X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fgcrypt%2Frsa.c;h=292c7739dec556d8e90c9081b9c020371ccf3711;hb=c45a3fd7319d03bd147448a017f5aaed3b46fdfe;hp=5d12985d63d366d7ed2fc5951217bb1bede10db0;hpb=77cd819058de43a5fcea54300dde50e03088c318;p=tinc diff --git a/src/gcrypt/rsa.c b/src/gcrypt/rsa.c index 5d12985d..292c7739 100644 --- a/src/gcrypt/rsa.c +++ b/src/gcrypt/rsa.c @@ -1,6 +1,6 @@ /* rsa.c -- RSA key handling - Copyright (C) 2007-2012 Guus Sliepen + Copyright (C) 2007-2022 Guus Sliepen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -17,14 +17,17 @@ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "system.h" +#include "../system.h" #include -#include "logger.h" -#include "rsa.h" #include "pem.h" -#include "xalloc.h" + +#include "asn1.h" +#include "rsa.h" +#include "../logger.h" +#include "../rsa.h" +#include "../xalloc.h" // BER decoding functions @@ -62,14 +65,14 @@ static size_t ber_read_len(unsigned char **p, size_t *buflen) { if(**p & 0x80) { size_t result = 0; - int len = *(*p)++ & 0x7f; + size_t len = *(*p)++ & 0x7f; (*buflen)--; if(len > *buflen) { return 0; } - while(len--) { + for(; len; --len) { result = (size_t)(result << 8); result |= *(*p)++; (*buflen)--; @@ -82,20 +85,11 @@ static size_t ber_read_len(unsigned char **p, size_t *buflen) { } } - -static bool ber_read_sequence(unsigned char **p, size_t *buflen, size_t *result) { +static bool ber_skip_sequence(unsigned char **p, size_t *buflen) { int tag = ber_read_id(p, buflen); - size_t len = ber_read_len(p, buflen); - if(tag == 0x10) { - if(result) { - *result = len; - } - - return true; - } else { - return false; - } + return tag == TAG_SEQUENCE && + ber_read_len(p, buflen) > 0; } static bool ber_read_mpi(unsigned char **p, size_t *buflen, gcry_mpi_t *mpi) { @@ -117,32 +111,45 @@ static bool ber_read_mpi(unsigned char **p, size_t *buflen, gcry_mpi_t *mpi) { return mpi ? !err : true; } -rsa_t *rsa_set_hex_public_key(char *n, char *e) { - rsa_t *rsa = xzalloc(sizeof(rsa_t)); +rsa_t *rsa_new(void) { + return xzalloc(sizeof(rsa_t)); +} + +rsa_t *rsa_set_hex_public_key(const char *n, const char *e) { + rsa_t *rsa = rsa_new(); - gcry_error_t err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL) - ? : gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, e, 0, NULL); + gcry_error_t err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL); + + if(!err) { + err = gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, e, 0, NULL); + } if(err) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); - free(rsa); + rsa_free(rsa); return false; } return rsa; } -rsa_t *rsa_set_hex_private_key(char *n, char *e, char *d) { - rsa_t *rsa = xzalloc(sizeof(rsa_t)); +rsa_t *rsa_set_hex_private_key(const char *n, const char *e, const char *d) { + rsa_t *rsa = rsa_new(); - gcry_error_t err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL) - ? : gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, e, 0, NULL) - ? : gcry_mpi_scan(&rsa->d, GCRYMPI_FMT_HEX, d, 0, NULL); + gcry_error_t err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL); + + if(!err) { + err = gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, e, 0, NULL); + } + + if(!err) { + err = gcry_mpi_scan(&rsa->d, GCRYMPI_FMT_HEX, d, 0, NULL); + } if(err) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); - free(rsa); - return false; + rsa_free(rsa); + return NULL; } return rsa; @@ -159,14 +166,14 @@ rsa_t *rsa_read_pem_public_key(FILE *fp) { return