On Fri, Dec 18, 2020 at 08:41:01AM +0900, Michael Paquier wrote: > Knowing that we are in a period of vacations for a lot of people, and > that this is a sensitive area of the code that involves > authentication, I think that it is better to let this thread brew > longer and get more eyes to look at it. As this also concerns > external SSL libraries like libnss, making sure that the APIs have a > shape flexible enough would be good. Based on my own checks with > OpenSSL and libnss, I think that's more than enough. But let's be > sure.
FWIW, I got my eyes on this stuff again today, and please find attached a v2, where I have fixed a certain number of issues: - Fixed a memory leak with the shrink buffer in the fallback implementation. - Fixed a couple of incorrect comments. - The logic around the resowner was a bit busted with OpenSSL <= 1.0.2. So I haev reorganized the code a bit. This has been tested on Windows and Linux across all the versions of OpenSSL we support on HEAD. I am also attaching a small module called hmacfuncs that I used as a way to validate this patch across all the versions of OpenSSL and the fallback implementation. As a reference, this matches with the results from Wikipedia here: https://en.wikipedia.org/wiki/HMAC#Examples -- Michael
From 4b4699b9d24f7b26edf7cdb9892b32a71965c396 Mon Sep 17 00:00:00 2001 From: Michael Paquier <mich...@paquier.xyz> Date: Fri, 18 Dec 2020 15:43:41 +0900 Subject: [PATCH v2] Refactor HMAC implementations --- src/include/common/hmac.h | 33 +++ src/include/common/md5.h | 2 + src/include/common/scram-common.h | 13 -- src/include/pg_config.h.in | 6 + src/include/utils/resowner_private.h | 7 + src/backend/libpq/auth-scram.c | 61 ++--- src/backend/utils/resowner/resowner.c | 61 +++++ src/common/Makefile | 4 +- src/common/hmac.c | 309 ++++++++++++++++++++++++++ src/common/hmac_openssl.c | 241 ++++++++++++++++++++ src/common/scram-common.c | 158 +++---------- src/interfaces/libpq/fe-auth-scram.c | 70 +++--- configure | 2 +- configure.ac | 2 +- src/tools/msvc/Mkvcbuild.pm | 2 + src/tools/msvc/Solution.pm | 4 + src/tools/pgindent/typedefs.list | 3 +- 17 files changed, 780 insertions(+), 198 deletions(-) create mode 100644 src/include/common/hmac.h create mode 100644 src/common/hmac.c create mode 100644 src/common/hmac_openssl.c diff --git a/src/include/common/hmac.h b/src/include/common/hmac.h new file mode 100644 index 0000000000..0b69f7a730 --- /dev/null +++ b/src/include/common/hmac.h @@ -0,0 +1,33 @@ +/*------------------------------------------------------------------------- + * + * hmac.h + * Generic headers for HMAC + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/include/common/hmac.h + * + *------------------------------------------------------------------------- + */ + +#ifndef PG_HMAC_H +#define PG_HMAC_H + +#include "common/cryptohash.h" + +typedef struct pg_hmac_ctx +{ + pg_cryptohash_type type; + /* private area used by each HMAC implementation */ + void *data; +} pg_hmac_ctx; + +extern pg_hmac_ctx *pg_hmac_create(pg_cryptohash_type type); +extern int pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len); +extern int pg_hmac_update(pg_hmac_ctx *ctx, const uint8 *data, size_t len); +extern int pg_hmac_final(pg_hmac_ctx *ctx, uint8 *dest); +extern void pg_hmac_free(pg_hmac_ctx *ctx); + +#endif /* PG_HMAC_H */ diff --git a/src/include/common/md5.h b/src/include/common/md5.h index 5dac70cbc5..ff22270416 100644 --- a/src/include/common/md5.h +++ b/src/include/common/md5.h @@ -18,6 +18,8 @@ /* Size of result generated by MD5 computation */ #define MD5_DIGEST_LENGTH 16 +/* Block size for MD5 */ +#define MD5_BLOCK_SIZE 64 /* password-related data */ #define MD5_PASSWD_CHARSET "0123456789abcdef" diff --git a/src/include/common/scram-common.h b/src/include/common/scram-common.h index f4a7c60725..9138b751d2 100644 --- a/src/include/common/scram-common.h +++ b/src/include/common/scram-common.h @@ -46,19 +46,6 @@ */ #define SCRAM_DEFAULT_ITERATIONS 4096 -/* - * Context data for HMAC used in SCRAM authentication. - */ -typedef struct -{ - pg_cryptohash_ctx *sha256ctx; - uint8 k_opad[SHA256_HMAC_B]; -} scram_HMAC_ctx; - -extern int scram_HMAC_init(scram_HMAC_ctx *ctx, const uint8 *key, int keylen); -extern int scram_HMAC_update(scram_HMAC_ctx *ctx, const char *str, int slen); -extern int scram_HMAC_final(uint8 *result, scram_HMAC_ctx *ctx); - extern int scram_SaltedPassword(const char *password, const char *salt, int saltlen, int iterations, uint8 *result); extern int scram_H(const uint8 *str, int len, uint8 *result); diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index de8f838e53..5258c0bac8 