULL); - ECP_VALIDATE_RET(P != NULL); - ECP_VALIDATE_RET(n != NULL); - ECP_VALIDATE_RET(Q != NULL); return mbedtls_ecp_muladd_restartable(grp, R, m, P, n, Q, NULL); } #endif /* MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */ +#endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) #if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) -#define ECP_MPI_INIT(s, n, p) { s, (n), (mbedtls_mpi_uint *) (p) } +#define ECP_MPI_INIT(_p, _n) { .p = (mbedtls_mpi_uint *) (_p), .s = 1, .n = (_n) } #define ECP_MPI_INIT_ARRAY(x) \ - ECP_MPI_INIT(1, sizeof(x) / sizeof(mbedtls_mpi_uint), x) + ECP_MPI_INIT(x, sizeof(x) / sizeof(mbedtls_mpi_uint)) /* * Constants for the two points other than 0, 1, -1 (mod p) in * https://cr.yp.to/ecdh.html#validate @@ -3090,9 +3027,6 @@ static int ecp_check_pubkey_mx(const mbedtls_ecp_group *grp, const mbedtls_ecp_p int mbedtls_ecp_check_pubkey(const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(pt != NULL); - /* Must use affine coordinates */ if (mbedtls_mpi_cmp_int(&pt->Z, 1) != 0) { return MBEDTLS_ERR_ECP_INVALID_KEY; @@ -3117,9 +3051,6 @@ int mbedtls_ecp_check_pubkey(const mbedtls_ecp_group *grp, int mbedtls_ecp_check_privkey(const mbedtls_ecp_group *grp, const mbedtls_mpi *d) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(d != NULL); - #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) if (mbedtls_ecp_get_type(grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) { /* see RFC 7748 sec. 5 para. 5 */ @@ -3208,10 +3139,6 @@ int mbedtls_ecp_gen_privkey(const mbedtls_ecp_group *grp, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(d != NULL); - ECP_VALIDATE_RET(f_rng != NULL); - #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) if (mbedtls_ecp_get_type(grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) { return mbedtls_ecp_gen_privkey_mx(grp->nbits, d, f_rng, p_rng); @@ -3227,6 +3154,7 @@ int mbedtls_ecp_gen_privkey(const mbedtls_ecp_group *grp, return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; } +#if defined(MBEDTLS_ECP_C) /* * Generate a keypair with configurable base point */ @@ -3237,12 +3165,6 @@ int mbedtls_ecp_gen_keypair_base(mbedtls_ecp_group *grp, void *p_rng) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(d != NULL); - ECP_VALIDATE_RET(G != NULL); - ECP_VALIDATE_RET(Q != NULL); - ECP_VALIDATE_RET(f_rng != NULL); - MBEDTLS_MPI_CHK(mbedtls_ecp_gen_privkey(grp, d, f_rng, p_rng)); MBEDTLS_MPI_CHK(mbedtls_ecp_mul(grp, Q, d, G, f_rng, p_rng)); @@ -3258,11 +3180,6 @@ int mbedtls_ecp_gen_keypair(mbedtls_ecp_group *grp, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) { - ECP_VALIDATE_RET(grp != NULL); - ECP_VALIDATE_RET(d != NULL); - ECP_VALIDATE_RET(Q != NULL); - ECP_VALIDATE_RET(f_rng != NULL); - return mbedtls_ecp_gen_keypair_base(grp, &grp->G, d, Q, f_rng, p_rng); } @@ -3273,17 +3190,35 @@ int mbedtls_ecp_gen_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECP_VALIDATE_RET(key != NULL); - ECP_VALIDATE_RET(f_rng != NULL); - if ((ret = mbedtls_ecp_group_load(&key->grp, grp_id)) != 0) { return ret; } return mbedtls_ecp_gen_keypair(&key->grp, &key->d, &key->Q, f_rng, p_rng); } +#endif /* MBEDTLS_ECP_C */ + +int mbedtls_ecp_set_public_key(mbedtls_ecp_group_id grp_id, + mbedtls_ecp_keypair *key, + const mbedtls_ecp_point *Q) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + if (key->grp.id == MBEDTLS_ECP_DP_NONE) { + /* Group not set yet */ + if ((ret = mbedtls_ecp_group_load(&key->grp, grp_id)) != 0) { + return ret; + } + } else if (key->grp.id != grp_id) { + /* Group mismatch */ + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + return mbedtls_ecp_copy(&key->Q, Q); +} + #define ECP_CURVE25519_KEY_SIZE 32 +#define ECP_CURVE448_KEY_SIZE 56 /* * Read a private key. */ @@ -3292,9 +3227,6 @@ int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, { int ret = 0; - ECP_VALIDATE_RET(key != NULL); - ECP_VALIDATE_RET(buf != NULL); - if ((ret = mbedtls_ecp_group_load(&key->grp, grp_id)) != 0) { return ret; } @@ -3304,7 +3236,7 @@ int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) { /* - * If it is Curve25519 curve then mask the key as mandated by RFC7748 + * Mask the key as mandated by RFC7748 for Curve25519 and Curve448. */ if (grp_id == MBEDTLS_ECP_DP_CURVE25519) { if (buflen != ECP_CURVE25519_KEY_SIZE) { @@ -3329,20 +3261,35 @@ int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, mbedtls_mpi_set_bit(&key->d, ECP_CURVE25519_KEY_SIZE * 8 - 2, 1) ); - } else { - ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; + } else if (grp_id == MBEDTLS_ECP_DP_CURVE448) { + if (buflen != ECP_CURVE448_KEY_SIZE) { + return MBEDTLS_ERR_ECP_INVALID_KEY; + } + + MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary_le(&key->d, buf, buflen)); + + /* Set the two least significant bits to 0 */ + MBEDTLS_MPI_CHK(mbedtls_mpi_set_bit(&key->d, 0, 0)); + MBEDTLS_MPI_CHK(mbedtls_mpi_set_bit(&key->d, 1, 0)); + + /* Set the most significant bit to 1 */ + MBEDTLS_MPI_CHK( + mbedtls_mpi_set_bit(&key->d, + ECP_CURVE448_KEY_SIZE * 8 - 1, 1) + ); } } - #endif #if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS) { MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&key->d, buf, buflen)); + } +#endif + if (ret == 0) { MBEDTLS_MPI_CHK(mbedtls_ecp_check_privkey(&key->grp, &key->d)); } -#endif cleanup: if (ret != 0) { @@ -3355,13 +3302,11 @@ cleanup: /* * Write a private key. */ +#if !defined MBEDTLS_DEPRECATED_REMOVED int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key, unsigned char *buf, size_t buflen) { - int ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; - - ECP_VALIDATE_RET(key != NULL); - ECP_VALIDATE_RET(buf != NULL); + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) { @@ -3370,12 +3315,13 @@ int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key, return MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL; } - MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary_le(&key->d, buf, buflen)); - } else { - ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE; + } else if (key->grp.id == MBEDTLS_ECP_DP_CURVE448) { + if (buflen < ECP_CURVE448_KEY_SIZE) { + return MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL; + } } + MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary_le(&key->d, buf, buflen)); } - #endif #if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS) { @@ -3387,19 +3333,63 @@ cleanup: return ret; } +#endif /* MBEDTLS_DEPRECATED_REMOVED */ + +int mbedtls_ecp_write_key_ext(const mbedtls_ecp_keypair *key, + size_t *olen, unsigned char *buf, size_t buflen) +{ + size_t len = (key->grp.nbits + 7) / 8; + if (len > buflen) { + /* For robustness, ensure *olen <= buflen even on error. */ + *olen = 0; + return MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL; + } + *olen = len; + + /* Private key not set */ + if (key->d.n == 0) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + +#if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED) + if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) { + return mbedtls_mpi_write_binary_le(&key->d, buf, len); + } +#endif + +#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) + if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS) { + return mbedtls_mpi_write_binary(&key->d, buf, len); + } +#endif + + /* Private key set but no recognized curve type? This shouldn't happen. */ + return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; +} + +/* + * Write a public key. + */ +int mbedtls_ecp_write_public_key(const mbedtls_ecp_keypair *key, + int format, size_t *olen, + unsigned char *buf, size_t buflen) +{ + return mbedtls_ecp_point_write_binary(&key->grp, &key->Q, + format, olen, buf, buflen); +} +#if defined(MBEDTLS_ECP_C) /* * Check a public-private key pair */ -int mbedtls_ecp_check_pub_priv(const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv) +int mbedtls_ecp_check_pub_priv( + const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv, + int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_point Q; mbedtls_ecp_group grp; - ECP_VALIDATE_RET(pub != NULL); - ECP_VALIDATE_RET(prv != NULL); - if (pub->grp.id == MBEDTLS_ECP_DP_NONE || pub->grp.id != prv->grp.id || mbedtls_mpi_cmp_mpi(&pub->Q.X, &prv->Q.X) || @@ -3415,7 +3405,7 @@ int mbedtls_ecp_check_pub_priv(const mbedtls_ecp_keypair *pub, const mbedtls_ecp mbedtls_ecp_group_copy(&grp, &prv->grp); /* Also checks d is valid */ - MBEDTLS_MPI_CHK(mbedtls_ecp_mul(&grp, &Q, &prv->d, &prv->grp.G, NULL, NULL)); + MBEDTLS_MPI_CHK(mbedtls_ecp_mul(&grp, &Q, &prv->d, &prv->grp.G, f_rng, p_rng)); if (mbedtls_mpi_cmp_mpi(&Q.X, &prv->Q.X) || mbedtls_mpi_cmp_mpi(&Q.Y, &prv->Q.Y) || @@ -3431,8 +3421,68 @@ cleanup: return ret; } +int mbedtls_ecp_keypair_calc_public(mbedtls_ecp_keypair *key, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng) +{ + return mbedtls_ecp_mul(&key->grp, &key->Q, &key->d, &key->grp.G, + f_rng, p_rng); +} +#endif /* MBEDTLS_ECP_C */ + +mbedtls_ecp_group_id mbedtls_ecp_keypair_get_group_id( + const mbedtls_ecp_keypair *key) +{ + return key->grp.id; +} + +/* + * Export generic key-pair parameters. + */ +int mbedtls_ecp_export(const mbedtls_ecp_keypair *key, mbedtls_ecp_group *grp, + mbedtls_mpi *d, mbedtls_ecp_point *Q) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + if (grp != NULL && (ret = mbedtls_ecp_group_copy(grp, &key->grp)) != 0) { + return ret; + } + + if (d != NULL && (ret = mbedtls_mpi_copy(d, &key->d)) != 0) { + return ret; + } + + if (Q != NULL && (ret = mbedtls_ecp_copy(Q, &key->Q)) != 0) { + return ret; + } + + return 0; +} + #if defined(MBEDTLS_SELF_TEST) +#if defined(MBEDTLS_ECP_C) +/* + * PRNG for test - !!!INSECURE NEVER USE IN PRODUCTION!!! + * + * This is the linear congruential generator from numerical recipes, + * except we only use the low byte as the output. See + * https://en.wikipedia.org/wiki/Linear_congruential_generator#Parameters_in_common_use + */ +static int self_test_rng(void *ctx, unsigned char *out, size_t len) +{ + static uint32_t state = 42; + + (void) ctx; + + for (size_t i = 0; i < len; i++) { + state = state * 1664525u + 1013904223u; + out[i] = (unsigned char) state; + } + + return 0; +} + /* Adjust the exponent to be a valid private point for the specified curve. * This is sometimes necessary because we use a single set of exponents * for all curves but the validity of values depends on the curve. */ @@ -3487,7 +3537,7 @@ static int self_test_point(int verbose, MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(m, 16, exponents[0])); MBEDTLS_MPI_CHK(self_test_adjust_exponent(grp, m)); - MBEDTLS_MPI_CHK(mbedtls_ecp_mul(grp, R, m, P, NULL, NULL)); + MBEDTLS_MPI_CHK(mbedtls_ecp_mul(grp, R, m, P, self_test_rng, NULL)); for (i = 1; i < n_exponents; i++) { add_c_prev = add_count; @@ -3499,7 +3549,7 @@ static int self_test_point(int verbose, MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(m, 16, exponents[i])); MBEDTLS_MPI_CHK(self_test_adjust_exponent(grp, m)); - MBEDTLS_MPI_CHK(mbedtls_ecp_mul(grp, R, m, P, NULL, NULL)); + MBEDTLS_MPI_CHK(mbedtls_ecp_mul(grp, R, m, P, self_test_rng, NULL)); if (add_count != add_c_prev || dbl_count != dbl_c_prev || @@ -3519,12 +3569,14 @@ cleanup: } return ret; } +#endif /* MBEDTLS_ECP_C */ /* * Checkup routine */ int mbedtls_ecp_self_test(int verbose) { +#if defined(MBEDTLS_ECP_C) int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_group grp; mbedtls_ecp_point R, P; @@ -3577,7 +3629,7 @@ int mbedtls_ecp_self_test(int verbose) } /* Do a dummy multiplication first to trigger precomputation */ MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&m, 2)); - MBEDTLS_MPI_CHK(mbedtls_ecp_mul(&grp, &P, &m, &grp.G, NULL, NULL)); + MBEDTLS_MPI_CHK(mbedtls_ecp_mul(&grp, &P, &m, &grp.G, self_test_rng, NULL)); ret = self_test_point(verbose, &grp, &R, &m, &grp.G, sw_exponents, @@ -3638,10 +3690,14 @@ cleanup: } return ret; +#else /* MBEDTLS_ECP_C */ + (void) verbose; + return 0; +#endif /* MBEDTLS_ECP_C */ } #endif /* MBEDTLS_SELF_TEST */ #endif /* !MBEDTLS_ECP_ALT */ -#endif /* MBEDTLS_ECP_C */ +#endif /* MBEDTLS_ECP_LIGHT */ |