NULL; } - rsa_t *rsa = xzalloc(sizeof(rsa_t)); + rsa_t *rsa = rsa_new(); - if(!ber_read_sequence(&derp, &derlen, NULL) + if(!ber_skip_sequence(&derp, &derlen) || !ber_read_mpi(&derp, &derlen, &rsa->n) || !ber_read_mpi(&derp, &derlen, &rsa->e) || derlen) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while decoding RSA public key"); - free(rsa); + rsa_free(rsa); return NULL; } @@ -182,9 +189,9 @@ rsa_t *rsa_read_pem_private_key(FILE *fp) { return NULL; } - rsa_t *rsa = xzalloc(sizeof(rsa_t)); + rsa_t *rsa = rsa_new(); - if(!ber_read_sequence(&derp, &derlen, NULL) + if(!ber_skip_sequence(&derp, &derlen) || !ber_read_mpi(&derp, &derlen, NULL) || !ber_read_mpi(&derp, &derlen, &rsa->n) || !ber_read_mpi(&derp, &derlen, &rsa->e) @@ -196,59 +203,62 @@ rsa_t *rsa_read_pem_private_key(FILE *fp) { || !ber_read_mpi(&derp, &derlen, NULL) // u || derlen) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while decoding RSA private key"); - free(rsa); - return NULL; + rsa_free(rsa); + rsa = NULL; } + memzero(derbuf, sizeof(derbuf)); return rsa; } -size_t rsa_size(rsa_t *rsa) { +size_t rsa_size(const rsa_t *rsa) { return (gcry_mpi_get_nbits(rsa->n) + 7) / 8; } +static bool check(gcry_error_t err) { + if(err) { + logger(DEBUG_ALWAYS, LOG_ERR, "gcrypt error %s/%s", gcry_strsource(err), gcry_strerror(err)); + } + + return !err; +} + /* Well, libgcrypt has functions to handle RSA keys, but they suck. * So we just use libgcrypt's mpi functions, and do the math ourselves. */ -// TODO: get rid of this macro, properly clean up gcry_ structures after use -#define check(foo) { gcry_error_t err = (foo); if(err) {logger(DEBUG_ALWAYS, LOG_ERR, "gcrypt error %s/%s at %s:%d", gcry_strsource(err), gcry_strerror(err), __FILE__, __LINE__); return false; }} +static bool rsa_powm(const gcry_mpi_t ed, const gcry_mpi_t n, const void *in, size_t len, void *out) { + gcry_mpi_t inmpi = NULL; -bool rsa_public_encrypt(rsa_t *rsa, void *in, size_t len, void *out) { - gcry_mpi_t inmpi; - check(gcry_mpi_scan(&inmpi, GCRYMPI_FMT_USG, in, len, NULL)); + if(!check(gcry_mpi_scan(&inmpi, GCRYMPI_FMT_USG, in, len, NULL))) { + return false; + } - gcry_mpi_t outmpi = gcry_mpi_new(len * 8); - gcry_mpi_powm(outmpi, inmpi, rsa->e, rsa->n); + gcry_mpi_t outmpi = gcry_mpi_snew(len * 8); + gcry_mpi_powm(outmpi, inmpi, ed, n); size_t out_bytes = (gcry_mpi_get_nbits(outmpi) + 7) / 8; size_t pad = len - MIN(out_bytes, len); + unsigned char *pout = out; for(; pad; --pad) { - *(char *)out++ = 0; + *pout++ = 0; } - check(gcry_mpi_print(GCRYMPI_FMT_USG, out, len, NULL, outmpi)); - - return true; -} - -bool rsa_private_decrypt(rsa_t *rsa, void *in, size_t len, void *out) { - gcry_mpi_t inmpi; - check(gcry_mpi_scan(&inmpi, GCRYMPI_FMT_USG, in, len, NULL)); + bool ok = check(gcry_mpi_print(GCRYMPI_FMT_USG, pout, len, NULL, outmpi)); - gcry_mpi_t outmpi = gcry_mpi_new(len * 8); - gcry_mpi_powm(outmpi, inmpi, rsa->d, rsa->n); + gcry_mpi_release(outmpi); + gcry_mpi_release(inmpi); - size_t pad = len - (gcry_mpi_get_nbits(outmpi) + 7) / 8; - - for(; pad; --pad) { - *(char *)out++ = 0; - } + return ok; +} - check(gcry_mpi_print(GCRYMPI_FMT_USG, out, len, NULL, outmpi)); +bool rsa_public_encrypt(rsa_t *rsa, const void *in, size_t len, void *out) { + return rsa_powm(rsa->e, rsa->n, in, len, out); +} - return true; +bool rsa_private_decrypt(rsa_t *rsa, const void *in, size_t len, void *out) { + return rsa_powm(rsa->d, rsa->n, in, len, out); } void rsa_free(rsa_t *rsa) {