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -268,6 +268,12 @@ /* Define to 1 if you have the `history_truncate_file' function. */ #undef HAVE_HISTORY_TRUNCATE_FILE +/* Define to 1 if you have the `HMAC_CTX_new' function. */ +#undef HAVE_HMAC_CTX_FREE + +/* Define to 1 if you have the `HMAC_CTX_free' function. */ +#undef HAVE_HMAC_CTX_NEW + /* Define to 1 if you have the <ifaddrs.h> header file. */ #undef HAVE_IFADDRS_H diff --git a/src/include/utils/resowner_private.h b/src/include/utils/resowner_private.h index c373788bc1..4da5d40aa2 100644 --- a/src/include/utils/resowner_private.h +++ b/src/include/utils/resowner_private.h @@ -102,4 +102,11 @@ extern void ResourceOwnerRememberCryptoHash(ResourceOwner owner, extern void ResourceOwnerForgetCryptoHash(ResourceOwner owner, Datum handle); +/* support for HMAC context management */ +extern void ResourceOwnerEnlargeHMAC(ResourceOwner owner); +extern void ResourceOwnerRememberHMAC(ResourceOwner owner, + Datum handle); +extern void ResourceOwnerForgetHMAC(ResourceOwner owner, + Datum handle); + #endif /* RESOWNER_PRIVATE_H */ diff --git a/src/backend/libpq/auth-scram.c b/src/backend/libpq/auth-scram.c index 6879a81618..6850c4fa0e 100644 --- a/src/backend/libpq/auth-scram.c +++ b/src/backend/libpq/auth-scram.c @@ -95,6 +95,7 @@ #include "catalog/pg_authid.h" #include "catalog/pg_control.h" #include "common/base64.h" +#include "common/hmac.h" #include "common/saslprep.h" #include "common/scram-common.h" #include "common/sha2.h" @@ -1100,7 +1101,7 @@ verify_client_proof(scram_state *state) uint8 ClientSignature[SCRAM_KEY_LEN]; uint8 ClientKey[SCRAM_KEY_LEN]; uint8 client_StoredKey[SCRAM_KEY_LEN]; - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256); int i; /* @@ -1108,23 +1109,25 @@ verify_client_proof(scram_state *state) * here even when processing the calculations as this could involve a mock * authentication. */ - if (scram_HMAC_init(&ctx, state->StoredKey, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, - state->client_first_message_bare, - strlen(state->client_first_message_bare)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->server_first_message, - strlen(state->server_first_message)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->client_final_message_without_proof, - strlen(state->client_final_message_without_proof)) < 0 || - scram_HMAC_final(ClientSignature, &ctx) < 0) + if (pg_hmac_init(ctx, state->StoredKey, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_first_message_bare, + strlen(state->client_first_message_bare)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->server_first_message, + strlen(state->server_first_message)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_final_message_without_proof, + strlen(state->client_final_message_without_proof)) < 0 || + pg_hmac_final(ctx, ClientSignature) < 0) { elog(ERROR, "could not calculate client signature"); } + pg_hmac_free(ctx); + /* Extract the ClientKey that the client calculated from the proof */ for (i = 0; i < SCRAM_KEY_LEN; i++) ClientKey[i] = state->ClientProof[i] ^ ClientSignature[i]; @@ -1359,26 +1362,28 @@ build_server_final_message(scram_state *state) uint8 ServerSignature[SCRAM_KEY_LEN]; char *server_signature_base64; int siglen; - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256); /* calculate ServerSignature */ - if (scram_HMAC_init(&ctx, state->ServerKey, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, - state->client_first_message_bare, - strlen(state->client_first_message_bare)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->server_first_message, - strlen(state->server_first_message)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->client_final_message_without_proof, - strlen(state->client_final_message_without_proof)) < 0 || - scram_HMAC_final(ServerSignature, &ctx) < 0) + if (pg_hmac_init(ctx, state->ServerKey, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_first_message_bare, + strlen(state->client_first_message_bare)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->server_first_message, + strlen(state->server_first_message)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_final_message_without_proof, + strlen(state->client_final_message_without_proof)) < 0 || + pg_hmac_final(ctx, ServerSignature) < 0) { elog(ERROR, "could not calculate server signature"); } + pg_hmac_free(ctx); + siglen = pg_b64_enc_len(SCRAM_KEY_LEN); /* don't forget the zero-terminator */ server_signature_base64 = palloc(siglen + 1); diff --git a/src/backend/utils/resowner/resowner.c b/src/backend/utils/resowner/resowner.c index 546ad8d1c5..e66470bee0 100644 --- a/src/backend/utils/resowner/resowner.c +++ b/src/backend/utils/resowner/resowner.c @@ -22,6 +22,7 @@ #include "common/cryptohash.h" #include "common/hashfn.h" +#include "common/hmac.h" #include "jit/jit.h" #include "storage/bufmgr.h" #include "storage/ipc.h" @@ -130,6 +131,7 @@ typedef struct ResourceOwnerData ResourceArray dsmarr; /* dynamic shmem segments */ ResourceArray jitarr; /* JIT contexts */ ResourceArray cryptohasharr; /* cryptohash contexts */ + ResourceArray hmacarr; /* HMAC contexts */ /* We can remember up to MAX_RESOWNER_LOCKS references to local locks. */ int nlocks; /* number of owned locks */ @@ -178,6 +180,7 @@ static void PrintSnapshotLeakWarning(Snapshot snapshot); static void PrintFileLeakWarning(File file); static void PrintDSMLeakWarning(dsm_segment *seg); static void PrintCryptoHashLeakWarning(Datum handle); +static void PrintHMACLeakWarning(Datum handle); /***************************************************************************** @@ -448,6 +451,7 @@ ResourceOwnerCreate(ResourceOwner parent, const char *name) ResourceArrayInit(&(owner->dsmarr), PointerGetDatum(NULL)); ResourceArrayInit(&(owner->jitarr), PointerGetDatum(NULL)); ResourceArrayInit(&(owner->cryptohasharr), PointerGetDatum(NULL)); + ResourceArrayInit(&(owner->hmacarr), PointerGetDatum(NULL)); return owner; } @@ -568,6 +572,16 @@ ResourceOwnerReleaseInternal(ResourceOwner owner, PrintCryptoHashLeakWarning(foundres); pg_cryptohash_free(context); } + + /* Ditto for HMAC contexts */ + while (ResourceArrayGetAny(&(owner->hmacarr), &foundres)) + { + pg_hmac_ctx *context = (pg_hmac_ctx *) PointerGetDatum(foundres); + + if (isCommit) + PrintHMACLeakWarning(foundres); + pg_hmac_free(context); + } } else if (phase == RESOURCE_RELEASE_LOCKS) { @@ -741,6 +755,7 @@ ResourceOwnerDelete(ResourceOwner owner) Assert(owner->dsmarr.nitems == 0); Assert(owner->jitarr.nitems == 0); Assert(owner->cryptohasharr.nitems == 0); + Assert(owner->hmacarr.nitems == 0); Assert(owner->nlocks == 0 || owner->nlocks == MAX_RESOWNER_LOCKS + 1); /* @@ -769,6 +784,7 @@ ResourceOwnerDelete(ResourceOwner owner) ResourceArrayFree(&(owner->dsmarr)); ResourceArrayFree(&(owner->jitarr)); ResourceArrayFree(&(owner->cryptohasharr)); + ResourceArrayFree(&(owner->hmacarr)); pfree(owner); } @@ -1432,3 +1448,48 @@ PrintCryptoHashLeakWarning(Datum handle) elog(WARNING, "cryptohash context reference leak: context %p still referenced", DatumGetPointer(handle)); } + +/* + * Make sure there is room for at least one more entry in a ResourceOwner's + * hmac context reference array. + * + * This is separate from actually inserting an entry because if we run out of + * memory, it's critical to do so *before* acquiring the resource. + */ +void +ResourceOwnerEnlargeHMAC(ResourceOwner owner) +{ + ResourceArrayEnlarge(&(owner->hmacarr)); +} + +/* + * Remember that a HMAC context is owned by a ResourceOwner + * + * Caller must have previously done ResourceOwnerEnlargeHMAC() + */ +void +ResourceOwnerRememberHMAC(ResourceOwner owner, Datum handle) +{ + ResourceArrayAdd(&(owner->hmacarr), handle); +} + +/* + * Forget that a HMAC context is owned by a ResourceOwner + */ +void +ResourceOwnerForgetHMAC(ResourceOwner owner, Datum handle) +{ + if (!ResourceArrayRemove(&(owner->hmacarr), handle)) + elog(ERROR, "HMAC context %p is not owned by resource owner %s", + DatumGetPointer(handle), owner->name); +} + +/* + * Debugging subroutine + */ +static void +PrintHMACLeakWarning(Datum handle) +{ + elog(WARNING, "HMAC context reference leak: context %p still referenced", + DatumGetPointer(handle)); +} diff --git a/src/common/Makefile b/src/common/Makefile index af891cb0ce..ab895bc7f6 100644 --- a/src/common/Makefile +++ b/src/common/Makefile @@ -82,10 +82,12 @@ OBJS_COMMON = \ ifeq ($(with_openssl),yes) OBJS_COMMON += \ protocol_openssl.o \ - cryptohash_openssl.o + cryptohash_openssl.o \ + hmac_openssl.o else OBJS_COMMON += \ cryptohash.o \ + hmac.o \ md5.o \ sha2.o endif diff --git a/src/common/hmac.c b/src/common/hmac.c new file mode 100644 index 0000000000..04b3fdf5ce --- /dev/null +++ b/src/common/hmac.c @@ -0,0 +1,309 @@ +/*------------------------------------------------------------------------- + * + * hmac.c + * Implements Keyed-Hashing for Message Authentication (HMAC) + * + * Fallback implementation of HMAC, as specified in RFC 2104. + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/common/hmac.c + * + *------------------------------------------------------------------------- + */ + +#ifndef FRONTEND +#include "postgres.h" +#else +#include "postgres_fe.h" +#endif + +#include "common/cryptohash.h" +#include "common/hmac.h" +#include "common/md5.h" +#include "common/sha2.h" + +/* + * In backend, use palloc/pfree to ease the error handling. In frontend, + * use malloc to be able to return a failure status back to the caller. + */ +#ifndef FRONTEND +#define ALLOC(size) palloc(size) +#define FREE(ptr) pfree(ptr) +#else +#define ALLOC(size) malloc(size) +#define FREE(ptr) free(ptr) +#endif + +/* + * Internal structure for pg_hmac_ctx->data with this implementation. + */ +typedef struct pg_hmac_state +{ + pg_cryptohash_ctx *hash; + uint8 *k_ipad; + uint8 *k_opad; + int block_size; + int digest_size; +} pg_hmac_state; + +#define HMAC_IPAD 0x36 +#define HMAC_OPAD 0x5C + +/* + * pg_hmac_create + * + * Allocate a hash context. Returns NULL on failure for an OOM. The + * backend issues an error, without returning. + */ +pg_hmac_ctx * +pg_hmac_create(pg_cryptohash_type type) +{ + pg_hmac_ctx *ctx; + pg_hmac_state *state; + + ctx = ALLOC(sizeof(pg_hmac_ctx)); + if (ctx == NULL) + return NULL; + memset(ctx, 0, sizeof(pg_hmac_ctx)); + + ctx->type = type; + + state = ALLOC(sizeof(pg_hmac_state)); + if (state == NULL) + { + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); + FREE(ctx); + return NULL; + } + memset(state, 0, sizeof(pg_hmac_state)); + ctx->data = state; + + /* + * Initialize the context data. This requires to know the digest and + * block lengths, that depend on the type of hash used. + */ + switch (type) + { + case PG_MD5: + state->digest_size = MD5_DIGEST_LENGTH; + state->block_size = MD5_BLOCK_SIZE; + break; + case PG_SHA224: + state->digest_size = PG_SHA224_DIGEST_LENGTH; + state->block_size = PG_SHA224_BLOCK_LENGTH; + break; + case PG_SHA256: + state->digest_size = PG_SHA256_DIGEST_LENGTH; + state->block_size = PG_SHA256_BLOCK_LENGTH; + break; + case PG_SHA384: + state->digest_size = PG_SHA384_DIGEST_LENGTH; + state->block_size = PG_SHA384_BLOCK_LENGTH; + break; + case PG_SHA512: + state->digest_size = PG_SHA512_DIGEST_LENGTH; + state->block_size = PG_SHA512_BLOCK_LENGTH; + break; + } + + state->k_opad = ALLOC(state->block_size); + if (state->k_opad == NULL) + goto err; + + memset(state->k_opad, 0, state->block_size); + + state->k_ipad = ALLOC(state->block_size); + if (state->k_ipad == NULL) + goto err; + + memset(state->k_ipad, 0, state->block_size); + + state->hash = pg_cryptohash_create(type); + if (state->hash == NULL) + goto err; + + return ctx; + +err: + if (state->k_ipad) + { + explicit_bzero(state->k_ipad, state->block_size); + FREE(state->k_ipad); + } + if (state->k_opad) + { + explicit_bzero(state->k_opad, state->block_size); + FREE(state->k_opad); + } + + explicit_bzero(state, sizeof(pg_hmac_state)); + FREE(state); + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); + FREE(ctx); + return NULL; +} + +/* + * pg_hmac_init + * + * Initialize a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len) +{ + int i; + int digest_size; + int block_size; + uint8 *shrinkbuf = NULL; + pg_hmac_state *state; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + digest_size = state->digest_size; + block_size = state->block_size; + + memset(state->k_opad, HMAC_OPAD, state->block_size); + memset(state->k_ipad, HMAC_IPAD, state->block_size); + + /* + * If the key is longer than the block size, pass it through the hash once + * to shrink it down. + */ + if (len > block_size) + { + pg_cryptohash_ctx *hash_ctx; + + /* temporary buffer for one-time shrink */ + shrinkbuf = ALLOC(digest_size); + if (shrinkbuf == NULL) + return -1; + memset(shrinkbuf, 0, digest_size); + + hash_ctx = pg_cryptohash_create(ctx->type); + if (hash_ctx == NULL) + { + FREE(shrinkbuf); + return -1; + } + + if (pg_cryptohash_init(hash_ctx) < 0 || + pg_cryptohash_update(hash_ctx, key, len) < 0 || + pg_cryptohash_final(hash_ctx, shrinkbuf) < 0) + { + pg_cryptohash_free(hash_ctx); + FREE(shrinkbuf); + return -1; + } + + key = shrinkbuf; + len = digest_size; + pg_cryptohash_free(hash_ctx); + } + + for (i = 0; i < len; i++) + { + state->k_ipad[i] ^= key[i]; + state->k_opad[i] ^= key[i]; + } + + /* tmp = H(K XOR ipad, text) */ + if (pg_cryptohash_init(state->hash) < 0 || + pg_cryptohash_update(state->hash, state->k_ipad, state->block_size) < 0) + { + if (shrinkbuf) + FREE(shrinkbuf); + return -1; + } + + if (shrinkbuf) + FREE(shrinkbuf); + return 0; +} + +/* + * pg_hmac_update + * + * Update a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_update(pg_hmac_ctx *ctx, const uint8 *data, size_t len) +{ + pg_hmac_state *state; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + + if (pg_cryptohash_update(state->hash, data, len) < 0) + return -1; + + return 0; +} + +/* + * pg_hmac_final + * + * Finalize a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_final(pg_hmac_ctx *ctx, uint8 *dest) +{ + uint8 *h; + pg_hmac_state *state; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + + h = ALLOC(state->digest_size); + if (h == NULL) + return -1; + memset(h, 0, state->digest_size); + + if (pg_cryptohash_final(state->hash, h) < 0) + return -1; + + /* H(K XOR opad, tmp) */ + if (pg_cryptohash_init(state->hash) < 0 || + pg_cryptohash_update(state->hash, state->k_opad, state->block_size) < 0 || + pg_cryptohash_update(state->hash, h, state->digest_size) < 0 || + pg_cryptohash_final(state->hash, dest) < 0) + { + return -1; + } + + return 0; +} + +/* + * pg_hmac_free + * + * Free a HMAC context. + */ +void +pg_hmac_free(pg_hmac_ctx *ctx) +{ + pg_hmac_state *state; + + if (ctx == NULL) + return; + + state = (pg_hmac_state *) ctx->data; + + pg_cryptohash_free(state->hash); + explicit_bzero(state->k_ipad, state->block_size); + FREE(state->k_ipad); + explicit_bzero(state->k_opad, state->block_size); + FREE(state->k_opad); + explicit_bzero(state, sizeof(pg_hmac_state)); + FREE(state); + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); + FREE(ctx); +} diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c new file mode 100644 index 0000000000..ba48afb05e --- /dev/null +++ b/src/common/hmac_openssl.c @@ -0,0 +1,241 @@ +/*------------------------------------------------------------------------- + * + * hmac_openssl.c + * Implementation of HMAC with OpenSSL. + * + * This should only be used if code is compiled with OpenSSL support. + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/common/hmac_openssl.c + * + *------------------------------------------------------------------------- + */ + +#ifndef FRONTEND +#include "postgres.h" +#else +#include "postgres_fe.h" +#endif + +#include <openssl/hmac.h> + +#include "common/hmac.h" +#ifndef FRONTEND +#include "utils/memutils.h" +#include "utils/resowner.h" +#include "utils/resowner_private.h" +#endif + +/* + * In backend, use palloc/pfree to ease the error handling. In frontend, + * use malloc to be able to return a failure status back to the caller. + */ +#ifndef FRONTEND +#define ALLOC(size) palloc(size) +#define FREE(ptr) pfree(ptr) +#else +#define ALLOC(size) malloc(size) +#define FREE(ptr) free(ptr) +#endif + +/* + * Internal structure for pg_hmac_ctx->data with this implementation. + */ +typedef struct pg_hmac_state +{ + HMAC_CTX *hmacctx; + +#ifndef FRONTEND + ResourceOwner resowner; +#endif +} pg_hmac_state; + +/* + * pg_hmac_create + * + * Allocate a hash context. Returns NULL on failure for an OOM. The + * backend issues an error, without returning. + */ +pg_hmac_ctx * +pg_hmac_create(pg_cryptohash_type type) +{ + pg_hmac_ctx *ctx; + pg_hmac_state *state; + + ctx = ALLOC(sizeof(pg_hmac_ctx)); + if (ctx == NULL) + return NULL; + memset(ctx, 0, sizeof(pg_hmac_ctx)); + + ctx->type = type; + + state = ALLOC(sizeof(pg_hmac_state)); + if (state == NULL) + { + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); + FREE(ctx); + return NULL; + } + memset(state, 0, sizeof(pg_hmac_state)); + ctx->data = state; + + /* + * Initialization takes care of assigning the correct type for OpenSSL. + */ +#ifdef HAVE_HMAC_CTX_NEW +#ifndef FRONTEND + ResourceOwnerEnlargeHMAC(CurrentResourceOwner); +#endif + state->hmacctx = HMAC_CTX_new(); +#else + state->hmacctx = ALLOC(sizeof(HMAC_CTX)); +#endif + + if (state->hmacctx == NULL) + { + explicit_bzero(state, sizeof(pg_hmac_state)); + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); +#ifndef FRONTEND + ereport(ERROR, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("out of memory"))); +#endif + FREE(state); + FREE(ctx); + return NULL; + } + +#ifdef HAVE_HMAC_CTX_NEW +#ifndef FRONTEND + state->resowner = CurrentResourceOwner; + ResourceOwnerRememberHMAC(CurrentResourceOwner, PointerGetDatum(ctx)); +#endif +#else + memset(state->hmacctx, 0, sizeof(HMAC_CTX)); +#endif /* HAVE_HMAC_CTX_NEW */ + + return ctx; +} + +/* + * pg_hmac_init + * + * Initialize a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len) +{ + pg_hmac_state *state; + int status = 0; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + + switch (ctx->type) + { + case PG_MD5: + status = HMAC_Init_ex(state->hmacctx, key, len, EVP_md5(), NULL); + break; + case PG_SHA224: + status = HMAC_Init_ex(state->hmacctx, key, len, EVP_sha224(), NULL); + break; + case PG_SHA256: + status = HMAC_Init_ex(state->hmacctx, key, len, EVP_sha256(), NULL); + break; + case PG_SHA384: + status = HMAC_Init_ex(state->hmacctx, key, len, EVP_sha384(), NULL); + break; + case PG_SHA512: + status = HMAC_Init_ex(state->hmacctx, key, len, EVP_sha512(), NULL); + break; + } + + /* OpenSSL