X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fgcrypt%2Frsa.c;h=5d12985d63d366d7ed2fc5951217bb1bede10db0;hb=77cd819058de43a5fcea54300dde50e03088c318;hp=ea18a0e10f3c6dddd65dec783de1b17c71e0d65e;hpb=07a560eab66b575f382428a956550817697e25e2;p=tinc diff --git a/src/gcrypt/rsa.c b/src/gcrypt/rsa.c index ea18a0e1..5d12985d 100644 --- a/src/gcrypt/rsa.c +++ b/src/gcrypt/rsa.c @@ -1,6 +1,6 @@ /* rsa.c -- RSA key handling - Copyright (C) 2007 Guus Sliepen + Copyright (C) 2007-2012 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 @@ -12,11 +12,9 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - $Id$ + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" @@ -25,101 +23,31 @@ #include "logger.h" #include "rsa.h" - -// Base64 decoding table - -static const uint8_t b64d[128] = { - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, - 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, - 0x3a, 0x3b, 0x3c, 0x3d, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, - 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, - 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, - 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, - 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, - 0x19, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, - 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, - 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, - 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, - 0x31, 0x32, 0x33, 0xff, 0xff, 0xff, - 0xff, 0xff -}; - -// PEM encoding/decoding functions - -static bool pem_decode(FILE *fp, const char *header, uint8_t *buf, size_t size, size_t *outsize) { - bool decode = false; - char line[1024]; - uint16_t word = 0; - int shift = 10; - size_t i, j = 0; - - while(!feof(fp)) { - if(!fgets(line, sizeof line, fp)) - return false; - - if(!decode && !strncmp(line, "-----BEGIN ", 11)) { - if(!strncmp(line + 11, header, strlen(header))) - decode = true; - continue; - } - - if(decode && !strncmp(line, "-----END", 8)) { - break; - } - - if(!decode) - continue; - - for(i = 0; line[i] >= ' '; i++) { - if((signed char)line[i] < 0 || b64d[(int)line[i]] == 0xff) - break; - word |= b64d[(int)line[i]] << shift; - shift -= 6; - if(shift <= 2) { - if(j > size) { - errno = ENOMEM; - return false; - } - - buf[j++] = word >> 8; - word <<= 8; - shift += 8; - } - } - } - - if(outsize) - *outsize = j; - return true; -} - +#include "pem.h" +#include "xalloc.h" // BER decoding functions static int ber_read_id(unsigned char **p, size_t *buflen) { - if(*buflen <= 0) + if(*buflen <= 0) { return -1; + } if((**p & 0x1f) == 0x1f) { int id = 0; bool more; + while(*buflen > 0) { id <<= 7; id |= **p & 0x7f; more = *(*p)++ & 0x80; (*buflen)--; - if(!more) + + if(!more) { break; + } } + return id; } else { (*buflen)--; @@ -128,18 +56,21 @@ static int ber_read_id(unsigned char **p, size_t *buflen) { } static size_t ber_read_len(unsigned char **p, size_t *buflen) { - if(*buflen <= 0) + if(*buflen <= 0) { return -1; + } if(**p & 0x80) { size_t result = 0; int len = *(*p)++ & 0x7f; (*buflen)--; - if(len > *buflen) + + if(len > *buflen) { return 0; + } while(len--) { - result <<= 8; + result = (size_t)(result << 8); result |= *(*p)++; (*buflen)--; } @@ -150,15 +81,17 @@ static size_t ber_read_len(unsigned char **p, size_t *buflen) { return *(*p)++; } } - + static bool ber_read_sequence(unsigned char **p, size_t *buflen, size_t *result) { int tag = ber_read_id(p, buflen); size_t len = ber_read_len(p, buflen); if(tag == 0x10) { - if(result) + if(result) { *result = len; + } + return true; } else { return false; @@ -170,94 +103,104 @@ static bool ber_read_mpi(unsigned char **p, size_t *buflen, gcry_mpi_t *mpi) { size_t len = ber_read_len(p, buflen); gcry_error_t err = 0; - if(tag != 0x02 || len > *buflen) + if(tag != 0x02 || len > *buflen) { return false; + } - if(mpi) + if(mpi) { err = gcry_mpi_scan(mpi, GCRYMPI_FMT_USG, *p, len, NULL); - + } + *p += len; *buflen -= len; return mpi ? !err : true; } -bool rsa_set_hex_public_key(rsa_t *rsa, char *n, char *e) { - gcry_error_t err = 0; +rsa_t *rsa_set_hex_public_key(char *n, char *e) { + rsa_t *rsa = xzalloc(sizeof(rsa_t)); - err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL) - ?: gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, n, 0, NULL); + 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); if(err) { - logger(LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); + logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); + free(rsa); return false; } - return true; + return rsa; } -bool rsa_set_hex_private_key(rsa_t *rsa, char *n, char *e, char *d) { - gcry_error_t err = 