internals return 1 on success, 0 on failure */ + if (status <= 0) + return -1; + + return 0; +} + +/* + * pg_hmac_update + * + * Update a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_update(pg_hmac_ctx *ctx, const uint8 *data, size_t len) +{ + pg_hmac_state *state; + int status = 0; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + status = HMAC_Update(state->hmacctx, data, len); + + /* OpenSSL internals return 1 on success, 0 on failure */ + if (status <= 0) + return -1; + return 0; +} + +/* + * pg_hmac_final + * + * Finalize a HMAC context. Returns 0 on success, -1 on failure. + */ +int +pg_hmac_final(pg_hmac_ctx *ctx, uint8 *dest) +{ + pg_hmac_state *state; + int status = 0; + uint32 len; + + if (ctx == NULL) + return 0; + + state = (pg_hmac_state *) ctx->data; + status = HMAC_Final(state->hmacctx, dest, &len); + + /* OpenSSL internals return 1 on success, 0 on failure */ + if (status <= 0) + return -1; + return 0; +} + +/* + * pg_hmac_free + * + * Free a HMAC context. + */ +void +pg_hmac_free(pg_hmac_ctx *ctx) +{ + pg_hmac_state *state; + + if (ctx == NULL) + return; + + state = (pg_hmac_state *) ctx->data; + +#ifdef HAVE_HMAC_CTX_FREE + HMAC_CTX_free(state->hmacctx); +#ifndef FRONTEND + ResourceOwnerForgetHMAC(state->resowner, PointerGetDatum(ctx)); +#endif +#else + explicit_bzero(state->hmacctx, sizeof(HMAC_CTX)); + FREE(state->hmacctx); +#endif + + explicit_bzero(state, sizeof(pg_hmac_state)); + FREE(state); + explicit_bzero(ctx, sizeof(pg_hmac_ctx)); + FREE(ctx); +} diff --git a/src/common/scram-common.c b/src/common/scram-common.c index caab68926d..922cabe24e 100644 --- a/src/common/scram-common.c +++ b/src/common/scram-common.c @@ -20,118 +20,10 @@ #endif #include "common/base64.h" +#include "common/hmac.h" #include "common/scram-common.h" #include "port/pg_bswap.h" -#define HMAC_IPAD 0x36 -#define HMAC_OPAD 0x5C - -/* - * Calculate HMAC per RFC2104. - * - * The hash function used is SHA-256. Returns 0 on success, -1 on failure. - */ -int -scram_HMAC_init(scram_HMAC_ctx *ctx, const uint8 *key, int keylen) -{ - uint8 k_ipad[SHA256_HMAC_B]; - int i; - uint8 keybuf[SCRAM_KEY_LEN]; - - /* - * If the key is longer than the block size (64 bytes for SHA-256), pass - * it through SHA-256 once to shrink it down. - */ - if (keylen > SHA256_HMAC_B) - { - pg_cryptohash_ctx *sha256_ctx; - - sha256_ctx = pg_cryptohash_create(PG_SHA256); - if (sha256_ctx == NULL) - return -1; - if (pg_cryptohash_init(sha256_ctx) < 0 || - pg_cryptohash_update(sha256_ctx, key, keylen) < 0 || - pg_cryptohash_final(sha256_ctx, keybuf) < 0) - { - pg_cryptohash_free(sha256_ctx); - return -1; - } - key = keybuf; - keylen = SCRAM_KEY_LEN; - pg_cryptohash_free(sha256_ctx); - } - - memset(k_ipad, HMAC_IPAD, SHA256_HMAC_B); - memset(ctx->k_opad, HMAC_OPAD, SHA256_HMAC_B); - - for (i = 0; i < keylen; i++) - { - k_ipad[i] ^= key[i]; - ctx->k_opad[i] ^= key[i]; - } - - ctx->sha256ctx = pg_cryptohash_create(PG_SHA256); - if (ctx->sha256ctx == NULL) - return -1; - - /* tmp = H(K XOR ipad, text) */ - if (pg_cryptohash_init(ctx->sha256ctx) < 0 || - pg_cryptohash_update(ctx->sha256ctx, k_ipad, SHA256_HMAC_B) < 0) - { - pg_cryptohash_free(ctx->sha256ctx); - return -1; - } - - return 0; -} - -/* - * Update HMAC calculation - * The hash function used is SHA-256. Returns 0 on success, -1 on failure. - */ -int -scram_HMAC_update(scram_HMAC_ctx *ctx, const char *str, int slen) -{ - Assert(ctx->sha256ctx != NULL); - if (pg_cryptohash_update(ctx->sha256ctx, (const uint8 *) str, slen) < 0) - { - pg_cryptohash_free(ctx->sha256ctx); - return -1; - } - return 0; -} - -/* - * Finalize HMAC calculation. - * The hash function used is SHA-256. Returns 0 on success, -1 on failure. - */ -int -scram_HMAC_final(uint8 *result, scram_HMAC_ctx *ctx) -{ - uint8 h[SCRAM_KEY_LEN]; - - Assert(ctx->sha256ctx != NULL); - - if (pg_cryptohash_final(ctx->sha256ctx, h) < 0) - { - pg_cryptohash_free(ctx->sha256ctx); - return -1; - } - - /* H(K XOR opad, tmp) */ - if (pg_cryptohash_init(ctx->sha256ctx) < 0 || - pg_cryptohash_update(ctx->sha256ctx, ctx->k_opad, SHA256_HMAC_B) < 0 || - pg_cryptohash_update(ctx->sha256ctx, h, SCRAM_KEY_LEN) < 0 || - pg_cryptohash_final(ctx->sha256ctx, result) < 0) - { - pg_cryptohash_free(ctx->sha256ctx); - return -1; - } - - pg_cryptohash_free(ctx->sha256ctx); - return 0; -} - /* * Calculate SaltedPassword. * @@ -149,7 +41,10 @@ scram_SaltedPassword(const char *password, j; uint8 Ui[SCRAM_KEY_LEN]; uint8 Ui_prev[SCRAM_KEY_LEN]; - scram_HMAC_ctx hmac_ctx; + pg_hmac_ctx *hmac_ctx = pg_hmac_create(PG_SHA256); + + if (hmac_ctx == NULL) + return -1; /* * Iterate hash calculation of HMAC