0; +rsa_t *rsa_set_hex_private_key(char *n, char *e, char *d) { + rsa_t *rsa = xzalloc(sizeof(rsa_t)); - err = gcry_mpi_scan(&rsa->n, GCRYMPI_FMT_HEX, n, 0, NULL) - ?: gcry_mpi_scan(&rsa->e, GCRYMPI_FMT_HEX, n, 0, NULL) - ?: gcry_mpi_scan(&rsa->d, GCRYMPI_FMT_HEX, n, 0, NULL); + 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); if(err) { - logger(LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); + logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading RSA public key: %s", gcry_strerror(errno)); + free(rsa); return false; } - return true; + return rsa; } // Read PEM RSA keys -bool rsa_read_pem_public_key(rsa_t *rsa, FILE *fp) { +rsa_t *rsa_read_pem_public_key(FILE *fp) { uint8_t derbuf[8096], *derp = derbuf; size_t derlen; - if(!pem_decode(fp, "RSA PUBLIC KEY", derbuf, sizeof derbuf, &derlen)) { - logger(LOG_ERR, "Unable to read RSA public key: %s", strerror(errno)); + if(!pem_decode(fp, "RSA PUBLIC KEY", derbuf, sizeof(derbuf), &derlen)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read RSA public key: %s", strerror(errno)); return NULL; } + rsa_t *rsa = xzalloc(sizeof(rsa_t)); + if(!ber_read_sequence(&derp, &derlen, NULL) - || !ber_read_mpi(&derp, &derlen, &rsa->n) - || !ber_read_mpi(&derp, &derlen, &rsa->e) - || derlen) { - logger(LOG_ERR, "Error while decoding RSA public key"); + || !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); return NULL; } - return true; + return rsa; } -bool rsa_read_pem_private_key(rsa_t *rsa, FILE *fp) { +rsa_t *rsa_read_pem_private_key(FILE *fp) { uint8_t derbuf[8096], *derp = derbuf; size_t derlen; - if(!pem_decode(fp, "RSA PRIVATE KEY", derbuf, sizeof derbuf, &derlen)) { - logger(LOG_ERR, "Unable to read RSA private key: %s", strerror(errno)); + if(!pem_decode(fp, "RSA PRIVATE KEY", derbuf, sizeof(derbuf), &derlen)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read RSA private key: %s", strerror(errno)); return NULL; } + rsa_t *rsa = xzalloc(sizeof(rsa_t)); + if(!ber_read_sequence(&derp, &derlen, NULL) - || !ber_read_mpi(&derp, &derlen, NULL) - || !ber_read_mpi(&derp, &derlen, &rsa->n) - || !ber_read_mpi(&derp, &derlen, &rsa->e) - || !ber_read_mpi(&derp, &derlen, &rsa->d) - || !ber_read_mpi(&derp, &derlen, NULL) // p - || !ber_read_mpi(&derp, &derlen, NULL) // q - || !ber_read_mpi(&derp, &derlen, NULL) - || !ber_read_mpi(&derp, &derlen, NULL) - || !ber_read_mpi(&derp, &derlen, NULL) // u - || derlen) { - logger(LOG_ERR, "Error while decoding RSA private key"); + || !ber_read_mpi(&derp, &derlen, NULL) + || !ber_read_mpi(&derp, &derlen, &rsa->n) + || !ber_read_mpi(&derp, &derlen, &rsa->e) + || !ber_read_mpi(&derp, &derlen, &rsa->d) + || !ber_read_mpi(&derp, &derlen, NULL) // p + || !ber_read_mpi(&derp, &derlen, NULL) // q + || !ber_read_mpi(&derp, &derlen, NULL) + || !ber_read_mpi(&derp, &derlen, NULL) + || !ber_read_mpi(&derp, &derlen, NULL) // u + || derlen) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error while decoding RSA private key"); + free(rsa); return NULL; } - return true; + return rsa; } size_t rsa_size(rsa_t *rsa) { @@ -269,7 +212,7 @@ size_t rsa_size(rsa_t *rsa) { */ // TODO: get rid of this macro, properly clean up gcry_ structures after use -#define check(foo) { gcry_error_t err = (foo); if(err) {logger(LOG_ERR, "gcrypt error %s/%s at %s:%d\n", gcry_strsource(err), gcry_strerror(err), __FILE__, __LINE__); return false; }} +#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; }} bool rsa_public_encrypt(rsa_t *rsa, void *in, size_t len, void *out) { gcry_mpi_t inmpi; @@ -278,7 +221,14 @@ bool rsa_public_encrypt(rsa_t *rsa, void *in, size_t len, void *out) { gcry_mpi_t outmpi = gcry_mpi_new(len * 8); gcry_mpi_powm(outmpi, inmpi, rsa->e, rsa->n); - check(gcry_mpi_print(GCRYMPI_FMT_USG, out,len, NULL, outmpi)); + size_t out_bytes = (gcry_mpi_get_nbits(outmpi) + 7) / 8; + size_t pad = len - MIN(out_bytes, len); + + for(; pad; --pad) { + *(char *)out++ = 0; + } + + check(gcry_mpi_print(GCRYMPI_FMT_USG, out, len, NULL, outmpi)); return true; } @@ -290,7 +240,31 @@ bool rsa_private_decrypt(rsa_t *rsa, void *in, size_t len, void *out) { gcry_mpi_t outmpi = gcry_mpi_new(len * 8); gcry_mpi_powm(outmpi, inmpi, rsa->d, rsa->n); - check(gcry_mpi_print(GCRYMPI_FMT_USG, out,len, NULL, outmpi)); + size_t pad = len - (gcry_mpi_get_nbits(outmpi) + 7) / 8; + + for(; pad; --pad) { + *(char *)out++ = 0; + } + + check(gcry_mpi_print(GCRYMPI_FMT_USG, out, len, NULL, outmpi)); return true; } + +void rsa_free(rsa_t *rsa) { + if(rsa) { + if(rsa->n) { + gcry_mpi_release(rsa->n); + } + + if(rsa->e) { + gcry_mpi_release(rsa->e); + } + + if(rsa->d) { + gcry_mpi_release(rsa->d); + } + + free(rsa); + } +}