entry using given salt. This is @@ -158,11 +53,12 @@ scram_SaltedPassword(const char *password, */ /* First iteration */ - if (scram_HMAC_init(&hmac_ctx, (uint8 *) password, password_len) < 0 || - scram_HMAC_update(&hmac_ctx, salt, saltlen) < 0 || - scram_HMAC_update(&hmac_ctx, (char *) &one, sizeof(uint32)) < 0 || - scram_HMAC_final(Ui_prev, &hmac_ctx) < 0) + if (pg_hmac_init(hmac_ctx, (uint8 *) password, password_len) < 0 || + pg_hmac_update(hmac_ctx, (uint8 *) salt, saltlen) < 0 || + pg_hmac_update(hmac_ctx, (uint8 *) &one, sizeof(uint32)) < 0 || + pg_hmac_final(hmac_ctx, Ui_prev) < 0) { + pg_hmac_free(hmac_ctx); return -1; } @@ -171,10 +67,11 @@ scram_SaltedPassword(const char *password, /* Subsequent iterations */ for (i = 2; i <= iterations; i++) { - if (scram_HMAC_init(&hmac_ctx, (uint8 *) password, password_len) < 0 || - scram_HMAC_update(&hmac_ctx, (const char *) Ui_prev, SCRAM_KEY_LEN) < 0 || - scram_HMAC_final(Ui, &hmac_ctx) < 0) + if (pg_hmac_init(hmac_ctx, (uint8 *) password, password_len) < 0 || + pg_hmac_update(hmac_ctx, (uint8 *) Ui_prev, SCRAM_KEY_LEN) < 0 || + pg_hmac_final(hmac_ctx, Ui) < 0) { + pg_hmac_free(hmac_ctx); return -1; } @@ -183,6 +80,7 @@ scram_SaltedPassword(const char *password, memcpy(Ui_prev, Ui, SCRAM_KEY_LEN); } + pg_hmac_free(hmac_ctx); return 0; } @@ -218,15 +116,20 @@ scram_H(const uint8 *input, int len, uint8 *result) int scram_ClientKey(const uint8 *salted_password, uint8 *result) { - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256); - if (scram_HMAC_init(&ctx, salted_password, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, "Client Key", strlen("Client Key")) < 0 || - scram_HMAC_final(result, &ctx) < 0) + if (ctx == NULL) + return -1; + + if (pg_hmac_init(ctx, salted_password, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, (uint8 *) "Client Key", strlen("Client Key")) < 0 || + pg_hmac_final(ctx, result) < 0) { + pg_hmac_free(ctx); return -1; } + pg_hmac_free(ctx); return 0; } @@ -236,15 +139,20 @@ scram_ClientKey(const uint8 *salted_password, uint8 *result) int scram_ServerKey(const uint8 *salted_password, uint8 *result) { - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256); - if (scram_HMAC_init(&ctx, salted_password, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, "Server Key", strlen("Server Key")) < 0 || - scram_HMAC_final(result, &ctx) < 0) + if (ctx == NULL) + return -1; + + if (pg_hmac_init(ctx, salted_password, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, (uint8 *) "Server Key", strlen("Server Key")) < 0 || + pg_hmac_final(ctx, result) < 0) { + pg_hmac_free(ctx); return -1; } + pg_hmac_free(ctx); return 0; } diff --git a/src/interfaces/libpq/fe-auth-scram.c b/src/interfaces/libpq/fe-auth-scram.c index 6dcf574f62..cbf326c9ef 100644 --- a/src/interfaces/libpq/fe-auth-scram.c +++ b/src/interfaces/libpq/fe-auth-scram.c @@ -15,6 +15,7 @@ #include "postgres_fe.h" #include "common/base64.h" +#include "common/hmac.h" #include "common/saslprep.h" #include "common/scram-common.h" #include "fe-auth.h" @@ -766,7 +767,11 @@ calculate_client_proof(fe_scram_state *state, uint8 ClientKey[SCRAM_KEY_LEN]; uint8 ClientSignature[SCRAM_KEY_LEN]; int i; - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx; + + ctx = pg_hmac_create(PG_SHA256); + if (ctx == NULL) + return false; /* * Calculate SaltedPassword, and store it in 'state' so that we can reuse @@ -776,26 +781,28 @@ calculate_client_proof(fe_scram_state *state, state->iterations, state->SaltedPassword) < 0 || scram_ClientKey(state->SaltedPassword, ClientKey) < 0 || scram_H(ClientKey, SCRAM_KEY_LEN, StoredKey) < 0 || - scram_HMAC_init(&ctx, StoredKey, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, - state->client_first_message_bare, - strlen(state->client_first_message_bare)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->server_first_message, - strlen(state->server_first_message)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - client_final_message_without_proof, - strlen(client_final_message_without_proof)) < 0 || - scram_HMAC_final(ClientSignature, &ctx) < 0) + pg_hmac_init(ctx, StoredKey, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_first_message_bare, + strlen(state->client_first_message_bare)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->server_first_message, + strlen(state->server_first_message)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) client_final_message_without_proof, + strlen(client_final_message_without_proof)) < 0 || + pg_hmac_final(ctx, ClientSignature) < 0) { + pg_hmac_free(ctx); return false; } for (i = 0; i < SCRAM_KEY_LEN; i++) result[i] = ClientKey[i] ^ ClientSignature[i]; + pg_hmac_free(ctx); return true; } @@ -810,27 +817,34 @@ verify_server_signature(fe_scram_state *state, bool *match) { uint8 expected_ServerSignature[SCRAM_KEY_LEN]; uint8 ServerKey[SCRAM_KEY_LEN]; - scram_HMAC_ctx ctx; + pg_hmac_ctx *ctx; + + ctx = pg_hmac_create(PG_SHA256); + if (ctx == NULL) + return false; if (scram_ServerKey(state->SaltedPassword, ServerKey) < 0 || /* calculate ServerSignature */ - scram_HMAC_init(&ctx, ServerKey, SCRAM_KEY_LEN) < 0 || - scram_HMAC_update(&ctx, - state->client_first_message_bare, - strlen(state->client_first_message_bare)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->server_first_message, - strlen(state->server_first_message)) < 0 || - scram_HMAC_update(&ctx, ",", 1) < 0 || - scram_HMAC_update(&ctx, - state->client_final_message_without_proof, - strlen(state->client_final_message_without_proof)) < 0 || - scram_HMAC_final(expected_ServerSignature, &ctx) < 0) + pg_hmac_init(ctx, ServerKey, SCRAM_KEY_LEN) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_first_message_bare, + strlen(state->client_first_message_bare)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->server_first_message, + strlen(state->server_first_message)) < 0 || + pg_hmac_update(ctx, (uint8 *) ",", 1) < 0 || + pg_hmac_update(ctx, + (uint8 *) state->client_final_message_without_proof, + strlen(state->client_final_message_without_proof)) < 0 || + pg_hmac_final(ctx, expected_ServerSignature) < 0) { + pg_hmac_free(ctx); return false; } + pg_hmac_free(ctx); + /* signature processed, so now check after it */ if (memcmp(expected_ServerSignature, state->ServerSignature, SCRAM_KEY_LEN) != 0) *match = false; diff --git a/configure b/configure index 11a4284e5b..1570c769a6 100755 --- a/configure +++ b/configure @@ -12414,7 +12414,7 @@ done # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it # doesn't have these OpenSSL 1.1.0 functions. So check for individual # functions. - for ac_func in OPENSSL_init_ssl BIO_get_data BIO_meth_new ASN1_STRING_get0_data + for ac_func in OPENSSL_init_ssl BIO_get_data BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free do : as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh` ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var" diff --git a/configure.ac b/configure.ac index fc523c6aeb..cf28742160 100644 --- a/configure.ac +++ b/configure.ac @@ -1228,7 +1228,7 @@ if test "$with_openssl" = yes ; then # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it # doesn't have these OpenSSL 1.1.0 functions. So check for individual # functions. - AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_get_data BIO_meth_new ASN1_STRING_get0_data]) + AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_get_data BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free]) # OpenSSL versions before 1.1.0 required setting callback functions, for # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock() # function was removed. diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm index f92c14030d..e37a7291af 100644 --- a/src/tools/msvc/Mkvcbuild.pm +++ b/src/tools/msvc/Mkvcbuild.pm @@ -130,11 +130,13 @@ sub mkvcbuild if ($solution->{options}->{openssl}) { push(@pgcommonallfiles, 'cryptohash_openssl.c'); + push(@pgcommonallfiles, 'hmac_openssl.c'); push(@pgcommonallfiles, 'protocol_openssl.c'); } else { push(@pgcommonallfiles, 'cryptohash.c'); + push(@pgcommonallfiles, 'hmac.c'); push(@pgcommonallfiles, 'md5.c'); push(@pgcommonallfiles, 'sha2.c'); } diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index 22d6abd367..9bc3be9879 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -279,6 +279,8 @@ sub GenerateFiles HAVE_GETTIMEOFDAY => undef, HAVE_GSSAPI_GSSAPI_H => undef, HAVE_GSSAPI_H => undef, + HAVE_HMAC_CTX_FREE => undef, + HAVE_HMAC_CTX_NEW => undef, HAVE_HISTORY_H => undef, HAVE_HISTORY_TRUNCATE_FILE => undef, HAVE_IFADDRS_H => undef, @@ -531,6 +533,8 @@ sub GenerateFiles $define{HAVE_ASN1_STRING_GET0_DATA} = 1; $define{HAVE_BIO_GET_DATA} = 1; $define{HAVE_BIO_METH_NEW} = 1; + $define{HAVE_HMAC_CTX_FREE} = 1; + $define{HAVE_HMAC_CTX_NEW} = 1; $define{HAVE_OPENSSL_INIT_SSL} = 1; } } diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index a9dca717a6..f3d9e0983a 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -3188,6 +3188,8 @@ pg_enc2gettext pg_enc2name pg_encname pg_gssinfo +pg_hmac_ctx +pg_hmac_state pg_int64 pg_local_to_utf_combined pg_locale_t @@ -3331,7 +3333,6 @@ role_auth_extra row_security_policy_hook_type rsv_callback save_buffer -scram_HMAC_ctx scram_state scram_state_enum sem_t -- 2.29.2
hmacfuncs.tar.gz
Description: application/gzip
signature.asc
Description: PGP signature